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

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.