Controversies in Implantable Cardioverter-defibrillator Therapy

2011 ◽  
Vol 7 (3) ◽  
pp. 199
Author(s):  
Alessandro Marinelli ◽  
Mario Luzi ◽  
Alessandro Capucci ◽  
◽  
◽  
...  

Implantable cardioverter-defibrillator (ICD) therapy is a mainstay in sudden cardiac death (SCD) prevention. Its efficacy has been proven in several conditions such as heart failure and reduced left ventricular ejection fraction (LVEF) and in familial SCD syndromes. In contrast to the fairly clear role of ICD therapy for secondary prevention, its role and indications for primary prevention of SCD has been more difficult to define. Many questions remain unresolved in this setting, such as the choice of the optimal time for implantation after a myocardial infarction and the degree of LVEF reduction that is able to predict future events and to justify the risks of ICD implant. The choice of ICD therapy may also be challenging in patients with different demographic features and comorbidities from that enrolled in clinical trials. Finally, the relative rarity of familial SCD syndromes seriously limits the data upon which recommendations are based and therefore many questions concerning the risk-benefit of ICD implantation remain unresolved.

2002 ◽  
Vol 103 (s2002) ◽  
pp. 233S-236S ◽  
Author(s):  
Andrea SZÜCS ◽  
Katalin KELTAI ◽  
Endre ZIMA ◽  
Hajnalka VÁGÓ ◽  
Pál SOÓS ◽  
...  

The incidence of ventricular tachyarrhythmias in the early post-operative period following implantable cardioverter-defibrillator (ICD) implantation is relatively high compared with that in control periods. Since endothelin-1 (ET-1) has been proven to be an endogenous arrhythmogenic substance, we investigated the changes in serum ET-1 and big-ET levels in patients undergoing ICD implantation. Serum concentrations of ET-1 and big-ET were measured in 14 patients with various heart diseases before the operation, as well as 1min and 1h after the last shock therapy. Big-ET levels and the sum of ET-1 and big-ET levels were unchanged immediately after the operation, but had increased significantly by 1h after implantation (before, 1.57±0.61pmol/l; 1min, 1.86±0.87pmol/l; 1h, 4.29±1.65pmol/l for big-ET; before, 3.44±1.07pmol/l; 1min, 3.79±1.29pmol/l; 1h, 6.36±2.03pmol/l for big-ET+ET-1). There was a significant correlation between left ventricular ejection fraction and big-ET level measured 1h after the last shock delivery (r =-0.542, P<0.05). We conclude that the increased big-ET level observed 1h after the last induction and shock therapy of ventricular fibrillation might have a pathophysiological role in the increased incidence of post-operative spontaneous ventricular arrhythmias.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Benjamin H Buck ◽  
Eric Kellett ◽  
Rana Elgazzar ◽  
Chad Ward ◽  
Omar Kahaly ◽  
...  

Background: Implantable cardioverter-defibrillator (ICD) therapy prevents sudden cardiac death in selected patients with heart failure. When a primary prevention ICD arrives at elective replacement interval (ERI), conventional management is to replace the device. However, the effectiveness of ICDs in patients with nonischemic and ischemic cardiomyopathy (NICM and ICM, respectively) whose left ventricular ejection fraction (LVEF) improved to ≥50% before replacement is unclear. Hypothesis: The therapeutic benefit of primary prevention ICD for NICM is attenuated by the recovery of LVEF at the time of ERI. Methods: Consecutive patients presenting for first time primary prevention ICD battery change-out at a single quaternary care center between 1/1/2008 and 6/27/2019 were included. The primary endpoint was the rate of ICD therapy (ICD discharge and anti-tachycardia pacing) according to LVEF recovery at ERI. Results: During the study period 6851 ICDs were placed, of which 310 underwent battery change-out, of whom 100 did not receive therapy from the first ICD, of whom 44 had NICM. The demographics of the NICM cohort are in the table. Following ERI, 0 (0%) with NICM and recovered LVEF had received ICD therapy, whereas 13 (30%) with persistently low LVEF had received therapy (p = 0.07). Furthermore, among patients without recovered LVEF, the NICM group had a lower rate of therapy (4, 12%) than the ICM group (12, 32%) (p=0.04). Conclusion: Rates of ICD therapy provided by primary prevention ICD after first battery change out trended towards a significantly lower rate in NICM patients with LVEF that recovered to ≥50% than those without LVEF recovery. No other patient demographic significantly predicted therapy-free survival but the analysis was limited by sample size. A prospective study with a larger cohort would be necessary to better estimate therapy-free survival.


2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Bandar Al-Ghamdi

Patients with complex congenital heart disease (CHD) and low left ventricular ejection fraction are at an increased risk of sudden cardiac death (SCD). Prevention of SCD by subcutaneous implantable cardioverter defibrillator (S-ICD) implantation may represent a valuable option in certain CHD patients. Patients with CHD and dextrocardia pose a challenge in S-ICD system implantation, and nonstandard device placement may be required. Furthermore, electrocardiogram (ECG) screening prior to S-ICD implantation in CHD patients has significant limitations. This case represents the placement of a S-ICD system on the right side of the chest in a 26-year-old male with severe biventricular failure and nonsustained ventricular tachycardia following multiple corrective surgeries of situs inversus totalis, double-outlet right ventricle with a ventricular septal defect, and pulmonary atresia. The use of S-ICDs in a CHD population and in particular CHD patients with dextrocardia and right-sided S-ICD implantation is briefly discussed.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J Freeman ◽  
J Bjerre ◽  
C Parzynski ◽  
K Minges ◽  
T Ahmad ◽  
...  

Abstract Background/Introduction Uncertainty remains regarding the benefit of primary prevention ICDs overall in contemporary practice, and particularly in those with NICM compared with ICM. Purpose To evaluate the contemporary risk of death and readmission following following implantable cardioverter-defibrillator (ICD) implantation in patients with non-ischemic cardiomyopathies (NICM) compared with ischemic cardiomyopathies (ICM) in a large nationally representative cohort in the United States. Methods We used data from the American College of Cardiology (ACC) National Cardiovascular Data Registry (NCDR) ICD Registry linked with Medicare claims from April 1, 2010 to December 31, 2013 to establish a cohort of NICM and ICM patients with a left ventricular ejection fraction ≤35% who received a de novo, primary prevention ICD. We compared mortality, all-cause readmission, and heart failure readmission using Kaplan-Meier curves and Cox proportional hazard regressions models. We also evaluated temporal trends in mortality. Results Among 31,044 NICM and 68,458 ICM patients with a median follow up of 2.4 years, one-year mortality was significantly higher in ICM patients (12.3%) compared with NICM (7.9%, p&lt;0.001). The higher mortality in ICM patients remained significant after adjustment for covariates (hazard ratio (HR) 1.40; 95% confidence interval (CI) 1.36 to 1.45), and was consistent in subgroup analyses. These findings were consistent across the duration of the study. ICM patients were also significantly more likely to be readmitted for all causes (adjusted HR 1.15, CI 1.12 to 1.18) and for heart failure (adjusted HR 1.25, CI 1.21 to 1.31). Conclusions The risks of mortality and hospital readmission after primary prevention ICD implantation were significantly higher in patients with ICM compared with NICM, and these findings were consistent across all patient subgroups tested and over the duration of the study. Funding Acknowledgement Type of funding source: None


2021 ◽  
Vol 22 (13) ◽  
pp. 7115
Author(s):  
Laura Keil ◽  
Céleste Chevalier ◽  
Paulus Kirchhof ◽  
Stefan Blankenberg ◽  
Gunnar Lund ◽  
...  

Non-ischemic cardiomyopathy (NICM) is one of the most important entities for arrhythmias and sudden cardiac death (SCD). Previous studies suggest a lower benefit of implantable cardioverter–defibrillator (ICD) therapy in patients with NICM as compared to ischemic cardiomyopathy (ICM). Nevertheless, current guidelines do not differentiate between the two subgroups in recommending ICD implantation. Hence, risk stratification is required to determine the subgroup of patients with NICM who will likely benefit from ICD therapy. Various predictors have been proposed, among others genetic mutations, left-ventricular ejection fraction (LVEF), left-ventricular end-diastolic volume (LVEDD), and T-wave alternans (TWA). In addition to these parameters, cardiovascular magnetic resonance imaging (CMR) has the potential to further improve risk stratification. CMR allows the comprehensive analysis of cardiac function and myocardial tissue composition. A range of CMR parameters have been associated with SCD. Applicable examples include late gadolinium enhancement (LGE), T1 relaxation times, and myocardial strain. This review evaluates the epidemiological aspects of SCD in NICM, the role of CMR for risk stratification, and resulting indications for ICD implantation.


2010 ◽  
Vol 138 (3-4) ◽  
pp. 236-239
Author(s):  
Ruzica Jurcevic ◽  
Lazar Angelkov ◽  
Dejan Vukajlovic ◽  
Velibor Ristic ◽  
Milosav Tomovic ◽  
...  

Introduction. We described the first case of oversensing due to electric shock in Serbia, in a 54-year-old man who had implantable cardioverter-defibrillator (ICD). Case Outline. In July 2002, the patient had acute anteroseptal myocardial infarction and ventricular fibrillation (VF) which was terminated with six defibrillation shocks of 360 J. Coronary angiography revealed 30% stenosis of circumflex artery, the left anterior descending coronary artery was recanalized and the right coronary artery was without stenosis. Left ventricular ejection fraction was 20%. In December 2003, an electrophysiology study was performed and ventricular tachycardia (VT) was induced and terminated with 200 J defibrillation shock. Single chamber ICD Medtronic Gem III VR was implanted in January 2004 and defibrillation threshold was 12 J. The patient was followed up during three years every three months and there were no VT/VF episodes and VT/VF therapies. In December 2007, the patient experienced electric shock through the fork while he was making barbecue on the electric grill. ICD recognized this event in VF zone (oversensing) and delivered defibrillation shock of 18 J. The electrogram of the episode showed ventricular sensing - intrinsic sinus rhythm with electric shock potentials which were misidentified as VF. After charge time of 3.16 seconds, ICD delivered defibrillation shock and sinus rhythm was still present. Conclusion. Oversensing of ICD has different aetiology and the most common cause is supraventricular tachyarrhythmia.


2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Andrea Demarchi ◽  
Stefano Cornara ◽  
Antonio Sanzo ◽  
Simone Savastano ◽  
Barbara Petracci ◽  
...  

Background When implantable cardioverter defibrillator (ICD) battery is depleted most patients undergo generator replacement (GR) even in the absence of persistent ICD indication. The aim of this study was to assess the incidence of ventricular arrhythmias and the overall prognosis of patients with and without persistent ICD indication undergoing GR. Predictors of 1‐year mortality were also analyzed. Methods and Results Patients with structural heart disease implanted with primary prevention ICD undergoing GR were included. Patients were stratified based on the presence/absence of persistent ICD indication (left ventricular ejection fraction ≤35% at the time of GR and/or history of appropriate ICD therapies during the first generator's life). The study included 371 patients (82% male, 40% with ischemic heart disease). One third of patients (n=121) no longer met ICD indication at the time of GR. During a median follow‐up of 34 months after GR patients without persistent ICD indication showed a significantly lower incidence of appropriate ICD shocks (1.9% versus 16.2%, P <0.001) and ICD therapies. 1‐year mortality was also significantly lower in patients without persistent ICD indication (1% versus 8.3%, P =0.009). At multivariable analysis permanent atrial fibrillation, chronic advanced renal impairment, age >80, and persistent ICD indication were found to be significant predictors of 1‐year mortality. Conclusions Patients without persistent ICD indication at the time of GR show a low incidence of appropriate ICD therapies after GR. Persistent ICD indication, atrial fibrillation, advanced chronic renal disease, and age >80 are significant predictors of 1‐year mortality. Our findings enlighten the need of performing a comprehensive clinical reevaluation of ICD patients at the time of GR.


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