A. Zunida, Ulas Bildirici, Ji Yan, S. Noor Asyikin, Aysen Agacdiken, Xizhen Fan, David L. Hayes, Tayfun Sahin, Xianlin Sun, Teoman Kilic, Ian P. Clements, Chunsheng An, H. Azlan, O. Razali, Jian Xu, E. Barin, Brian P. Mullan, Dilek Ural, Ahmet Vural, Umut Celikyurt, K. Surinder, G. S. Tay, and Kangyu Chen
The role of reverse remodelling of the right and left ventricle and symptom improvement after biventricular upgrade {#article-title-2} Background and objectives The role of right (R) and left (L) ventricular (V) reverse remodelling in symptom improvement after biventricular upgrade is unclear. Methods Tomographic radionuclide angiocardiographic RV and LV end-diastolic (EDV, mL) and end-systolic (ESV, mL) and New York Heart Association heart failure class (NYHA) were determined before and 3–6 months after upgrading from persistent RV pacing to persistent biventricular pacing in 19 patients. Results Symptoms improved (a decline in at least one NYHA class) in 9 patients (2.89 ± 0.33 to 1.67 ± 0.5) with no improvement in 10 (2.6 ± 0.52 to 2.6 ± 0.52). During chronic RV pacing and before biventricular upgrade, patients with symptom compared with those without symptom improvement had significantly larger LV EDV (221 ± 75 vs. 160 ± 42, P = 0.04). After biventricular upgrade, in patients with symptom improvement, significant declines in LV EDV (221 ± 75 to 180 ± 54, P = 0.04) and ESV (147 ± 58 to 109 ± 46, P = 0.01) occurred; no significant changes occurred in RV EDV (256 ± 64 vs. 220 ± 33) and ESV (157 ± 74 vs. 122 ± 43). After biventricular upgrade, patients without symptomatic improvement showed no significant changes in LV and RV volumes. Conclusions Symptomatic improvement after upgrading from chronic RV to biventricular pacing was associated with a larger baseline LV EDV and subsequent significant reduction in LV EDV and ESV. Reverse remodelling of the LV but not the RV after biventricular pacing upgrade was associated with symptom improvement. # CRT response score predicts the effects of cardiac resynchronization therapy {#article-title-3} Background and objectives The effectiveness of cardiac resynchronization therapy (CRT) has been verified by large multi-centre studies, but non-response phenomenon occurs in ∼30% of patients according to the indications of CRT recently. This study was designed to evaluate the factors that affect the effects of CRT, summarize CRT response score to predict clinical effects. Methods From December 2001 to August 2009, 110 patients with chronical heart failure were enrolled in this study. The patients underwent a clinical examination, 12-lead electrocardiography, echocardiographic evaluations before implantation. Patients were divided into control and response group which was defined as a decrease in left ventricular end-diastolic diameter of ≥15% at 6 months after operation. The follow-up duration was 12 months. The clinical endpoint considered was cardiovascular death and hospitalization due to heart failure. Results CRT-P/D devices were successfully implanted in 107 patients. Of the patients, 61.3% showed a response to CRT. Multiple logistic regression identified an independent association between duration of heart failure, ischaemic cardiomyopathy, ΔQRS, septal-to-posterior wall motion delay (SPWMD), and effects of CRT. Four score was assigned to duration of heart failure ≥5.0 years, ischaemic cardiomyopathy, ΔQRS 150 ms: what are the LV conduction delays in RBBB vs. LBBB? {#article-title-4} Rationale Surface QRS duration (QRSd) exceeding 150 ms predicts greater likelihood of CRT response in patients with LV dysfunction (HF). The reason may be greater delay of LV activation time (LVAT) since the premise of CRT requires late LV activation. However, the relation of QRSd and configuration to LVAT is unknown. This was assessed. Methods In HF patients (LV ejection fraction 23 ± 8%, n = 85) with QRS >120 ms left bundle branch block (LBBBHF, n = 54) and right bundle branch block (RBBBHF, n = 31), LVAT was estimated by interval from QRS onset to basal inferolateral LV depolarization during intrinsic conduction. Results QRSd in LBBBHF did not differ to RBBBHF (161 ± 29 vs. 165 ± 18 ms, P = NS), but LVAT was greater (136 ± 33 vs. 100 ± 24 ms, P 150/ < 150 ms (see figure). LVAT correlations with QRS duration were RBBBHF: P = 0.1; LBBBHF: P < 0.001. ![Figure][1] Conclusion LV activation delay in patients with LV dysfunction is greater when QRSd >150 ms. However, QRSd >150 ms with RBBBHF is less likely to contain prolonged LVAT. The probability distribution of LVAT according to QRS duration and configuration may determine the likelihood of response if CRT is applied universally to HF patients with QRS >150 ms. # Relationship between dyssynchrony improvement and reverse remodelling {#article-title-5} We aimed to investigate reverse remodelling (RR) according to a decrease in left ventricular end-systolic volume (LVESV) and an increase in left ventricular ejection fraction (LVEF) and their relationship between dyssynchrony improvements. Thirty patients with severe heart failure, scheduled for implantation of a CRT device, were identified as echocardiographic responders by 10% decrease in LVESV and/or 25% increase in LVEF. Intraventricular dyssynchrony was measured with TDI. Patients were divided in RR developed and non-developed groups. RR according to LVESV was developed in 18, 22, and 22 patients at 1st, 3rd, and 6th months, respectively. RR according to LVEF was developed in 10, 14, and 18 patients at 1st, 3rd, and 6th months, respectively. Ventricular dyssynchony improvement was significant at the end of the first month in both of RR developed and non-developed groups according to LVESV. Dyssynchrony improvement was continued in the RR developed group. However, it does not improve regularly in the RR non-developed group. Dyssynchrony improvement was significant at the end of the first month in the RR developed and non-developed patient groups according to LVEF and there was not any difference at the end of the 6th month. Ventricular dyssynchrony improvement plays an important role in RR according to LVESV. Synchronized contraction of the interventricular non-contracting chamber areas with CRT may be one of the reasons. However, there was not any difference in dyssynchrony improvement in RR developed and non-developed groups according to LVEF. RR in these groups may develop with a different mechanism. # Cardiac resynchronization therapy in heart failure patients with narrow QRS {#article-title-6} Background Cardiac resynchronization therapy (CRT) is an established therapy for severe symptomatic heart failure with depressed left ventricle (LV) systolic function and a wide QRS >120 ms. However, only 30% heart failure patients will fulfil these criteria. Studies have demonstrated benefits of CRT with narrow QRS