PATH - Cardiomyopathies

Question 1

Dilated cardiomyopathy

Answer 1

Most common cardiomyopathy

Systolic dysfunction ensues.

Eccentric (dilated) hypertrophy (sarcomeres added in
*series)

Findings:
HF, *S3, systolic regurgitant murmur, *dilated heart on echocardiogram, *balloon
appearance of heart on CXR.

Often idiopathic or familial

Other etiologies include:
ABCCCD
Alcohol abuse
wet Beriberi
Coxsackie B viral myocarditis
chronic Cocaine use
Chugs disease
Doxorubicin toxicity
hemochromatosis
sarcoidosis
peripartum cardiomyopathy.

Question 2

Hypertrophic cardiomyopathy

Answer 2

autosomal dominant

60–70% of cases are familial

Diastolic dysfunction ensues.

Marked ventricular hypertrophy, often septal
predominance.

Myofibrillar disarray and
fibrosis

Findings:
*S4, systolic murmur. May see *mitral regurgitation due to impaired mitral valve closure

Can be associated with Friedrich ataxia.

Causes syncope during exercise and may lead to sudden death in young athletes due to ventricular arrhythmia

Obstructive hypertrophic cardiomyopathy—asymmetric septal hypertrophy and systolic anterior motion of mitral valve–>outflow obstruction–>dyspnea, possible syncope.

Question 3

Restrictive/infiltrative cardiomyopathy

Answer 3

Diastolic dysfunction ensues.

Can have low voltage ECG despite thick myocardium
(especially amyloid).

Major causes include sarcoidosis, amyloidosis,
postradiation fibrosis, endocardial fibroelastosis, Löffler syndrome, and hemochromatosis