INTERNAL MEDICINE BOARDS - PART 3 pptx

Rheumatic aortic stenosis is usually not hemodynamically significant and almost always occurs in the presence of mitral valve disease.. Aortic Regurgitation Can be caused by destruction o

Incidence ↑ with age Etiologies are as follows:

■ Intrinsic causes: Idiopathic senile degeneration; ischemia (usually

involv-ing the inferior wall); infectious processes (endocarditis, Chagas’ disease,Lyme disease); infiltrative diseases (sarcoidosis, amyloidosis, hemochro-matosis); autoimmune disease (SLE, RA, scleroderma); iatrogenic factors(heart transplant, surgery); inherited/congenital disease (myotonic muscu-lar dystrophy); conditioned heart (trained athletes)

■ Extrinsic causes: Autonomic (neurocardiac, carotid sinus hypersensitivity,

situational), medications (β-blockers, calcium channel blockers, clonidine,digoxin, antiarrhythmics), metabolic (electrolyte abnormalities, hypothy-roidism, hypothermia), neurologic (↑ ICP, obstructive sleep apnea)

S YMPTOMS

Patients may be asymptomatic or may present with dizziness, weakness, tigue, heart failure, or loss of consciousness (syncope) Symptoms can also berelated to the underlying cause of the bradycardia

fa-E XAM

Look for evidence of ↓ pulse rate and evidence of the underlying cause of

bradycardia Look for cannon A waves in cases of complete AV dissociation

(complete heart block)

D IAGNOSIS

■ ECG: Look for the origin of the rhythm and whether dropped beats or AV

dissociation is present (evidence of AV block; see Table 3.15)

■ Telemetry, event monitors, tilt-table testing, and electrophysiologic studies

can also be helpful

T REATMENT

■ If the patient is unstable, follow ACLS protocols.

■ If possible, treat the underlying cause (e.g., endocarditis)

■ Medications: Atropine, glucagon (for β-blocker overdose), calcium (for

If left untreated, Lyme disease

can cause varying degrees of

AV conduction block at any

time in the course of the

disease.

T A B L E 3 1 5 ECG Findings with AV Block

First degree Prolonged PR interval (> 200 msec).

Second degree Progressive prolongation of the PR interval until there is a dropped type I (Wenckebach) QRS Progressive shortening of the RR interval and a constant PP

interval are other signs.

Second degree Regularly dropped QRS (e.g., every third QRS complex dropped) type II Constant PR interval (no prolongation) Usually associated with

bundle branch blocks.

Third degree Complete dissociation of P waves and QRS complexes (P-wave rate >

QRS rate).

■ Indication for permanent pacemakers: Documented symptomatic

brady-cardia If the patient is asymptomatic, pacemakers may be considered in

patients with third-degree AV block with > 3 seconds of asystole or a heart

rate < 40 bpm while the patient is awake In second-degree type II AV

block, pacemakers have a class II indication (there is conflicting evidence

and opinion regarding the need for permanent pacing)

Indications for Permanent Pacing

Indications for permanent cardiac pacing, based on expert guidelines, are

classified as follows: I (definite indications), II (indications with conflicting

ev-idence or opinion), or III (not indicated or harmful) All indications assume

that transient causes such as drugs, electrolytes, and ischemia have been

corrected or excluded.

CLASSI

■ Third-degree AV block and advanced second-degree AV block associated

with the following:

■ Symptomatic bradycardia

■ Arrhythmias or other conditions requiring medications that result in

symptomatic bradycardia

■ Documented asystole of > 3 seconds or escape rates < 40 bpm in

awake, asymptomatic patients.

■ After AV junction ablation

■ Post–cardiac surgery when AV block is not expected to resolve

■ Neuromuscular diseases with AV block due to the unpredictable

pro-gression of AV conduction disease in these patients

■ Second-degree AV block (regardless of type) associated with symptomatic

bradycardia

CLASSIIA

■ Asymptomatic third-degree AV block with awake escape rates of> 40 bpm

■ Asymptomatic type II second-degree block with narrow QRS (with wide

QRS, it becomes a class I indication)

■ Asymptomatic type I second-degree block with intra- or infra-His levels

found on an electrophysiologic study done for another indication

■ First- and second-degree AV block with symptoms suggestive of pacemaker

syndrome

CLASSIIB

■ Marked first-degree AV block (PR > 300 msec) in patients with left

ven-tricular dysfunction

■ Neuromuscular diseases with any level of AV block due to the

unpre-dictable progression of block in these patients

■ Asymptomatic first-degree AV block.

■ Asymptomatic type I second-degree AV block not known to be due to aproblem within or below the bundle of His

■ AV block that is expected to resolve and/or is not likely to recur

Sudden Cardiac Death

Approximately 450,000 sudden cardiac deaths occur annually in the UnitedStates Etiologies include CAD, MI, pulmonary embolism, aortic dissection,cardiac tamponade, and other acute cardiopulmonary insults Seventy-fivepercent of patients do not survive cardiac arrest

■ In young athletes, the causes of sudden cardiac death differ from those inthe overall population Causes in this population include the following (inorder of decreasing incidence):

Ehlers-■ Arrhythmogenic right ventricular dysplasia, in which the right ventricle

is replaced by fat and fibrosis, causing ↑ frequency of ventricular rhythmias

ar-■ Aortic stenosis

■ Myocardial bridge causing coronary ischemia during ventricular traction

con-■ Atherosclerotic CAD

■ Coronary artery vasospasm

■ Brugada syndrome, which is caused by a sodium channel defect thatpredisposes to VF The baseline ECG shows incomplete RBBB andST-segment elevation in the precordial leads

■ Long QT syndrome

■ Noncardiac precipitants of sudden cardiac death in young athletes

in-clude asthma, illicit drug use (e.g., cocaine, ephedra, amphetamines), andheat stroke

■ It is difficult to assess patients for risk factors of sudden cardiac death cause these conditions are rare and because millions of young athletesneed to be screened

be-■ Although screening usually involves history taking and physical tion, these measures alone lack the sensitivity to detect even the most com-mon causes of sudden cardiac death in athletes (e.g., hypertrophic car-diomyopathy)

examina-■ In patients with a suggestive history or physical examination, furtherworkup with ECG and echocardiography is warranted

Implantable Cardioverter-Defibrillators (ICDs)

Include dilated cardiomyopathy (with a reduced EF), hypertension,

hyperlipi-demia, tobacco, diabetes, a family history of sudden cardiac death, myocardial

ischemia and reperfusion, and toxins (e.g., cocaine)

■ Goal: To prevent recurrent sudden cardiac death in patients with a history

of VT or VF

■ Drugs: Antiarrhythmic drugs have been disappointing in the 2° prevention

of sudden cardiac death, especially in the large group of patients who are

post-MI Standard therapies for CAD alone (especially β-blockers) play a

significant role in decreasing sudden cardiac death in these patients

■ Devices: ICDs are superior to amiodarone in patients with CAD who

have survived cardiac arrest and have a low EF.

■ There is no survival advantage of ICDs over amiodarone in patients who

have an EF > 35%

■ Goal: To prevent sudden cardiac death in patients who have no history of

VT and/or VF

■ Studies have shown that in patients with a history of MI who have an EF

< 30%, ICD therapy improves mortality and is superior to antiarrhythmic

therapy

■ Etiology of heart failure: Recent studies indicate that ICD therapy

ap-pears effective for both ischemic and nonischemic cardiomyopathy.

■ Severity of heart failure: Consider ICDs in patients with an EF < 30%

■ Noninvasive testing:

■ T-wave alternans: Microfluctuations in the morphology of T waves on

ECG may indicate an ↑ risk of sudden cardiac death (requires

special-ized testing)

■ Heart rate variability:↓ heart rate variability corresponds to worsening

heart failure and may be associated with an ↑ risk of sudden cardiac

death

VA LV U L A R H E A RT D I S E A S E

Aortic Stenosis

The most common causes are senile calcific aortic stenosis and congenital

bi-cuspid aortic valve Rheumatic aortic stenosis is usually not hemodynamically

significant and almost always occurs in the presence of mitral valve disease.

S YMPTOMS

Presents with a long asymptomatic period followed by the development of the

classic triad of angina, syncope, and heart failure The normal valve area is

3 cm2, and symptoms usually do not develop until the area is < 1 cm2

Aortic valve replacement should be performed as soon

as symptoms develop in aortic stenosis to prevent cardiac

death.

■ Diminished carotid upstrokes (parvus et tardus) and a sustained PMI due

to LVH may be present

■ A systolic ejection click can occur in patients with a bicuspid aortic valve.A2 diminishes in intensity, and S2 may be single

D IFFERENTIAL

■ Sub- or supravalvular stenosis: Due to left ventricular outflow tract

mem-brane or fibromuscular ring (rare)

■ Hypertrophic obstructive cardiomyopathy: Murmur accentuated with

Valsalva or standing and ↓ by hand grip

D IAGNOSIS

■ Echocardiography: A modified Bernoulli equation is used to derive the

pressure gradient across the aortic valve The aortic valve area is derived bythe continuity equation The severity of aortic stenosis per the 2006AHA/ACC guidelines can be classified as follows:

■ Mild disease: A valve area > 1.5 cm2, mean gradient < 25 mmHg

■ Moderate disease: A valve area 1–1.5 cm2, mean gradient 25–40mmHg

■ Severe disease: A valve area < 1 cm2, mean gradient > 40 mmHg

■ Follow-up echocardiography is recommended every year for severe tic stenosis; every 1–2 years for moderate aortic stenosis; and every 3–5years for mild aortic stenosis

aor-■ Cardiac catheterization: Required to exclude significant coronary stenoses in symptomatic patients who are scheduled for surgery and are

at risk for CAD Also needed to confirm the severity of aortic stenosis

when there is a discrepancy between clinical and noninvasive data

■ Dobutamine stress testing: Used in cases of low-gradient aortic stenosis

(severe aortic stenosis by valve area, but mean gradient < 40 mmHg) to tinguish true stenosis from pseudostenosis caused by ↓ systolic function Iftrue aortic stenosis is present, the gradient will ↑ and the valve area will re-main unchanged If pseudostenosis is present, the valve area will ↑

dis-T REATMENT

■ Aortic valve replacement: The only therapy for symptomatic aortic

steno-sis Older patients do quite well after aortic valve replacement and shouldnot be disqualified by age alone Patients who are unlikely to outlive a bio-prothesis can be spared the lifelong anticoagulation that is required formechanical valves

■ Antibiotic prophylaxis against subacute bacterial endocarditis: Indicated for all patients.

■ Aortic valvuloplasty: May be effective in young adults with congenital aortic stenosis Less effective in patients with degenerative aortic steno- sis, and should be considered palliative therapy or a bridge to surgery.

C OMPLICATIONS

■ Sudden death occurs but is uncommon (< 1% per year) in patients withsevere asymptomatic aortic stenosis

Aortic stenosis has been

associated with an ↑ risk of GI

bleeding, which is now

thought to be due to acquired

von Willebrand’s disease from

disruption of von Willebrand

factor multimers as they pass

through the stenotic aortic

valve.

■ If left untreated, the average time to death is as follows:

■ After onset of syncope: 2.5–3 years.

■ After onset of angina: Three years.

■ After onset of dyspnea: Two years.

■ After onset of CHF: 1.5 years.

Aortic Regurgitation

Can be caused by destruction or malfunction of the valve leaflets (infective

endocarditis, bicuspid aortic valve, rheumatic valve disease) or dilatation of

the aortic root such that the leaflets no longer coapt (Marfan’s syndrome,

aor-tic dissection)

S YMPTOMS

■ Acute aortic regurgitation: Presents with rapid onset of cardiogenic shock.

■ Chronic aortic regurgitation: A long asymptomatic period followed by

progressive dyspnea on exertion and other signs of heart failure

E XAM

■ Exam reveals a soft S1 (usually due to a long PR interval) and a soft or

ab-sent A2 with a decrescendo blowing diastolic murmur at the base

■ A wide pulse pressure with water-hammer peripheral pulses is also seen

■ Other peripheral signs include a bruit over the femoral artery (Duroziez’s

sign); nail-bed pulsations (Quincke’s pulse); and a popliteal-brachial BP

difference of > 20 mmHg (Hill’s sign)

■ In acute aortic regurgitation, these signs are usually not present, and the

only clues may be ↓ intensity of S1 and a short, blowing diastolic murmur

■ In severe aortic regurgitation, the anterior mitral valve leaflet can vibrate

in the aortic regurgitation jet, creating an apical diastolic rumble that

mimics mitral stenosis (Flint murmur)

D IFFERENTIAL

Other causes of diastolic murmurs include mitral stenosis, tricuspid stenosis,

pulmonic insufficiency, and atrial myxoma

D IAGNOSIS

■ Echocardiography: Essential for determining left ventricular size and

function as well as the structure of the aortic valve TEE is often necessary

to rule out endocarditis in acute aortic regurgitation

■ Cardiac catheterization: Aortography can be used to estimate the degree

of regurgitation if noninvasive studies are inconclusive Coronary

angiog-raphy is indicated to exclude CAD in patients at risk prior to surgery

T REATMENT

■ In asymptomatic patients with normal left ventricular function, afterload

reduction may be considered, but evidence for benefit is lacking ACEIs

or other vasodilators may ↓ left ventricular volume overload and

progres-sion to heart failure

■ Aortic valve replacement: Should be considered in symptomatic patients

or in those without symptoms who develop worsening left ventricular

di-latation and systolic failure

Indications for valve replacement in aortic regurgitation include the development of symptoms or left ventricular systolic failure even in the absence of symptoms.

■ Acute aortic regurgitation: Surgery is the definitive therapy, since

mortal-ity is high in this setting IV vasodilators may be used as a bridge to surgery

■ Endocarditis prophylaxis: Consider in all patients.

C OMPLICATIONS

Irreversible left ventricular systolic dysfunction if valve replacement is layed

de-Mitral Stenosis

Almost exclusively due to rheumatic heart disease, with rare cases due to

congenital lesions and calcification of the mitral annulus The normal mitralvalve area is 4–6 cm2 Severe mitral stenosis occurs when the valve area is < 1

cm2

S YMPTOMS

Characterized by a long asymptomatic period followed by gradual onset ofdyspnea on exertion and findings of right heart failure and pulmonary hyper-tension Hemoptysis and thromboembolic stroke are late findings

■ Left atrial myxoma: Causes obstruction of mitral inflow.

■ Cor triatriatum: Left atrial septations cause postcapillary pulmonary

hy-pertension

■ Aortic insufficiency: Can mimic the murmur of mitral stenosis (Flint

murmur) due to restriction of mitral valve leaflet motion by regurgitantblood from the aortic valve, but no opening snap is present

D IAGNOSIS

■ Echocardiography: Used to estimate valve area and to measure the

trans-mitral pressure gradient Mitral valve morphology on echocardiographydetermines a patient’s suitability for percutaneous valvuloplasty

■ TEE: Indicated to exclude left atrial thrombus in patients scheduled for

balloon valvotomy

■ Cardiac catheterization: Can be used to directly measure the valve

gradi-ent through simultaneous recording of PCWP and left vgradi-entricular diastolicpressure Rarely needed for diagnosis; performed prior to percutaneousballoon valvotomy

T REATMENT

■ Percutaneous mitral balloon valvotomy: Unlike aortic valvuloplasty,

bal-loon dilatation of the mitral valve has proven to be a successful strategy inpatients without concomitant mitral regurgitation Consider this interven-tion in symptomatic patients with isolated mitral stenosis and an effectivevalve area < 1.0 cm2 This is the appropriate intervention in pregnant

women for whom medical therapy has failed Severe annular calcification,

severe mitral regurgitation, and atrial thrombus are all contraindications to

balloon valvuloplasty

■ Mitral valve replacement: For patients who are not candidates for

valvo-tomy or if the effective valve area is < 0.6 cm2

■ Endocarditis prophylaxis is indicated for all patients

C OMPLICATIONS

■ Left atrial enlargement and AF with resultant stasis is common and can

re-sult in left atrial thrombus formation and embolic stroke

■ Pulmonary hypertension and 2° tricuspid regurgitation

Mitral Regurgitation

Common causes of mitral regurgitation include mitral valve prolapse,

myxo-matous (degenerative) mitral valve disease, dilated cardiomyopathy (which

causes functional mitral regurgitation due to dilatation of the mitral valve

an-nulus), rheumatic heart disease (acute mitral valvulitis produces the Carey

Coombs murmur of acute rheumatic fever), acute ischemia (due to rupture of

a papillary muscle), mitral valve endocarditis, and trauma to the mitral valve

S YMPTOMS

■ Acute mitral regurgitation: Abrupt onset of dyspnea due to pulmonary

edema

■ Chronic mitral regurgitation: Can be asymptomatic In severe cases, can

present with dyspnea and symptoms of heart failure

E XAM

■ Presents with a soft S1 and a holosystolic, blowing murmur heard best at

the apex with radiation to the axilla S3 can be due to mitral regurgitation

alone (in the absence of systolic heart failure), and its presence suggests

se-vere mitral regurgitation

■ Acute mitral regurgitation can be associated with hypotension and

pul-monary edema; murmur may be early systolic

■ The intensity of the murmur does not generally correlate with mitral

re-gurgitation severity as documented by echocardiogram

D IFFERENTIAL

■ Aortic stenosis: Can mimic the murmur of mitral regurgitation (Gallavardin

phenomenon)

■ Tricuspid regurgitation: Characterized by a holosystolic murmur best

heard at the left sternal border; ↑ in intensity with inspiration

D IAGNOSIS

■ Early detection of mitral regurgitation is essential because treatment

should be initiated before symptoms occur.

■ Exercise stress testing: Document exercise limitation before symptoms

oc-cur at rest

■ Echocardiography: Transthoracic echocardiography (TTE) is important

for diagnosis as well as for grading the severity of mitral regurgitation TEE

Patients with rheumatic heart disease typically have involvement of the mitral valve Isolated involvement of the aortic or tricuspid valve with sparing of the mitral valve is exceedingly rare in patients with rheumatic heart

disease.

regur-■ Medications: ACEIs are useful only in patients with left ventricular

dys-function or hypertension Medical therapy is generally the only option inpatients with an EF < 30%

■ Surgical intervention:

■ Indications for surgery include symptoms related to mitral

regurgita-tion, left ventricular dysfuncregurgita-tion, AF, or pulmonary hypertension

■ Optimal timing of surgery is early in the course of the disease, when

patients progress from a chronic, compensated state to symptomaticmitral regurgitation

■ Surgical outcomes are best in patients who have an EF > 60% and aleft ventricular end-systolic diameter < 4.5 cm

In patients with mitral

regurgitation, the intensity of

the murmur on physical exam

does not correlate with

disease severity In patients

with acute myocardial

ischemia, even a low-intensity

murmur of mitral regurgitation should alert the

physician to the possibility of

papillary rupture.

F I G U R E 3 1 4 Management of advanced mitral regurgitation.

(Reproduced, with permission, from Braunwald E et al Harrison’s Manual of Medicine, 15th

ed New York: McGraw-Hill, 2001.)

Mitral regurgitation (MR)

• Afterload reduction—

e.g., IV nitroprusside

• Diuretics if needed for LV failure

? acute severe MR yes

• Control ventricular rate (e.g., β- blockers, digoxin)

• Anticoagulation (heparin, warfarin)

If AF poorly tolerated:

• Chemical/electrical cardioversion (ideally ≥ 3 weeks

of anticoagulation)

? atrial fibrillation

no yes

no yes

no

? symptoms yes

Surgical reconstruction

or replacement

? surgical candidate no

• Oral afterload reduction (ACEI or hydralazine)

• Diuretics and/or digoxin for CHF symptoms

? LV Progressive enlargement or ESD > 45 mm/m 2

Chronic management

of asymptomatic patient:

• Endocarditis prophylaxis

• Serial assessment of LV function by echo

■ Mitral valve repair: Associated with better outcomes than mitral valve

replacement Repair is most successful when mitral regurgitation is

due to prolapse of the posterior mitral valve leaflet

■ Mitral valve replacement: For symptomatic patients with an EF > 30%

when the mitral valve is not technically repairable (can be predicted by

echocardiography)

Mitral Valve Prolapse

Defined by a displaced and abnormally thickened, redundant mitral valve

leaflet that projects into the left atrium during systole Most recent studies

demonstrate a prevalence of approximately 0.5–2.5% in the general

popula-tion, with men and women affected equally Mitral valve prolapse may be

complicated by chordal rupture or endocarditis, both of which can lead to

se-vere mitral regurgitation Etiologies are as follows:

■ 1 °: Familial, sporadic, Marfan’s syndrome, connective tissue disease.

■ 2 °: CAD, rheumatic heart disease, “flail leaflet,” ↓ left ventricular

dimen-sion (hypertrophic cardiomyopathy, pulmonary hypertendimen-sion,

dehydra-tion)

S YMPTOMS

Most patients have no symptoms, and the diagnosis is often found incidentally

on physical exam or echocardiography However, some patients may present

with atypical chest pain, palpitations, or TIAs

E XAM

Exam reveals a midsystolic click and midsystolic murmur with characteristic

response to maneuvers In more severe cases, listen for the holosystolic

mur-mur of mitral regurgitation

D IAGNOSIS

Echocardiography should be used for initial assessment; then follow every

3–5 years unless symptomatic or associated with mitral regurgitation (check

echocardiogram yearly)

T REATMENT

■ Aspirin: After a TIA and for patients < 65 years of age with lone AF

■ Warfarin: After a stroke and for those > 65 years of age with coexistent AF,

hypertension, mitral regurgitation, or heart failure

■ β-blockers and electrophysiologic testing for control of arrhythmias

■ Surgery for cases of severe mitral regurgitation

Prosthetic Valves

■ Bioprosthetic valves: Older patients; patients with a life expectancy

< 10–15 years; or those who cannot take long-term anticoagulant therapy

(e.g., bleeding diathesis, high risk for trauma, poor compliance)

■ Mechanical valves: Young patients; patients with a life expectancy

> 10–15 years or with other indications for chronic anticoagulation (e.g.,

AF)

Endocarditis prophylaxis is not needed for patients with mitral valve prolapse unless they have evidence of mitral regurgitation, thickened mitral valves leaflets, or an audible systolic murmur associated with the midsystolic click.

■ Repair: Mitral valve prolapse, ischemic mitral regurgitation, bicuspid

aor-tic valve with prolapse, mitral or tricuspid annular dilatation with normalleaflets

■ Replacement: Rheumatic heart disease, endocarditis, heavily calcified

valve, restricted leaflet motion, extensive leaflet destruction

■ No anticoagulation is needed for porcine valves after three months of

war-farin therapy Aspirin can be used in high-risk patients

■ For patients with mechanical valves, the level of anticoagulation depends

on the location and type of valve (valves in the mitral and tricuspid

posi-tion and older caged-ball valves are most prone to thrombosis).

■ Risk factors for thromboembolic complications include AF, previous temic emboli, left atrial thrombus, and severe left ventricular dysfunction

■ Conduction disturbances

■ Endocarditis:

■ Early prosthetic valve endocarditis: Occurs during the first 60 days

af-ter valve replacement, most commonly due to S epidermidis; often

ful-minant and associated with high mortality rates

■ Late prosthetic valve endocarditis: Most often occurs in patients with

multiple valves or bioprosthetic valves Microbiology is similar to that

of native valve endocarditis

■ Hemolysis: Look for schistocytes on peripheral smear Usually occurs in

the presence of perivalvular leak

■ Often presents acutely with hemodynamic instability

■ Diagnose with echocardiogram

■ For small thrombi (< 5 mm) that are nonobstructive, IV heparinshould be tried initially For large thrombi (> 5 mm), use more aggres-sive therapy such as fibrinolysis or valve replacement

■ Perivalvular leak: Rare In severe cases, look for hemolytic anemia and

valvular insufficiency causing heart failure

■ Emboli: Typically present as stroke, but can present as intestinal or limb

lines the extent to which patients with congenital cardiac malformations can

tolerate pregnancy Examples of adult congenital heart disease follow

Atrial Septal Defect (ASD)

There are three major types: ostium secundum (most common), ostium

pri-mum, and sinus venosus

S YMPTOMS

Most cases are asymptomatic and are either diagnosed incidentally on

echocardiography or found during workup of paradoxical emboli Large

shunts can cause dyspnea on exertion and orthopnea

E XAM

■ Characterized by a fixed wide splitting of S2 with a loud P2 as pulmonary

hypertension develops

■ Exam reveals a systolic flow murmur (usually best heard at the left upper

sternal border) and occasionally a diastolic rumble across the tricuspid

valve due to ↑ flow

D IAGNOSIS

■ ECG: Shows incomplete RBBB with right axis deviation in ostium

secun-dum ASD Left axis deviation suggests ostium primum ASD; RVH may be

present in all forms

■ CXR: Shows a prominent pulmonary artery, an enlarged right atrium, and

an enlarged right ventricle

■ Echocardiography with agitated saline bubble study: Can be used to

vi-sualize the intracardiac shunt and to determine the ratio of

pulmonary-to-systemic blood flow (Qp/Qs)

■ TEE: Extremely useful for documenting the location and size of the

de-fect and for excluding associated lesions

T A B L E 3 1 6 Tolerance of Pregnancy by Patients with Congenital Cardiac Malformations

Reproduced, with permission, from Kasper DL et al Harrison’s Principles of Internal Medicine, 16th ed New York: McGraw-Hill,

2005: 1383.

Correction of ASD carries a long-term survival rate better than that of medical therapy alone and is recommended even for asymptomatic patients with significant shunts (Q p /Q s > 1.5:1).

Pulmonic or tricuspid regurgitation (if

low pressure, even severe)

Pulmonic stenosis (mild to moderate)

Well-repaired tetralogy of Fallot

NYHA class II–III Repaired transposition of the great arteries

Fontan repairs Aortic or mitral stenosis (moderate) Ebstein’s anomaly

NHYA class IV Right-to-left shunt; unrepaired cyanotic heart disease

Pulmonary hypertension and/or pulmonary vascular disease (e.g., Eisenmenger’s, 1 ° pulmonary hypertension)

Aortic or mitral stenosis (severe) Pulmonic stenosis (severe) Marfan’s or aortic coarctation

■ Paradoxical embolization leading to TIAs and strokes.

■ AF and atrial flutter

■ Pulmonary hypertension and Eisenmenger’s syndrome.

■ Endocarditis is rare in patients with secundum ASD but can occur inother types

Coarctation of the Aorta

Proximal narrowing of the descending aorta just beyond the left subclavianartery with development of collateral circulation involving the internal mam-mary, intercostal, and axillary arteries A bicuspid aortic valve is present in

> 50% of patients with coarctation of the aorta More common in males than

■ Other causes of 2° hypertension, including renal artery stenosis

■ Peripheral arterial disease leads to diminished femoral pulses and tion

■ Medical treatment of hypertension

■ Surgical correction is appropriate for patients < 20 years of age and inolder patients with upper extremity hypertension and a gradient of ≥ 20mmHg

■ Balloon dilatation with or without stent placement is an alternative for

na-tive or recurrent coarctation

■ Requires prophylaxis for endocarditis during dental procedures where

there may be perforation of the oral mucosa

C OMPLICATIONS

■ LVH and dilatation due to ↑ afterload

■ Severe hypertension

■ Aortic dissection or rupture

■ SAH due to rupture of aneurysms of the circle of Willis (rare)

■ Premature CAD

Patent Ductus Arteriosus (PDA)

Uncommon in adults Risk factors include premature birth and exposure to

rubella virus in the first trimester

S YMPTOMS

Usually asymptomatic, but moderate to large shunts can cause dyspnea,

fa-tigue, and eventually signs and symptoms of pulmonary hypertension and

right heart failure

E XAM

■ Exam reveals a continuous “machinery-like” murmur at the left upper

ster-nal border and bounding peripheral pulses due to rapid aortic runoff to

the pulmonary artery

■ In the presence of pulmonary hypertension (Eisenmenger’s syndrome),

the murmur is absent or soft, and there is differential cyanosis involving

the lower extremities and sparing the upper extremities

D IFFERENTIAL

Other shunts, including ASDs and VSDs

D IAGNOSIS

■ ECG: Nonspecific; LVH and left atrial enlargement in the absence of

pul-monary hypertension can be seen

■ Echocardiography: Can be used to calculate the shunt fraction and to

es-timate pulmonary artery systolic pressure Abnormal ductal flow can be

vi-sualized in the pulmonary artery

■ Cardiac catheterization: Can be used to document an increase in O2

sat-uration from the right ventricle to the pulmonary artery

Differential cyanosis of the fingers (pink) and toes (blue and clubbed) is pathognomonic for Eisenmenger’s syndrome caused by an uncorrected

PDA.

Ventricular Septal Defect (VSD)

Most VSDs occur in close proximity to the membranous portion of the ventricular septum, but muscular, supracristal, inlet, and outlet VSDs canalso occur

be-■ ECG: Nonspecific; LVH and left atrial enlargement in the absence of

pul-monary hypertension can be seen Right atrial enlargement, RVH, andRBBB can develop with the development of pulmonary hypertension

■ CXR: Cardiomegaly and enlarged pulmonary arteries.

T REATMENT

■ Endocarditis prophylaxis for a VSD of any size

■ Diuretics and vasodilators to ↓ left-to-right shunt and symptoms of rightheart failure

■ Surgical correction is appropriate for patients with significant shunt(Qp/Qs> 1.7:1)

■ Once pulmonary hypertension occurs (systolic pulmonary artery pressure

hyper-■ Symptoms include dyspnea, chest pain, syncope, and hemoptysis

■ Paradoxical embolism leading to TIAs or stroke

■ Infective endocarditis

Surgical closure is contraindicated once

Eisenmenger’s syndrome

develops because it can ↑

pulmonary hypertension and

right heart failure.

Approximately 2000 cases are diagnosed each year in the United States Aortic

dissection is associated with uncontrolled hypertension, medial degeneration

of the aorta (Marfan’s syndrome, Ehlers-Danlos syndrome), cocaine use,

coarctation, congenital bicuspid valve, trauma, cardiac surgery, pregnancy,

and syphilitic aortitis Type A = proximal dissection; type B = distal

dissec-tion (the dissecdissec-tion flap originates distal to the left subclavian artery).

S YMPTOMS

■ Classically presents as a sudden-onset “tearing” or “ripping” sensation

orig-inating in the chest and radiating to the back, but symptoms may not be

classic

■ Unlike MI, pain is maximal at the onset and is not gradual in nature

■ Can present with organ hypoperfusion due to occlusion of arteries by the

dissection flap (e.g., coronary ischemia, stroke, intestinal ischemia, renal

failure, limb ischemia)

■ Other presentations include cardiac tamponade and aortic insufficiency in

cases of proximal aortic dissection

E XAM

■ BP is elevated (although hypotension can be seen with proximal

dissec-tions associated with tamponade)

■ In proximal dissection, listen for the diastolic murmur of aortic

insuffi-ciency

■ Exam reveals pulse deficits or unequal pulses between the right and left

arms

■ Can present with focal neurologic deficits (from associated

cerebrovascu-lar infarct) or with paraplegia (from associated anterior spinal artery

com-promise)

D IFFERENTIAL

Acute MI, cardiac tamponade, thoracic or abdominal aortic aneurysm,

pul-monary embolism, tension pneumothorax, esophageal rupture

D IAGNOSIS

■ Three major clinical predictors are sudden, tearing chest pain; differential

pulses or blood pressures between the right and left arms; and abnormal

aortic or mediastinal contour on CXR If all three are present, the positive

likelihood ratio is 0.66 The negative likelihood ratio if all three are absent

is 0.07

■ CXR: Look for a widened mediastinum (occurs in approximately 60% of

all aortic dissections)

■ TEE: The fastest and most portable method for unstable patients, but may

not be available at all hospitals Sensitivity is 98% and specificity 95%

■ Chest CT: Sensitivity is 94% and specificity 87%.

■ MRI: Highly sensitive (98%) and specific (98%), but the test is slow and

may not be available at many hospitals Good for following patients with

type B dissections

■ Aortography: Not ideal given the invasive nature of the test and the

associated delay in initiating definitive surgical therapy

Proximal (type A) aortic dissection can present as acute inferior or right-sided

MI due to involvement of the right coronary artery (prone

to occlusion by the dissection

flap).

■ Type A: Surgical repair.

■ Type B: Admit to the ICU for medical management of hypertension Treat

first with β-blockers (esmolol, labetalol) and then with IV nitroprusside.Avoid anticoagulation Surgery is indicated for complications of dissection,end-organ damage, or failure to control hypertension

C OMPLICATIONS

■ Acute MI from occlusion of the right coronary artery by the dissection flap

or dissection of the coronary artery

■ Acute aortic insufficiency, which can present as hemodynamic instabilityand heart failure

■ Cardiac tamponade due to dissection into the pericardium

■ Cardiac arrest

■ Cerebrovascular accident (due to concomitant carotid artery dissection)

■ Occlusion of distal arteries can lead to end-organ damage (e.g., paraplegia,renal failure, intestinal ischemia, limb ischemia)

Peripheral Vascular Disease

Atherosclerosis of the peripheral arterial system is associated with the sameclinical risk factors as coronary disease (smoking, diabetes, hypertension, andhyperlipidemia)

S YMPTOMS

Intermittent claudication is reproducible pain in the lower extremity musclesthat is brought on by exercise and relieved by rest; however, most peripheralvascular disease is asymptomatic

■ Nonarterial causes of limb pain include spinal stenosis tion), deep venous thrombosis, and peripheral neuropathy (often coexistswith peripheral vascular disease in diabetics)

(pseudoclaudica-D IAGNOSIS

■ Ankle-brachial index (ABI) < 0.90 (the highest ankle systolic pressure

measured by Doppler divided by the highest brachial systolic pressure)

■ MRI is a useful noninvasive diagnostic test.

■ Lower extremity angiography is the gold standard.

T REATMENT

■ Aggressive cardiac risk factor reduction, including control of smoking, pertension, and hyperlipidemia

hy-■ Initiate a structured exercise rehabilitation program

Proximal (type A) aortic

dissection can present as

acute paraplegia due to

occlusion of the anterior

spinal artery.