Table: Diagnosis and Treatment of Cardiomyopathies-Merck Manual Professional Edition

Diagnosis and Treatment of Cardiomyopathies

Feature or Method	Dilated Cardiomyopathy	Hypertrophic Cardiomyopathy	Restrictive Cardiomyopathy
Pathophysiology	Systolic dysfunction	Diastolic dysfunction ± outflow obstruction	Diastolic dysfunction
Clinical findings	LV and RV failure, sudden death Cardiomegaly Functional AV valve regurgitation S3 and/or S4	Exertional dyspnea, angina, syncope, sudden death Systolic murmur ± mitral regurgitation murmur, S4 Bifid carotid pulse with a brisk upstroke and rapid downstroke	Exertional dyspnea and fatigue LV ± RV failure Functional AV valve regurgitation
ECG	Nonspecific ST- and T-wave abnormalities Q waves ± BBB	LV hypertrophy and ischemia Deep septal Q waves	LV hypertrophy or low QRS voltage
Echocardiography	Dilated hypokinetic ventricles ± mural thrombus Low EF and, frequently, functional AV valve regurgitation	Hypertrophied ventricle, high, normal or low EF ± mitral systolic anterior motion ± asymmetric hypertrophy ± LV gradient	Increased wall thickness ± cavity obliteration LV diastolic dysfunction
X-ray	Cardiomegaly Pulmonary venous congestion	No or mild cardiomegaly	No or mild cardiomegaly
Hemodynamics	Normal or high EDP, low EF, diffusely dilated hypokinetic ventricles ± AV valve regurgitation Low CO	High EDP ± outflow subvalvular gradient ± mitral regurgitation Normal or low CO	High EDP, dip and plateau diastolic LV pressure curve Normal or low CO
Prognosis	20% mortality in first year, and about 10%/year thereafter	About 1% annual risk of sudden death	70% 5-year mortality
Treatment	Diuretics, ACE inhibitors, angiotensin II	Beta-blockers, ±	Phlebotomy for hemochromatosis Endocardial resection
ACE = angiotensin-converting enzyme; ARNI = angiotensin II receptor blocker and neprilysin inhibitor; AV = atrioventricular; BBB = bundle branch block; CO = cardiac output; EDP = end-diastolic pressure; EF = ejection fraction; ICD = implantable cardioverter-defibrillator ; LV = left ventricular; RV = right ventricular; S3 = 3rd heart sound; S4 = 4th heart sound; SGLT2 = sodium glucose cotransporter 2 protein; ± = with or without.

Feature or Method

Dilated Cardiomyopathy

Hypertrophic Cardiomyopathy

Restrictive Cardiomyopathy

Pathophysiology

Systolic dysfunction

Diastolic dysfunction ± outflow obstruction

Diastolic dysfunction

Clinical findings

LV and RV failure, sudden death

Cardiomegaly

Functional AV valve regurgitation

S3 and/or S4

Exertional dyspnea, angina, syncope, sudden death

Systolic murmur ± mitral regurgitation murmur, S4

Bifid carotid pulse with a brisk upstroke and rapid downstroke

Exertional dyspnea and fatigue

LV ± RV failure

Functional AV valve regurgitation

ECG

Nonspecific ST- and T-wave abnormalities

Q waves ± BBB

LV hypertrophy and ischemia

Deep septal Q waves

LV hypertrophy or low QRS voltage

Echocardiography

Dilated hypokinetic ventricles ± mural thrombus

Low EF and, frequently, functional AV valve regurgitation

Hypertrophied ventricle, high, normal or low EF ± mitral systolic anterior motion ± asymmetric hypertrophy ± LV gradient

Increased wall thickness ± cavity obliteration

LV diastolic dysfunction

X-ray

Cardiomegaly

Pulmonary venous congestion

No or mild cardiomegaly

Hemodynamics

Normal or high EDP, low EF, diffusely dilated hypokinetic ventricles ± AV valve regurgitation

Low CO

High EDP ± outflow subvalvular gradient ± mitral regurgitation

Normal or low CO

High EDP, dip and plateau diastolic LV pressure curve

Normal or low CO

Prognosis

20% mortality in first year, and about 10%/year thereafter

About 1% annual risk of sudden death

70% 5-year mortality

Treatment

Diuretics, ACE inhibitors, angiotensin II

Beta-blockers, ±

Phlebotomy for hemochromatosis

Endocardial resection

ACE = angiotensin-converting enzyme; ARNI = angiotensin II receptor blocker and neprilysin inhibitor; AV = atrioventricular; BBB = bundle branch block; CO = cardiac output; EDP = end-diastolic pressure; EF = ejection fraction; ICD = implantable cardioverter-defibrillator ; LV = left ventricular; RV = right ventricular; S3 = 3rd heart sound; S4 = 4th heart sound; SGLT2 = sodium glucose cotransporter 2 protein; ± = with or without.