Dual- versus single-coil implantable defibrillator leads: review of the literature

Additional coils mitigate elevated defibrillation threshold in right-sided implantable cardioverter defibrillator generator placement: a simulation study

AIMS

The standard implantable cardioverter defibrillator (ICD) generator (can) is placed in the left pectoral area; however, in certain circumstances, right-sided cans may be required which may increase defibrillation threshold (DFT) due to suboptimal shock vectors. We aim to quantitatively assess whether the potential increase in DFT of right-sided can configurations may be mitigated by alternate positioning of the right ventricular (RV) shocking coil or adding coils in the superior vena cava (SVC) and coronary sinus (CS).

METHODS AND RESULTS

A cohort of CT-derived torso models was used to assess DFT of ICD configurations with right-sided cans and alternate positioning of RV shock coils. Efficacy changes with additional coils in the SVC and CS were evaluated. A right-sided can with an apical RV shock coil significantly increased DFT compared to a left-sided can [19.5 (16.4, 27.1) J vs. 13.3 (11.7, 19.9) J, P < 0.001]. Septal positioning of the RV coil led to a further DFT increase when using a right-sided can [26.7 (18.1, 36.1) J vs. 19.5 (16.4, 27.1) J, P < 0.001], but not a left-sided can [12.1 (8.1, 17.6) J vs. 13.3 (11.7, 19.9) J, P = 0.099). Defibrillation threshold of a right-sided can with apical or septal coil was reduced the most by adding both SVC and CS coils [19.5 (16.4, 27.1) J vs. 6.6 (3.9, 9.9) J, P < 0.001, and 26.7 (18.1, 36.1) J vs. 12.1 (5.7, 13.5) J, P < 0.001].

CONCLUSION

Right-sided, compared to left-sided, can positioning results in a 50% increase in DFT. For right-sided cans, apical shock coil positioning produces a lower DFT than septal positions. Elevated right-sided can DFTs may be mitigated by utilizing additional coils in SVC and CS.

Postcardiac injury syndrome after cardiac implantable electronic device implantation

Background

Postcardiac injury syndrome (PCIS) is an inflammatory complication that derives from injury to the epicardium, myocardium, or endocardium. It occurs after trauma, myocardial infarction, percutaneous coronary intervention, cardiac surgery, intracardiac ablation, and implantation of cardiac implantable electronic device (CIED). In this study we assessed the incidence of PCIS after CIED implantation and its possible risk factors.

Material and methods

All patients who received CIED implantation at Heidelberg University Hospital between 2000 and 2014 were evaluated (n = 4989 patients). Clinical data including age, sex, underlying cardiac disease, type of implanted CIED, location of electrode implantation, clinical symptoms, time of symptom onset of PCIS, therapy, and outcome were extracted and analyzed.

Results

We identified 19 cases of PCIS in 4989 patients, yielding an incidence of 0.38%. The age of patients with PCIS ranged from 39 to 86 years. Dilated cardiomyopathy (DCM) as underlying cardiac disease and right atrial (RA) lead implantation had a significant association with occurrence of PCIS (p = 0.045 in DCM and p < 0.001 in RA lead implantation). Dyspnea, chest pain, dry cough, and fever were the most frequently reported symptoms in patients with PCIS. Pericardial and pleura effusion as well as elevated C‑reactive protein (CRP), increased erythrocyte sedimentation rate (ESR), and leukocytosis were the most common findings.

Conclusion

To the best of our knowledge, this is the largest cohort evaluating the incidence of PCIS after CIED implantation. The data show that PCIS is a rare complication after CIED implantation and occurs more frequently in patients with DCM and those with RA lead implantation. Although rare and mostly benign, PCIS can lead to potentially lethal complications and physicians must be aware of its symptoms.

Electronic supplementary material

The online version of this article (10.1007/s00059-020-04910-6) contains supplementary material, which is available to authorized users.

Effectiveness of single- vs dual-coil implantable defibrillator leads: An observational analysis from the SIMPLE study

INTRODUCTION

Dual-coil leads (DC-leads) were the standard of choice since the first nonthoracotomy implantable cardioverter/defibrillator (ICD). We used contemporary data to determine if DC-leads offer any advantage over single-coil leads (SC-leads), in terms of defibrillation efficacy, safety, clinical outcome, and complication rates.

METHODS AND RESULTS

In the Shockless IMPLant Evaluation study, 2500 patients received a first implanted ICD and were randomized to implantation with or without defibrillation testing. Two thousand and four hundred seventy-five patients received SC-coil or DC-coil leads (SC-leads in 1025/2475 patients; 41.4%). In patients who underwent defibrillation testing (n = 1204), patients with both lead types were equally likely to achieve an adequate defibrillation safety margin (88.8% vs 91.2%; P = 0.16). There was no overall effect of lead type on the primary study endpoint of "failed appropriate shock or arrhythmic death" (adjusted HR 1.18; 95% CI, 0.86-1.62; P = 0.300), and on all-cause mortality (SC-leads: 5.34%/year; DC-leads: 5.48%/year; adjusted HR 1.16; 95% CI, 0.94-1.43; P = 0.168). However, among patients without prior heart failure (HF), and SC-leads had a significantly higher risk of failed appropriate shock or arrhythmic death (adjusted HR 7.02; 95% CI, 2.41-20.5). There were no differences in complication rates.

CONCLUSION

In this nonrandomized evaluation, there was no overall difference in defibrillation efficacy, safety, outcome, and complication rates between SC-leads and DC-leads. However, DC-leads were associated with a reduction in the composite of failed appropriate shock or arrhythmic death in the subgroup of non-HF patients. Considering riskier future lead extraction with DC-leads, SC-leads appears to be preferable in the majority of patients.

Comparison of single-coil lead versus dual-coil lead of implantable cardioverter defibrillator on lead-related venous complications in a canine model

PURPOSE

Dual- coil lead (DCL) of implantable cardioverter defibrillator (ICD) is preferred clinically in patients. However, it is related to higher risk of venous stenosis and thrombosis. The present study was done to compare the fibrosis and extraction of the leads between the single-coil lead (SCL) and DCL in animal models.

METHODS

This was a chronic animal study with a follow-up duration of 6 months. Twenty mongrel dogs were randomly divided into DCL group or SCL group. Venography was performed before the sacrifice to evaluate the venous stenosis in vivo. The maximum pulling-out tension of the ICD lead was measured by a tensometer. Hematoxylin-eosin stain and toluidine blue O stain were applied to show the pathological changes of the superior vena cava (SVC) to evaluate the fibrosis and the thickness of the SVC adjacent to the leads.

RESULTS

The DCL group showed higher incidence of venous stenosis (OR = 31.5; 95% CI, 2.35-422.3; p = 0.005). It revealed increased tension to extract the leads in the DCL group (5.96 ± 1.86 vs. 3.68 ± 1.46 N, p = 0.027). The difference of venous wall thickness of SVC was 4.3 ± 0.3 fold-changes between two groups (p = 0.007). Moreover, the degree of venous wall fibrosis in DCL group was more serious than that it in SCL group (3.61 ± 1.26 vs. 1.08 ± 1.35 mm², p = 0.015).

CONCLUSION

The DCL was proved to increase thrombosis, fibrosis, and stenosis in the SVC. Likewise, the DCL was mechanically harder to be extracted than the SCL. Our study showed that lead-related complications of the DCLs were higher than those of the SCLs regardless of the equal defibrillation thresholds between them. Results of the present study would help to choose the proper lead which could be removed.

Low efficacy of cardioversion of persistent atrial fibrillation with the implantable cardioverter-defibrillator

AIMS

Atrial fibrillation (AF) and heart failure are conditions that often coexist. Consequently, many patients with an implantable cardioverter-defibrillator (ICD) present with AF. We evaluated the effectiveness of internal cardioversion of AF in patients with an ICD.

METHODS

Retrospectively, we included 27 consecutive ICD patients with persistent AF who underwent internal cardioversion using the ICD. When ICD cardioversion failed, external cardioversion was performed.

RESULTS

Patients were predominantly male (89 %) with a mean (SD) age of 65 ± 9 years and left ventricular ejection fraction of 36 ± 17 %. Only nine (33 %) patients had successful internal cardioversion after one, two or three shocks. The remaining 18 patients underwent external cardioversion after they failed internal cardioversion, which resulted in sinus rhythm in all. A smaller left atrial volume (99 ± 36 ml vs. 146 ± 44 ml; p = 0.019), a longer right atrial cycle length (227 (186-255) vs. 169 (152-183) ms, p = 0.030), a shorter total AF history (2 (0-17) months vs. 40 (5-75) months, p = 0.025) and dual-coil ICD shock (75 % vs. 26 %, p = 0.093) were associated with successful ICD cardioversion.

CONCLUSION

Internal cardioversion of AF in ICD patients has a low success rate but may be attempted in those with small atria, a long right atrial fibrillatory cycle length and a short total AF history, especially when a dual-coil ICD is present. Otherwise, it seems reasonable to prefer external over internal cardioversion when it comes to termination of persistent AF.

Clinical impact, safety, and efficacy of single- versus dual-coil ICD leads in MADIT-CRT

BACKGROUND

Current data on efficacy, safety and impact on clinical outcome of single- versus dual-coil implantable cardioverter-defibrillator (ICD) leads are limited and contradictory.

METHODS

Defibrillation threshold (DFT) at implantation and first shock efficacy were compared in patients implanted with single- versus dual-coil ICD leads in MADIT-CRT. The risk for atrial tachyarrhythmias and all-cause mortality were evaluated. Short- (< 30 days after the implantation) and long-term (throughout the entire study duration) complications were assessed.

RESULTS

Patients with dual-coil ICD leads had significantly lower DFTs compared to patients with single-coil ICD leads (17.6 ± 5.8 J vs 19.4 ± 6.1 J, P < 0.001). First shock efficacy was similar among patients with dual and single-coil ICD leads (89.6% vs 92.3%, P = 1.00). When comparing patients with dual versus single-coil ICD leads, there was no difference in the risk of atrial tachyarrhythmias (HR = 1.57, 95% CI: 0.81-3.02, P = 0.18), or in the risk of all-cause mortality (HR = 1.10, 95% CI: 0.58-2.07, P = 0.77). Patients implanted with single- or dual-coil ICD lead had similar short and long-term complication rates (short-term HR = 0.96, 95% CI: 0.56-1.65, P = 0.88, long-term procedure-related HR = 0.99, 95% CI: 0.62-1.59, P = 1.00, long-term ICD lead related: HR = 1.2, 95% CI: 0.5-2.9, P = 0.68) during the mean follow-up of 3.3 years.

CONCLUSIONS

Patients with single-coil ICD leads have slightly higher DFTs compared to those with dual-coil leads, but the efficacy, safety, and clinical impact on atrial tachyarrhythmias, and mortality is similar. Implantation of single-coil ICD leads may be favorable in most patients.