Restrictive cardiomyopathy: definition and diagnosis

Area of Science:

• Cardiology
• Cardiovascular Diseases
• Heart Failure

Background:

• Restrictive cardiomyopathy (RCM) is defined by increased myocardial stiffness leading to rapid ventricular pressure rise.
• Key features include persistent restrictive pathophysiology, diastolic dysfunction, and non-dilated ventricles with atrial dilatation.
• RCM presents a wide phenotypic spectrum, complicating classification.

Purpose of the Study:

• To elucidate the heterogeneous nature of restrictive cardiomyopathy.
• To outline the classification of RCM based on underlying disease mechanisms.
• To review diagnostic modalities and current therapeutic limitations.

Main Methods:

• Cardiac catheterization and Doppler echocardiography demonstrate restrictive pathophysiology.
• Diagnosis relies on clinical data, ECG, echocardiography, nuclear medicine, and cardiovascular magnetic resonance.
• Further investigations may include endomyocardial biopsy and genetic evaluation.

Main Results:

• RCM is classified into four mechanisms: fibrosis, infiltration, storage material accumulation, and endomyocardial fibrosis.
• Phenotypes can evolve, with some disorders showing restrictive pathophysiology only at specific stages.
• Coexisting hypertrophic and restrictive phenotypes present classification challenges.

Conclusions:

• Restrictive cardiomyopathy is a complex condition with diverse etiologies and presentations.
• Diagnostic approaches are multi-modal, requiring advanced investigations in some cases.
• Effective disease-modifying therapies are currently limited, primarily for cardiac amyloidosis and iron overload cardiomyopathy.