Time course of left ventricular volumes in severe congestive heart failure patients treated by optimized AV sequential left ventricular pacing alone--a 3-dimensional echocardiographic study

Time-Course of the Effects of QSYQ in Promoting Heart Function in Ameroid Constrictor-Induced Myocardial Ischemia Pigs

We aim to investigate the therapeutic effects of QSYQ on a pig myocardial ischemia (MI) model and to determine its mechanism of action. The MI model was induced by Ameroid constriction of the left anterior descending coronary (LAD) in Ba-Ma miniature pigs. Four groups were created: model group, digoxin group, QSYQ group, and sham-operated group. Heart function, Ang II, CGMP, TXB2, BNP, and cTnT were evaluated before (3 weeks after operation: 0 weeks) and at 2, 4, and 8 weeks after drug administration. After 8 weeks of administration, the pigs were sacrificed for cardiac injury measurements. Pigs with MI showed obvious histological changes, including BNP, cTnT, Ang II, CGRP, TXB2, and ET, deregulated heart function, and increased levels of apoptotic cells in myocardial tissue. Treatment with QSYQ improved cardiac remodeling by counteracting those events. The administration of QSYQ was accompanied by a restoration of heart function and of the levels of Ang II, CGRP, TXB2, ET BNP, and cTnT. In addition, QSYQ attenuated administration, reduced the apoptosis, and decreased the level of TNF- α and active caspase-3. In conclusion, administration of QSYQ could attenuate Ameroid constrictor induced myocardial ischemia, and TNF- α and active caspase-3 seemed to be the critical potential target of QSYQ.

Improvement of left ventricular function under cardiac resynchronization therapy goes along with a reduced incidence of ventricular arrhythmia

Objectives

The beneficial effects of cardiac resynchronization therapy (CRT) are thought to result from favorable left ventricular (LV) reverse remodeling, however CRT is only successful in about 70% of patients. Whether response to CRT is associated with a decrease in ventricular arrhythmias (VA) is still discussed controversially. Therefore, we investigated the incidence of VA in CRT responders in comparison with non-responders.

Methods

In this nonrandomized, two-center, observational study patients with moderate-to-severe heart failure, LV ejection fraction (LVEF) ≤35%, and QRS duration >120 ms undergoing CRT were included. After 6 months patients were classified as CRT responders or non-responders. Incidence of VA was compared between both groups by Kaplan-Meier analysis and Cox regression analysis. ROC analysis was performed to determine the aptitude of LVEF cut-off values to predict VA.

Results

In total 126 consecutive patients (64±11years; 67%male) were included, 74 were classified as responders and 52 as non-responders. While the mean LVEF at baseline was comparable in both groups (25±7% vs. 24±8%; P = 0.4583) only the responder group showed an improvement of LVEF (36±6% vs. 24±7; p<0.0001) under CRT. In total in 56 patients VA were observed during a mean follow-up of 28±14 months, with CRT responders experiencing fewer VA than non-responders (35% vs. 58%, p<0.0061). Secondary preventive CRT implantation was associated with a higher likelihood of VA. As determined by ROC analysis an increase of LVEF by >7% was found to be a predictor of a significantly lower incidence of VA (AUC = 0.606).

Conclusions

Improvement of left ventricular function under cardiac resynchronization therapy goes along with a reduced incidence of ventricular arrhythmia.

Long-term response of the left ventricle to cardiac resynchronization therapy: insights from standard and strain echocardiography

Left ventricular (LV) response to cardiac resynchronization therapy (CRT) has typically been studied over 3- to 12-month periods. Longer-term data are unclear and response of strain parameters has not been reported. The authors evaluated long-term response with standard and strain echocardiography in 57 patients (52±15 years; 40 male; 30 white; 15 with ischemic etiology) who received a CRT-defibrillator between January 2004 and December 2005. Median ejection fraction (EF) at baseline was 22% (17%-25%). Global longitudinal, radial, and circumferential strain were -6.5% (-5.0% to -8.4%), 10.4% (6.9%-15.1%), and -7.6% (-5.5% to -10.8%), respectively. After a median of 42 months, EF increased by 5% (-1% to 15%; P<.001), with improvements in circumferential (-3.2% [-5.2% to 1.5%]; P=.001), longitudinal (-0.5% [-3.4% to 1.2%]; P=.035), and radial (1.4% [-1.1% to 9.2%]; P=.035) strain. Changes in volumes were nonsignificant. EF improvement ≥5% was observed in 29 patients (50.9%). Relative improvement ≥15% in longitudinal, radial, and circumferential strain was observed in 26 (45.6%), 29 (50.9%), and 37 (64.9%) patients, respectively. Improvement in longitudinal strain and EF was strongly associated with lower rates of heart failure-related and all-cause readmissions. A wide range of long-term LV responses to CRT was observed, with approximately 50% of patients showing favorable responses.