Pacemaker-detected severe sleep apnea predicts new-onset atrial fibrillation

Sleep apnea (SA) diagnosed on overnight polysomnography is a risk factor for atrial fibrillation (AF). Advanced pacemakers are now able to monitor intrathoracic impedance for automatic detection of SA events

The "Defibrillation Testing, Why Not?" survey. Testing of subcutaneous and transvenous defibrillators in the Italian clinical practice

Background: Defibrillation testing (DT) can be omitted in patients undergoing transvenous implantable cardioverter-defibrillator (T-ICD) implantation, but it is still recommended for patients at risk for a high defibrillation threshold and for ICD generator changes. Moreover, DT is still recommended on implantation of subcutaneous ICD (S-ICD). The aim of the present survey was to analyze the current practice of DT during T-ICD and S-ICD implantations.Methods: In March 2021, an ad hoc questionnaire on the current performance of DT and the standard practice adopted during testing was completed at 72 Italian centers implanting S-ICD and T-ICD.Results: 48 (67%) operators reported never performing DT during de-novo T-ICD implantations, while no operators perform it systematically. The remaining respondents perform it for patients at risk for a high defibrillation threshold. DT is never performed at T-ICD generator change. At the time of de-novo S-ICD implantation, DT is never performed by 9 (13%) operators and performed systematically by 48 (66%). The remaining operators frequently omit DT in patients with more severe systolic dysfunction. DT is not performed at S-ICD generator change by 92% of operators. DT is conducted by delivering a first shock energy of 65 J by 60% of operators, while the remaining 40% test lower energy values.Conclusions: In current clinical practice, most operators omit DT at T-ICD implantation, even when still recommended in the guidelines. DT is also frequently omitted at S-ICD implantation, and a wide variability exists among operators in the procedures followed during DT

Acute shock efficacy of the subcutaneous implantable cardioverter-defibrillator according to the implantation technique

Background: The traditional technique for subcutaneous implantable cardioverter defibrillator (S-ICD) implantation involves three incisions and a subcutaneous (SC) pocket. An intermuscular (IM) 2-incision technique has been recently adopted. Aims: We assessed acute defibrillation efficacy (DE) of S-ICD (DE ≤65 J) according to the implantation technique. Methods: We analyzed consecutive patients who underwent S-ICD implantation and DE testing at 53 Italian centers. Regression analysis was used to determine the association between DFT and implantation technique. Results: A total of 805 patients were enrolled. Four groups were assessed: IM + 2 incisions (n = 546), SC + 2 incisions (n = 133), SC + 3 incisions (n = 111), and IM + 3 incisions (n = 15). DE was ≤65 J in 782 (97.1%) patients. Patients with DE ≤65 J showed a trend towards lower body mass index (25.1 vs. 26.5; p = .12), were less frequently on antiarrhythmic drugs (13% vs. 26%; p = .06) and more commonly underwent implantation with the 2-incision technique (85% vs. 70%; p = .04). The IM + 2-incision technique showed the lowest defibrillation failure rate (2.2%) and shock impedance (66 Ohm, interquartile range: 57-77). On multivariate analysis, the 2-incision technique was associated with a lower incidence of shock failure (hazard ratio: 0.305; 95% confidence interval: 0.102-0.907; p = .033). Shock impedance was lower with the IM than with the SC approach (66 vs. 70 Ohm p = .002) and with the 2-incision than the 3-incision technique (67 vs. 72 Ohm; p = .006). Conclusions: In a large population of S-ICD patients, we observed a high defibrillation success rate. The IM + 2-incision technique provides lower shock impedance and a higher likelihood of successful defibrillation

Effective nonapical left ventricular pacing with quadripolar leads for cardiac resynchronization therapy

Background: Current guidelines recommend avoiding apical left ventricular (LV) pacing for cardiac resynchronization therapy (CRT). Aims: We investigated the feasibility of nonapical pacing with the current quadripolar LV lead technology. Methods: We analyzed consecutive patients who received CRT with an LV quadripolar lead. The post­­implantation position of each electrode of the LV lead was designated as basal, mid, or apical. The pacing capture threshold (PCT) and phrenic nerve stimulation (PNS) threshold were assessed for each electrode. Results: We enrolled 168 patients. A total of 8 CRT defibrillators were from Biotronik (with Sentus OTW QP leads), 98 were from Boston Scientific (with 21 Acuity X4 Spiral and 77 Acuity X4 Straight leads), and 62 from St. Jude Medical (with Quartet leads). The median (interquartile range) number of electrodes at nonapical segments per patient was 3 (1–4) with Biotronik Sentus leads, 4 (3–4) with spiral ­design Boston Scientific leads, 4 (3–4) with straight Boston Scientific leads, and 3 (3–4) with St. Jude Medical Quartet leads (P = 0.045). Three patients (38%) with Biotronik Sentus leads, 21 (100%) with spiral ­design Boston Scientific leads, 69 (90%) with straight ­design Boston Scientific leads, and 49 (79%) with St. Jude Medical Quartet leads (P < 0.001) had at least 1 electrode located at nonapical segments linked with a PNS ­PCT safety margin of more than 2 V. During the 6­month follow ­up, PNS was detected in 4 patients and was eliminated with reprogramming. No significant changes in PCT were detected during follow ­up. Conclusions: Quadripolar leads allowed nonapical pacing with acceptable electrical parameters in the majority of CRT recipients, although differences were found among the currently available devices

Subcutaneous implantable cardioverter defibrillator eligibility according to a novel automated screening tool and agreement with the standard manual electrocardiographic morphology tool

Since subcutaneous implantable cardioverter defibrillator (S-ICD) introduction, the pre-implant screening based on a dedicated manual ECG tool (MST) was required to assure adequate sensing by the S-ICD. A novel automated screening tool (AST) has been recently developed. We assessed and compared the pass rate with AST and MST, and we measured the agreement between screening tools.Purpose Since subcutaneous implantable cardioverter defibrillator (S-ICD) introduction, the pre-implant screening based on a dedicated manual ECG tool (MST) was required to assure adequate sensing by the S-ICD. A novel automated screening tool (AST) has been recently developed. We assessed and compared the pass rate with AST and MST, and we measured the agreement between screening tools.Methods Three electrodes were positioned at locations mimicking the placement of the S-ICD, and ECG recordings were collected in the supine and standing postures at rest. The three sensing vectors were analyzed with the MST and the AST. Eligibility was defined by the presence of at least one or two appropriate vectors in both postures.Results A total of 235 patients with an indication to ICD and no need for permanent pacing were enrolled. At least one suitable vector was identified in 214 (91%) patients with MST and 221 (94%) patients with AST (p = 0.219). At least two vectors were appropriate in 162 (69%) patients with MST and 187 (80%) patients with AST (p = 0.008). Overall, out of 1587 ECG analyzed, 1035 (65%) qualifying leads were identified with MST and 1111 (70%) with AST (p = 0.004). The agreement between the results of MST and AST ECG analysis was moderate (Kappa = 0.570; standard error = 0.022; CI = 0.526-0.613). The results were consistent regardless of the underlying cardiomyopathy. The most frequent reason for screening failure with MST was a high-amplitude T-wave (31% of failures). With AST, 23% of recordings that failed with MST for high-amplitude T-wave were classified as acceptable.Conclusion The AST is associated with higher pass rate than the standard MST. It seems more tolerant of high-amplitude T-waves. Consequently, the agreement between MST and AST findings was only moderate

Patient acceptance of subcutaneous versus transvenous defibrillator systems: a multi-center experience

Background The subcutaneous implantable cardioverter-defibrillator (S-ICD) is an effective alternative to the transvenous ICD. No study has yet compared S-ICD and transvenous ICD by assessing patient acceptance as a patient-centered outcome. Objective To evaluate the patient acceptance of the S-ICD and to investigate its association with clinical and implantation variables. In patients with symptomatic heart failure and reduced ejection fraction (HFrEF), the acceptance of the S-ICD was compared with a control group of patients who received a transvenous ICD. Methods Patient acceptance was calculated with the Florida Patient Acceptance Survey (FPAS) which measures four factors: return to function (RTF), device-related distress (DRD), positive appraisal (PA), and body image concerns (BIC). The survey was administered 12 months after implantation. Results 176 patients underwent S-ICD implantation. The total FPAS and the single factors did not differ according to gender, body habitus, or generator positioning. Patients with HFrEF had lower FPAS and RTF. Younger patients showed better RTF (75 [56-94] vs. 56 [50-81], p = .029). Patients who experienced device complications or device therapies showed higher DRD (40 [35-60] vs. 25 [10-50], p = .019). Patients with HFrEF receiving the S-ICD had comparable FPAS, RTF, DRD, and BIC to HFrEF patients implanted with the transvenous ICD while exhibited significantly better PA (88 [75-100] vs. 81 [63-94], p = .02). Conclusions Our analysis revealed positive patient acceptance of the S-ICD, even in groups at risk of more distress such as women or patients with thinner body habitus, and regardless of the generator positioning. Among patients receiving ICDs for HFrEF, S-ICD was associated with better PA versus transvenous ICD

Time to therapy delivery and effectiveness of subcutaneous implantable cardioverter-defibrillator

BACKGROUND: At the time of subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation, successful termination of ventricular fibrillation (VF) is confirmed. A previous study reported cases of prolonged time to therapy during defibrillation testing. OBJECTIVE: We sought to evaluate the time to therapy, identify possible predictors of delay and investigate the impact of delayed therapy on VF conversion. METHODS: We analyzed consecutive S-ICD patients who underwent initial conversion testing at a shock energy of 65J in 53 Italian centers. RESULTS: We analyzed 570 patients (82% male, 48±15 years, BMI 25±6Kg/m2, ejection fraction 47±17%). General anesthesia was used in 29% of patients, with sub-/inter-muscular positioning of the generator in 74%. Cardioversion was successful at 65J in 97.7% of patients. In 12 patients the shock did not convert VF and in 1 patient the shock was not delivered due to noise from entrapped subcutaneous air. All failures were successfully managed by reprogramming or repositioning the device. The mean time to therapy was 15±3s and it exceeded 18s in 51 (9%) patients. Independent predictors of delayed therapy (>18s) were ejection fraction (OR, 0.98; 95%CI, 0.96-0.99; p=0.016) and a 2x gain programmed (OR, 3.66; 95%CI, 1.44-9.30; p=0.006). Effectiveness at 65J was not associated with the time to therapy (OR, 1.13; 95%CI, 0.97-1.32; p=0.122). CONCLUSIONS: In this analysis of a large population of S-ICD patients, delayed therapy during defibrillation testing occurred less frequently than previously reported and had no effect on VF conversion success. Delayed therapies seemed more common when a vector with 2x gain was programmed

Long-term monitoring of respiratory rate in patients with heart failure: the Multiparametric Heart Failure Evaluation in Implantable Cardioverter-Defibrillator Patients (MULTITUDE-HF) study

Monitoring respiratory rate (RR) is recommended at the time of hospital presentation for acute decompensation in heart failure (HF). Device-based continuous monitoring of RR may be helpful for diagnostic and prognostic stratification after implantable cardioverter-defibrillator (ICD) implantation. This study was undertaken to analyze short- and long-term changes in ICD-measured RR and to relate RR with the patient's clinical status and the occurrence of HF events

Safety of Omitting Defibrillation Efficacy Testing With Subcutaneous Defibrillators: A Propensity-Matched Case-Control Study

No abstract availabl