Ebook Fundamentals of cardiology: Part 1

(BQ) Part 1 book Fundamentals of cardiology presents the following contents: Embryology of heart, anatomy, physiology, arterial pathology, venous pathology. Invite you to consult.

CHAPTER!1!6!EMBRYOLOGY!OF!HEART! !10

Vascular+Development+ +12

Fetal+Circulation+ +14

Septation+of+Heart+Tube+ +15

CHAPTER!2!6!ANATOMY! !19

Mediastinum+ +19

Internal+Structures+ +23

External+Structures+ +23

Cardiac+Territories+ +24

Cardiac+Projection+ +25

Cardiac+Muscle+fibre+ +27

Conduction+Pathway+ +28

Coronary+Arteries+ +29

CHAPTER!3!6!PHYSIOLOGY! !31

Concepts+of+Preload,+Ejection+Fraction+&+Cardiac+Output+ +31

Concepts+of++Velocity,+Area,+Resistance+and+Flow+ +33

Auto9Regulation+of+Blood+Flow+ +35

Resistance+In+Series+And+Parallel+Circuits+ +36

Blood+Pressure+ +38

Compliance+and+Elasticity+of+Vessels+ +42

Relationship+Between+Contractility+&+Preload+ +45

Action+Potential+ +48

Normal+ECG+ +50

Autoregulation+of+Blood+Pressure+ +51

Renin9Angiotension9Aldosterone+System+ +53

Phases+of+Cardiac+Cycle+ +55

Valvular+Problems+and+Pressure9Volume+Loops+ +57

Ventricular+Pressure+Testing+ +62

Heart+sounds+ +64

Murmurs+ +66

Effect+of+Posture,+Amyl+Nitrate+&+Arterioconstriction+on+Murmurs+ +73

Jugular+venous+pressure+ +74

CHAPTER!4!–!ARTERIAL!PATHOLOGY! !77

Hypertension+ +77

Hypertension+in+Pregnancy+ +86

Hypertensive+Crisis+ +87

Arteriosclerosis+ +90

Monckeberg!arteriosclerosis! !90

Arteriolosclerosis! !92

Atherosclerosis! !93

Aneurysms+ +98

Aortic+Dissection+ +101

Coarctation+of+Aorta+ +106

Vasculitis+ +109

Raynaud+Phenomenon+ +115

Tumors+ +118

CHAPTER!5!–!VENOUS!PATHOLOGY! !120

Venous+System+of+Leg+ +120

Deep+Venous+Thrombosis+ +123

Superficial+Thrombophlebitis+ +127

Leg+Ulcers+ +128

CHAPTER!6!6!CARDIAC!PATHOLOGY! !130

Ischemic+Heart+Disease+ +130

Cardiac+Arrest+vs+Respiratory+Arrest+ +149

Cardiopulmonary+Resuscitation+ +150

Broken+Heart+Syndrome+ +153

Heart+Failure+ +156

Left!Heart!Failure! !156

Right!Heart!Failure! !160

High!Output!Heart!Failure! !161

Cardiomyopathy+ +163

Dilated!Cardiomyopathy! !163

Restrictive!Cardiomyopathy! !164

Hypertrophic!cardiomyopathy! !165

Arrhythmogenic!Right!Ventricular!Cardiomyopathy! !168

Peripartum!Cardiomyopathy! !171

Circulatory+Shock+ +174

Myocarditis+ +180

Pericarditis+ +182

Constrictive+Pericarditis+ +184

Cardiac+Tamponade+ +185

Valvular+Pathology+ +188

Infective!Endocarditis! !191

Aortic!stenosis! !197

Aortic!regurgitation! !200

Rheumatic!Heart!Disease! !202

Mitral!Stenosis! !205

Mitral!Regurgitation! !208

Tricuspid!Regurgitation! !210

Tricuspid!Stenosis! !211

Pulmonary!Stenosis!and!Regurgitation! !212

CHAPTER!7!6!CONGENITAL!HEART!DISEASE! !215

Acyanotic+condition+ +216

Atrial!Septal!Defect! !217

Ventricular!Septal!Defects! !218

Patent!Ductus!Arteriosus! !220

Cyanotic+conditions+ +222

Tetralogy!of!Fallot! !222

Transposition!of!the!great!vessels! !224

Tricuspid!atresia! !225

Valvular+Defects+ +226

Coronary!Artery!Abnormalities! !227

Other!Congenital!Cardiac!Pathology! !228

CHAPTER!8!6!ARRHYTHMIAS! !230

Narrow+QRS+Complex+ +230

Wide+QRS+Complex+ +236

Torsade9de9Pointes+ +240

Wolf+Parkinson+White+Syndrome+ +242

Focal+Junctional+Tachycardia+ +243

Multifocal+Atrial+Tachycardia+ +243

Premature+Atrial+Contractions+ +244

Heart+Blocks+ +247

First!Degree!AV!Block! !247

Second!Degree!AV!Block!(Mobitz!Type!1)! !248

Second!Degree!AV!Block!(Mobitz!Type!2)! !249

3rd!Degree!AV!Block! !250

SA!BLOCK! !251

Right!&!Left!Bundle!Branch!Blocks! !251

Brugada!syndrome! !254

CHAPTER!9!–!CARDIAC!TUMORS! !256

Benign+tumors+ +256

Malignant+Tumors+ +257

CHAPTER!10!6!CARDIAC!PHARMACOLOGY! !258

Antiarrhythmic+drugs+ +258

Antihypertensive+drugs+ +263

Antihyperlipidemic+drugs+ +267

Anticoagulants+ +269

Non+Pharmacological+Treatments+ +271

!

Sincerely,!

++++All+printed+and/or+digital+content+is+for+educational+and/or+learning+use+only.+MEDRX+is+not+responsible+for+the+use+of+any+knowledge,+information+or+facts+gained+from+the+printed+and/or+digital+content+in+the+practice+of+medicine,+medical+research+or+any+related+medical+or+science+applications.+

In+addition,+while+materials+available+in+this+book+may+be+useful+for+medical+coursework+examinations+and+qualifying+examinations+such+as+the+NCLEX™,+USMLE™+and+ABIM™,+you+understand+that+MEDRX+is+not+affiliated+with+any+other+third+party+and+does+not+(directly+or+by+implication)+make+any+guarantees+that+the+materials+provided+by+us+will+be+tested+on+these+examinations.++

95%+of+the+investigations+and+management+mentioned+in+this+book+are+from+year+201092014,+however+you+realize+that+errors+can+occur+and+thus+managements+mentioned+in+this+book+should+not+be+directly+use+in+clinical+practice+without+any+guidance.+We+are+not+responsible+for+any+harm+done+to+anybody+by+the+managements+mentioned+in+this+book.++

Finally,+we+want+to+hear+what+you+would+like+to+improve+in+our+book?+This+will+help+us+to+create+even+better+subsequent+editions.+If+you+can+give+your+2+minutes,+please+leave+us+495+star+feedback+on+amazon.+If+you+even+think+about+193+stars,+please+contact+us+through+our+website++

&+we+will+consider+to+refund+you+your+full+purchase+price+(book+must+be+purchased+from+our+website+or+amazon.com+official+store+(not+valid+on+purchases+from+amazon+private+sellers+or+other+places).+

TO+THE+PUBLISHERS++9+Certain+images+were+freely+available+on+internet+and+we+had+adapted+some+of+them+with+full+credits.+Most+of+the+images+are+taken+with+permission,+however+we+were+unable+to+reach+at+all+places+or+don’t+know+the+real+owner+in+few+cases.+If+anybody+have+any+objection+for+the+image+use+in+this+book,+feel+free+to+contact+us+through+our+website+and+

• The!heart+develops+from+splanchnic!mesoderm+in+later+half+of+3 rd !week+and+starts+ beating+by+4 th !week.!!

• Neural+crest+cell+migration+play+an+important+role+in+heart+development.+

• Single+heart+tube+is+formed+by+the+fusion+of+primordial+heart+tubes+that+are+in+turn+

developed+from+cardiogenic!cells.+Heart+tube+will+then+undergo+dextral!looping+ (bend+to+right)+and!rotation.+!

• Heart+tube+will+undergo+further+morphological+changes+and+will+give+rise+to+various+embryological+dilations+like+truncus+arteriosus,+bulbus+cordis,+primitive+ventricle,+primitive+atrium+and+sinus+venosus.+

+

Image+Courtesy+9+http://embryology.med.unsw.edu.au+

+Various+adult+structures+are+derived+from+these+dilations,+which+are+as+follow+9+

Right+side+–+proximal+part+of+pulmonary+artery.+

Left+side+9+ductus+arteriosus.+

• As+septum+grows+downward,+foramen+primum+become+narrower+&+narrower.++Before+foramen+primum+disappears+foramen+secundum+is+formed+in+septum+primum+which+allows+flow+of+blood+from+right+to+left+side+in+fetus.+

+

• After+formation+of+foramen+secundum,+septum+secundum+starts+developing+on+its+right+side+&+covers+most+of+foramen+secundum.++

+

• It+does+not+fuse+with+endocardial+cushion+and+thus+allow+continuous+flow+of+blood+from+right+to+left+through+foramen+ovale.+

+

• Please+note+that+foramen+secundum+is+not+equal+to+foramen+ovale+(foramen+secundum+is+due+to+fenestrations+in+septum+primum+while+foramen+ovale+is+residual+foramen+after+septum+secundum+covers+most+foramen+secundum.+

+

• Closure+of+foramen+ovale+occurs+immediately+after+the+birth+due+to+increase+in+left+atrial+pressure.+++

+

• There+will+be+decrease+in+resistance+of+pulmonary+circulation+with+the+1st+breath+of+infant.+Now+all+blood+will+have+to+undergo+pulmonary+circulation+for+oxygenation+from+right+atrium.++

Patent!Foramen!Ovale+

• PFO+is+a+condition+in+which+septum+primum+and+septum+secundum+fails+to+fuse+after+birth.++

+

• It+is+an+acyanotic+condition+at+the+time+of+birth+because+some+volume+of+oxygenated+blood+from+the+left+side+will+flow+towards+right+atrium+according+to+pressure+gradient.+This+blood+will+then+again+undergo+pulmonary+circulation+and+thus+no+deoxygenated+blood+is+delivered+systematically.+++

+

• Over+the+long+period+of+time,+volume+overload+in+pulmonary+artery+will+cause+

hypertrophy!and!hyperplasia!(pulmonary!stenosis!like!situation).+This+will+

narrow+the+lumen+of+pulmonary+artery+leading+to+increase+in+pressure+on+the+right+side+of+heart+and+thus+deoxygenated+blood+from+right+atrium+will+flow+toward+left+

atrium+through+foramen+ovale.+This+reversal+of+blood+flow+is+called+as+eissenmenger! syndrome.!

+

• Thus+the+main+complication+that+can+develop+due+to+patent+foramen+ovale+is+an+increases+risk+of+paradoxical+emboli.+

+

• Most+PFO+are+left+untreated+because+they+usually+fuse+off+later+on+in+life.+

+

VENTRICULAR!SEPTATION!

Ventricular+septation+begins+at+4th+week+&+is+completed+by+7th+week.+

Basically,+there+are+2+parts+in+septum+

development++

One+which+grow+downward+from+endocardial+cushion+&+conotruncal+ridge+c/a+membranous+part+&+other+part+grows+upward+from+floor+of+ventricles+c/a+muscular+part.++

Majority+of+the+septum+is+made+up!of!muscular! part.!Failure!in+fusion!of!upper!&!lower!

septum+will+lead+to+ventricular+septal+defect.+

Thus+endocardial!cushion+that+is+a+neural+crest+derivative+play+a+very+important+role+in+

development+of+interatrial+&+interventricular+septum.+

They+also+contribute+in+development+of+all+valves+&+thus+play+a+significant+role+in+Intra9heart+partitions.++Various+Neural+crest+cell+abnormalities+will+affect+cardiac+septal+development.+

+

THUNDERNOTE!

Neural!Crest!Cell!abnormalities!

• Neuroblastoma+(most+common+extracranial+tumor+in+infancy,+most+common+location+is+supra9adrenal)+

• Di9George+syndrome+(due+to+deletion+in+chromosome+22,+associated+with+truncus+arteriosus+and+tetralogy+of+fallot)+

• Neurofibromatosis+type+1+(mutation+of+neurofibromin+(RAS+pathway)+gene+on+

chromosome+17,+Café+au+lait+spot+are+characteristic+of+NF+1)+

• Hirshsprung+disease+(aganglionic+segment+in+intestine,+baby+fails+to+pass+meconium+within+48+hr+of+delivery,+part+of+colon+near+to+anus+is+usually+first+to+be+affected,+definitive+diagnosis+by+suction+biopsy)+

• Tetralogy+of+fallot+(pulmonary+stenosis,+overriding+aorta,+ventricular+septal+defect+and+right+ventricular+hypertrophy)+

• Treacher9Collins+syndrome+(congenital+disorder+characterized+by+craniofacial+

(aortic+dissection+type+A).+Courtesy9+J.+Heusar,+

www.wikipedia.org+

Widened+mediastinum+is+when+the+diameter+is+>+6+cm+on+upright+chest+x9ray+or+>+8cm+on+supine+chest+x9ray.++

Some+causes+of+widened+mediastinum+are++

• Aortic+dissection+

• Dorsal+spinal+verterbral+fracture+(T49T8)+

• Infections+with+bacillus+anthracis+(anthrax)+

• Aortic+aneurysm+and+other.++

+

• Esophageal+rupture+will+have+air+in+mediastinum.+It+is+diagnosed+with+water9soluble+contrast.+

Image!courtesy!6!www.escholarship.org !

Superior!vena!cava!(SVC)!syndrome!

Large+mediastinal+mass+can+be+anything+like:+

• Primary+lung+cancer+like+small+cell+carcinoma.+

These+masses+can+compress+superior+vena+cava.+You+cannot+distinguish+them+merely+base+upon+CXR.+Further+investigations+like+biopsy+are+required.+++

+

Image+Courtesy+9+Sylvia+S.+Mader,+Inquiry+into+Life,+8 th +Edition+EXTERNAL+STRUCTURES+

+

Image+Courtesy:+www.droualb.faculty.mjc.edu+

CARDIAC PROJECTION

+Various+borders+of+heart+can+be+determined+by+joining+these+surface+projections.+

Right!border! Between+3rd++right+coastal+cartilage+to+6th+right+coastal+cartilage+

Left!border! Between+5th+left+intercoastal+space+at+midclavicular+line+to+2nd+left+coastal+

+

+

+

+

Image+Courtesy+9+www.cnx.org++

Organ!System! Blood+Flow+ Explanation+

+

vessels+will+constrict+under+SNS+activity+and+thus+blood+flow+decreases+during+exercise.+!

Heat+causes+vasodilation+and+cold+temperature+vasoconstriction.+This+is+the+reason,+why+patients+will+be+flushed+in+fever+and+exercise+(increases+in+heat+loss+by+cutaneous+

vasodilation).+

AUTO9REGULATION+OF+BLOOD+FLOW+

1)!Coronary!circulation+–+Auto9regulated+by+endogenous+adenosine!and!nitric!oxide+–+

when+heart+will+be+under+stress,+more+ATP+will+be+used+up+&+thus+adenosine+will+form+as+byproduct+which+dilates+coronary+vessels+and+provide+sufficient+blood+flow+to+the+heart+to+meet+its+energy+requirements.+

2)!Cerebral!circulation!–+Our+brain+is+regulator+of+our+body+and+should+not+be+left+at+mercy+of+

other+organs+like+heart+and+blood+pressure.+So,+brain+maintains+its+circulation+mainly+by+

arterial!carbon+di+oxide+level+(PaCO2).++

Increase+in+partial+pressure+of+carbon+di+oxide+will!increase!cerebral!circulation!during! hypoventilation+&+vice+versa.+

3)+Skeletal!muscle!(during!exercise!only)!6+By+myogenic+stretch+receptors+(pressure+

related)+&+vasodilator+metabolites+like+lactic+acid,+Thus+exercising+muscle+will+have+increase+in+blood+flow.+In+resting+muscle,+flow+is+controlled+mainly+by+SNS+(alpha91+&+beta+2+receptors).++

4)+Renal!blood!flow!6+Is+also+commonly+referred+as+autoregulation+even+though+it+is+partially+

controlled+by+neuronal+and+hormonal+influences.+

During+hypertension,+renal+afferents+will+vasoconstrict+and+thus+maintains+its+blood+flow+to+kidney+to+some+extent.+Chronically,+it+will+lead+to+hypertensive+nephropathy.++

+

LAMINAR!FLOW!vs!TURBULENT!FLOW!

!

Normally,+we+have+laminar+blood+flow+throughout+the+body+except+the+flow+in+heart+&+conducting+airways+of+respiratory+tree+(due+to+excessive+vessel+branching).+The+layer+with+highest+velocity+is+in+the+center+of+vessel.++

Heavier+particles+like+unactivated+neutrophils,+platelets+move+in+the+center+of+vessel+while+light+particles+are+at+the+periphery.+This+is+because+center+of+flow+will+have+least+resistance+while+periphery+will+have+maximum+resistance.+

Activation+of+cells+like+neutrophils+or+platelets+due+to+endothelial+injury+or+inflammatory+process+will+pull+them+toward+periphery+and+the+1st+step+of+inflammation+will+occur.+

narrowed+vessels+(e.g.+atherosclerosis+of+renal+artery).+High+velocity+of+blood+flow+can+also+create+turbulent+flow+and+can+cause+bruits+(e.g.+anemia).+

• Type+of+flow+can+be+calculated+by+Reynold’s+number+9+which+is+given+as:+

Reynold’s+number+=+Diameter+*+Velocity+*+Density+/!Viscosity!

• From+this+formula+we+can+say+that+when+diameter,+velocity+&+density+of+blood+

increases,+then+it+will+lead+to+turbulent+flow+while+decrease+in+viscosity+will+create+turbulent+flow+&+vice+versa.+

• Increase!in!viscosity+is+seen+in+–+polycythemia,+lung+diseases+(hypoxia+induced+

erythropoietin+production+from+kidney),+multiple+myeloma,+hereditary+spherocytosis++

• Decrease!in!viscosity+is+seen+in+anemia.++

+RESISTANCE+IN+SERIES+AND+PARALLEL+CIRCUITS+

• This+is+the+reason+why+most+of+the+cardiac+or+antihypertensive+pharmacological+therapy+is+aimed+to+decrease+total+peripheral+resistance.+

• Maximum+resistance+is+offered+by+arterioles+&+thus+the+steepest+decrease+in+blood+pressure+will+occur+at+this+point.++

From+this+point+onward+blood+pressure+will+be+as+low+as+30mmHg.+

+

+

• Calculated+as+sum+of+all+resistance:+R1+R2+R3!=!R!(maximum).+

• Example+of+series+connection+is:+Aorta+to+Intestinal+vessels+to+Liver+to+Inferior+vena+cava.+

• Total+resistance+will+be+higher+than+individual+resistance.+

If+R2+is+constricted,+it+will+lead+to+decreased+blood+flow+and+decreases+pressure+at+R3+while+upstream+at+R1+will+have+increased+pressure+&+vice+versa+when+R2+is+dilated.+

• This+concept+can+be+applied+in+pulmonary+edema+due+to+congestive!heart!failure.+

When+left+heart+fails+to+pump+blood+out+(due+to+aortic+stenosis,+chronic+hypertension+or+myocardial+infarction),+pressure+increases+backward.+

(e.g.+Kidney),+it+will+lead+to+increase+in+TPR+(because!parallel! circuit!is!removed).+As+TPR+has+increased+cardiac+output+will+

decrease+&+so+heart+rate.+

Coronary+arteries+have+greatest+resistance+while+pulmonary+

circulation+have+least+resistance.!

+

• The+main+factor+determining+Systolic+Blood+Pressure+(SBP)!is+stroke!volume.+

Increase+preload+or+increase+in+contractility+will+increase+stroke+volume+and+thus+increase+SBP.+

Decrease+in+compliance+of+vessels+(age+related+arteriosclerosis)+also+increases+SBP.+

• The+main+factor+determining+Diastolic+Blood+Pressure+(DBP)+is!total!peripheral! resistance.+

+

THUNDERNOTE!

Effect!of!Position!Change!on!Blood!Pressure!

• We+measure+lower+extremity+blood+pressure+by+asking+patient+to+lay+down+on+their+stomach+because+in+standing+position,+pressure+in+lower+extremities+will+be+very+high+(around+180mmHg+in+arteries)+due+to+effect+of+gravity+and+the+pressure+above+the+heart+will+be+negative+(less+than+120mmHg).+

• Thus+gravity+also+plays+a+major+role+in+our+vascular+systems.++

• As+pressure+decreases+above+the+heart+in+upright+position,+carotid+sinus+reflex+will+immediately+fire+and+increases+TPR+&+heart+rate+to+maintain+enough+perfusion+to+the+brain+&+this+is+the+reason+why+standing+person+will+have+rapid+heart+rate+or+

contraction+as+compared+to+person+laying+down.+

+

++

• Dynamic!&!aerobic!exercises!will!not!significantly!affect!mean!arterial!pressure+

(minor+isolated+systolic+rise+in+BP+can+be+seen).+

This+is+because+decrease+in+TPR+(due+to+dilation+of+arterioles+in+exercising+muscle)+is+accompanied+by+equivalent+increase+in+cardiac+output.+

!

! THUNDERNOTE+

may+express+the+TSH+receptor+which+leads+to+accumulation+of+glycosaminoglycans+behind+the+eyeball).++