Detecting deceased patients on cardiac device remote monitoring: A case series and management guide for cardiac device services.

BACKGROUND: Remote monitoring (RM) of implantable cardiac devices provides substantial and complex information, presenting new challenges such as detection of a patient's death. OBJECTIVE: This study aims to describe RM transmissions indicating death and propose a management strategy for services. METHODS: The study included consecutive ambulatory outpatients whose deaths were detected via RM. Clinical and device data were collected from electronic records, and ethical approval was obtained from the service's institutional review board. RESULTS: Over a 9-year period (2014-2023), 28 patients were detected. The deceased patients had implantable cardioverter-defibrillators, pacemakers, and implantable loop recorders. In 54% of the cases, the patient's death had already been recognized. Alert transmissions indicating death were commonly related to ventricular arrhythmia events, but also due to lead measurements, and implantable loop recorder battery status. Several diagnostic features may indicate a patient's death. The most reliable was the presenting electrogram, demonstrating base rate pacing with no capture. Device diagnostics, lead parameters, and arrhythmia recordings may indicate death; however, not all cases present with recordings and diagnosis may not be conclusive. A majority (82%) had ventricular arrhythmia at the time of death. In cases where defibrillator shocks were delivered, the arrhythmia reinitiated shortly after successful cardioversion. Delayed therapy was observed, and some patients did not receive defibrillator shocks because of discriminators or because the arrhythmia rate fell below the shock zone. CONCLUSION: Detecting a patient death via RM presents unique challenges and considerations for services. Standard operational policies and legal consultation should be established to address the implications.

Contact force and catheter stability are predictive metrics of successful pulmonary vein isolation with high-power short duration ablation in atrial fibrillation.

INTRODUCTION: Preliminary data suggest that high power short duration (HPSD) ablation for pulmonary vein isolation (PVI) are safe. Limited data are available on its effectiveness. Aim was to evaluate HPSD ablation in atrial fibrillation ablation using a novel Qdot Micro catheter. METHODS AND RESULTS: Prospective multicenter study evaluating safety and efficacy of PVI with HPSD ablation. First pass isolation (FPI) and sustained PVI was assessed. If FPI was not achieved additional ablation index (AI)-guided ablation with 45 W was performed and metrics predictive of this were determined. Sixty-five patients and 260 veins were treated. Procedural and LA dwell time was 93.9 ± 30.4 and 60.5 ± 23.1 min, respectively. FPI was achieved in 47 (72.3%) patients and 231 veins (88.8%) with an ablation duration of 4.6 ± 1.0 min. Twenty-nine veins required additional AI-guided ablation to achieve initial PVI with 24 anatomical sites ablated with the right posterior carina being the most common site (37.5%). A contact force of ≥8 g (area under the curve [AUC]: 0.81; p < 0.001) and catheter position variation of ≤1.2 mm (AUC: 0.79; p < 0.001) with HPSD were strongly predictive of not requiring additional AI-guided ablation. Out of the 260 veins, only 5 (1.9%) veins showed acute reconnection. HPSD ablation was associated with shorter procedure times (93.9 vs. 159.4 min; p < 0.001), ablation times (6.1 vs. 27.7 min; p < 0.001), and lower rates of PV reconnection (9.2% vs. 30.8%; p = 0.004) compared to moderate power cohort. CONCLUSIONS: HPSD ablation is an effective ablation modality which results in effective PVI whilst maintaining a safety profile. Its superiority needs to be evaluated in randomized controlled trials.

Simultaneous Comparison of Electrocardiographic Imaging and Epicardial Contact Mapping in Structural Heart Disease.

BACKGROUND: The accuracy of ECG imaging (ECGI) in structural heart disease remains uncertain. This study aimed to provide a detailed comparison of ECGI and contact-mapping system (CARTO) electrograms. METHODS: Simultaneous epicardial mapping using CARTO (Biosense-Webster, CA) and ECGI (CardioInsight) in 8 patients was performed to compare electrogram morphology, activation time (AT), and repolarization time (RT). Agreement between AT and RT from CARTO and ECGI was assessed using Pearson correlation coefficient, ρ AT and ρ RT, root mean square error, E AT and E RT, and Bland-Altman plots. RESULTS: After geometric coregistration, 711 (439-905; median, first-third quartiles) ECGI and CARTO points were paired per patient. AT maps showed ρ AT=0.66 (0.53-0.73) and E AT=24 (21-32) ms, RT maps showed ρ RT=0.55 (0.41-0.71) and E RT=51 (38-70) ms. The median correlation coefficient measuring the morphological similarity between the unipolar electrograms was equal to 0.71 (0.65-0.74) for the entire signal, 0.67 (0.59-0.76) for QRS complexes, and 0.57 (0.35-0.76) for T waves. Local activation map correlation, ρ AT, was lower when default filters were used (0.60 (0.30-0.71), P=0.053). Small misalignment of the ECGI and CARTO geometries (below ±4 mm and ±4°) could introduce variations in the median ρ AT up to ±25%. Minimum distance between epicardial pacing sites and the region of earliest activation in ECGI was 13.2 (0.0-28.3) mm from 25 pacing sites with stimulation to QRS interval <40 ms. CONCLUSIONS: This simultaneous assessment demonstrates that ECGI maps activation and repolarization parameters with moderate accuracy. ECGI and contact electrogram correlation is sensitive to electrode apposition and geometric alignment. Further technological developments may improve spatial resolution.

Trends in implantable cardioverter defibrillator and cardiac resynchronisation therapy lead parameters for patients with arrhythmogenic and dilated cardiomyopathies.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) lead parameters may deteriorate due to right ventricular (RV) disease such as arrhythmogenic right ventricular cardiomyopathy (ARVC), with implications for safe delivery of therapies. We compared ICD and CRT-D (cardiac resynchronisation therapy-defibrillator) lead parameters in patients with ARVC and dilated cardiomyopathy (DCM). METHODS: RV lead sensing (R wave amplitude) and pacing (threshold and amplitude-pulse width product (APWP)), left ventricular (LV) pacing (APWP), and imaging parameter trends were assessed in 18 patients with ARVC and 18 with DCM. RESULTS: R wave amplitude did not change significantly over time in either group (over 5 years, ARVC -0.4 mV, 95% CI -3.8-3.0 mV; DCM -1.8 mV, 95% CI -5.0-1.3 mV). Within ARVC group, divergent trends were seen according to lead position. DCM patients experienced an increase in RV lead threshold (+1.1 V over 5 years, 95% CI + 0.5 to +1.7 V) and RV APWP (+0.48 Vms over 5 years, 95% CI + 0.24 to +0.71 Vms); ARVC patients had no change. ARVC patients had a higher LVEF at baseline than DCM patients (52 vs 20%, p < 0.001), though LVEF decreased over time for the former, while increasing for the latter. TAPSE did not change over time for ARVC patients. CONCLUSIONS: Lead parameters in ARVC patients were stable over medium-term follow up. In DCM patients, RV lead threshold and RV and LV APWP increased over time. These differential responses for DCM and ARVC were not explained by imaging indices, and may reflect distinct patterns of disease progression.