Restrictive cardiomyopathy heart sounds
Restrictive cardiomyopathy commonly produces an S4 and may also produce an S3. [1][2]
Timing of the characteristic extra heart sound
S4 occurs in late diastole and is related to atrial contraction against a noncompliant ventricle. [2][3]
Third heart sound in restrictive cardiomyopathy
An S3 may occur in restrictive cardiomyopathy due to abnormal early diastolic ventricular filling. [1][2]
Differentiation from constrictive pericarditis
Presence of a ventricular gallop sound constellation in restrictive cardiomyopathy requires differentiation from the precordial knock of constrictive pericarditis. [1]
Heart sounds beyond gallops
Restrictive cardiomyopathy can also produce systolic murmurs from associated valve regurgitation such as mitral and tricuspid regurgitation. [4]
Practical bedside characterization
A low-pitched diastolic gallop pattern of S3 and/or S4 supports restrictive physiology when other causes of abnormal filling are considered. [1][2][4]