TY - CHAP U1 - Konferenzveröffentlichung A1 - Ismer, Bruno A1 - Kleimenhagen, Frank A1 - Heinke, Matthias A1 - Rösch, Lena A1 - Rotter, Kirsten-Maria A1 - Melzer, Christoph A1 - Weber, Frank T1 - Significance of new electrocardiographic parameters to improve cardiac resynchronization therapy T2 - Biomedical Engineering / Biomedizinische Technik N2 - Introduction: Oesophageal left heart electrogram (LHE) is a valuable tool providing electrocardiographic parameters for cardiac resynchronization therapy (CRT). It can be utilized to measure left ventricular (LVCD) and intra-leftventricular conduction delays (ILVCD) in heart failure patients to justify implantation of CRT systems. In the follow-up, LHE enables measurement of implant-related interatrial conduction times (IACT) which are the key intervals defining the hemodynamically optimal AV delay (AVD). Methods: By TOSlim oesophageal electrode and Rostockfilter (Osypka AG, Rheinfelden, Germany), LHE was recorded in 39 heart failure patients (10f, 29m, 65±8yrs., QRS=163±21ms) after implantation of CRT systems according to guidelines. In position of maximal left ventricular deflection, LVCD and ILVCD were measured and compared with QRS width. In position of maximal left atrial deflection (LA), IACT was determined in VDD and DDD operation as interval As-LA and Ap-LA between atrial sense event (As) or stimulus (Ap), resp., and onset of LA. AVD was individualized using SAV =As-LA + 50ms for VDD and PAV=Ap-LA + 50ms for DDD operation. Results: The CRT patients were characterized by minimal transoesophageal LVCD of 40ms but 73±20ms, at mean, ILVCD of 90±24ms and QRS/LVCD ratio of 2.4±0.6. The measured As-LA of 39±24ms and Ap-LA of 124±26ms resulted into SAV of 89±24ms and PAV of 174±26ms. In case of empirical AVD programming using 120ms for SAV and 180ms for PAV, the LHE revealed inverse sequences of LA and Vp in 4 patients (10%) during VDD and 13 patients (33%) in DDD pacing. In these patients, Vp preceded LA as IACT exceeded the programmed AVD. Conclusion: Guideline indication of CRT systems is associated with LVCD of 40ms or more. Therefore, individual LVCD offers the minimal target interval that should be reached during left ventricular electrode placement to increase responder rate. Postoperatively, AV delay optimization respecting implant-related IACTs excludes adverse hemodynamic effects. Y1 - 2011 SN - 0013-5585 (Print) SS - 0013-5585 (Print) SN - 1862-278X (Online) SS - 1862-278X (Online) U6 - https://doi.org/10.1515/bmt.2011.850 DO - https://doi.org/10.1515/bmt.2011.850 VL - 56 IS - S1 SP - 3 S1 - 1 PB - Walter de Gruyter CY - Berlin, Boston ER -