Sustained cavity obliteration and apical aneurysm formation in apical hypertrophic cardiomyopathy

Objectives In patients with apical hypertrophic cardiomyopathy (ApHCM), we estimated the severity of cavity obliteration (CO) in the apical potion of the left ventricle and correlated it with various clinical findings including apical aneurysm. Background Apical hypertrophic cardiomyopathy sometimes develops apical aneurysm. The apical CO is often exhibited in ApHCM along with apical hypertrophy and ischemia. It remains unclear, however, how the CO and others are related to aneurysm. Methods In 46 patients with ApHCM, we measured CO time on M-mode echocardiography and corrected it by the R-R interval (cCOT). We divided the 46 patients into the following groups: 17 with cCOT ≤200 ms (no/mild CO group); 18 with cCOT >200 to ≤350 ms (moderate CO group); and 11 with cCOT >350 ms (severe CO group). We then compared apical aneurysm, hypertrophy, ischemia, QT interval, and the like between the three groups. Results The severe CO group exclusively comprised 11 patients having apical aneurysm and paradoxic jet flow. Of the 11 patients, 10 exhibited irreversible defects on exercise single photon emission computed tomography with thallium-201. All with moderate CO showed reversible defects, and none with no/mild CO showed any defects. Left ventricular hypertrophy and the corrected QT interval (QTc) were largest in the severe CO group. There were high correlations between the cCOT, hypertrophy, ischemia, and QTc. Of the 11 patients with severe CO, 6 had nonsustained ventricular tachycardia and 1 had mural thrombus. Conclusions In ApHCM, sustained CO is an important pathophysiologic condition as well as hypertrophy, ischemia, and prolonged QTc, which are considered jointly related to the development of aneurysm through interactions.