Atrioventricular and ventricular properties in patients implanted with CRT as descriptors of acute changes during device optimization

Background. There is strong evidence that CRT reduces mortality and hospitalization. Unfortunately, there are still no available parameters to identify non-responders. Purpose. We test if parameters, describing dyssynchrony and efficiency, can better identified acute recovery of ventricles treated with a CRT and if lead position can modify this relationship. Methods. We enrolled 65 patients referred for CRT implantation. We performed a CRT-off and /–on 2d- and 3d echocardiogram during devices optimization. We assessed left ventricular (LV) volumes 3D; then, by the peckletracking analysis we evaluated ventricular dyssynchrony, based on temporary uniformity of strain (TUS) 3D long and circ. We obtained also non-invasivally myocardial efficiency (Effic) based on interaction between pressure work index (PWI), representing an estimation of myocardial oxygen consumption, and mechanical external work. At the end, we indicate as concordant, patients presenting LV lead position (defined from a chest X-ray) in the same segment as the latest systolic 3Dcircunferantial strain curves. Results. No statistically significant differences were found both in the diastolic parameters and in atrial function. There was some trend for improvement for both longitudinal and circumferential 3D TUS during CRT-on. Only Effic demonstrated an important gain between CRT-off/-on phase. The analysis of the matrix CRT off/on and LV lead, demonstrated only a statistically significant improvement for Effic between CRT-off/on phase (p=0,01), although without any significant interaction. At the end, the MANOVA test suggested a statistically significant interaction (p=0,04) between the behavior of our ventricular parameters (Effic, PWI and TUS 3Dlong) in relation to CRT on/off and LV lead concordance/discordance. Conclusions. Evaluation of lead position relative to the LV segment with latest 3D circ strain could ameliorate concordance, improving Effic and minimizing the number of non-responders.