Clinical scenario: dyspnea | elevated JVP | cardiomegaly | diagnosis
A 12-year-old boy presents with progressive exertional dyspnea, fatigue, and abdominal distension over the past 6 months. Examination reveals elevated jugular venous pressure, hepatomegaly, and bilateral pedal edema. Cardiac auscultation is normal except for a soft third heart sound. Echocardiography demonstrates marked biatrial enlargement, normal-sized ventricles with preserved systolic function, and severe diastolic dysfunction. There is no ventricular hypertrophy.
Which of the following is the most likely diagnosis?
A. Dilated cardiomyopathy
B. Hypertrophic cardiomyopathy
C. Restrictive cardiomyopathy
D. Arrhythmogenic right ventricular cardiomyopathy
E. Constrictive pericarditis
Correct answer & Explanation:
Correct Answer: C. Restrictive cardiomyopathy
Explanation
Restrictive cardiomyopathy is characterized by:
- Marked diastolic dysfunction due to decreased ventricular compliance.
- Normal or near-normal ventricular size and systolic function in the early stages.
- Marked biatrial enlargement due to chronically elevated filling pressures.
- Clinical features of systemic and pulmonary venous congestion, including raised JVP, hepatomegaly, ascites, and peripheral edema.
In children, restrictive cardiomyopathy is uncommon but carries a poor prognosis, with many patients ultimately requiring heart transplantation.
Why the other options are incorrect
- A. Dilated cardiomyopathy: Typically presents with ventricular dilatation and reduced systolic function.
- B. Hypertrophic cardiomyopathy: Characterized by ventricular hypertrophy, often asymmetric septal hypertrophy, rather than normal ventricular wall thickness.
- D. Arrhythmogenic right ventricular cardiomyopathy: Presents predominantly with ventricular arrhythmias and fibrofatty replacement of the right ventricle.
- E. Constrictive pericarditis: Produces similar signs of right heart failure but is caused by a rigid pericardium. Echocardiography usually demonstrates characteristic respiratory variation in ventricular filling and a normal-sized atria are less typical than the marked biatrial enlargement seen in restrictive cardiomyopathy.
Learning Point
The hallmark echocardiographic features of restrictive cardiomyopathy are:
- Biatrial enlargement
- Normal ventricular size
- Preserved systolic function
- Severe diastolic dysfunction
This combination distinguishes restrictive cardiomyopathy from dilated and hypertrophic cardiomyopathies and is a classic examination finding in FCPS, MD, and MRCPCH.
