Left Ventricular Apical Thinning as Normal Anatomy

OBJECTIVE: Apical thinning of the left ventricular myocardium has been described by anatomists as a normal feature. Nonetheless, it does not appear in most anatomic atlases. We investigated its presence in healthy patients and patients with left ventricular hypertrophy using coronary computed tomographic arteriography (CCTA). METHODS: Sixty-four patients without a history of cardiac disease and 8 patients with left ventricular hypertrophy were imaged using coronary computed tomographic arteriography. RESULTS: All 64 patients had a focus of myocardial thinning at the left ventricular apex (mean, 1.2 mm [SD, 1.1 mm]). Its average span in the oblique coronal plane was 4.4 mm (2.9 mm), corresponding to a median area of 14.3 mm2 with an interquartile range of 3.9 to 31.6. The focus faced 4.8 degrees (5.9 degrees) toward the diaphragmatic side of the apex. The 8 hypertrophied hearts also had a zone of apical thinning. In a subset of 12 patients in whom functional data were analyzed, this focus did not thicken or move over the cardiac cycle. CONCLUSIONS: A zone of substantial thinning of the left ventricular apex is a normal anatomic feature.