Echocardiography assessment of the left ventricle apical morphology and dynamics in patients with unexplainable deep T-wave inversion and apical wall thickness<15 mm

Background: There exists a group of patients with the same ECG characteristics as typical apical hypertrophic cardiomyopathy (AHCM) but fails to reach the diagnostic criteria. The objective of this study was to evaluate the apical morphological and dynamical features of this type of patients using echocardiography.Methods:A total of 30 subjects with unexplainable T-wave inversion (TWI) on ECG and apical myocardium thickness <15 mm by echocardiography were recruited. The apical morphological and dynamic features included the left ventricular (LV) apical-to-basal posterior wall thickness ratio (ABR), apical angle (apA) and its percentage change in cardiac cycle, peak blood flow velocity at the apical cavity (Vap) and its ratio to the velocity at LV outflow tract (Vap/VLVOT). The results were compared to those from 32 patients with typical AHCM, 44 with essential hypertension and 43 healthy controls.Results: Compared to healthy controls and hypertension patients, the suspected AHCM group had a significantly higher ABR (1.37±0.23 vs. 0.75±0.08 and 0.75±0.11, P<0.001), lower apAs, higher percent change of apA (74±23% vs. 16±8% and 28±13%, P<0.001) and higher Vap/VLVOT (0.5±0.3 vs. 0.3±0.1 and 0.3±0.1, P<0.05). Patients with typical AHCM had similar apAs and its change and significantly higher ABR (1.85±0.42, P<0.001) and Vap/VLVOT (0.8±0.5, p=0.009) than the suspected AHCM group.Conclusion: Apical morphology and dynamic features of subjects with TWI and LV apical thickness <15 mm were significantly different from healthy controls and hypertension patients, but shared similarities with typical AHCM patients. The results suggest this suspected group may be in an early stage or exhibit a mild phenotype of AHCM. With careful assessment and additional quantitative measurements, it is possible to detect this suspected AHCM group using echocardiography.