Relation Between Early Diastolic Mid-Ventricular Flow and Elastic Forces Indicating Aneurysm Formation in Hypertrophic Cardiomyopathy

Abstract

Background: The early diastolic paradoxical midventricular flow is suggestive of apical aneurysm (AA) formation in hypertrophic cardiomyopathy (HCM). We aimed to determine whether early diastolic paradoxical midventricular flow may be a useful screening tool in patients, following the time progression of HCM to the aneurysmal stage.

Methods: One hundred twenty-one HCM patients with dominant hypertrophy in the mid and apical segments, based on echocardiography and/or cardiovascular magnetic resonance, were selected from our HCM database, which comprises 1,332 patients. They were further stratified according to the presence of AA. All imaging studies in a period of 16 years (2005-2021) were considered for time progression. Midventricular Doppler (pulsed-wave, continuous-wave, color, and color M mode) were analyzed.

Results: Thirty-five patients (29% of the study group and 2.6% of all HCM patients) had AA. Early diastolic paradoxical midventricular flow had a sensitivity of 92% and specificity of 98.6% for the detection of AA in the study group. In 108 patients, follow-up echocardiography was performed (median, 5 [3-9] studies). Sixteen patients (15%) with 10 [7-12] years of follow-up displayed progressive time changes in left ventricle (LV) apical morphology and/or mid-LV flow. Ten patients (9%) progressed to an AA, during 7 [4-11] years of follow-up. Patients progressing to AA were younger (P = .009), with more severe LV hypertrophy (P = .01) and more often a significant mid-LV systolic gradient (≥30 mm Hg, P < .001). A wall thickness over 20 mm had 70% sensitivity and 69% specificity in detecting evolution toward AA. With significant systolic gradient, sensitivity was 80% and specificity was 62%. Furthermore, patients with AA had a higher incidence of ventricular tachycardia (log-rank P = .03).

Conclusions: Early diastolic paradoxical midventricular flow reliably detects AA presence and should prompt extra imaging studies. In HCM with mid and apical dominant involvement there is a progressive trend toward aneurysm formation, especially in patients with wall thickness over 20 mm and significant mid-LV systolic gradient (≥30 mm Hg), which can be monitored through serial Doppler studies.

Keywords: Apical aneurysm; Early diastolic paradoxical flow; Hypertrophic cardiomyopathy.