Longitudinal Left Ventricular Strain in Hypertrophic Cardiomyopathy: Correlation with Nonsustained Ventricular Tachycardia

AIMS: Stratifying risk of sudden death is a major issue in the management of hypertrophic cardiomyopathy (HCM). Existing risk factors have low positive predictive value and new parameters are needed. Determination of myocardial deformation (strain) by 2D Speckle tracking is a new methodology for determining LV regional function and could correlate with myocite disarray and fibrosis. The aim of this study was to assess the relationship between strain analysis and nonsustained ventricular tachycardia (NSVT) in patients with HCM. METHODS: Thirty-two consecutive patients with HCM (mean age 55, 17-78) were studied. All underwent standard echocardiographic and two-dimensional strain examination. Twenty-four-hour Holter monitoring was performed and echocardiographic parameters were correlated with NSVT. RESULTS: Nine patients (28%) had one or more episodes of NSVT. Patients with NSVT had a higher value of maximal LV thickness (23.6 mm vs. 19.4 mm, P = 0.027). There were no significant associations between NSVT on Holter monitoring and LV outflow gradient left atrial diameter, E/Em or left ventricle ejection fraction. Patients with HCM and NSVT had significant reductions in mid septal, apical-septal, apical-lateral strain, and in mean longitudinal strain. Midseptal strain >-10.5% had a sensitivity of 89% and a specificity of 74% (area under the curve, 0.787; P < 0.0013) for predicting NSVT independently of age or maximum wall thickness. CONCLUSION: Lower end-systolic peak longitudinal strain obtained by 2D speckle tracking was a predictor of NSVT in HCM patients. This parameter could become a useful tool in stratifying SCD risk in this population.