Question

A patient with multiple myeloma presents with shortness of breath, and his 2D echocardiogram shows characteristic findings. Which of the following statements is true?

• A. Frequent blood transfusion is a risk factor
• B. Associated with Beta MYH mutation
• C. ECG will meet criteria for LVH
• D. RCMP is most common presentation

Hint:

The classic triad pointing to cardiac amyloidosis on investigations is:
1. Heart failure with preserved ejection fraction (HFpEF).
2. Echocardiogram showing thick walls with a "sparkling" texture.
3. ECG showing low voltage in the limb leads and poor R-wave progression.

Answer 1

The Correct Option is D

Concept:
A patient with Multiple Myeloma presenting with new-onset heart failure (shortness of breath) should raise a high clinical suspicion for cardiac amyloidosis.
Multiple Myeloma is a plasma cell dyscrasia that frequently leads to the overproduction of monoclonal light chains, which misfold and deposit in tissues as AL (amyloid light-chain) amyloid.
Explanation:
• The characteristic 2D echocardiogram finding in cardiac amyloidosis is symmetrically thickened ventricular walls with a distinct "granular sparkling" or speckled myocardial texture.

• As amyloid fibrils deposit in the extracellular space of the myocardium, the heart muscle becomes stiff, rigid, and non-compliant.

• This pathological stiffness leads to profound diastolic dysfunction while systolic function (ejection fraction) is initially preserved. This clinical syndrome is termed Restrictive Cardiomyopathy (RCMP).

• Therefore, Restrictive Cardiomyopathy (RCMP) is the most common cardiac presentation of AL amyloidosis.

• Option (A) is incorrect. Frequent blood transfusions lead to iron overload (Hemochromatosis), which can also cause restrictive cardiomyopathy, but it is not the etiology in Multiple Myeloma.

• Option (B) is incorrect. Mutations in the Beta-myosin heavy chain (Beta-MYH) gene cause Hypertrophic Cardiomyopathy (HCM), a genetic disorder distinct from infiltrative amyloidosis.

• Option (C) is classically incorrect. Despite the echocardiogram showing very thick ventricular walls, the ECG typically shows low voltage QRS complexes because the thickness is due to inert amyloid protein deposition, not true electrically active muscle hypertrophy. This discordance (thick walls on echo + low voltage on ECG) is a hallmark of cardiac amyloidosis.
Final answer:
Restrictive cardiomyopathy (RCMP) is the most common and classic presentation of multiple myeloma-associated cardiac amyloidosis.