Simultaneous Leadless Pacemaker and Subcutaneous ICD Implantation With Intraoperative Screening: Workflow in Two Patients.

A communicating subcutaneous implantable cardioverter-defibrillator (ICD) and leadless pacemaker system is being developed for patients who require both pacing and ICD therapy. It is important to ensure that the paced morphology from the leadless pacemaker will be sensed appropriately by the subcutaneous ICD. We present 2 cases illustrating our approach and workflow. (Level of Difficulty: Intermediate.).

Use of Ambulatory Patch Monitoring Devices to Supplement Inpatient Telemetry-A Descriptive Study of a Single-center Experience During the Coronavirus Disease 2019 Pandemic.

To accommodate the surge in patients with coronavirus disease 2019 during the spring of 2020, outpatient areas in our health system were repurposed as inpatient units. These spaces often lacked the same resources as the standard inpatient unit, including telemetry equipment. We utilized mobile cardiac outpatient telemetry (MCOT) in place of traditional telemetry and suggest that MCOT is an appropriate substitution only for patients at low risk of developing arrhythmia given the prolonged time to notification of the care team regarding events and imprecise measurements of the corrected QT interval when compared to 12-lead electrocardiography.

Patient Perceptions of Cardiac Electrophysiology Procedural Postponement at an Urban Center During the SARS-CoV-2 Pandemic.

To curb transmission of SARS-CoV-2 and preserve hospital resources, elective procedures were postponed in the United States, affecting patients previously scheduled for electrophysiology (EP) procedures. We aimed to understand patients' perceptions related to procedural postponements during the first wave of the SARS-CoV-2 pandemic. We performed a telephone survey between May 1-15 2020, of consecutive patients who experienced procedural postponement from March-April. Of 112 patients, 20% may have been lost to follow up and 12% lost interest in having their procedures done. The level of anxiety related to postponement was moderate to high in more than two thirds of patients.

Racial and ethnic differences in left atrial appendage occlusion wait time, complications, and periprocedural management.

PURPOSE: Non-white patients are underrepresented in left atrial appendage occlusion (LAAO) trials, and racial disparities in LAAO periprocedural management are unknown. METHODS: We assessed sociodemographics and comorbidities of consecutive patients at our institution undergoing LAAO between 2015 and 2020, then in adjusted analyses, compared procedural wait time, procedural complications, and post-procedure oral anticoagulation (OAC) use in whites versus non-whites. RESULTS: Among 109 patients undergoing LAAO (45% white), whites had lower CHA2 DS2 VASc scores, on average, than non-whites (4.0 vs. 4.8, p = .006). There was no difference in median time from index event (IE) or initial outpatient cardiology encounter to LAAO procedure (whites 10.5 vs. non-whites 13.7 months, p = .9; 1.9 vs. 1.8 months, p = .6, respectively), and there was no difference in procedural complications (whites 4% vs. non-whites 5%, p = .33). After adjusting for CHA2 DS2 VASc score, OAC use at discharge tended to be higher in whites (OR 2.4, 95% CI [0.9-6.0], p = .07). When restricting the analysis to those with prior gastrointestinal (GI) bleed, adjusting for CHA2 DS2 VASc score and GI bleed severity, whites had a nearly five-fold odds of being discharged on OAC (OR 4.6, 95% CI [1-21.8], p = 0.05). The association between race and discharge OAC was not mediated through income category (total mediation effect 19% 95% CI [-.04-0.11], p = .38). CONCLUSION: Despite an increased prevalence of comorbidities amongst non-whites, wait time for LAAO and procedural complications were similar in whites versus non-whites. Among those with prior GI bleed, whites were nearly five-fold more likely to be discharged on OAC than non-whites, independent of income.

Racial differences in the incidence of atrial fibrillation after cryptogenic stroke.

BACKGROUND: The incidence of atrial fibrillation (AF) is lower in nonwhites than in whites despite a higher burden of AF risk factors. However, the incidence of new AF after cryptogenic stroke in minorities is unknown. OBJECTIVE: The purpose of this study was to determine the incidence of AF after cryptogenic stroke in different racial/ethnic groups. METHODS: We retrospectively analyzed 416 consecutive patients undergoing insertable cardiac monitor implantation at our hospital from 2014 through 2019. Incidence of AF was identified through the review of device monitoring, including adjudication of AF episodes for accuracy, and compared by race. RESULTS: The mean follow-up time was 1.5 ± 1.1 years. The predominantly nonwhite cohort included 244 (59%) blacks and 109 (26%) Hispanics, and 45% (n=189) were male. The mean age was 62 ± 12 years; Blacks and Hispanics had more hypertension, diabetes, and chronic kidney disease and higher body mass index than did whites. In blacks and Hispanics, the cumulative incidences of AF at 1, 2, and 3 years were 14.1%, 19.9%, and 24% and 12.9%, 18.3%, and 20.9%, respectively. By comparison, the incidence in whites was significantly higher: 20.8%, 34.3%, and 40.3%. In a Cox proportional hazards model adjusting for common AF risk factors, blacks (hazard ratio 0.49; confidence interval 0.26-0.82; P = .03) and Hispanics (hazard ratio 0.39; confidence interval 0.18-0.83; P = .01) were less likely to have incident AF than whites. CONCLUSION: In patients with an insertable cardiac monitor after cryptogenic stroke, the incidence of newly detected AF is approximately double in whites compared with both blacks and Hispanics. This has important implications for the investigation and treatment of nonwhites with cryptogenic stroke.

Impact of High-Power Short-Duration Radiofrequency Ablation on Long-Term Lesion Durability for Atrial Fibrillation Ablation.

OBJECTIVES: The goal of this study was to compare lesion durability between high-power short-duration (HP-SD) and moderate-power moderate-duration (MP-MD) ablation strategies. BACKGROUND: HP-SD radiofrequency ablation (RFA) was developed to improve pulmonary vein isolation (PVI) by reducing the effect of catheter instability inherent to MP-MD ablation strategies. However, its long-term effect on lesion durability for the treatment of atrial fibrillation is unknown. METHODS: Patients with atrial fibrillation (n = 112) underwent PVI using HP-SD ablation (45 to 50 W, 8 to 15 s) with contact force-sensing open irrigated catheter. Cavotricuspid isthmus, mitral annular, and roof lines were permitted. A control group (n = 112) underwent ablation using MP-MD ablation (20 to 40 W, 20 to 30 s) with similar technology. Chronic PV reconnection was examined in patients who required a redo procedure (HP-SD ablation, n = 18; MP-MD ablation, n = 23). RESULTS: The rate of PVI at the completion of the initial encirclement was similar between the HP-SD and MP-MD ablation strategies (90.2% vs. 83.0%; p = 0.006). The HP-SD strategy required shorter RFA time (17.2 ± 3.4 min vs. 31.1 ± 5.6 min; p < 0.001). The incidence of chronic PV reconnection was lower with HP-SD ablation (16.6% vs. 52.2%; p = 0.03). Areas of chronic reconnection were associated with catheter motion ≥1 mm for ≥50% application duration. In a higher proportion of HP-SD applications, catheter motion was <1 mm during ≥50% duration (88.6% vs. 72.8%; p < 0.001), allowing energy delivery with greater stability. Both ablation strategies were effective for cavotricuspid isthmus; however, the HP-SD strategy was less effective for mitral annular lines, requiring ablation at lower power for longer duration to avoid steam pops. CONCLUSIONS: HP-SD ablation may improve PVI durability, and it shortens RFA time. However, ablation in thicker myocardium often requires lower power applied for longer duration, allowing deeper lesions without tissue overheating.

Electrolyte Abnormalities in Patients Presenting With Ventricular Arrhythmia (from the LYTE-VT Study).

Electrolyte abnormalities are a known trigger for ventricular arrhythmia, and patients with heart disease on diuretic therapy may be at higher risk for electrolyte depletion. Our aim was to determine the prevalence of electrolyte depletion in patients presenting to the hospital with sustained ventricular tachycardia or ventricular fibrillation (VT/VF) versus heart failure, and identify risk factors for electrolyte depletion. Consecutive admissions to a tertiary care hospital for VT/VF were identified between July 2016 and October 2018 using the electronic medical record and compared with an equal number of consecutive admissions for heart failure (CHF). The study included 280 patients (140 patients in each group; mean age 63, 60% male, 59% African American). Average EF in the VT/VF and CHF groups was 30% and 33%, respectively. Hypokalemia (K < 3.5 mmol/L) and severe hypokalemia (K < 3.0 mmol/L) were present in 35.7% and 13.6%, respectively, of patients with VT/VF, compared to 12.9% and 2.7% of patients with CHF (p < 0.001 and p = 0.001, respectively, between groups). Hypomagnesemia was found in 7.8% and 5.8% of VT/VF and CHF patients, respectively (p = 0.46). Gastrointestinal illness and recent increases in diuretic dose were strongly associated with severe hypokalemia in VT/VF patients (odds ratio: 11.1 and 21.9, respectively; p < 0.001). In conclusion, hypokalemia is extremely common in patients presenting with VT/VF, much more so than in patients with CHF alone. Preceding gastrointestinal illness and increase in diuretic dose were strongly associated with severe hypokalemia in the VT/VF population, revealing a potential opportunity for early intervention and arrhythmia risk reduction.