Imaging systolic and diastolic heart murmurs in hypertrophic cardiomyopathy

Abstract

Muscular obstruction in hypertrophic cardiomyopathy can occur not only in systole, but also in diastole. Here we report a case of hypertrophic cardiomyopathy in a middle-aged lady: echocardiography and cardiovascular magnetic resonance confirmed the diagnosis of hypertrophic cardiomyopathy with significant systolic and diastolic midventricular obstruction, corresponding to the murmurs audible in mid-systole and early-diastole respectively. Moreover, the mid-systolic murmur was clearly distinguishable from the mitral regurgitation murmur, which was audible throughout systole (pan-systolic) and likely related to systolic anterior motion of the mitral chords; similarly, the early-diastolic heart murmur due to diastolic obstruction was  better audible at the apex and clearly distinguishable from common diastolic murmurs due to aortic regurgitation.

Echocardiography (with Doppler recordings) and magnetic resonance (with turbulence flows at steady state free precession imaging) allowed a detailed visualization of each audible murmur (systolic obstruction, mitral regurgitation, diastolic obstruction). In particular, while systolic obstruction has been extensively studied in hypertrophic cardiomyopathy, only very few reports about diastolic obstruction exist, describing either a normodirected midventricular diastolic obstruction (forward flow) similar to this case or a paradoxical midventricular diastolic obstruction (backward flow) in patients with an apical aneurysm emptying during early diastole into the left ventricular base through a narrow midventricular channel. Whether diastolic obstruction implies worse prognosis or requires specific treatment, deserves further research.