Postoperative Performance of the Quartet® Left Ventricular Heart Lead

Promote^® Q CRT‐D and Quartet^® LV Lead Study . Introduction: The Quartet^® left ventricular (LV) lead is the first with 4 pacing electrodes (tip and 3 rings) that enables pacing from 10 different pacing vectors. Postoperative performance of this lead was evaluated in a prospective, nonrandomized, multicenter IDE study. Methods: Patients with standard indications for CRT‐D were enrolled. Electrical performance and presence of phrenic nerve stimulation (PNS) were assessed during pacing from each of 10 vectors at predischarge (within 7 days), 1 month, and 3 months postimplant. Results: The Quartet LV lead was implanted successfully in 170 patients (95.5% implant success rate, 68 ± 11 years, 68.5% male, LVEF: 25 ± 7%, NYHA class III: 98.3% and class IV: 1.7%). Mean follow‐up was 4.7 ± 1.9 months. Capture threshold and impedance for each of the 10 LV lead pacing vectors remained stable during follow‐up. LV lead dislodgement occurred in 6 (3.5%) patients and PNS was observed in 23 (13.5%) patients. PNS was resolved noninvasively in all 23 (100%) patients, either by reprogramming to pace from the additional LV lead pacing vectors alone (13 pts, 56.5%), reprogramming to pace from the additional LV lead pacing vectors and reprogramming pacing output (4 pts, 17.4%), or by reprogramming pacing output alone (6 pts, 26.1%). Conclusions: The Quartet LV lead electrical performance was stable and was associated with a high implant success and low dislodgement rate during 3‐month follow‐up. In all patients with PNS, the 10 pacing vectors combined with reduced output programming enabled the elimination of PNS noninvasively. (J Cardiovasc Electrophysiol, Vol. 24, pp. 449‐456, April 2013)     

心脏再同步治疗中膈神经刺激的单中心回顾分析

目的 探讨心脏再同步治疗(CRT)植入术中、术后膈神经刺激发生情况及处理方法.方法 心力衰竭患者79例,其中男性45例,女性34例,年龄35～86岁,接受CRT/CRT-D植入术.术后平均随访24个月,观察膈神经刺激发生情况,同时给予相应的处理措施.结果 78例患者成功植入,成功率为98.7%.植入术中、术后膈神经刺激发生率为12.8%.后静脉、侧后静脉是其好发部位,身材偏矮小及心脏增大的患者CRT植入中出现膈神经刺激危险性增高.调整电极导线位置、输出电压和脉宽以及改变极性等方法,可以有效消除膈神经刺激.结论 膈神经刺激是CRT/CRT-D植入术中、术后的常见并发症;严格做好术中预防、术后随访,及时采取有效的干预手段,以减少或避免膈神经刺激的发生.     

Predicting hyperresponse among pacemaker-dependent nonischemic cardiomyopathy patients upgraded to cardiac resynchronization

Resynchronizing Pacemaker‐Dependent Patients. Introduction: Right ventricular (RV) pacing engenders left ventricular (LV) dyssynchrony and may diminish LV systolic function, promote adverse cardiac remodeling, and foster heart failure (HF). This process may be reversible in some pacemaker‐dependent patients upgraded to cardiac resynchronization therapy (CRT). We examined the clinical characteristics of pacemaker‐dependent patients who exhibit hyperresponse (i.e., normalization of LV function) with CRT upgrade. Methods and Results : We identified 51 chronically RV‐paced patients with no coronary artery disease, LV ejection fraction (EF) ≤ 35%, and severe HF symptoms who were upgraded to CRT‐defibrillators (CRT‐D). Echocardiograms were performed before and ≥6 months after CRT. Patients with follow‐up LVEF ≥ 50% were deemed hyperresponders. Clinical outcomes of death, cardiac transplant, mechanical circulatory support, and HF hospitalizations were assessed. Fifteen patients were CRT hyperresponders; all demonstrated ≥15% relative LV end‐systolic volume decrease. Hyperresponders had smaller baseline LV dimensions and shorter known cardiomyopathy duration than nonhyperresponders (P < 0.01). The best predictors of hyperresponse using receiver operating characteristic analysis were LV end‐systolic dimension <48 mm (area under the curve [AUC] 0.92, P < 0.001), LV end‐diastolic dimension <58 mm (AUC 0.86, P < 0.001), and cardiomyopathy duration <24 months (AUC 0.82, P < 0.001). No hyperresponders died, received a cardiac transplant, or required mechanical circulatory support during 42 ± 22 months follow‐up, whereas 5 nonhyperresponders died, 2 underwent transplant, and 1 required an assist device (log rank P = 0.049). Conclusion : Among chronically RV paced patients who are upgraded to CRT‐D, smaller baseline LV dimensions and shorter known cardiomyopathy duration predict hyperresponse. Hyperresponders have excellent long‐term survival. (J Cardiovasc Electrophysiol, Vol. 22, pp. 905‐911, August 2011)     

Eligibility of cardiac resynchronization therapy patients for subcutaneous implantable cardioverter defibrillators

The eligibility for subcutaneous implantable cardioverter-defibrillators (S-ICD) was assessed among patients already implanted with cardiac resynchronization therapy (CRT). We included 20 patients (15 men, age 73 ± 10 years, LVEF 35 ± 10%). Seventeen (85%) patients were eligible for S-ICDs: 11 (55%) patients on only 1 vector and 6 (30%) patients on 2 or 3 vectors. Patients who were eligible on 2–3 vectors had narrower paced QRS than patients who were not eligible or were eligible on only one vector (133 ± 18 ms vs 167 ± 17 ms, p = 0.007). If necessary, S-ICD implantation could be considered in most patients with CRT.     

Right ventricular versus biventricular antitachycardia pacing in the termination of ventricular tachyarrhythmia in patients receiving cardiac resynchronization therapy: the ADVANCE CRT-D trial

BACKGROUND: The purpose of this investigation is to compare the efficacy of antitachycardia pacing (ATP) delivered via the right ventricular (RV) lead versus ATP delivered simultaneously via the right and left ventricular leads (biventricular [BiV]) in the termination of ventricular tachyarrhythmia (VT) in patients receiving cardiac resynchronization therapy (CRT) with ICD capabilities. METHODS AND RESULTS: The ADVANCE CRT is a prospective, multicenter, randomized, parallel trial evaluating RV versus BiV ATP in the termination of VT in CRT patients. The study will test the hypothesis that BiV ATP is superior to RV ATP in the termination of VT and fast VT. All patients with class I and IIa indications for an ICD implantation and CRT are included. The sample size has been estimated to 400 participants followed for 12 months to show a 10% benefit of BiV versus RV ATP. The efficacy of BiV ATP to terminate all VT presents the primary endpoint. The investigation is expected to be completed in 2007. CONCLUSIONS: The ADVANCE CRT trial is the first large randomized clinical investigation evaluating the efficacy of BiV ATP in patients under CRT and ICD therapy.     

Outcome Studies with Device Therapy in Patients with Heart Failure

Device Therapy for Heart Failure. Heart failure is a common debilitating condition for which pharmacologic therapy thus far has provided only partial relief. Despite, and sometimes because of, medical therapy, the overall prognosis remains poor, with high rates of sudden death and death from progressive heart failure. Device‐based therapies offer considerable promise for relief of symptoms and for improving prognosis. It is clear that implantable defibrillators should be considered for patients with heart failure who have been resuscitated from ventricular fibrillation or sustained ventricular tachycardia. Several large studies currently are investigating the effects of implantable defibrillators on total mortality in patients with major left ventricular systolic dysfunction but without other risk factors for sudden death. Cardiac resynchronization is a promising new therapy that may relieve the symptoms of heart failure in appropriately selected patients resistant to optimal pharmacologic therapy. Two large trials (CARE‐HF and COMPANION) currently are investigating the effects of cardiac resynchronization therapy (CRT) on morbidity and mortality. It is important that those involved in these trials enroll patients quickly and minimize device implantation into patients who have not been assigned this therapy (cross‐overs). Overenthusiasm for the benefits that doctors believe devices might bring could destroy the future basis for our clinical practice, denying future generations of patients and the doctors themselves access to what they believe to be effective treatments.     

Depression and severe heart failure: benefits of cardiac resynchronization therapy

Depression and Cardiac Resynchronization Therapy . Background: The relationship between depression and heart failure is neither coincidental nor trivial, since depression is a powerful predictor of re‐hospitalization and mortality. We prospectively studied the prevalence and impact of depression on the clinical outcomes of patients attending for cardiac resynchronization therapy (CRT). We specifically examined whether patients with depression have a different rate of response to CRT and whether CRT has an effect on depressive symptoms. Methods: Sixty‐eight recipients of CRT systems were included. The depressive status was evaluated before implant and after 6 months by a structured diagnostic interview measuring Diagnostic and Statistical Manual of Mental Disorders (DSM‐IV) criteria of major depression and by a self‐report questionnaire (Center for Epidemiological Studies Depression Scale, CES‐D). The CRT response was assessed at 6 months by a clinical composite score. Results: At inclusion, DSM‐IV criteria of major depression were identified in 41% of the population, while using the self‐report questionnaire 65% were observed to have mild to major depressive symptoms (CES‐D ≥ 16). Only 4 patients were taking antidepressants. At 6 months, 75% were considered responders to CRT. Response to CRT did not differ between those with and without depression at baseline. The rate of patients with depression at 6 months was significantly lower in responders to CRT compared with nonresponders. Conclusions: We found a high prevalence of depressive symptoms in patients receiving CRT systems. Patients with depression should not be excluded from CRT, because they demonstrate a similar rate of response than the persons without depression and the responders are less likely to be depressed at 6 months. (J Cardiovasc Electrophysiol, Vol. 23, pp. 631–636, June 2012)     

Predictors of appropriate defibrillator therapy among patients with an implantable defibrillator that delivers cardiac resynchronization therapy

INTRODUCTION: The purpose of this study was to determine predictors of appropriate implantable defibrillator (ICD) therapy among patients with heart failure who are treated with a cardiac resynchronization therapy-defibrillator (CRT-D). METHODS AND RESULTS: Patients enrolled in the Ventak CHF/Contak CD study were treated with a CRT-D device and were required to have NYHA class II-IV CHF, QRS duration > or = 120 msec, and a class I or II indication for an ICD. The study database was retrospectively analyzed during the 6-month postimplant period to identify predictors of appropriate ICD therapy. Five hundred and one of the 581 patients enrolled in the trial had successful device implantation and were included in this analysis. Patients were mostly male (83%), 66 +/- 11 years old, and had coronary artery disease (69%), a mean left ventricular ejection fraction (EF) = 0.22 +/- 0.07, and NYHA class II (33%), III (58%), or IV (9%) CHF symptoms. During 6 months of follow-up, 73 of 501 (14%) patients received an appropriate ICD therapy. Two independent predictors of appropriate therapy were identified: a history of a spontaneous, sustained ventricular arrhythmia (HR = 2.05; 95% CI = 1.31-3.20; P = 0.002) and NYHA class IV CHF (HR = 1.81; 95% CI = 1.10-2.96; P = 0.019). When patients with NYHA class II were excluded from analysis, a history of a sustained ventricular arrhythmia and the presence of NYHA class IV CHF symptoms remained as independent predictors of appropriate ICD therapy. CONCLUSIONS: In a select population of advanced heart failure patients receiving a CRT-D, NYHA class IV CHF was a powerful independent predictor of appropriate ICD therapy. Approximately one-quarter of the patients with NYHA class IV CHF who received a CRT-D device received an appropriate ICD therapy within 3 months after implant. Additional studies are needed to confirm an association between class IV CHF symptoms and an increased frequency of ICD shocks.     

Improved outcome with preventive cardiac resynchronization therapy in the elderly: a MADIT-CRT substudy

Preventive Cardiac Resynchronization in the Elderly. Background: Elderly patients comprise a large portion of patients with heart failure (HF). Limited data exist on the effectiveness of cardiac resynchronization therapy with defibrillator (CRT‐D) in patients with mild HF symptoms in this population. Methods and Results: The benefit of CRT‐D compared with ICD‐only therapy in reducing HF or death was assessed by age categories (prespecified as <60 [n = 548], 60–74 [n = 941], and ≥75 [n = 331] years) among 1,820 patients in MADIT‐CRT. In patients with ICD‐only, there was a graded age‐related increase in the Kaplan–Meier cumulative probability of HF or death at 3‐year follow‐up (19%, 33%, and 36%, in patients aged <60, 60–74, and ≥75 years, respectively, P = 0.003). Multivariate analysis demonstrated that CRT‐D therapy was associated with a significant reduction in the risks of HF or death in patients aged 60–74, and ≥75 years (HR = 0.57, P = <0.001 and HR = 0.59, P = 0.017, respectively), and no significant benefit in patients aged <60 years (HR = 0.81, P = 0.3; P‐value for all treatment‐by‐age interactions >0.10). There was no significant difference in the rate of device‐related adverse events within 90 days following CRT‐D implantation among age‐subgroups (16.7%, 15.7%, and 11.7%, in patients <60, 60–74, and ≥75 years, respectively, P = 0.42) . Conclusion: CRT‐D was associated with a significant clinical benefit in older patients (≥60 years) during an average 2.4‐year follow‐up. These effects were preserved for the elderly patients ≥75 years of age but attenuated in patients <60 years. Elderly patients had no increase in device‐related adverse events compared with younger patients . (J Cardiovasc Electrophysiol, Vol. 22, pp. 892‐897, August 2011)     

心脏同步化治疗慢性心力衰竭疗效及临床经验总结

目的总结心脏同步化起搏治疗慢性心力衰竭的疗效及临床经验。方法回顾性分析接受再同步化治疗的26例慢性心力衰竭伴心室内传导延迟患者的临床资料,着重分析再同步化治疗的方法和疗效。结果患者均接受心脏再同步化治疗,年龄（57.0±11.6）岁,男22例（84.6%,22/26）,其中再同步化转复除颤器16例（62%,16/26）,非缺血性心肌病22例（85%,22/26）,9例（35%,9/26）有慢性房性心律失常,2例需外科植入左心室心外膜电极。心脏再同步化治疗后QRS波时限由（161±29）ms缩短为（137±15）ms,差异有统计学意义（P≤0.01）;患者心功能均有明显改善,心功能分级比治疗前降低,差异有统计学意义[（1.9±0.9）级vs.（3.2±0.6）级,P≤0.01];射血分数比治疗前提高,差异有统计学意义（34.0%±13.3%vs.24.9%±6.8%,P≤0.01）。6分钟步行距离、血清脑钠肽浓度以及左心室舒张或收缩末内径均有显著改善（P≤0.05）。术后随访（2.5±1.7）年,7例（27%,7/26）死亡,其中2例心源性猝死。结论心脏同步化起搏治疗显著改善慢性心力衰竭患者心功能,逆转心肌重构,减低病死率。     

Optimization of cardiac resynchronization therapy: importance of programmed parameters

One of the basic tenets of cardiac resynchronization therapy (CRT) is that optimization of programmed parameters is important to maximize the therapeutic response. Both atrioventricular (AV) and interventricular (VV) timing intervals have been suggested as potential methods to improve response rates. A variety of techniques have been described to determine the optimal AV and VV delays. Many of these methods have demonstrated acute hemodynamic benefits; however, multicenter data proving long-term clinical benefit have been lacking. Echocardiography-guided methods have been most commonly employed, but no technique has been shown to be superior. In fact, many of these techniques have poor reproducibility and are time-consuming. Device-based algorithms allow for a rapid, simplified approach to CRT optimization; however, their clinical value has also been called into question. This review will describe the different techniques for CRT optimization and evaluate their potential value and limitations.     

左室四极起搏导线在心脏再同步治疗中的应用

目的初步评估左心室四极导线的安全性和有效性。方法入选符合心脏再同步治疗（CRT）适应证的患者,植入应用左心室四极导线的心脏再同步除颤器（CRT—D）。评估其安全性和急性期疗效。结果2例患者均通过静脉途径成功植入CRT—D装置,仅1例在头端（第1极）起搏测试时有膈神经刺激,未出现其他手术并发症。程控发现,优化的起搏向量下,2例患者的QRS时限和心脏同步性均最佳,左室射血分数改善。结论初步的应用结果表明,左心室四极导线在减少相关并发症的同时,提高CRT急性期疗效。     

心脏再同步治疗中膈神经刺激的单中心回顾分析

Objective To analyze the phrenic nerve stimulation and the appropriate treatment during and after CRT/CRT-D implantation. Methods Seventy-nine patients (45 men and 34 women, aged 35 ～ 86 years) received CRT/CRT-D implantation. The patients were followed up for average 24 months. The phrenic nerve stimulations was analyzed and the corresponding treatments were taken. Results Seventy-eight patients received successful implantation(98. 7% ). The incidence rates of the phrenic nerve stimulation is 12. 8% during and after the implantation. Posterior veins and posterior lateral veins are predilection sites. The risk increased in the patients with short stature and enlarged heart. Phrenic nerve stumilation can be eliminated by adjusting the electrode position, output voltage pulse, width and changing the polarity. Nobody needs another operation because of the phrenic nerve stimulation. Conclusions Phrenic nerve stimulation is a common complication of CRT/CRT-D implantation operation. Doctors should take great attention to prevent this complication during the implanting procedure and follow-up.     

心脏再同步治疗中膈神经刺激的单中心回顾分析

Objective To analyze the phrenic nerve stimulation and the appropriate treatment during and after CRT/CRT-D implantation. Methods Seventy-nine patients (45 men and 34 women, aged 35 ～ 86 years) received CRT/CRT-D implantation. The patients were followed up for average 24 months. The phrenic nerve stimulations was analyzed and the corresponding treatments were taken. Results Seventy-eight patients received successful implantation(98. 7% ). The incidence rates of the phrenic nerve stimulation is 12. 8% during and after the implantation. Posterior veins and posterior lateral veins are predilection sites. The risk increased in the patients with short stature and enlarged heart. Phrenic nerve stumilation can be eliminated by adjusting the electrode position, output voltage pulse, width and changing the polarity. Nobody needs another operation because of the phrenic nerve stimulation. Conclusions Phrenic nerve stimulation is a common complication of CRT/CRT-D implantation operation. Doctors should take great attention to prevent this complication during the implanting procedure and follow-up.