Cardiomyopathies are primary disorders of the myocardium not attributable to coronary artery disease, abnormal loading conditions (eg, valvular abnormalities, hypertension), or congenital heart disease. Based on phenotype, they are classified into several categories (1) (see figure ):
Non-dilated left ventricular cardiomyopathy
Non-dilated left ventricular cardiomyopathy (NDLVC) is another category defined by the presence of left ventricular fibrosis or fatty replacement without left ventricular (LV) cavity dilation; it may occur with or without global LV dysfunction or regional wall motion abnormalities (2). This category can have or develop phenotypic features of other specific cardiomyopathies, such as a non-dilated variant of dilated cardiomyopathy or arrhythmogenic left ventricular cardiomyopathy. Management is based on phenotype and etiology.
Arrhythmogenic right ventricular cardiomyopathy, left ventricular noncompaction cardiomyopathy, and other arrhythmogenic cardiomyopathies are covered elsewhere.
Ischemic cardiomyopathy, characterized by left ventricular dilation and systolic dysfunction due to obstructive coronary artery disease, is not considered a primary cardiomyopathy.
Clinical manifestations of cardiomyopathies are typically those of heart failure and vary by the presence of systolic and/or diastolic dysfunction; patients may also present with chest pain, syncope, arrhythmias, or sudden cardiac death. Evaluation includes clinical assessment with family history, physical examination, laboratory testing, electrocardiography, chest radiography, echocardiography, and cardiac magnetic resonance imaging (MRI). Endomyocardial biopsy and additional testing are reserved for selected cases. Management is guided by the cause and specific cardiomyopathy subtype (see table ).
Forms of Cardiomyopathy
Not pictured: Non-dilated left ventricular cardiomyopathy. |
Diagnosis and Treatment of Cardiomyopathies
Feature or Method | Non-Dilated LV Cardiomyopathy* | |||
|---|---|---|---|---|
Predominant pathophysiology | Systolic and diastolic dysfunction with ventricular dilation | Diastolic dysfunction ± dynamic LVOT obstruction; often hyperdynamic systolic function | Diastolic dysfunction with relatively preserved systolic function | Non-ischemic LV scarring ± LV systolic dysfunction without ventricular dilation |
Clinical findings | LV ± RV failure, atrial and ventricular arrhythmias, sudden death Functional mitral/tricuspid regurgitation S3 and/or S4 | Exertional dyspnea, angina, syncope, sudden death Dynamic systolic murmur (in obstructive HCM) ± mitral regurgitation murmur, S4 Bifid carotid pulse with a brisk upstroke and rapid downstroke | Exertional dyspnea, fatigue, peripheral edema, arrhythmias LV ± RV failure Functional mitral/tricuspid regurgitation, atrial enlargement | Often asymptomatic, may develop shortness of breath, palpitations or syncope, S3 and/or S4 |
ECG | Nonspecific ST- and T-wave abnormalities Conduction abnormalities, including BBB/IVCD Poor R-wave progression and Q waves (precordial/lateral leads Q Conduction abnormalities: BBB/IVCD, poor R-wave progression, Q waves (precordial/lateral leads) Atrial fibrillation common | LV hypertrophy and repolarization abnormalities Deep septal Q waves | LV hypertrophy or low QRS voltage (especially in infiltrative cardiomyopathies), conduction abnormalities, atrial arrhythmias | AV block Low QRS amplitude BBB |
Echocardiography | Dilated hypokinetic ventricles ± mural thrombus Systolic dysfunction and, frequently, functional mitral/tricuspid regurgitation | LV hypertrophy, typically normal or hyperdynamic LV systolic function, ± systolic anterior motion of the mitral valve ± LVOT obstruction ± mitral regurgitation | Normal or reduced ventricular cavity size, increased wall thickness (in infiltrative disease), biatrial enlargement LV diastolic dysfunction with restrictive filling pattern | Normal LV cavity size LV systolic dysfunction (± regional wall motion abnormalities) OR normal LV systolic function with non-ischemic LV scarring |
Radiography | Enlarged cardiac silhouette ± Pulmonary venous congestion | No or mild cardiomegaly | No or mild cardiomegaly; possible atrial enlargement ± Pulmonary venous congestion | Cardiac silhouette normal in size ± Pulmonary venous congestion |
Hemodynamics | Normal or high EDP Normal or low CO | High EDP ± LVOT gradient ± mitral regurgitation Normal or low CO | High EDP, "dip and plateau" sign Normal or low CO | Normal or high EDP Normal or low CO |
Prognosis | Variable; improved with guideline-directed therapy; mortality remains significant in advanced disease | Generally favorable; < 0.5% annual risk of sudden death (higher in high-risk patients)† | Often poor depending on etiology; high morbidity and mortality | Not well defined |
Treatment | GDMT: ARNi (ACE inhibitors orangiotensin II receptor blockers if ARNi not feasible), SGLT2 inhibitor, beta-blockers, mineralocorticoid receptor antagonists ; diuretics for congestion; ICD/CRT-D in selected patients | For obstructive HCM: Beta-blockers or non-dihydropyridine calcium channel blockers, cardiac myosin inhibitors, disopyramide, septal reduction therapy ICD in high-risk patients | Diuretics for symptom relief Treatment of underlying cause if known | GDMT Diuretics for congestion relief ICD/CRT-D in selected patients |
* Arbelo E, Protonotarios A, Gimeno JR, et al. 2023 ESC Guidelines for the management of cardiomyopathies. Eur Heart J. 2023;44(37):3503-3626. doi:10.1093/eurheartj/ehad194 | ||||
† Abdelfattah OM, Martinez M, Sayed A, et al. Temporal and Global Trends of the Incidence of Sudden Cardiac Death in Hypertrophic Cardiomyopathy. JACC Clin Electrophysiol. 2022;8(11):1417-1427. doi:10.1016/j.jacep.2022.07.012 | ||||
ACE = angiotensin-converting enzyme; ARNi = angiotensin II receptor blocker and neprilysin inhibitor; AV = atrioventricular; BBB = bundle branch block; CO = cardiac output; CRT-D = cardiac resynchronization therapy with defibrillation; EDP = end-diastolic pressure; EF = ejection fraction; GDMT = guideline-directed medical therapy; HCM = hypertropic cardiomyopathy; ICD = implantable cardioverter-defibrillator; IVCD = intraventricular conduction delay; LV = left ventricular; LVOT = left ventricular outflow tract; RV = right ventricular; S3 = third heart sound; S4 = fourth heart sound; SGLT2 = sodium glucose cotransporter 2 protein; ± = with or without. | ||||
References
1. Elliott P, Andersson B, Arbustini E, et al. Classification of the cardiomyopathies: a position statement from the European Society Of Cardiology Working Group on Myocardial and Pericardial Diseases. Eur Heart J. 2008;29(2):270-276. doi:10.1093/eurheartj/ehm342
2. Arbelo E, Protonotarios A, Gimeno JR, et al. 2023 ESC Guidelines for the management of cardiomyopathies. Eur Heart J. 2023;44(37):3503-3626. doi:10.1093/eurheartj/ehad194
