Is right ventricular cardiomyopathy (RVC) a term used to describe conditions affecting the right ventricle's muscle?

Right Ventricular Cardiomyopathy: Definition and Clinical Significance

Right ventricular cardiomyopathy (RVC) is a recognized term in cardiology, specifically referring to arrhythmogenic right ventricular cardiomyopathy (ARVC) or arrhythmogenic cardiomyopathy (AC), which is characterized by fibrofatty replacement of the right ventricular myocardium leading to life-threatening ventricular arrhythmias and sudden cardiac death.

Definition and Classification

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is one of the five major types of cardiomyopathies recognized by major cardiology societies, including:

1. Dilated Cardiomyopathy (DCM)
2. Hypertrophic Cardiomyopathy (HCM)
3. Restrictive Cardiomyopathy (RCM)
4. Arrhythmogenic Cardiomyopathy (AC), which includes ARVC
5. Left Ventricular Non-Compaction Cardiomyopathy (LVNC) 1

The term "arrhythmogenic cardiomyopathy" (AC) has become preferred over ARVC in recent literature, as the disease can affect both ventricles, not just the right ventricle 2.

Pathophysiology

ARVC/AC is characterized by:

• Progressive fibrofatty replacement of the right ventricular myocardium 2, 3
• Primarily caused by genetic defects in desmosomal proteins 2, 4
• Pathological process typically starts from the subepicardium and extends to the endocardium 4
• Can involve the left ventricle in up to 50% of cases 4

Clinical Presentation and Significance

ARVC/AC is clinically significant because:

• It's a major cause of sudden cardiac death in young people and athletes 2, 3
• The prevalence is estimated at 1:2,000 to 1:5,000 individuals 2, 3
• It's characterized by life-threatening ventricular arrhythmias that are often provoked by exercise-induced catecholamine discharge 3
• It represents a common cause of sudden cardiac death in prospective studies of young athletes 2

Diagnostic Criteria

The diagnosis of ARVC/AC is based on multiple parameters according to the international diagnostic criteria, including:

1. Global or regional dysfunction and structural alteration of the right ventricle demonstrated on imaging
2. Tissue characterization by endomyocardial biopsy
3. Repolarization abnormalities on ECG
4. Depolarization/conduction abnormalities
5. Arrhythmias
6. Family history 5

Common ECG findings include:

• T-wave inversion in right precordial leads (V1-V3)
• Prolonged QRS duration >110 ms with right bundle branch block pattern
• Delayed upstroke of the S wave in V1-V2
• Epsilon waves (a pathognomonic feature) 2, 6

Imaging

• Echocardiography is the primary imaging modality, though ARVC may be present in the absence of imaging criteria 2
• Cardiac MRI has superior diagnostic value in identifying segmental morphological RV abnormalities and regional wall motion anomalies 2
• Contrast-enhanced cardiac MRI can depict fibrosis as late gadolinium enhancement, though this is not yet included in the revised diagnostic criteria 5

Prognosis and Risk Factors

Epsilon waves on ECG have been identified as a predictor of poor prognosis and are associated with sudden cardiac death, heart failure-related death, or heart transplant 6.

Management Recommendations

For athletes with ARVC/AC, the European Association of Preventive Cardiology recommends:

• Athletes with definite diagnosis of ARVC should be advised to abstain from participation in competitive sports
• These patients should limit their exercise programs to leisure-time physical activities and remain under regular clinical surveillance 2

Differential Diagnosis

It's important to distinguish physiological RV remodeling in athletes (characterized by proportionate increase in inflow and outflow tract without wall motion abnormalities) from pathological RV remodeling in ARVC 2.

In conclusion, right ventricular cardiomyopathy, specifically ARVC/AC, is a well-established clinical entity with significant implications for morbidity and mortality, particularly in young individuals and athletes. Early recognition and appropriate management are crucial to prevent sudden cardiac death.