Narrower QRS may be enough to respond to cardiac resynchronization therapy in lightweight patients (original) (raw)
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Cardiac Resynchronization Therapy in Patients With Heart Failure and a QRS Complex <120 Milliseconds
Circulation, 2013
H eart failure (HF) is considered an epidemic of the modern era. 1-3 Cardiac resynchronization therapy (CRT) has emerged as a valuable adjunctive therapy for patients with severe HF and a prolonged QRS duration. In selected candidates on optimal medical therapy, studies have shown that CRT reduces cardiac-related hospitalizations and improves New York Heart Association (NYHA) functional class, exercise tolerance, left ventricular (LV) systolic function, and survival. 4-8 Response to CRT in patients with severe HF and a QRS duration <120 milliseconds is less well established. Although small single-center studies support the hypothesis that such patients may also benefit from CRT, most reports are observational in nature. 9-13 To date, 1 clinical trial found no benefit of CRT in 178 patients with a QRS duration <130 milliseconds. 14 Moreover, a single-arm feasibility study of CRT in 68 patients with a QRS duration <120 milliseconds was recently abandoned because of lack of benefit. 15 The primary outcome for both studies was maximum oxygen uptake (peak. Vo 2), which has been criticized for its poor sensitivity in detecting therapeutic responses. In contrast, a nonblinded, randomized trial that compared CRT Background-Although the benefits of cardiac resynchronization therapy are well established in selected patients with heart failure and a prolonged QRS duration, salutary effects in patients with narrow QRS complexes remain to be demonstrated. Methods and Results-The Evaluation of Resynchronization Therapy for Heart Failure (LESSER-EARTH) trial is a randomized, double-blind, 12-center study that was designed to compare the effects of active and inactive cardiac resynchronization therapy in patients with severe left ventricular dysfunction and a QRS duration <120 milliseconds. The trial was interrupted prematurely by the Data Safety and Monitoring Board because of futility and safety concerns after 85 patients were randomized. Changes in exercise duration after 12 months were no different in patients with and without active cardiac resynchronization therapy (−0.7 minutes [95% confidence interval (CI), −2.9 to 1.5] versus 0.8 minutes [95% CI, −1.2 to 2.9]; P=0.31]. Similarly, no significant differences were observed in left ventricular endsystolic volumes (−6.4 mL [95% CI, −18.8 to 5.9] versus 3.1 mL [95% CI, −9.2 to 15.5]; P=0.28) and ejection fraction (3.3% [95% CI, 0.7-6.0] versus 2.1% [95% CI, −0.5 to 4.8]; P=0.52). Moreover, cardiac resynchronization therapy was associated with a significant reduction in the 6-minute walk distance (−11.3 m [95% CI, −31.7 to 9.7] versus 25.3 m [95% CI, 6.1-44.5]; P=0.01), an increase in QRS duration (40.2 milliseconds [95% CI, 34.2-46.2] versus 3.4 milliseconds [95% CI, 0.6-6.2]; P<0.0001), and a nonsignificant trend toward an increase in heart failure-related hospitalizations (15 hospitalizations in 5 patients versus 4 hospitalizations in 4 patients). Conclusions-In patients with a left ventricular ejection fraction ≤35%, symptoms of heart failure, and a QRS duration <120 milliseconds, cardiac resynchronization therapy did not improve clinical outcomes or left ventricular remodeling and was associated with potential harm.
Heart, 2010
Introduction Current guidelines recommend cardiac resynchronisation therapy (CRT) in patients with severe symptomatic heart failure, depressed left ventricular (LV) systolic function and a wide QRS complex ($120 ms). However, patients with heart failure having a narrow QRS complex might also benefit from CRT. Design setting patients interventions During the Predictors of Response to Cardiac Resynchronisation Therapy (PROSPECT) trial, 41 patients were enrolled in a 'narrow' QRS sub-study. These patients had a QRS complex <130 ms, but documented evidence of mechanical dyssynchrony by any of seven pre-defined echocardiographic measures. Results After 6 months of CRT, 26 (63.4%) patients showed improvement according to the Clinical Composite Score, 4 (9.8%) remained unchanged and 11 (26.8%) worsened. In patients with paired data, the 6min walking distance increased from 3346118 m to 3826128 m, (p¼0.003) and quality-of-life score improved from 44.2619.7 to 26.8620.2 (p<0.0001). Furthermore, there was a significant decrease in LV endsystolic diameter (from 5969 to 55612 mm, p¼0.002) and in LV end-diastolic diameter (from 6769 to 63611 mm, p¼0.007). Conclusion The results suggest that CRT may have a beneficial effect in heart failure patients with a narrow QRS complex and mechanical dyssynchrony as assessed by echocardiography. The majority of patients improved on clinical symptoms, and there was an evident reduction in LV diameters. Larger studies are needed to clearly define selection criteria for CRT in patients with a narrow QRS complex.
European heart journal, 2015
In EchoCRT, a randomized trial evaluating the effect of cardiac resynchronization therapy (CRT) in patients with a QRS duration of <130 ms and echocardiographic evidence of left ventricular dyssynchrony, the primary outcome occurred more frequently in the CRT when compared with the control group. According to current heart failure guidelines, CRT is recommended in patients with a QRS duration of ≥120 ms. However, there is some ambiguity from clinical trial data regarding the benefit of patients with a QRS duration of 120-130 ms. The main EchoCRT trial was prematurely terminated due to futility. For the current subgroup analysis we compared data for CRT-ON vs. -OFF in patients with QRS < 120 (n = 661) and QRS 120-130 ms (n = 139). On uni- and multivariable analyses, no significant interaction was observed between the two groups and randomized treatment for the primary or any of the secondary endpoints. On multivariable analysis, a higher risk for the primary endpoint was observ...
PubMed, 2016
Objective: Impairment of heart rate turbulence (HRT) and heart rate variability (HRV) are associated with poor prognosis in chronic heart failure (CHF). Although previous studies have demonstrated that patients with a left bundle branch block (LBBB) have a better outcome with cardiac resynchronization therapy (CRT), the effect of QRS morphology on HRV and HRT is not known. We aimed to evaluate the effect of QRS morphology on HRV and HRT after CRT implantation in patients with CHF. Patients and methods: Patients who had been implanted a CRT device with cardioversion-defibrillation feature were included to the study. Forty-three patients with LBBB (group 1) were compared with 21 patients without LBBB (group 2). HRV and HRT parameters were compared before and one month after CRT implantation. Results: We compared the echocardiographic and electrocardiographic changes in both groups after CRT. Cardiac output (CO) was found to be significantly much more increased in group 1 (1.1 ± 0.4 vs. 0.6 ± 0.4, p = 0.001). Similarly, except SDNN and LF, all HRT and HRV parameters were significantly changed in the patients with LBBB (TO 1.4 ± 0.3 vs. 1.2 ± 0.2, p = 0.001; TS -1.8 ± 0.7 vs. -0.9 ± 0.7, p = 0.001; RMSSD -15.7 ± 9.9 vs. -6.3 ± 6.2, p = 0.001; PNN50 -7.0 ± 4.6 vs. -1.7 ± 1.1, p = 0.001; HF -13.3 ± 6.7 vs. -4.3 ± 3.5, p = 0.001; LF/HF 1.9 ± 0.4 vs. 1.5 ± 0.2, p = 0.001) compared to those without LBBB. Lineer regression analysis showed that the CO (β = 0.2, t = 2.8, p = 0.007) and QRS configuration (β = 0.6, t = 0.5, p = 0.001) were independent parameters affecting TO. Conclusions: HRV and HRT are improved after CRT but these improvements are more remarkable in patients with LBBB. CO, QRS configuration (but not duration) were two independent parameters affecting TO, LF and LF/HF ratio after CRT.
Vectorcardiographic QRS area as a novel predictor of response to cardiac resynchronization therapy
Journal of Electrocardiology, 2015
Background: QRS duration and left bundle branch block (LBBB) morphology are used to select patients for cardiac resynchronization therapy (CRT). We investigated whether the area of the QRS complex (QRS AREA) on the 3-dimensional vectorcardiogram (VCG) can improve patient selection. Methods: VCG (Frank orthogonal lead system) was recorded prior to CRT device implantation in 81 consecutive patients. VCG parameters, including QRS AREA , were assessed, and compared to QRS duration and morphology. Three LBBB definitions were used, differing in requirement of mid-QRS notching. Responders to CRT (CRT-R) were defined as patients with ≥ 15% reduction in left ventricular end systolic volume after 6 months of CRT. Results: Fifty-seven patients (70%) were CRT-R. QRS AREA was larger in CRT-R than in CRT nonresponders (140 ± 42 vs 100 ± 40 μVs, p b 0.001) and predicted CRT response better than QRS duration (AUC 0.78 vs 0.62, p = 0.030). With a 98 μVs cutoff value, QRS AREA identified CRT-R with an odds ratio (OR) of 10.2 and a 95% confidence interval (CI) of 3.4 to 31.1. This OR was higher than that for QRS duration N 156 ms (OR = 2.5; 95% CI 0.9 to 6.6), conventional LBBB classification (OR = 5.5; 95% CI 0.9 to 32.4) or LBBB classification according to American guidelines (OR = 4.5; 95% CI 1.6 to 12.6) or Strauss (OR = 10.0; 95% CI 3.2 to 31.1). Conclusion: QRS AREA is an objective electrophysiological predictor of CRT response that performs at least as good as the most refined definition of LBBB. Condensed abstract: In 81 candidates for cardiac resynchronization therapy (CRT) we measured the area of the QRS complex (QRS AREA) using 3-dimensional vectorcardiography. QRS AREA was larger in echocardiographic responders than in non-responders and predicted CRT response better than QRS duration and than simple LBBB criteria. QRS AREA is a promising electrophysiological predictor of CRT response.
Circulation: Arrhythmia and Electrophysiology, 2021
Background: Women are less likely to receive cardiac resynchronization therapy, yet, they are more responsive to the therapy and respond at shorter QRS duration. The present study hypothesized that a relatively larger left ventricular (LV) electrical dyssynchrony in smaller hearts contributes to the better cardiac resynchronization therapy response in women. For this, the vectorcardiography-derived QRS area is used, since it allows for a more detailed quantification of electrical dyssynchrony compared with conventional electrocardiographic markers. Methods: Data from a multicenter registry of 725 cardiac resynchronization therapy patients (median follow-up, 4.2 years [interquartile range, 2.7–6.1]) were analyzed. Baseline electrical dyssynchrony was evaluated using the QRS area and the corrected QRS area for heart size using the LV end-diastolic volume (QRSarea/LVEDV). Impact of the QRSarea/LVEDV ratio on the association between sex and LV reverse remodeling (LV end-systolic volume ...
Eskisehir Medical Journal Eskisehir City Hospital, 2022
Introduction: Cardiac resynchronization therapy (CRT) is an effective treatment in heart failure however; identifying the suitable patients is difficult. Fragmented QRS (fQRS) complex is a myocardial conduction abnormality that indicates myocardial scar. This study was conducted to find out the response of nonischemic dilated cardiomyopathy (NCMP) to CRT by using fQRS. Methods: 56 patients were enrolled. 32 patients had fQRS (57.1%) and 24 had no fQRS (46.9%) on electrocardiography (ECG). All patients were suitable for CRT treatment. The two groups (fQRS and no fQRS) were evaluated before and after (1 year) CRT by using clinical status, ECG, and echocardiographic parameters. Continuous parameters were compared with Paired Samples T-test. Results: During the follow-up period; comparison of QRS (p=0.46, p=0.61), and NYHA class (p=0.29, p=0.57) were not statistically significant before and after CRT, respectively (fQRS and no fQRS). In addition, the change in left ventricular ejection fraction is not statistically significant (p=0.12). Conclusion: fQRS presence is not associated with CRT response in patients with NCMP.