Ebook Clinical examinations in cardiology: Part 1

(BQ) Part 1 book Clinical examinations in cardiology presents the following contents: Basic anatomy and physiology, the history and symptomatology, general physical examination, general physical examination, cardiovascular system examination.

Clinical Examination in

B.N Vijay Raghawa Rao

■ ■ ■

■ ■ ■

B.N Vijay Raghawa Rao

MD, DM(CARDIOLOGY), DHA, FCCP, FICC, MBA(HM)

Formerly Addl Director, Professor & HOD Gandhi Medical College/Gandhi Hospital,

Secunderabad, Hyderabad, India Presently Consultant Interventional Cardiologist Vijay Marie and Yashoda Superseciality Hospitals,

B.N Vijay Raghawa Rao

ELSEVIER

A division of

Reed Elsevier India Private Limited

Mosby, Saunders, Churchill Livingstone, Butterworth Heinemann and Hanley & Belfus are the Health Science imprints of Elsevier.

© 2007 Elsevier

First Edition 2007

All rights are reserved No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the publisher.

ISBN-13: 978-81-312-0964-6

Medical knowledge is constantly changing As new information becomes available, changes in treatment, procedures, equipment and the use of drugs become necessary The authors, editors, contributors and the publisher have,

as far as it is possible, taken care to ensure that the information given in this text is accurate and up-to-date However, readers are strongly advised to confirm that the information, especially with regard to drug dose/usage, complies with current legislation and standards of practice.

Published by Elsevier, a division of Reed Elsevier India Private Limited Sri Pratap Udyog, 274, Captain Gaur Marg, Sriniwaspuri

New Delhi – 110 065, India.

Publishing Director: Sanjay K Singh

Commissioning Editor: Sonali Dasgupta

Developmental Editor: Dr Shelley Narula

Manager (Editorial Projects): Dr Radhika Menon

Production Executive: Ambrish Choudhary

Typeset by Olympus Infotech Pvt Ltd, Chennai, India.

Printed and bound at Nutech Photolithographer, New Delhi.

my wife Dr Shashikala, my daughters Dr Visha Rao & Vishala Rao

and my teachers, students & patients who constantly encouraged to write & revise this clinical treatise.

P REFACE TO R EVISED R EPRINT

First Edition of Clinical Examination in Cardiology was published in 2007 by Elsevier India Pvt Ltd which was

well received and appreciated by PG students of Gen Medicine, Pediatrics and Cardiology as well as by the ticing physicians, besides being a great helpful to undergraduate students However there were some printingerrors which were overlooked inadvertently These errors have been corrected and even some figures, graphs, photographs and tables have been revised and updated in this revised reprint which will be an asset to clinicaldecision making

prac-I am thankful to Elsevier prac-India Pvt for their keen interest shown in revising and reprinting this clinical textbook

Dr B.N Vijay Raghawa Rao

MD , DM ( CARDIOLOGY ), DHA , FCCP , FICC , MBA ( HM )

P REFACE TO THE E ARLIER E DITION

“It is man’s mission to learn to understand”

Clinical Examination in Cardiology is primarily a clinical treatise It provides a simple, lucid and comprehensive

description of “Basic Anatomy and Physiology of Cardiovascular Medicine, Clinical Cardiology, and Basic Bedside

Investigations (Electrocardiogram and X-ray Chest)” in a single book It is the first of its kind in the present millenniumhighlighting the forgotten “Clinical Cardiology, in a scenario” where cardiovascular disease is now a global problemwith enormous economic consequences

Besides index, this book consists of six parts with 34 chapters Part 1 deals with “Basic Anatomy and Physiology

of Cardiovascular Medicine” with ten chapters comprehensively described for better understanding of clinical diology Part 2 follows the initial chapters which deal with “Cardiac Symptomatology” in two chapters Part 3 withthree chapters consists of “General Physical Examination, Arterial Pulse and Blood Pressure” described in detail.Part 4 has two chapters describing “Jugular Venous Pulse and Jugular Venous Pressure” in detail Part 5 follows withfive chapters which describe cardiovascular examination–“Inspection, Palpation, Percussion and Precordium inCommon Heart Diseases, and Auscultation” Finally, basic investigations are described in two portions, which areessential for comprehensive discussion of diagnosis and management of a cardiovascular disease This Part 6includes, Part 6a: “Clinical Electrocardiography” with nine chapters, which include basic concepts, normal ECG,common disease conditions, drugs effects, arrhythmias and prediction of coronary artery occlusion in a patient ofacute myocardial infarction Part 6b: “Radiology of the Heart and Great Vessels” includes four chapters, describingintroduction, technical facts, routine reporting of an x-ray chest, calcifications and other views Each chapter hasadequate figures, tables and references, which can be used for rapid review of the material described In total, thereare 749 figures, 245 tables, and 675 references

car-This book is primarily focused for postgraduate students of “General Medicine, Cardiology and Paediatrics”.However, it will also be useful for the undergraduate students for better understanding of clinical cardiology, which

is a part of general medicine It may also prove useful to those who wish to broaden their knowledge of clinical ology and will aid in their day-to-day practice of cardiology Besides my teaching experience of undergraduate andpostgraduate medical students, I have also used standard textbooks and journals of Cardiovascular Medicine as references in compiling this clinical entity

cardi-I am thankful to my postgraduates, Dr Pramod, Dr Rajkiran and Dr Narender for providing beautiful graphs I am indebted to my patients at my clinic, Remedy Superspeciality Hospital and Gandhi Medical College &Hospital for their immense cooperation

photo-My special thanks to Mr Sanjay Singh and Dr Shelley Narula of Elsevier India Pvt Ltd for their constant agement and keen interest shown in completing this clinical treatise

encour-Dr B.N Vijay Raghawa Rao

MD , DM ( CARDIOLOGY ), DHA , FCCP , FICC , MBA ( HM )

C ONTENTS

Chapter 17 Estimation of venous pressure and JVP in diseased conditions 283

Chapter 20 Percussion of the precordium and precordial findings in

Chapter 34 Evaluation of extracardiac structures and chest X-ray in other views 701

A BBREVIATIONS

PART 1

ADP: adenosine diphosphate

AHA: american heart association

AJR: abdominal jugular reflux

AML: anterior mitral leaflet

ANP: atrial natriuretic peptide

ATP: adenosine triphosphate

AV node: atrio ventricular node

AV: atrioventricular

AVT: anterior interventricular trunk

CICR: calcium induced calcium release

CLN: cardiac lymph node

CT: chordae tendinae

CVA: cerebrovascular accident

CVC: cardiac vagal center

IVC: inferior vena cava

JSR: junctional sarcoplasmic reticulum

LA: left atrium

LAD: left anterior descending

LBB: left bundle branch

LCx: left circumflex

LCC: left coronary channel

LMCA: left main coronary artery

LV: left ventricle

MHC: myosin heavy chain

MLC: myosin light chain

MSC: main supracardiac channel

OM: obtuse marginal

OMT: obtuse marginal trunk

PDA: patent ductus arteriosus

PFO: patent foreman ovale

PML: posterior mitral leaflet

PM: papillary muscle

pCO2: partial pressure of carbon dioxide

pO2: partial pressure of oxygen

PVT: posterior interventricular trunk

RA: right atrium

RBB: right bundle branch

RCA: right coronary artery

RCC: right coronary channel

RFW: rapid filling waveRLD: right lymphatic ductRV: right ventricle

SA node: Sinoatrial nodeSERCA: sarco endoplasmic reticulum calcium ATPaseSFW: slow filling wave

SL: semilunarSVC: superior vena cavaVMC: vasomotor center

PART 2

Af: atrial fibrillationALCAPA: anomalous left coronary artery from

pulmonary arteryAMI: acute myocardial infarctionAP: angina pectoris

AR: aortic regurgitationARVD: arrhythmogenic right ventricular dysplasiaAS: aortic stenosis

ASD: atrial septal defectAVRT: atrioventicular reciprocating tachycardiaBBB: bundle branch block

CAD: coronary artery diseaseCCS: Canadian cardiovascular societyCHF: congestive heart failureCHD: congenital heart diseaseCHB: complete heart blockCM: cardiomyoapthyCOA: coarctation of aortaCOPD: chronic obstructive pulmonary diseaseCRF: chronic renal failure

CT: cardiac tamponadeCVA: cerebrovascular accidentDCM: dilated cardiomyoapthyDORV: doublet outlet right ventricleHCM: hypertrophic cardiomyopathyHOCM: hypertrophic obstructive cardiomyopathyLAD: left anterior descending

LAHB: left anterior hemi blockLBBB: left bundle branch block

LCA: left coronary artery

LVF: left ventricular failure

LVOTO: left ventricular outflow tract obstruction

MI: myocardial infarction

MR: mitral regurgitation

MS: mitral stenosis

MVP: mitral valve prolapse

MVV: maximum voluntary ventilation

NYHA: New York heart association

PAPVC: partial anomalous pulmonary venous

connection

PAT: paroxysmal atrial tachycardia

PDA: patent ductus arteriosus

PE: pulmonary embolism

PND: paroxysmal nocturnal dyspnea

PS: pulmonary stenosis

PVR: pulmonary vascular resistance

PTCA: percutaneous transluminal coronary angioplasty

RBBB: right bundle branch block

RVOTO: right ventricular outflow tract obstruction

SAC: specific activity scale

SLE: systemic lupus erythematosus

SSS: sick sinus syndrome

TGA: transposition of great arteries

TOF: tetralogy of Fallot

TV: tidal volume, tricuspid valve

VC: vital capacity

VSD: ventricular septal defect

VT: ventricular tachycardia

PART 3

ABPM: ambulatory blood pressure monitoring

AD: autosomal dominant inheritance

AP window: aortopulmonary window

AS: aortic stenosis

ASD: atrial septal defect

AR: aortic regurgitation

AR: autosomal recessive inheritance

BMI: basal metabolic index

CAD: coronary artery disease

CHF: congestive heart failure

CO: cardiac output

COA: coarctation of aorta

CT: cardiac tamponadeCT: computed tomographyDCM: dilated cardiomyopathyDM: diabetes mellitus

HCM: hypertrophic cardiomyopathyHOCM: hypertrophic obstructive cardiomyopathyMI: myocardial infarction

MRI: magnetic resonance imagingMS: mitral stenosis

MVP: mitral valve prolapsePAPVC: partial anomalous pulmonary venous

connectionPDA: patent ductus arteriosusPR: peripheral resistance, pulmonary regurgitationPS: pulmonary stenosis

PVC: premature ventricular contractionPVR: pulmonary vascular resistanceRSOV: rupture of sinus of ValsalvaSLE: systemic lupus erythematosusSVC: superior vena cava

SV: stroke volumeTAPVC: total anomalous pulmonary venous

connectionTGA: transposition of great arteriesTOF: tetralogy of Fallot

TR: tricuspid regurgitationTS: tricuspid stenosisVSD: ventricular septal defect

PART 4

AJR: abdominal jugular refluxASD: atrial septal defectCHB: complete heart blockCHF: congestive heart failureCOPD: chronic obstructive pulmonary diseaseCVP: central venous pressure

EJV: external jugular veinEMF: endomyocardial fibrosisIJV: internal jugular veinLVF: left ventricular failureMR: mitral regurgitationMS: mitral stenosisPE: pulmonary embolismPS: pulmonary stenosisRVF: right ventricular failureRVEDP: right ventricular end diastolic pressureSVT: supraventricular tachycardia

TR: tricuspid regurgitation

TS: tricuspid stenosis

TV: tricuspid valve

VT: ventricular tachycardia

PART 5

ACG: apex cardiogram

AFM: Austin Flint murmur

ALCAPA: anomalous left coronary artery from

pulmonary artery

AML: anterior mitral leaflet

AP window: aortopulmonary window

AR: aortic regurgitation

AS: aortic stenosis

ASD: atrial septal defect

BVH: biventricular hypertrophy

CAD: coronary artery disease

CC: closing click

CHD: congenital heart disease

CHF: congestive heart failure

COA: coarctation of aorta

COPD: chronic obstructive pulmonary disease

DM: diastolic murmur

DORV: double outlet right ventricle

EDM: early diastolic murmur

ES: ejection sound

ESM: ejection systolic murmur

HCM: hypertrophic cardiomyopathy

HOCM: hypertrophic obstructive cardiomyopathy

ICS: intercostal space

LAP: left atrial pressure

LVF: left ventricular failure

LBBB: left bundle branch block

LPSA: left para sternal area

LVH: left ventricular hypertrophy

LVD: left ventricular dysfunction

LVED: left ventricular end diastolic

LVEDP: left ventricular end diastolic pressure

LVOT: left ventricular outflow tract

LVOTO: left ventricular outflow tract

MSM: mid systolic murmur

MVP: mitral valve prolapse

NES: non ejection sound

OC: opening click

OS: opening snapPADP: pulmonary artery diastolic pressurePBF: pulmonary blood flow

PDA: patent ductus arteriosusPH: pulmonary hypertensionPSM: pan systolic murmurPSL: para sternal liftPVC: premature ventricular contractionRSOV: rupture of sinus of ValsalvaRVF: right ventricular failureRVEDP: right ventricular end diastolic pressureRVH: right ventricular hypertrophy

RVOT: right ventricular outflow tractSM: systolic murmur

TAPVC: total anomalous pulmonary venous

connectionTB: tuberculosisTGA: transposition of great arteriesTOF: tetralogy of Fallot

TR: tricuspid regurgitationTS: tricuspid stenosisTV: tricuspid valveVSD: ventricular septal defect

PART 6A

Af: atrial fibrillationAfl: atrial flutterAHA: American Heart AssociationAIVR: accelerated idioventricular rhythmAMI: acute myocardial infarctionARVD: arrhythmogenic right ventricular dysplasiaAR: aortic regurgitation

AS: aortic stenosisASD: atrial septal defectAT: atrial tachycardiaAVC: aberrant ventricular conductionAVNRT: atrioventricular nodal reciprocating

tachycardiaAVRT: atrioventricular reentry tachycardiaBBB: bundle branch block

CAD: coronary artery diseaseCABG: coronary artery bypass graftCHF: congestive heart failureCOA: coarctation of aortaCOPD: chronic obstructive pulmonary diseaseCP: constrictive pericarditis

CT: cardiac tamponadeCTI: cavo tricuspid isthmus

DAD: delayed after depolarization

GUSTO: global utilization of streptokinase and

tissue plasminogen activator for occluded

coronary arteries

HTN: hypertension

ICS: intercostal space

IVC: inferior vena cava

LAA: left atrial abnormality

LAE: left atrial enlargement

LAD: left anterior descending,

left axis deviation

LAFB: left anterior fascicular block

LBBB: left bundle branch block

LCx: left circumflex

LGL: Lown Ganong Levine

LPFB: left posterior fascicular block

LVH: left ventricular hypertrophy

LVOT: left ventricular outflow tract

MAT: multifocal atrial tachycardia

MI: myocardial infarction

MR: mitral regurgitation

MVP: mitral valve prolapse

NCTI: non cavo tricuspid isthmus

PAPVC: partial anomalous pulmonary venous

connection

PAC: premature atrial contraction

PAT: paroxysmal atrial tachycardia

PDA: patent ductus arteriosus

PES: preexcitation syndromes

PTCA: percutaneous transluminal coronary angioplasty

PVC: premature ventricular contraction

RAD: right axis deviation

RAA: right atrial abnormality

RAE: right atrial enlargement

RBBB: right bundle branch block

RCA: right coronary artery

RVH: right ventricular hypertrophy

RVOT: right ventricular outflow tract

SVC: superior vena cavaSVT: supraventricular tachycardiaTDP: torsades de pointesTGA: transposition of great arteriesTOF: tetralogy of Fallot

TR: tricuspid regurgitationVf: ventricular fibrillationVfl: ventricular flutterVPC: ventricular premature contractionVT: ventricular tachycardia

WPW: Wolffe Parkinson White

PART 6B

AP view: anteroposterior viewASD: atrial septal defectCAD: coronary artery diseaseCHF: congestive heart failureCOPD: chronic obstructive pulmonary diseaseCT: computed tomography

CT ratio: cardiothoracic ratioIVC: inferior vena cavaLAE: left atrial enlargementLAO: left anterior obliqueLPA: left pulmonary arteryLVE: left ventricular enlargementLVF: left ventricular failureMRI: magnetic resonance imagingPAPVC: partial anomalous pulmonary venous

connection

PA view: posteroanterior viewPBF: pulmonary blood flowPDA: patent ductus arteriosusPNS: paranasal sinusesRAO: right anterior obliqueRDPA: right descending pulmonary arteryRVF: right ventricular failure

RVOT: right ventricular outflow tractSVC: superior vena cava

TAPVC: total anomalous pulmonary venous

connectionTGA: transposition of great arteriesTOF: tetralogy of Fallot

VSD: ventricular septal defect

BASIC ANATOMY AND

PHYSIOLOGY

■ ■ ■ C HAPTER 1

Table 1.1 Gross anatomy of the heart

1 Shape Conical hollow muscular organ

2 Location Middle mediastinum behind the sternum

and costal cartilages of 3 rd –5 th ribs

ii The Surfaces of the Heart 5

iii The Borders of the Heart 6

4 THE FIBROUS SKELETON OF

i Components and Attachments 16

1 GROSS ANATOMY OF THE HEART

The heart is a conical, hollow muscular organ situated in the middle mediastinumbehind the sternum and costal cartilages of the 3rd, 4th& 5thribs It lies obliquely so that2/3 of the heart is to the left of the midline The heart rests upon the diaphragm and

is tilted forward and to the left so that the apex is anterior to the rest of the heart.The size and weight of the heart may vary depending upon the age, sex, bodylength, epicardial fat, and general nutrition The average human adult heart measuresabout 12 cm 9 cm and weighs about 325  75 g in males and 275  75 g infemales1(see Table 1.1) It is described as follows:

1 External features

2 Chambers of the heart

3 The fibrous skeleton of the heart

4 The valves of the heart

2 EXTERNAL FEATURES OF THE HEART

The heart has four chambers, right and left atria, and right and left ventricles, which areseparated from each other by sulci and consist of surfaces and borders The atria lieabove and behind the ventricles (see Table 1.2)

i The Sulci of the Heart

The atria are separated from the ventricles externally by the coronary (atrioventricular)sulci and from each other by an interatrial groove, which is faintly visible posteriorlyand hidden by the aorta and pulmonary trunk anteriorly

The two ventricles are separated from each other by the interventricular sulci(grooves), which descend from the coronary sulcus toward the apex:

● The anterior interventricular sulcus contains the left anterior descending coronaryartery which courses over the muscular ventricular septum between the right andleft ventricles to the apex (see Figs 1.1 and 1.2)

● The posterior interventricular sulcus which is situated on the diaphragmatic surface

of the heart is the pathway for the posterior descending coronary artery, which isusually the terminal branch of the right coronary artery or less frequently of the leftcircumflex artery

The right coronary artery travels in the right coronary sulcus between the right atriumand right ventricle until it descends on the posterior surface of the heart while the left cir-cumflex artery runs in the left coronary sulcus between the left atrium and left ventricle

The crux of the heart is the area on the posterior basal surface:

● Where the coronary sulcus meets the posterior interventricular sulcus

● The coronary artery which crosses the crux (usually the right coronary artery) gives

a small branch to the nearby AV node and

● Internally, the atrial septum joins the ventricular septum at this junction

Table 1.2 External features of the heart

Features Description

1 Chambers RA, RV, LA and LV

2 Sulci Right and left coronary sulci, interatrial groove and anterior and

posterior interventricular sulci

3 Surfaces Diaphragmatic or inferior, anterior or sternocostal and left surfaces

4 Borders Right border formed by: SVC and RA

Left border formed by: LV and left auricle Inferior border formed by: RV

RA: right atrium, RV: right ventricle, LA: left atrium, LV: left ventricle, SVC: superior vena cava

ii The Surfaces of the Heart

● The area below the crux is known as the diaphragmatic or inferior surface of theheart The diaphragmatic surface of the heart is formed in its left 2/3rd by the leftventricle and its right 1/3rdby the right ventricle

● The anterior or sternocostal surface of the heart is formed mainly by the rightatrium and right ventricle and partly by the left ventricle and left auricle

Left common carotid artery Left brachiocephalic vein Left subclavian artery Arch of aorta Left pulmonary artery Left auricle

Left ventricle Anterior interventricular groove

Posterior interventricular groove Apex of heart

Right ventricle Inferior vena cava

Coronary sulcus

Right atrium

Right pulmonary artery

Superior vena cava

Right brachiocephalic vein

Brachiocephalic artery

Fig 1.1 | External features of the heart—anterior view (diagrammatic).

Superior vena cava

Right atrial appendage

Left anterior descending coronary artery in interventricular groove Left ventricle Apex

Fig 1.2 | External features of the heart—anterior view.

● The left surface of the heart is mostly formed by the left ventricle and at the upperend by the left auricle (see Figs 1.3 and 1.4).

iii The Borders of the Heart

● The right border is more or less vertical which is formed by superior vena cava and theright atrium

Superior vena cava

Right pulmonary artery

Right pulmonary veins

Right atrium Left atrium

Inferior vena cava

Fig 1.3 | External features of the heart—posterior view (diagrammatic).

Aorta Left pulmonary artery

Pulmonary veins Left atrium Coronary sinus and circumflex coronary artery Crux of the heart

Left ventricle

Right pulmonary artery Superior vena cava Pulmonary veins

Right atrium Inferior vena cava

Posterior descending coronary artery in posterior interventricular groove Right ventricle

Fig 1.4 | External features of the heart—posterior view.

● The left border is oblique and curved, mainly formed by the left ventricle and partly

by the left auricle

● The inferior border is nearly horizontal and is formed mainly by the right ventricle

3 THE CHAMBERS OF THE HEART

i Right Atrium (RA)

It receives venous blood from whole of the body via the superior vena cava (SVC) at itsupper end and inferior vena cava (IVC) at its lower end and pumps it into the right ven-tricle through the right atrioventricular (tricuspid) valve during the ventricular diastole

a) External Features

● It is a somewhat quadrilateral chamber situated behind and to the right side of the

right ventricle, externally separated by the right coronary sulcus

● A hollow conical muscular projection, the right auricle (right atrial appendage)arises from the antero-superior part of the right atrium and extends upwards and tothe left of the ascending aorta

● Along the right border of the right atrium, there is a shallow vertical groove, the cus terminalis which extends between the orifices of the superior vena cava and infe-

sul-rior vena cava which is produced by an internal muscular ridge called the crista terminalis The upper part of the sulcus contains the SA node at the lateral margin

of the junction of the superior vena cava with right atrium and the atrial appendage(see Table 1.5)

b) Internal Features

The right atrial wall measures about 2 mm in thickness The interior of the rightatrium is broadly divided into three parts (see Figs 1.5, 1.6 and Table 1.3):

● The smooth posterior part or sinus venarum

● The rough anterior part or pectinate part (atrium proper) and

● The septal wall

(1) The smooth posterior part or sinus venarum

● Developmentally, this portion is derived from the right horn of the sinus venosus

● Superior vena cava opens at the upper end, inferior vena cava opens at the lower endand the coronary sinus opens between the opening of the inferior vena cava and theright atrioventricular (AV) orifice

● The orifice of the superior vena cava has no valve while the orifice of the inferior

vena cava is guarded by a rudimentary valve, the Eustachian valve The Thebesian valve guards the orifice of the coronary sinus (see Table 1.4).

● The caval orifices vary in shape and size depending upon the phase of respiration,the cardiac cycle and contraction or relaxation of the surrounding muscle bandswhich play a role in promoting venous return and preventing atrial reflux

Superior vena cava Openings of venae cordis minimae Right auricle Annulus ovalis

Fossa ovalis Valve of coronary sinus

Septal cusp of tricuspid valve Inferior vena cava

Valve of inferior vena cava

Musculi pectinati Crista terminalis

Fig 1.6 | Interior of the right atrium (diagrammatic).

Table 1.3 Development of the right heart

1 Right horn of sinus venosus Sinus venarum

2 Primitive atrial chamber Atrium proper

3 Septum primum and septum secundum Atrial septal wall

4 Primitive ventricle Inflow tract and body of right ventricle

5 Right part of the bulbus cordis Infundibulum of right ventricle

Superior

Right atrial appendage Pulmonary trunk

Tricuspid valve

Right ventricle

Right pulmonary

artery

Pulmonary veins

Fossa ovalis

Orifice of coronary

sinus Inferior vena cava

Fig 1.5 | Interior of right atrium.

(2) The rough anterior part or atrium proper

● Developmentally, this portion is derived from the primitive atrial chamber

● Crista terminalis, remnant of the upper part of the right venous valve is a smooth

muscle ridge which extends from the upper part of the atrial septum between theorifices of SVC and IVC

● A series of transverse muscular ridges called muscular pectinati arise from the crista terminalis, run forwards and downwards towards the TV orifice, giving the appear-

ance of the teeth of a comb The muscles are interconnected to form a reticular network

in the auricle

(3) The septal wall

● Developmentally, it is derived from the septum primum and septum secundum

● An oval depression above and to the left of the opening of the inferior vena cava

called fossa ovalis is formed by the septum primum A sickle shaped sharp margin

that surrounds the upper, anterior, and posterior margins of the fossa ovalis is the

limbus fossa ovalis, developed from the lower free margin of septum secundum.

The anterior limb of the limbus is continuous with the left horn of the valve of

infe-rior vena cava The remains of the foramen ovale is a small slit like valvular opening (patent foramen ovale, PFO) between the upper part of the fossa and the limbus

which is normally occluded after birth and is occasionally present (see Table 1.6)

● The triangle of Koch, a triangular area bounded in front by the base of the septal

leaflet of tricuspid valve, behind by the antero-medial margin of the opening of

coronary sinus and above by the tendon of Todaro, which is a subendocardial ridge

extending dorsally from the central fibrous body to the left horn of the valve of rior vena cava The AV node is located in this triangle anterior and medial to thecoronary sinus, just above the septal leaflet of the tricuspid valve

infe-● The torus aorticus is a slight bulge in the antero-superior part of the septum and

is caused by the bulging of the right posterior aortic (non-coronary) cusp and theright coronary cusp of the aortic root The proximity of the aortic root to the

Table 1.4 Openings into the right atrium

1 Superior vena cava It has no valves

2 Inferior vena cava It has rudimentary Eustachian valve

3 Coronary sinus It has Thebesian valve

Table 1.5 Nodes of the heart

1 SA node In sulcus terminalis at the lateral margin of the

junction of SVC with right atrium

2 AV node In the triangle of Koch, anterior and medial to the

coronary sinus just above the septal tricuspid leaflet

right atrium permits an aneurysm of the sinus of Valsalva to rupture into the rightatrium.

● The proximal right coronary artery is in immediate vicinity of the septum as itenters the coronary sulcus

ii Right Ventricle (RV)

It is a triangular or a crescent shaped chamber, which receives the venous blood fromthe right atrium during ventricular diastole and pumps it into the pulmonary circula-tion during ventricular systole (see Table 1.7)

a) External Features

● The right ventricle is normally the most anterior cardiac chamber, lying directlybeneath the sternum It is partially below, in front of, and medial to the right atriumbut anterior and to the right of left ventricle

● It forms 2/3rdof the sterno-costal surface, most of the inferior surface and 1/3rdofthe diaphragmatic surface of the heart

Table 1.6 Description of the inter-atrial septum

1 Fossa ovalis Oval depression above and to the left of the opening of

the superior vena cava

2 Limbus fossa ovalis Sickle shaped sharp margin that surrounds upper, anterior

and posterior margins of the fossa ovalis

3 PFO (normally occluded after birth) Small slit like valvular opening between upper part of

fossa ovalis and limbus

4 Torus aorticus Bulge in antero-superior part of the septum due to bulging

of the right posterior and right coronary cusps of aorta

Table 1.7 Description of right heart

1 Shape of the right atrium (RA) Quadrilateral chamber

2 Verticle groove on the RA Sulcus terminalis: contains SA node

3 Wall thickness of the RA 2 mm

4 Internal portions of RA (i) Smooth sinus venarum

(ii) Rough pectinate (atrium proper) (iii) Atrial septal wall

5 Shape of the right ventricle (RV) Triangle or crescent

7 Portions of RV (i) Rough inflow tract

(ii) Smooth infundibulum (iii) Body of the RV

b) Internal Features

The right ventricular wall measures 4–5 mm in thickness,2thinner than that of leftventricle in the ratio of 1:3 The interior of the right ventricle consists of three por-tions (see Figs 1.7 and 1.8):

● The rough inflow tract

● The smooth outflow tract or infundibulum and

● The apical trabecular portion or body of the RV

Fig 1.8 | Interior of the right ventricle (diagrammatic)

Supraventricular crest

Pulmonary valve

Anterior cusp of tricuspid valve Chordae tandinae Moderator band Anterior papillary muscle

Inferior vena cava

Tricuspid valve

Parietal band

Right atrium

Right atrial appendage

Superior vena cava

Aorta

Pulmonary trunk Pulmonary valve Infundibulum Crista supra- ventricularis Septal band Left ventricle Moderator band

Fig 1.7 | Interior of the right ventricle

(1) The rough inflow tract

● Develops from the primitive ventricle of the heart tube, and consists of:

(i) Tricuspid valve and(ii) The trabecular muscles of the anterior and inferior walls which direct the bloodanteriorly, inferiorly, and to the left at an angle of 60 to the outflow tract

● The trabecular carnae (muscles) are arranged into ridges, bridges and pillars lary muscles) The septomarginal trabecula is a muscular ridge extending from theventricular septum to the base of the anterior papillary muscle It contains the rightbranch of the AV bundle and is presumed to prevent the over-distension of the right

(papil-ventricle, hence also called as the moderator band.

● The supraventricular crest, a muscular ridge situated between the tricuspid and

pulmonary orifices separates the inflow and outflow tracts

(2) The smooth outflow tract or infundibulum

● Develops from the right part of the bulbus cordis, forms the superior portion of theright ventricle and gives rise to the pulmonary trunk

● The apex of the conical shaped infundibulum has pulmonary orifice guarded by threesemilunar cusps

● The blood entering the infundibulum is ejected superiorly and posteriorly into thepulmonary trunk

(3) The apical trabecular portion or body of the RV: It is also derived from the primitiveventricle of the heart tube, and is much coarser than that of the left ventricle

iii Left Atrium (LA)

It is a quadrangular chamber situated posteriorly, behind and to the left of the right

atrium, and forms 2/3rdof the base of the heart

● The left atrium receives the oxygenated blood from the pulmonary veins and serves

as a reservoir during left ventricular systole and pumps the blood into the left ventriclethrough the left atrio-ventricular (mitral) orifice during the left ventricular diastole

● The posterior part is derived from the incorporation of the single pulmonary veinwhile the anterior part including the left auricle is developed from the left half of theprimitive atrium (see Table 1.8)

Table 1.8 Development of the left heart

1 Incorporated pulmonary veins Posterior portion of left atrium (LA)

2 Left half of primitive atrium (i) Anterior portion of LA and

(ii) Left auricle

3 Left part of bulbus cordis Outflow of left ventricle (LV)

4 Left part of primitive ventricle (i) Free wall, apex of LV

(ii) Inflow tract of LV

a) External Features

● The anterior wall of the left atrium is formed by the interatrial septum while theposterior surface of the left atrium forms the anterior wall of the oblique sinus of the pericardium

● Its appendage, the left auricle projects anteriorly to overlap the infundibulum of theright ventricle

b) Internal Features

● The wall of the left atrium is 3 mm thick, slightly thicker than that of the right atrium

Most of the wall is smooth and only a network of muscular pectinati is present within

the left auricle

● Two pulmonary veins open into the left atrium on each side of the posterior wall.

There are no true valves at the junction of the pulmonary veins and the left atrium,but the ‘sleeves of the atrial muscle extend from the left atrial wall around the pul-monary veins for 1 or 2 cm and may exert a partial sphincter-like influence, tending

to lessen the reflux during atrial systole or mitral regurgitation

● The atrial septum is also smooth and shows the fossa lunata corresponding to the

fossa ovalis of the right atrium

iv Left Ventricle (LV)

The left ventricle is roughly bullet-shaped with blunt tip directed anteriorly,

inferi-orly and to the left where it forms the apex of the heart with the lower ventricular septum

The left ventricle receives blood from the left atrium during ventricular diastole andejects blood into the systemic circulation during ventricular systole

a) External Features

The left ventricle forms:

● the apex (with lower ventricular septum)

● 1/3rdof the sterno-costal surface

● most of the left surface and

● 2/3rdof the inferior surface of the heart

The left ventricle is posterior and to left of the right ventricle and inferior, anterior and

to the left of the left atrium

b) Internal Features

The left ventricular chamber is approximately an ellipsoidal in shape and its wallsmeasure 8–15 mm thick However the tip of the LV apex is often thin, measuring

2 mm or less The left ventricle consists of (see Fig 1.9):

● The ventricular septum

● The free wall of the left ventricle

● The inflow tract

● The outflow tract

● The apical portion of the left ventricle

(1) Ventricular septum

● The medial wall of the left ventricle is the ventricular septum

● It is roughly triangular in shape, with the base of the triangle at the level of the aorticcusps

● It is entirely muscular but a small portion located superiorly just below the rightcoronary and posterior coronary cusps, is membranous (see Table 1.9) The upper1/3rd of the septum is smooth endocardium while the remaining 2/3rd of the septum and remaining LV walls are ridged by interlacing muscles, the trabeculaecarneae

(2) The free wall of the left ventricle: The ridged trabeculae carneae excluding theventricular septum is the free wall of the left ventricle (see Fig 1.10)

Table 1.9 Development of ventricular septum

Portion of the

Developed from ventricular septum

1 Muscular portion Trabeculae and medial walls between the primitive LV

and RV, appose and fuse together to form incomplete muscular septum at 3 mm stage

2 Membraneous portion Lower edge of conal septum and inferior

endocardial cushion at 6 mm stage

Pulmonary valve Right ventricle

Interventricular septum

Pulmonary trunk Transverse atrium Aortic valve Left atrium Left ventricle

Posterior cusp of mitral valve

Ascending aorta

Diaphragm

Fig 1.9 | Interior of the left ventricle (diagrammatic).

(3) The inflow tract

● The anteromedial leaflet of the mitral valve (MV) extending from the top of theposteromedial septum to the anterolateral ventricular wall separates the LV cavityinto an inflow tract and an outflow tract

● The funnel shaped inflow tract is developed from the left part of the primitive ventricleand consists of mitral orifice with its mitral valve apparatus, which directs the atrialblood inferiorly, anteriorly and to the left towards the LV apex

(4) The outflow tract

● The conical smooth walled outflow tract is situated above, in front of and slightly tothe right of the mitral orifice

● It is developed from the left part of the bulbus cordis

● It is surrounded by the inferior surface of the anteromedial mitral leaflet, the ventricularseptum and the left ventricular free wall

Pulmonary trunk Left atrial appendage

Pulmonary veins Fossa lunata Aorta

Fig 1.10 | Interior of the left heart with LV free wall and mitral valve removed.

Table 1.10 Description of the left heart

1 Shape of the left atrium (LA) Quadrangular chamber

3 Portions of LA (i) Auricle: has musculi pectinati

(ii) Smooth walled body (iii) Smooth interatrial septum with fossa lunata

4 Shape of the left ventricle (LV) Bullet shaped with ellipsoidal chamber

5 LV wall thickness 8–15 mm, while apex is 2 mm thick

6 Portions of LV (i) Triangular ventricular septum

(ii) Free wall is ridged with trabeculae carnae (iii) Funnel shaped inflow

(iv) Smooth conical shaped out flow

● It orients the blood flow from the LV apex to the right and superiorly at an angle of

90 to the inflow tract3 ejecting the blood into the ascending aorta through the aortic orifice during ventricular systole

● The summit of the aortic vestibule is occupied by the aortic annulus guarded bythree semilunar cusps

(5) The apical portion of the left ventricle is characterized by fine trabeculations, alsodeveloped from the primitive ventricle (see Table 1.10)

4 THE FIBROUS SKELETON OF THE HEART

i Components and Attachments

● The fibrous skeleton of the heart is made up of four fibrous rings (mitral, tricuspid,

pul-monary and aortic) (see Fig 1.11 and Table 1.11) at the bases of both ventricles aroundthe mitral, tricusid, pulmonary and aortic orifices, which provide the attachment to:(i) Atrial and ventricular musculature

(ii) Valves of the heart and(iii) Roots of the aorta and pulmonary trunk

Tricuspid valve

Tendon of infundibulum

Aortic valve Origin of right coronary artery

Fig 1.11 | Fibrous skeleton of the heart (diagrammatic).

Table 1.11 Fibrous skeleton of the heart

1 Four fibrous rings (i) Pulmonary

(ii) Aortic (iii) Mitral (iv) Tricuspid (iii  iv form central fibrous body)

2 Two trigones Right fibrous trigone

Left fibrous trigone

● The pulmonary ring lies above, in front of and slightly to the left of the aortic ring.Both the rings are set at right angles to each other and connected by a fibrous septum

known as tendon of infundibulum.

● The medial aspects of mitral and tricuspid rings are fused by the central fibrous

body known as trigonum fibrous dextrum or right fibrous trigone.

● The left margin of the trigone connects aortic and mitral rings, which is named as

trigonum fibrosum sinistrum or left fibrous trigone.

● The right and left fibrous trigones which partially encircle the mitral and tricuspid fices are the mitral and tricuspid annuli that give attachment to the mitral and tricuspidvalves, atrial and ventricular muscle

ori-ii Extensions

● An important extension of the fibrous skeleton is the membranous ventricular septum,which extends inferiorly and anteriorly from the right fibrous trigone It is located atthe summit of the muscular septum, and provides support for the right coronary andnoncoronary aortic cusps

● A portion of the membranous septum extends slightly above the tricuspid valve,forming a small portion of the medial wall of the right atrium

iii The Bundle of His

It penetrates the central fibrous body and travels along the inferior margin of themembranous ventricular septum At the crest of the muscular septum, above the level

of junction of the right coronary and noncoronary (posterior) aortic cusps, the His bundle divides into a left bundle branch and a right bundle branch The right fibroustrigone is sometimes calcified in old age while this a constant feature in sheep’s heart

5 THE VALVES OF THE HEART

There are two pairs of valves in the heart (see Fig 1.12)

● A pair of atrioventricular valves: mitral and tricuspid and

● A pair of semilunar valves: aorta and pulmonary

● The loose fibroelastic tissue on the atrial aspect of the AV valves is known as atrialis, ventricular surface of all four valves (AV & SL), the ventricularis, and aortic and pul- monary surfaces of SL valves are known as arterialis4(see Table 1.12).

● The endothelium and loose connective tissue of the AV valves are continuous withthe atrial and ventricular endothelium and those of the SL valves are continuouswith the aortic and pulmonary intima

● Smooth striated cardiac muscle may extend onto the proximal 1/3rdof the atrialis inthe AV valves and often contain blood vessels The distal 2/3rdof AV valves and both

SL valves are avascular.4–8

i Mitral Valve

Mitral valve develops primarily from (see Table 1.13):

● LV muscle wall: predominantly by delamination of the muscular ventricular wall,9hence valve cusps initially are thick and fleshy.10

Table 1.12 Valve leaflet surfaces

1 Atrialis Atrial surface of atrioventricular valve leaflets

2 Ventricularis Ventricular surface of all leaflets

3 Arterialis Arterial surface of the semilunar valve leaflets

Aortic orifice Left ventricle Anterior papillary m.

Mitral orifice Posterior papillary m.

Interventricular septum

Posterior or inferior papillary m.

Anterior papillary m.

Tricuspid orifice Septal papillary m.

Right ventricle Pulmonary orifice

Fig 1.12 | Transverse section through the ventricles showing the valves of the heart

(diagrammatic).

Table 1.14 Structure of the mitral valve

1 Annulus Saddle shaped; 4–6 cm 2 in size; fibrous anteromedial

portion and muscular posterolateral portion

C shaped scalloped PML

3 Papillary muscles Anterolateral PM at 4 o clock position

Posteromedial PM at 7 o clock position

4 Chordea tendinae 120 in number

Cuspal: primary, secondary and tertiary Commissural: anterolateral and posteromedial

Posterior leaflet Median

scallop

Middle scallop

Lateral scallop Anterior leaflet

Mitral annulus Clear zone Cuspal chordae

Ventricular wall Rough zone Commissural chordae Papillary muscle

Cuspal chordae Cuspal chordae

Basal zone

Fig 1.13 | Mitral valve complex (diagrammatic).

Table 1.13 Development of the valves

1 Mitral

Anterior mitral leaflet Superior and inferior endocardial cushions

Posterior mitral leaflet Left lateral endocardial cushion

2 Tricuspid

Anterior leaflet Right lateral and dextro dorsal endocardial cushions Posterior leaflet Right lateral endocardial cushion

Septal leaflet Inferior endocardial cushion

3 Semilunar valves Truncus arteriosus

Truncal and intercalated valve cushions

is devoid of fibrous tissue and formed by the myocardium of the LV and left atrium.

● The decrease in annular size during ventricular systole is due to contraction of thisposterolateral portion

b) Leaflets

Mitral valve has two leaflets: anterior mitral leaflet (AML) and posterior mitral leaflet(PML) However, it can have two small minor commissural cusps which are normallyincomplete.14

● PML is ‘C’ shaped, hinges on the posterolateral 2/3rdof the annulus

● It is longer at its base (6 cm of circumference) and shorter in its basal to apicallength (1.2 cm) than AML (3 cm of circumference and 2.3 cm of basal to api-cal length)15however both have similar surface area.11,12

● The surface area of both leaflets is about 2½ times that of the orifice area,16while the cross sectional area of both leaflets is 20% more than the mitral orifice

● PML is sub-divided by medial and lateral clefts into three scallops-posteromedial,middle and anterolateral portions with middle being the largest (1.3 cm widthcompared to 1.0 cm for other two).15

(iii) Surface of the leaflets

● The atrial surface of the cusps is generally smooth except near the free edgewhere chordae tendinea are attached Slightly away from the free edge on the

atrial surface are fine nodules called the noduli Albini.

● The ventricular surface of the cusps is irregular due to insertion of the chordaetendinae

(iv) Commissures: The leaflets are connected to each other at junctions called missures (SL valve commissures are ‘spaces’), anterolateral and posteromedial

com-commissures

c) Papillary Muscles (PM)

There are two papillary muscles: anterolateral and posteromedial, located below thecommissures projecting from the trabeculae carneae Interpapillary muscle distance isrelatively constant Each PM has six heads.14

(i) Anterolateral PM: It is situated at 4oclock position and is supplied by a diagonalbranch of left anterior descending) artery and obtuse marginal of left circumflex artery

(ii) Posteromedial PM: It is situated at 7oclock position and is supplied by posteriordescending artery of right coronary artery in 85%, left circumference artery in 7% and

by both in 8% (co-dominant) of individuals

(i) Cuspal (leaflet) chords are classified into three groups: primary, secondary andtertiary

● Primary group originate near the PM apices, divide into a number of finer

strands that insert at the extreme edge of the cusps These chordae prevent thecusp inversion into the left atrium during ventricular systole

● Secondary group of chordae also originate near the PM apices, are thicker in

diameter, but less in number as compared to the first group and tend to insert

on the ventricular surface of the cusps They serve to anchor the valve

● Tertiary group of chordae originate from the ventricular wall, may actively

contain muscle and are attached to the ventricular aspect of posterior leaflet.These chords are specific to the PML.14,18

(ii) Commissural chords arise from the anterolateral and posteromedial PM andbranch in a fan-like manner to be inserted on to both commissures

e) Mitral Valve Closure

The closure of mitral valve involves a complex interplay of active and passive processes

It consists of three phases: initial leaflet phase, annular phase and ventriculogenic phase

(i) Initial leaflet phase: At the end of the rapid filling phase, the leaflets graduallymove passively towards the closed position due to vortex currents generatedunder their ventricular surfaces

(ii) Annular phase:With the onset of atrial contraction, annular contraction beginswhich continues throughout the ventricular systole The annular contraction is animportant phase in MV closure and causes 20–40% decrease in annular orifice.Non-homogenous structure of the annulus produces an eccentric narrowing of theorifice during annular contraction

(iii) Ventriculogenic phase: With isometric contraction, the contraction of valvular muscle fibers occurs and leaflets become concave in shape which opposesleaflet eversion during ventricular systole The large sail shaped AML swings and

intra-is engulfed by Gusset like C shaped PML causing closure of mitral valve Leafletsare further sealed together by the opposing effect of intraluminal pressures.Papillary muscles and chordae maintain isometric tension and thereby stabilizesthe leaflets during ventricular systole

ii Tricuspid Valve

The tricuspid valve develops from: (see Table 1.13)(i) RV muscle wall  by delamination of muscle wall(ii) endocardial cushion:

● Anterior leaflet from right lateral and dextro-dorsal endocardial cushions

● Posterior leaflet from right lateral endocardial cushion and

● Septal leaflet from inferior endocardial cushion

The tricuspid valve like mitral valve also consists of six major anatomic components: rightatrial wall, annulus, leaflets, papillary muscles, chordae tendineae and right ventricularfree wall (see Fig 1.14 and Table 1.15)

Table 1.15 Structure of the tricuspid valve

1 Annulus Circumferential in shape, 5–8 cm 2 in size-anterior, posterior and septal portions

2 Leaflets Largest anterior, smallest medial or septal and scalloped posterior

3 Papillary muscles Anterior (largest), posterior (usually multiple) and septal (may be rudimentary)

4 Chordae tendinae Five types: fan shaped, rough, deep, basal and free edged

(deep and free edged are unique to TV)

Antero-septal commissure

Anterior leaflet Basal zone

Clear zone

Rough zone Rough zone chordae Papillary muscle

Free chordae Chordae Ventricular wall Basal chordae

Posterior leaflet Postero-septal commissure Septal leaflet

Commissural chordae

Deep chordae Tricuspid annulus

Fig 1.14 | Tricuspid valve complex (diagrammatic).

● The posterior leaflet makes up the largest portion of the annulus (7.5 cm), followed

by the anterior (3.7 cm), and septal (3.6 cm) leaflets.19

b) Leaflets

Tricuspid valve has three leaflets: anterior, posterior and septal

● Anterior leaflet is the largest with a width of 2.2 cm.19

● Septal (medial) leaflet is the smallest with a width of 1.5 cm.19

● The posterior leaflet measures 2.0 cm in width19and may have 1–3 scallops duced by small clefts

pro-There are three commissures:

● Anteroposterior with a size of 1.1 cm

● Posteroseptal with 0.8 cm size and

● Anteroseptal commissure with a size of 0.5 cm

c) Papillary Muscles (PM)

TV has three papillary muscles: anterior, septal (medial) and posterior

● The anterior PM is the largest, located below the anteroposterior commissure nating from the moderator band as well as from the anterolateral ventricular wall

origi-● The posterior PM lies beneath the posteroseptal commissure attached to the rior wall of the RV and receive chordae from posterior and septal leaflets It is usu-ally multiple

poste-● The septal PM is small originating from the wall of the infundibulum It has sive attachments to the ventricular septum and receives chordae from the anteriorand septal leaflets At times, septal PM is rudimentary, absent, double or multiple

exten-d) Chordae Tendineae

It may arise from the papillary muscles or from the muscle of the posterior or septalwalls of the RV

On an average, there are 25 chordae inserted into the tricuspid valve:

● 7 chordae are inserted into the anterior leaflet

● 6 into the posterior leaflet

● 9 into the septal leaflet and

● 3 into the commissures

TV has 5 types of chordae tendinea:19

● Fan shaped

● Rough

● Deep

● Basal and

● Free-edge

The deep and free-edge are unique to the tricuspid valve.19Deep chordae provide asecond arcade for leaflet attachment, while free-edge are single and inserted into theleaflet’s free edge

Fan shaped chordae are inserted into the three commissures while basal chordae arethe shortest and measure an average of 0.6 cm Rough and deep chordae may be aslong as 2.2 cm

iii Semilunar (SL) Valves

● Semilunar valves are derived from:

(i) the truncus arteriosus and(ii) truncal and intercalated valve cushions

● The aortic and pulmonary valves are called semilunar valves because their cusps aresemilunar in shape

● They are situated at the summit of the outflow tract of their corresponding ventricle, the pulmonary valve is anterior, superior and slightly to the left of the aortic valve

● Each semilunar valve consists of an annulus, three equal-sized semicircular cusps, three

equal spaced commissures and three sinuses of Valsalva (see Table 1.16).

a) Annulus

Unlike aortic valve the pulmonary valve has no discrete annulus or fibrous ring Theapex of the infundibulum presents the pulmonary orifice which is circular andguarded by three semilunar cusps The pulmonary valve annulus is about 1.5 cmabove the level of the aortic valve annulus, but its circumference is similar: 7–9 cm.The average size of the aortic annulus is 2.5 cm2

Table 1.16 Structure of the semilunar valves

1 Annulus PV: 7–9 cm in circumference

AV: 2.5 cm 2 in area

2 Leaflets AV: 2 anterior: right and left coronary cusps

1 posterior or noncoronary cusp PV: 2 posterior: right and left cusps

1 anterior cusp

3 Sinuses of Valsalva AV: 2 anterior: right and left

1 posterior PV: 2 posterior: right and left

1 anterior

PV: pulmonary valve; AV: aortic valve.

b) Leaflets (Cusps)

● Each cusp is attached by its semicircular border (lower edge) to the wall of the aorta

or pulmonary trunk while the upper free edges project into the lumen

● The aortic and pulmonary valves are similar in configuration except that the aorticcusps are slightly thicker.5

● The three aortic valve cusps: two anterior-right and left coronary cusps; one posterior ornoncoronary cusp, while the pulmonary valve has two posterior cusps-right and leftand one anterior cusp (see Figs 1.15 and 1.16)

● The aortic left and noncoronary cusps are continuous with AML of the mitral valve.The free margin of each cusp contains a central fibrous nodule on its ventricular sur-

face called noduli Arantii which marks the contact sites of closure From each side

of the nodule, a thin smooth margin (lunule) extends to the base of the cusp, which

is less prominent in the pulmonary valve (see Fig 1.17)

● There may be variation in the cusps and commissural sizes and positions of the sinuses of Valsalva which result in asymmetric lines of closure and may acceler-ate ‘wear and tear’ (aging) of the valve structure especially of that of the aortic valve

Right ventricular (RV) outflow

Fig 1.16 | Structure of the pulmonary valve (diagrammatic)—R: right posterior cusp,

L: left posterior cusp, A: anterior cusp.

R

Ventricular diastole

Anterior mitral leaflet

Fig 1.15 | Structure of the aortic valve (diagrammatic)—N: noncoronary cusp, R: right

anterior cusp, L: left anterior cusp, AML: anterior mitral leaflet.

Because of less systolic pressure in RV, these acquired senile (aging) changes in monary valve do not occur.

pul-c) Commissures

● Each semilunar valve has equally spaced three commissures i.e the small spacebetween the attachments of the adjacent cusps (vs AV valves)

● The circumference connecting these points is termed as the sinotubular junction,

which separates the sinuses of Valsalva from the adjacent tubular portion of the vessel

In aorta, a distinct hump or line marks this junction which was originally described

by Leonardo da Vinci as the ‘supra-aortic ridge’

● The circumference is measured at this sinotubular junction with echocardiographyand at necropsy

● While the lowermost portion of aorta (at the junction of the aortic valve with theventricular septum) which is referred as the aortic ring, is measured by the surgeons

to determine the size of the aortic prosthetic valve

d) Sinuses of Valsalva

A pouch-like dilatation above each cusp is known as sinus of Valsalva The aortic rightand left sinuses of Valsalva give rise to right and left coronary artery respectively.The aortic sinuses of Valsalva have close relation with right and left sided chambers.Hence, rupture of the right and non-coronary sinuses of Valsalva may communicate withright sided chambers (outflow tract RV and RA) while rupture of left sinus of Valsalvacommunicates with left sided chambers (LA or LV outflow tract) With age,

● The aortic cusps thicken

● Nodules thicken and enlarges

● Sinuses of Valsalva calcify and dilate and

● Lunules develop fenestrations

With age, the pulmonary valve cusps also thicken slightly but rest of the changes areless prominent

e) SL Valve Closure

During ventricular systole, the cusps are passively thrust upward away from the center

of the lumen During ventricular diastole, the cusps fall passively into the lumen of the

Left coronary artery

Ascending aorta

Nodule Lunule Anterior aortic sinus Right coronary artery

Fig 1.17 | Structure of the aortic valve (diagrammatic).

vessel as they support the column of blood above while the nodules meet in the centerwhich contributes to the support of the leaflets, thus preventing the regurgitation ofblood.

Electrocar-3 Walmsley R, Watson H Clinical Anatomy of the Heart New York Churchill Livingstone 1978:1–22.

4 Gross L, Kugel MA Topographical anatomy and history of the valves in the human heart Am J Pathol 1931;7:445–474.

5 Waller BF Morphological aspects of valvular heart disease Part I Curr Probl Cardiol 1984;9(7):1–66.

6 Clarke JA An X-ray microscopic study of the blood supply to the valves of the human heart Br Heart J 1965;27:420–423.

7 Duran CM, Gunning AJ The vascularization of the heart valve: A comparative study Cardiovasc Res 1968;2(3):290–296.

8 Montiel MM Muscular apparatus of the mitral valve in man and its involvement in left sided cardiac hypertrophy Am J Cardiol 1970;26(4):341–344.

9 Dox X, Corone P Embriologie cardiaque: Malformations (1) In: Embryologie Cardioaque-Editions Techniques Paris Encyclopedie Medico-Chirurgicale 1992:1–20.

10 Streeter GL Developmental horizons in human embryos: Description of age groups XI 13–20 somites and age group XII 21–29 somites Contrib embryol 1942;30:211–245.

11 Perloff JK, Roberts WC The mitral apparatus: Functional anatomy of mitral regurgitation Circulation 1972;46(2):227–239.

12 Waller BF, Morrow AG, Maron BJ, Del Negro AA, Kent KM, McGrath FJ, et al Etiology of cally isolated, severe, chronic, pure mitral regurgitation: Analysis of 97 patients over 30 years of age having mitral valve replacement Am Heart J 1982;104(2 Pt 1):276–288.

clini-13 Roberts WC Morphologic features of normal and abnormal mitral valve Am J Cardiol 1983;51(6): 1005–1028.

14 Netter FH CIBA collection of medical illustration: Heart vol 5 Summit NJ: CIBA pharmaceutcal 1987:9–112.

15 Ranganathan N, Lam JHC, Wigle ED, Silver MD Morphology of human mitral valve: II The valve leaflets Circulation 1970;41:459–467.

16 Brock RC The surgical and pathological anatomy of the mitral valve Br Heart J 1952;14(4):489–513.

17 Constant J Bedside Cardiology 3rd Boston, Mass: Little, Brown and Company; 1985 pp 38–39.

18 Carbello BA Mitral valve disease Curr Probl Cardiol 1993;18(7):423–478.

19 Silver MD, Lam JHC, Ranganathan N, Wigle ED Morphology of human tricuspid valve Circulation 1971;43(3):333–348.

■ ■ ■ C HAPTER 2

1 FORMATION OF RIGHT CORONARY

There are two main lymphatic channels:

● Right coronary channel (RCC) and

● Left coronary channel (LCC)

1 FORMATION OF RIGHT CORONARY CHANNEL

The posterior interventricular trunk (PVT) runs along with the posterior descending

artery (PDA) in the posterior interventricular sulcus up to the crus of the heart, andthen encircles around to the right from posterior to anterior in the right coronary

sulcus to become the right coronary channel.

2 FORMATION OF LEFT CORONARY CHANNEL

The two major LV channels are: anterior interventricular trunk and obtuse marginal