An implantable loop recorder or smartphone based single-lead electrocardiogram to detect arrhythmia in adults with congenital heart disease?

BackgroundThe European Society of Cardiology (ESC) guidelines for the management of adult congenital heart disease (ACHD) recommend screening in patients at risk for arrhythmic events. However, the optimal mode of detection is unknown.MethodsBaseline and follow-up data of symptomatic ACHD patients who received an implantable loop recorder (ILR) or who participated in a smartphone based single-lead electrocardiogram study were collected. The primary endpoint was time to first detected arrhythmia.ResultsIn total 116 ACHD patients (mean age 42 years, 44% male) were studied. The ILR group (n = 23) differed from the smartphone based single-lead electrocardiogram group (n = 93) in having a greater part of males and had more severe CHD and (near) syncope as qualifying diagnosis. In the smartphone based single-lead electrocardiogram group history of arrhythmia and palpitations were more frequent (all p < 0.05). Monitoring was performed for 40 and 79 patient-years for the ILR- and smartphone based single-lead electrocardiogram group, respectively. Arrhythmias occurred in 33 patients with an equal median time for both groups to first arrhythmia of 3 months (HR of 0.7, p = 0.81). Furthermore, atrial fibrillation occurred most often (n = 16) and common therapy changes included medication changes (n = 7) and implantation of pacemaker or Implantable Cardioverter Defibrillator (ICD) (N = 4). Symptoms or mode of detection were not a determinant of the first event.ConclusionNon-invasive smartphone based single-lead electrocardiogram monitoring could be an acceptable alternative for ILR implantation in detecting arrhythmia in symptomatic ACHD patients in respect to diagnostic yield, safety and management decisions, especially in those without syncope

Subcutaneous or Transvenous Defibrillator Therapy.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (ICD) was designed to avoid complications related to the transvenous ICD lead by using an entirely extrathoracic placement. Evidence comparing these systems has been based primarily on observational studies. METHODS: We conducted a noninferiority trial in which patients with an indication for an ICD but no indication for pacing were assigned to receive a subcutaneous ICD or transvenous ICD. The primary end point was the composite of device-related complications and inappropriate shocks; the noninferiority margin for the upper boundary of the 95% confidence interval for the hazard ratio (subcutaneous ICD vs. transvenous ICD) was 1.45. A superiority analysis was prespecified if noninferiority was established. Secondary end points included death and appropriate shocks. RESULTS: A total of 849 patients (426 in the subcutaneous ICD group and 423 in the transvenous ICD group) were included in the analyses. At a median follow-up of 49.1 months, a primary end-point event occurred in 68 patients in the subcutaneous ICD group and in 68 patients in the transvenous ICD group (48-month Kaplan-Meier estimated cumulative incidence, 15.1% and 15.7%, respectively; hazard ratio, 0.99; 95% confidence interval [CI], 0.71 to 1.39; P = 0.01 for noninferiority; P = 0.95 for superiority). Device-related complications occurred in 31 patients in the subcutaneous ICD group and in 44 in the transvenous ICD group (hazard ratio, 0.69; 95% CI, 0.44 to 1.09); inappropriate shocks occurred in 41 and 29 patients, respectively (hazard ratio, 1.43; 95% CI, 0.89 to 2.30). Death occurred in 83 patients in the subcutaneous ICD group and in 68 in the transvenous ICD group (hazard ratio, 1.23; 95% CI, 0.89 to 1.70); appropriate shocks occurred in 83 and 57 patients, respectively (hazard ratio, 1.52; 95% CI, 1.08 to 2.12). CONCLUSIONS: In patients with an indication for an ICD but no indication for pacing, the subcutaneous ICD was noninferior to the transvenous ICD with respect to device-related complications and inappropriate shocks. (Funded by Boston Scientific; PRAETORIAN ClinicalTrials.gov number, NCT01296022.)

The use of a wearable cardioverter defibrillator during postmastectomy radiotherapy as an alternative for relocation of the pulse generator

Purpose: We describe a case in which a breast cancer patient with an implantable cardioverter-defibrillator (ICD) was treated with postmastectomy followed by axillary radiation therapy. The ICD was partly within the target volume and according to the treatment planning system would receive a maximum dose of about 36 Gy. Methods and Materials: Postoperatively, the patient had a wound infection needing surgical intervention and 3 months of antibiotics. Therefore, it was decided not to relocate the ICD but instead to switch off the shock function of the ICD for the entire radiation therapy course. Results: The ICD was successfully substituted with a wearable cardioverter defibrillator (WCD), which the patient wore during the 3-week radiation therapy period until 2 weeks after the end of treatment. The ICD function was monitored from the start of the treatment until 6 months after treatment. Conclusions: In situations in which an ICD needs to be switched off semipermanently, a WCD can be used as alternative. The patient in this report tolerated the WCD well. Despite the high dose received by the ICD, the device and its battery continued to function normally

Inappropriate subcutaneous implantable cardioverter-defibrillator shocks due to T-wave oversensing can be prevented: implications for management

Inappropriate shocks (IASs) complicate implantable cardioverter-defibrillator (ICD) therapy. The management of IASs in patients with a subcutaneous ICD (S-ICD) differs from that in patients with a conventional ICD because of different sensing algorithms and programming options. To describe the management of IASs in patients with an S-ICD. Patients were implanted with an S-ICD between February 2009 and July 2012. The prevalence data and clinical determinants of IASs were prospectively collected. In the case of T-wave oversensing (TWOS), an exercise test was performed, and all possible sensing vectors were screened for TWOS. The absence of TWOS defined a suitable vector. Eleven of 69 patients (54% men; mean age 39 ± 14 years; 73% primary prevention) received IASs after 8.9 ± 10 months of implantation (10.8% annual incidence rate). In 8 cases, TWOS caused IASs. Seven of these IASs occurred during exercise and 1 during atrial fibrillation with a high ventricular rate. To manage TWOS, in 7 of 8 patients the sensing vector was changed and in 5 of 8 patients the (un)conditional zone was changed. Hereafter, IASs recurred in 3 of 8 patients, in 2 because of programming errors. Hence, after reprogramming, we observed no IASs in 87.5% of the patients with TWOS during a follow-up of 14.1 ± 13 months. IASs due to TWOS in the S-ICD can be managed by reprogramming the sensing vector and/or the therapy zones of the device using a template acquired during exercise. Exercise-optimized programming can reduce future IASs, and standard exercise testing shortly after the implantation of an S-ICD may be considered in patients at an increased risk for TWO

Predictors and permanency of cardiac conduction disorders and necessity of pacing after transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) with the Medtronic-CoreValve bioprosthesis (CoreValve Inc., Irvine, CA, USA) is associated with a high incidence of new-onset left bundle branch block (LBBB) and cardiac conduction disorders (CCDs) requiring permanent pacemaker (PPM) implantation. Our objective was to investigate the predictors and permanency of CCDs after TAVI and specifically to evaluate the necessity for pacing. In this single-center study, we included patients who underwent TAVI with the Medtronic-CoreValve bioprosthesis. Electrocardiographic evaluation was performed pre- and post-TAVI and at follow-up. Pacemaker follow-up data were obtained and analyzed. We included 121 patients (age 81 ± 8 years). LBBB developed in 47 patients, for which prosthesis size (26 mm; odds ratio [OR]: 4.1, 95% confidence interval [CI]: 1.32-12.34, P = 0.01) and prosthesis depth (OR: 1.3, 95% CI: 1.09-1.57, P = 0.004) were independent predictors. In 19%, this new-onset LBBB was temporary. Requirement for a PPM occurred in 23 patients, for which mitral annular calcification (MAC; OR: 1.3, 95% CI: 1.05-1.56, P = 0.02) and preexisting right bundle branch block (RBBB; OR: 8.5, 95%CI: 1.61-44.91, P = 0.01) were independent predictors. At follow-up, 52% of the patients were continuously paced, but 22% of the patients had adequate atrioventricular conduction without the necessity for pacing. In the other 26% of the patients there was intermittent pacing. There is a high incidence of new-onset LBBB and PPM implantation following TAVI with a Medtronic-CoreValve bioprosthesis. Prosthesis depth and size were predictors for new LBBB, while MAC and preexistent RBBB were predictors for PPM implantation. In approximately one fifth of the patients, new-onset LBBB and the necessity for pacing are only temporar

Surgical Management of Implantation-Related Complications of the Subcutaneous Implantable Cardioverter-Defibrillator

OBJECTIVES: This study assessed outcomes in patients in whom subcutaneous implantable cardioverter-defibrillator (S-ICD) therapy was continued after implantation-related complications, in order to avoid conversion to transvenous ICD therapy. BACKGROUND: Patients at risk for sudden cardiac death benefit from ICD therapy, despite a significant risk for complications. S-ICD has a similar complication rate as transvenous ICD therapy, but the absence of transvenous leads may hold long-term benefits, especially in young ICD patients. METHODS: In the largest single-center cohort available to date, S-ICD patients implanted between 2009 and 2015 were included. RESULTS: There were 123 patients at a median age of 40 years. During a median follow-up of 2 years, 10 patients (9.4%) suffered implant-related complications. There were 5 infections, 3 erosions, and 2 implant failures for which 21 surgical procedures were needed. In 9 of 10 patients, S-ICD therapy could be continued after intervention. In 6 patients, the period between extraction and reimplantation of the S-ICD system was bridged with a wearable cardioverter-defibrillator (WCD). The pulse generator was reimplanted at the original site in 5 patients and in 3 underneath the serratus anterior muscle. One patient was not reimplanted following extraction due to recurrent infections. Conversion to a transvenous ICD was not needed in any patient. CONCLUSIONS: In most patients with a complication, S-ICD therapy could be continued after intervention, avoiding the need to convert to a transvenous system. Bridging to recovery with a WCD and submuscular implantation of the pulse generator are effective treatment strategies to manage S-ICD complications

Which patients are not suitable for a subcutaneous ICD: incidence and predictors of failed QRS-T-wave morphology screening

The subcutaneous cardioverter-defibrillator (S-ICD) relies on a pre-implantation QRS-T morphology screening (TMS) of the ECG to assure that it reliably detects the QRS complexes and T waves. The prevalence and clinical characteristics of the patients who fail this TMS is unknown. QRS-TMS was done in 230 consecutive ICD outpatients (75% male, age 57 ± 15 years) without an indication for cardiac pacing, using an ECG simulating the 3 sensing vectors of the S-ICD (TMS-ECG). Patients were defined suitable when at least 1 sensing vector was considered appropriate in both supine and standing position. In total, 7.4% of patients, who were all male, were considered not suitable for a S-ICD according to the TMS-ECG. Independent predictors for TMS failure were hypertrophic cardiomyopathy (HCM; odds ratio [OR] 12.6), a heavy weight (OR 1.5), a prolonged QRS duration (OR 1.5) and a R:T ratio <3 in the lead with the largest T wave on a standard 12-lead surface ECG (OR 14.6). In patients without an indication for pacing, 7.4% would have been not suitable for a S-ICD according to the TMS. HCM, a heavy weight, a prolonged QRS duration and a R:T ratio <3 in the ECG lead with the largest T wave were independently associated with TMS failure. These data might alert physicians that selection of patients for a S-ICD should be considered with special caution in certain patient groups, because they may not satisfy ECG criteria for adequate sensin

An implantable loop recorder or smartphone based single-lead electrocardiogram to detect arrhythmia in adults with congenital heart disease?

Background: The European Society of Cardiology (ESC) guidelines for the management of adult congenital heart disease (ACHD) recommend screening in patients at risk for arrhythmic events. However, the optimal mode of detection is unknown. Methods: Baseline and follow-up data of symptomatic ACHD patients who received an implantable loop recorder (ILR) or who participated in a smartphone based single-lead electrocardiogram study were collected. The primary endpoint was time to first detected arrhythmia. Results: In total 116 ACHD patients (mean age 42 years, 44% male) were studied. The ILR group (n = 23) differed from the smartphone based single-lead electrocardiogram group (n = 93) in having a greater part of males and had more severe CHD and (near) syncope as qualifying diagnosis. In the smartphone based single-lead electrocardiogram group history of arrhythmia and palpitations were more frequent (all p < 0.05). Monitoring was performed for 40 and 79 patient-years for the ILR- and smartphone based single-lead electrocardiogram group, respectively. Arrhythmias occurred in 33 patients with an equal median time for both groups to first arrhythmia of 3 months (HR of 0.7, p = 0.81). Furthermore, atrial fibrillation occurred most often (n = 16) and common therapy changes included medication changes (n = 7) and implantation of pacemaker or Implantable Cardioverter Defibrillator (ICD) (N = 4). Symptoms or mode of detection were not a determinant of the first event. Conclusion: Non-invasive smartphone based single-lead electrocardiogram monitoring could be an acceptable alternative for ILR implantation in detecting arrhythmia in symptomatic ACHD patients in respect to diagnostic yield, safety and management decisions, especially in those without syncope

An implantable loop recorder or smartphone based single-lead electrocardiogram to detect arrhythmia in adults with congenital heart disease?

Background: The European Society of Cardiology (ESC) guidelines for the management of adult congenital heart disease (ACHD) recommend screening in patients at risk for arrhythmic events. However, the optimal mode of detection is unknown. Methods: Baseline and follow-up data of symptomatic ACHD patients who received an implantable loop recorder (ILR) or who participated in a smartphone based single-lead electrocardiogram study were collected. The primary endpoint was time to first detected arrhythmia. Results: In total 116 ACHD patients (mean age 42 years, 44% male) were studied. The ILR group (n = 23) differed from the smartphone based single-lead electrocardiogram group (n = 93) in having a greater part of males and had more severe CHD and (near) syncope as qualifying diagnosis. In the smartphone based single-lead electrocardiogram group history of arrhythmia and palpitations were more frequent (all p < 0.05). Monitoring was performed for 40 and 79 patient-years for the ILR- and smartphone based single-lead electrocardiogram group, respectively. Arrhythmias occurred in 33 patients with an equal median time for both groups to first arrhythmia of 3 months (HR of 0.7, p = 0.81). Furthermore, atrial fibrillation occurred most often (n = 16) and common therapy changes included medication changes (n = 7) and implantation of pacemaker or Implantable Cardioverter Defibrillator (ICD) (N = 4). Symptoms or mode of detection were not a determinant of the first event. Conclusion: Non-invasive smartphone based single-lead electrocardiogram monitoring could be an acceptable alternative for ILR implantation in detecting arrhythmia in symptomatic ACHD patients in respect to diagnostic yield, safety and management decisions, especially in those without syncope