New clinical insights and innovative techniques to optimize cardiac resynchronization therapy

Several important issues such as atrial fibrillation and CRT, response of elderly patients to CRT and the aspects of upgrading conventional pacemakers to biventricular devices are addressed. The peak endocardial acceleration (PEA) concept and PEAarea method are explained. Finally, the role of pressure-volume loop analysis in CRT is discussed. Chapter 2 We studied 130 patients with a biventricular pacemaker and advanced heart failure. Echocardiographic response (LVEF improvement ? 5 %) was documented in 69%, 88% and 91% of the survivors, after 3 months, 1 year and 2 years, respectively. Echocardiographic response after 3 months was associated with a significantly higher long-term survival. Chapter 3. CRT was performed in 96 patients with chronic AF and 167 patients with sinus rhythm. NYHA class, 6-minute walking distance, quality of life score, LV ejection fraction and mitral regurgitation improved significantly at 3 and 12 months in both groups. Reverse LV remodeling after 12 months was 82% in the AF group versus 83% in the sinus rhythm group. Chapter 4 The clinical and echocardiographic response to CRT in elderly (age >75 years) patients was compared to a group of younger patients (age ?75 years). Follow-up showed in both groups a comparable and sustained improvement in NYHA class, quality of life, LV ejection fraction and heart failure hospitalization. Analysis of 39 octogenarians showed also significant clinical and echocardiographic improvement. Chapter 5 CRT was performed in 194 symptomatic heart failure patients with a native LBBB and in 90 heart failure patients with a pacing-induced LBBB during chronic apical RV pacing. Although baseline characteristics differed slightly between the 2 groups, during the 2 years of follow-up clinical parameters, echocardiographic improvement, and survival after CRT implant were comparable. Chapter 6 We compared the optimal assessed VV interval measured by means of the PEAarea method to the optimal VV int erval determined by LV dP/dtmax. During CRT implantation in 15 patients, we simultaneously assessed LV dP/dtmax and the area under the PEA curve during AV scanning at different VV intervals. In 9 of the 12 responders, the optimal pacing configuration identified by the PEAarea method was in agreement with the greatest LV dP/dtmax. Chapter 7 The clinical use of pressure-volume loop analyses during CRT implantations was evaluated to assess the optimal lead position in 29 chronically RV-paced patients. Single-side LV pacing and biventricular pacing showed a significant improvement in LV function indices compared to baseline. Substantial inter- and intra-individual differences in LV function between different left-sided pacing sites were seen. In 42% of patients an alternative LV-lead position was chosen by guidance of the highest SW. Chapter 8 Forty heart failure patients with chronic RV apical pacing, decreased LV ejection fraction or dyssynchrony were included. During implantation, at th e optimal LV lead position, SW (37%), LV ejection fraction (16%), cardiac output (29%), and LV dP/dtmax (11%) increased significantly during biventricular pacing compared to baseline. During follow-up, VO2 max, Quality of Life Score, NYHA class and echocardiographic parameters improved significantly during CRT.