1027 Mechanical dispersion of the left and right ventricle and the correlation with ventricular arrhythmias in hypertrophic cardiomyopathy

Abstract

Abstract Funding Acknowledgements CREDO Project - ID: 49182, financed through the SOP IEC -A2-0.2.2.1-2013-1 cofinanced by the ERDF Introduction One important cause of sudden cardiac death in hypertrophic cardiomyopathy (HCM) are ventricular arrhythmias. In patients with HCM, non-sustained ventricular arrhythmias were analysed in relation with 2D speckle tracking mechanical dispersion of left ventricle (LVMD), but not in relation with mechanical dispersion of the right ventricle. Purpose To investigate the possible associations between mechanical dispersion and other echocardiographic parameters and the development of non-sustained ventricular tachycardias (NSVT) in HCM patients. Methods Clinical, 24 hours ECG-Holter, 2D and 3D echocardiography data were registered in HCM patients and in a healthy control group (with normal echocardiography). The 24 hours ECG-Holter was used for detecting NSVT. LVMD was calculated as the standard deviation of time to peak negative strain in the sixteenth segments of the left ventricle. The right ventricle mechanical dispersion (RVMD) was calculated on a three free wall segments model (FWMD), but also in six segments (three RV free wall segments plus three septal segments). Right and left ventricle function was evaluated by conventional echography and 2D speckle tracking imaging. Results Fifty-two patients with HCM and thirty-six age and sex matched subjects were included in the study. In HCM group, 6 patients (11,5%) associated biventricular hypertrophy, while 15 (28.8%) had NSVT on ECG monitoring (group HCM1). HCM1 patients had a much higher LVMD (77.38 ± 11.19 ms) compared with HCM patients without NSVT (group HCM2) (55.8 ± 23.85 ms, p = 0.001, CI:-33.9,-9.3) or compared with controls (43.07 ± 14.19 ms, p <0.001, CI: -44.68, -25.99). The 6 segments RVMD (60.23 ± 10.2 ms) was significantly higher in the CMH1 group compared with CMH2 (45.22 ± 9.8 ms, p = 0.01, CI: -32.1, -28.1) or with the control group (22 ±14 ms, p < 0.001,CI: -36.28, -30.12) independently of the existence of RV hypertrophy. Also, FWMD (55.2 ± 4.8 ms) was significantly higher in CMH1 group in comparation with CMH2 (42.3 ± 5.6 ms, p = 0.02, CI: -27.1, -8.2) or controls (32.1 ± 2.2 ms, p = 0.006, CI: -28.1, -12.1). The presence of NSVT correlated with global longitudinal strain (GS) 2C (-0.442, p = 0.009), GS LAX (r=-0.373, p = 0.03), GS mean value (r=-0.345, p = 0.046), LVMD (r = 0.462, p = 0.006), FWMD (r = 0.51, p = 0.004), 6 segments RVMD (r = 0.46, p = 0.05), 2D and 3D left atrial volume (r = 0.446, p = 0.008 and respectively, r = 0.512, p = 0.002). In a logistic regression, the only parameters associated with NSVT were LVMD (OR = 1.046, p = 0.05), FWMD (OR = 1.03, p = 0.05) and 6 segments MD (OR = 1.1, p = 0.04). Conclusions Increased mechanical dispersion of the left, but also right ventricle is associated with the risk of non-sustained ventricular tachycardias in HCM patients.