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Aim: To assess potential additional value of global left ventricular (LV) dyssynchrony markers in predicting cardiac resynchronization therapy (CRT) response in heart failure (HF) patients., Methods: We included 103 HF patients (mean age 67 ± 12 years, 83% male) who fulfilled the guidelines criteria for CRT treatment. All patients had undergone full clinical assessment, NT-proBNP and echocardiographic examination. Global LV dyssynchrony was assessed using total isovolumic time (t-IVT) and Tei index. On the basis of reduction in the NYHA class after CRT, patients were divided into responders and non-responders., Results: Prolonged t-IVT [0.878 (range, 0.802-0.962), p = 0.005], long QRS duration [0.978 (range, 0.960-0.996), p = 0.02] and high tricuspid regurgitation pressure drop [1.047 (range, 1.001-1.096), p = 0.046] independently predicted response to CRT. A t-IVT ≥ 11.6 s/min was 67% sensitive and 62% specific (AUC 0.69, p = 0.001) in predicting CRT response. Respective values for a QRS ≥ 151 ms were 66% and 62% (AUC 0.65, p = 0.01). Combining the two variables had higher specificity (88%) in predicting CRT response. In atrial fibrillation (AF) patients, only prolonged t-IVT [0.690 (range, 0.509-0.937), p = 0.03] independently predicted CRT response., Conclusion: Combining prolonged t-IVT and the conventionally used broad QRS duration has a significantly higher specificity in identifying patients likely to respond to CRT. Moreover, in AF patients, only prolonged t-IVT independently predicted CRT response.

Aims: Little is known about the optimal right ventricular (RV) pacing site in cardiac resynchronization therapy (CRT). This study compares bi-ventricular pacing at the left ventricular (LV) free wall combined with two different RV stimulation sites: RV outflow tract (RVOT+LV) vs. RV-apex (RVA+LV)., Methods and Results: Thirty-three patients (32 males) with chronic heart failure, NYHA class III-IV, optimal drug therapy, QRS-duration ≥150 ms, and chronic atrial fibrillation (AF) received CRT with two different RV leads, in the apex (RVA) or outflow tract (RVOT), together with an LV lead, all connected to a bi-ventricular pacemaker. Randomization to pacing in RVOT+LV or RVA+LV was made 1 month after implantation and cross-over to the alternate pacing configuration occurred after 3 months. The median age of patients was 69 ± 10 years, the mean QRS was 179 ± 23 ms, and 58% of patients had ischaemic heart disease. Seven patients had pacemaker rhythm at inclusion and 60% were treated with atrioventricular-junctional ablation before randomization. In the RVA+LV and RVOT+LV pacing modes, 67 and 63% (nonsignificant) responded symptomatically with a decrease of at least 10 points in the Minnesota Living with Heart Failure score. The secondary end-points (6-min walk test, peak oxygen uptake, N-Terminal fragment of B-type Natriuretic Peptide, and left ventricular ejection fraction) showed significant improvement between baseline and CRT, but not between RVOT+LV and RVA+LV., Conclusion: In this randomized controlled study, the exact RV pacing site, either apex or outflow tract, did not influence the benefits of CRT in a group of patients with chronic heart failure and AF. ClinicalTrials.gov ID: NCT00457834.

Aims Little is known about the optimal right ventricular (RV) pacing site in cardiac resynchronization therapy (CRT). This study compares bi-ventricular pacing at the left ventricular (LV) free wall combined with two different RV stimulation sites: RV outflow tract (RVOT+LV) vs. RV-apex (RVA+LV). Methods and results Thirty-three patients (32 males) with chronic heart failure, NYHA class III–IV, optimal drug therapy, QRS-duration ≥150 ms, and chronic atrial fibrillation (AF) received CRT with two different RV leads, in the apex (RVA) or outflow tract (RVOT), together with an LV lead, all connected to a bi-ventricular pacemaker. Randomization to pacing in RVOT+LV or RVA+LV was made 1 month after implantation and cross-over to the alternate pacing configuration occurred after 3 months. The median age of patients was 69 ± 10 years, the mean QRS was 179 ± 23 ms, and 58% of patients had ischaemic heart disease. Seven patients had pacemaker rhythm at inclusion and 60% were treated with atrioventricular-junctional ablation before randomization. In the RVA+LV and RVOT+LV pacing modes, 67 and 63% (nonsignificant) responded symptomatically with a decrease of at least 10 points in the Minnesota Living with Heart Failure score. The secondary end-points (6-min walk test, peak oxygen uptake, N-Terminal fragment of B-type Natriuretic Peptide, and left ventricular ejection fraction) showed significant improvement between baseline and CRT, but not between RVOT+LV and RVA+LV. Conclusion In this randomized controlled study, the exact RV pacing site, either apex or outflow tract, did not influence the benefits of CRT in a group of patients with chronic heart failure and AF. [ABSTRACT FROM PUBLISHER]

Background and Aim: Cardiac resynchronization therapy (CRT), based on broad QRS duration has proved successful for patients in late stage heart failure (HF), however almost 30% do not respond. Standard segmental Doppler echocardiographic measures of ventricular dyssynchrony are controversial in predicting response, particularly in atrial fibrillation (AF) patients. The aim of this study was to assess echo and clinical predictors of CRT response in AF patients. Methods: We studied the response of 27 HF patients in AF (mean age 74 ±7 years, 78% male) who fulfilled the guidelines for CRT treatment; NYHA class III-IV, despite full medical therapy, QRS duration >120 ms and left ventricular (LV) ejection fraction (EF) <35%, using clinical assessment, NT- proBNP and Doppler echocardiographic examination. Global LV dyssynchrony was assessed by total isovolumic time - t-IVT in s/min [calculated as: 60 - (total ejection time + total filling time)], and Tei index (t-IVT/ejection time). Based on a reduction in the NYHA class and NT-proBNP after CRT, patients were divided into responders (R) and non-responders (NR). Results: Thirteen (48%) of 27 patients were responders, who proved to have lower LVEF (p=0.02), longer t-IVT (p=0.000) and higher Tei index (p=0.03), before CRT compared with NR. All other clinical and echo parameters were not different between groups. Only prolonged t-IVT [0.690 (0.509-0.937), p = 0.02] independently predicted response to CRT. A t-IVT 11 s/min was 69% sensitive and 79% specific (AUC 0.78, p=0.015) in predicting CRT response. Conclusion: Prolonged total isovolumic time, a marker of global LV dyssynchrony, is an independent predictor of CRT response in heart failure patients with atrial fibrillation who fulfill the guidelines criteria for CRT. [ABSTRACT FROM AUTHOR]

Background and Aim: Cardiac resynchronization therapy (CRT), based on broad QRS duration has proved successful for patients in late stage heart failure (HF), however almost 30% do not respond. Standard segmental Doppler echocardiographic measures of ventricular dyssynchrony are controversial in predicting response. The aim of this study was to assess potential additional value of markers of global LV dyssynchrony in predicting CRT response in such patients. Methods: We included 103 HF patients (mean age 67 ±12 years, 82.5% male) who fulfilled the guidelines for CRT treatment; NYHA class III-IV, despite full medical therapy, QRS duration >120 ms and LV ejection fraction (EF) <35%. All patients had full clinical assessment, NT-proBNP and Doppler echocardiographic examination. Global LV dyssynchrony was assessed by total isovolumic time - t-IVT in s/min [calculated as: 60 - (total ejection time + total filling time)], and Tei index (t-IVT/ejection time). Based on a reduction in the NYHA class and NT-proBNP after CRT, patients were divided into responders (R) and non-responders (NR). Results: Sixty-one (50.2%) of 103 patients were responders, who proved to have longer QRS duration (p=0.01), faster heart rate (p=0.001), longer t-IVT (p=0.001), higher Tei index (p<0.01) and lower peak tricuspid regurgitation pressure drop - TRPD (p=0.03) before CRT compared with NR. All other clinical and echo parameters were not different between groups. In multivariate analysis, prolonged t-IVT [0.878 (0.802-0.962), p=0.005], long QRS duration [0.978 (0.960-0.996), p=0.02] and high TRPD [1.047 (1.001-1.096), p=0.047] independently predicted response to CRT. A t-IVT 11.6 s/min was 67% sensitive and 62% specific (AUC 0.69, p=0.001) in predicting CRT response. Respective values for a QRS 151ms were 66% and 62% (AUC 0.65, p=0.01). Combining the two variables had a sensitivity of 67% but higher specificity of 88% in predicting CRT response. Conclusion: Combining prolonged total isovolumic time, a marker of global LV dyssynchrony, and the conventionally used broad QRS duration has a significantly higher specificity in identifying patients likely to respond to CRT. [ABSTRACT FROM AUTHOR]