Sympathetic toggled paroxysmal atrial fibrillation and recurrent premature atrial contractions in ambulatory patients.

BACKGROUND: Autonomic nerve activity is important in the mechanisms of paroxysmal atrial fibrillation (PAF). OBJECTIVE: To test the hypothesis that a single burst of skin sympathetic nerve activity (SKNA) can toggle on and off PAF or premature atrial contraction (PAC) clusters. METHODS: We performed neuECG recording over 7 days in patients with PAF. RESULTS: In Study 1, we found 8 patients (7 men, 1 woman, 62±8 years) had 124 episodes of PAF. An SKNA burst toggled both on and off PAF in 8 (6.5%) episodes (Type 1), toggled on but not off in 12 (9.7%) episodes (Type 2), and toggled on a PAC cluster, followed by PAF in 4 (3.2%) episodes (Type 3). The duration of these PAF episodes was < 10 min. The remaining 100 (80.6%) episodes were associated with active SKNA bursts throughout PAF (Type 4) and lasted longer than Type 1 (p=0.0185) and Type 2 (p=0.0027) PAF. There were 47 PAC clusters. Among them, 24 (51.1%) were toggled on and off, and 23 (48.9%) were toggled on but not off by an SKNA burst. In Study 2, we found 17 patients (9 men, 8 women, 58±12 years) with < 10 min PAF (4, 8, 0, and 31 of Types 1-4, respectively). There were significant circadian variations of all types of PAF. CONCLUSIONS: A single SKNA burst can toggle short-duration PAF and PAC cluster episodes on and off. The absence of continued SKNA after the onset might have affected the maintenance of these arrhythmias.

Association between proactive esophageal cooling and increased lab throughput.

INTRODUCTION: Proactive esophageal cooling has been FDA cleared to reduce the likelihood of ablation-related esophageal injury resulting from radiofrequency (RF) cardiac ablation procedures. Data suggest that procedure times for RF pulmonary vein isolation (PVI) also decrease when proactive esophageal cooling is employed instead of luminal esophageal temperature (LET) monitoring. Reduced procedure times may allow increased electrophysiology (EP) lab throughput. We aimed to quantify the change in EP lab throughput of PVI cases after the introduction of proactive esophageal cooling. METHODS: EP lab throughput data were obtained from three EP groups. We then compared EP lab throughput over equal time frames at each site before (pre-adoption) and after (post-adoption) the adoption of proactive esophageal cooling. RESULTS: Over the time frame of the study, a total of 2498 PVIs were performed over a combined 74 months, with cooling adopted in September 2021, November 2021, and March 2022 at each respective site. In the pre-adoption time frame, 1026 PVIs were performed using a combination of LET monitoring with the addition of esophageal deviation when deemed necessary by the operator. In the post-adoption time frame, 1472 PVIs were performed using exclusively proactive esophageal cooling, representing a mean 43% increase in throughput (p < .0001), despite the loss of two operators during the post-adoption time frame. CONCLUSION: Adoption of proactive esophageal cooling during PVI ablation procedures is associated with a significant increase in EP lab throughput, even after a reduction in total number of operating physicians in the post-adoption group.

Atrioesophageal Fistula Rates Before and After Adoption of Active Esophageal Cooling During Atrial Fibrillation Ablation.

BACKGROUND: Active esophageal cooling reduces the incidence of endoscopically identified severe esophageal lesions during radiofrequency (RF) catheter ablation of the left atrium for the treatment of atrial fibrillation. A formal analysis of the atrioesophageal fistula (AEF) rate with active esophageal cooling has not previously been performed. OBJECTIVES: The authors aimed to compare AEF rates before and after the adoption of active esophageal cooling. METHODS: This institutional review board (IRB)-approved study was a prospective analysis of retrospective data, designed before collecting and analyzing the real-world data. The number of AEFs occurring in equivalent time frames before and after adoption of cooling using a dedicated esophageal cooling device (ensoETM, Attune Medical) were quantified across 25 prespecified hospital systems. AEF rates were then compared using generalized estimating equations robust to cluster correlation. RESULTS: A total of 14,224 patients received active esophageal cooling during RF ablation across the 25 hospital systems, which included a total of 30 separate hospitals. In the time frames before adoption of active cooling, a total of 10,962 patients received primarily luminal esophageal temperature (LET) monitoring during their RF ablations. In the preadoption cohort, a total of 16 AEFs occurred, for an AEF rate of 0.146%, in line with other published estimates for procedures using LET monitoring. In the postadoption cohort, no AEFs were found in the prespecified sites, yielding an AEF rate of 0% (P < 0.0001). CONCLUSIONS: Adoption of active esophageal cooling during RF ablation of the left atrium for the treatment of atrial fibrillation was associated with a significant reduction in AEF rate.

Sudden cardiac death during nighttime hours.

BACKGROUND: In the absence of apparent triggers, sudden cardiac death (SCD) during nighttime hours is a perplexing and devastating phenomenon. There are few published reports in the general population, with insufficient numbers to perform sex-specific analyses. Smaller studies of rare nocturnal SCD syndromes suggest a male predominance and implicate sleep-disordered breathing. OBJECTIVE: The purpose of this study was to identify mechanisms of nighttime SCD in the general population. METHODS: From the population-based Oregon Sudden Unexpected Death Study, we evaluated SCD cases that occurred in the community between 10 PM and 6 AM (nighttime) and compared them with daytime cases. Univariate comparisons were evaluated using Pearson χ2 tests and independent samples t tests. Logistic regression was used to further assess independent SCD risk. RESULTS: A total of 4126 SCD cases (66.2% male, 33.8% female) met criteria for analysis and 22.3% (n = 918) occurred during nighttime hours. Women were more likely to present with nighttime SCD than men (25.4% vs 20.6%; P < .001). In a multivariate regression model, female sex (odds ratio [OR] 1.3 [confidence interval (CI) 1.1-1.5]; P = .001), medications associated with somnolence/respiratory depression (OR 1.2 [CI 1.1-1.4]; P = .008) and chronic obstructive pulmonary disease/asthma (OR 1.4 [CI 1.1-1.6]; P < .001) were independently associated with nighttime SCD. Women were taking more central nervous system-affecting medications than men (1.9 ± 1.7 vs 1.4 ± 1.4; P = .001). CONCLUSION: In the general population, women were more likely than men to suffer SCD during nighttime hours and female sex was an independent predictor of nighttime events. Respiratory suppression is a concern, and caution is advisable when prescribing central nervous system-affecting medications to patients at an increased risk of SCD, especially women.

Do peak times exist for sudden cardiac arrest?

Sudden cardiac arrest remains an unexpected and dynamic cardiovascular disease process that continues to present challenges for accurate risk prediction and prevention. The notion of a circadian pattern in the occurrence of sudden cardiac arrest had long been supported by the presence of an early morning peak; however, more recent studies are calling this observation into question. This likely paradigm shift in the presentation and mechanisms of sudden cardiac arrest has major implications and needs to be carefully considered. In this review, we present the current state of the science of circadian and septadian trends in sudden cardiac arrest through an in-depth analysis of the published literature.

Cardiac arrhythmias in hospitalized patients with COVID-19: A prospective observational study in the western United States.

Arrhythmias have been reported frequently in COVID-19 patients, but the incidence and nature have not been well characterized. Patients admitted with COVID-19 and monitored by telemetry were prospectively enrolled in the study. Baseline characteristics, hospital course, treatment and complications were collected from the patients' medical records. Telemetry was monitored to detect the incidence of cardiac arrhythmias. The incidence and types of cardiac arrhythmias were analyzed and compared between survivors and non-survivors. Among 143 patients admitted with telemetry monitoring, overall in-hospital mortality was 25.2% (36/143 patients) during the period of observation (mean follow-up 23.7 days). Survivors were less tachycardic on initial presentation (heart rate 90.6 ± 19.6 vs. 99.3 ± 23.1 bpm, p = 0.030) and had lower troponin (peak troponin 0.03 vs. 0.18 ng/ml. p = 0.004), C-reactive protein (peak C-reactive protein 97 vs. 181 mg/dl, p = 0.029), and interleukin-6 levels (peak interleukin-6 30 vs. 246 pg/ml, p = 0.003). Sinus tachycardia, the most common arrhythmia (detected in 39.9% [57/143] of patients), occurred more frequently in non-survivors (58.3% vs. 33.6% in survivors, p = 0.009). Premature ventricular complexes occurred in 28.7% (41/143), and non-sustained ventricular tachycardia in 15.4% (22/143) of patients, with no difference between survivors and non-survivors. Sustained ventricular tachycardia and ventricular fibrillation were not frequent (seen only in 1.4% and 0.7% of patients, respectively). Contrary to reports from other regions, overall mortality was higher and ventricular arrhythmias were infrequent in this hospitalized and monitored COVID-19 population. Either disease or management-related factors could explain this divergence of clinical outcomes, and should be urgently investigated.

Experience With Hydroxychloroquine and Azithromycin in the Coronavirus Disease 2019 Pandemic: Implications for QT Interval Monitoring.

Background Despite a lack of clinical evidence, hydroxychloroquine and azithromycin are being administered widely to patients with verified or suspected coronavirus disease 2019 (COVID-19). Both drugs may increase risk of lethal arrhythmias associated with QT interval prolongation. Methods and Results We analyzed a case series of COVID-19-positive/suspected patients admitted between February 1, 2020, and April 4, 2020, who were treated with azithromycin, hydroxychloroquine, or a combination of both drugs. We evaluated baseline and postmedication QT interval (corrected QT interval [QTc]; Bazett) using 12-lead ECGs. Critical QTc prolongation was defined as follows: (1) maximum QTc ≥500 ms (if QRS <120 ms) or QTc ≥550 ms (if QRS ≥120 ms) and (2) QTc increase of ≥60 ms. Tisdale score and Elixhauser comorbidity index were calculated. Of 490 COVID-19-positive/suspected patients, 314 (64%) received either/both drugs and 98 (73 COVID-19 positive and 25 suspected) met study criteria (age, 62±17 years; 61% men). Azithromycin was prescribed in 28%, hydroxychloroquine in 10%, and both in 62%. Baseline mean QTc was 448±29 ms and increased to 459±36 ms (P=0.005) with medications. Significant prolongation was observed only in men (18±43 ms versus -0.2±28 ms in women; P=0.02). A total of 12% of patients reached critical QTc prolongation. Changes in QTc were highest with the combination compared with either drug, with much greater prolongation with combination versus azithromycin (17±39 ms versus 0.5±40 ms; P=0.07). No patients manifested torsades de pointes. Conclusions Overall, 12% of patients manifested critical QTc prolongation, and the combination caused greater prolongation than either drug alone. The balance between uncertain benefit and potential risk when treating COVID-19 patients should be carefully assessed.

Effects of Transendocardial Stem Cell Injection on Ventricular Proarrhythmia in Patients with Ischemic Cardiomyopathy: Results from the POSEIDON and TAC-HFT Trials.

Transendocardial stem cell injection in patients with ischemic cardiomyopathy (ICM) improves left ventricular function and structure but has ill-defined effects on ventricular arrhythmias. We hypothesized that mesenchymal stem cell (MSC) implantation is not proarrhythmic. Post hoc analyses were performed on ambulatory ECGs collected from the POSEIDON and TAC-HFT trials. Eighty-eight subjects (mean age 61 ± 10 years) with ICM (mean EF 32.2% ± 9.8%) received treatment with MSC (n = 48), Placebo (n = 21), or bone marrow mononuclear cells (BMC) (n = 19). Heart rate variability (HRV) and ventricular ectopy (VE) were evaluated over 12 months. VE did not change in any group following MSC implantation. However, in patients with ≥ 1 VE run (defined as ≥ 3 consecutive premature ventricular complexes in 24 hours) at baseline, there was a decrease in VE runs at 12 months in the MSC group (p = .01), but not in the placebo group (p = .07; intergroup comparison: p = .18). In a subset of the MSC group, HRV measures of standard deviation of normal intervals was 75 ± 30 msec at baseline and increased to 87 ± 32 msec (p =.02) at 12 months, and root mean square of intervals between successive complexes was 36 ± 30 msec and increased to 58.2 ± 50 msec (p = .01) at 12 months. In patients receiving MSCs, there was no evidence for ventricular proarrhythmia, manifested by sustained or nonsustained ventricular ectopy or worsened HRV. Signals of improvement in ventricular arrhythmias and HRV in the MSC group suggest a need for further studies of the antiarrhythmic potential of MSCs. Stem Cells Translational Medicine 2017;6:1366-1372.

Differences Between Access to Follow-Up Care and Inappropriate Shocks Based on Insurance Status of Implantable Cardioverter Defibrillator Recipients.

Differences in implantable cardioverter defibrillator (ICD) utilization based on insurance status have been described, but little is known about postimplant follow-up patterns associated with insurance status and outcomes. We collected demographic, clinical, and device data from 119 consecutive patients presenting with ICD shocks. Insurance status was classified as uninsured/Medicaid (uninsured) or private/Health Maintenance Organization /Medicare (insured). Shock frequencies were analyzed before and after a uniform follow-up pattern was implemented regardless of insurance profile. Uninsured patients were more likely to present with an inappropriate shock (63% vs 40%, p = 0.01), and they were more likely to present with atrial fibrillation (AF) as the shock trigger (37% vs 19%, p = 0.04). Uninsured patients had a longer interval between previous physician contact and index ICD shock (147 ± 167 vs 83 ± 124 days, p = 0.04). Patients were followed for a mean of 521 ± 458 days after being enrolled in a uniform follow-up protocol, and there were no differences in the rate of recurrent shocks based on insurance status. In conclusion, among patients presenting with an ICD shock, underinsured/uninsured patients had significantly longer intervals since previous physician contact and were more likely to present with inappropriate shocks and AF, compared to those with private/Medicare coverage. After the index shock, both groups were followed uniformly, and the differences in rates of inappropriate shocks were mitigated. This observation confirms the importance of regular postimplant follow-up as part of the overall ICD management standard.

Influence of Total Coronary Occlusion on Clinical Outcomes (from the Bypass Angioplasty Revascularization Investigation 2 DiabetesTrial).

Our aim was to evaluate the influence of chronic total occlusions (CTOs) on long-term clinical outcomes of patients with coronary heart disease and diabetes mellitus. We evaluated patients with coronary heart disease and diabetes mellitus enrolled in the Bypass Angioplasty Revascularization Investigation 2 Diabetes, who underwent either prompt revascularization (PR) with intensive medical therapy (IMT) or IMT alone according to the presence or absence of CTO. Of 2,368 patients enrolled in the trial, 972 patients (41%) had CTO of coronary arteries. Of those, 482 (41%) and 490 (41%) were in the PR with IMT versus IMT only groups, respectively. In the PR group, patients with CTO were more likely to be selected for the coronary artery bypass grafting stratum (coronary artery bypass grafting 62% vs percutaneous coronary intervention 31%, p <0.001). Compared to the non-CTO group, patients with CTO had more abnormal Q wave, abnormal ST depression, and abnormal T waves. The myocardial jeopardy score was higher in the CTO versus non-CTO group (52 [36 to 69] vs 37 [21 to 53], p <0.001). After adjustment, 5-year mortality rate was significantly higher in the CTO group in the entire cohort (hazard ratio [HR] 1.35, p = 0.013) and in patients with CTO managed with IMT (HR 1.46, p = 0.031). However, the adjusted risk of death was not increased in patients managed with PR (HR 1.26, p = 0.180). In conclusion, CTO of coronary arteries is associated with increased mortality in patients treated medically. However, the presence of a CTO may not increase mortality in patients treated with revascularization. Larger randomized trials are needed to evaluate the effects of revascularization on long-term survival in patients with CTO.

Association between anti-human heat shock protein-60 and interleukin-2 with coronary artery calcium score.

INTRODUCTION: Based upon evidence suggesting that concentrations of anti-heat shock protein-60 (anti-HSP60) and interleukin-2 (IL-2) are associated with atherogenesis, we tested the hypothesis that anti-HSP60 and IL-2 are associated with coronary artery calcium (CAC) score, a marker of subclinical atherosclerosis. METHODS: We evaluated 998 asymptomatic adults, age 45-84 years, without known coronary disease from the Multi-Ethnic Study of Atherosclerosis (MESA), who had anti-HSP60 measured at baseline. Tertiles of serum anti-HSP60 were evaluated. The associations of IL-2 and anti-HSP60 with CAC were assessed using multivariate analyses, with adjustments for coronary risk factors and Framingham risk score. RESULTS: Patients' demographics, diabetes, hypertension, obesity, or dyslipidaemia did not show differences in levels of anti-HSP60. The median (IQR) Framingham risk score was 11 (5-22), 8 (5-16), and 9 (5-18) for the first, second, and third tertiles, respectively (p=0.043). IL-2 and tumour necrosis factor α (TNF-α) were associated with increased CAC (IL-2: OR 3.70, p<0.001; TNF-α: OR 4.63, p<0.001). In multivariate regression, the highest tertiles of anti-HSP60 and IL-2 were associated with increased risk of CAC (HSP60 T3: OR 1.49, p=0.022; IL-2: OR 2.49, p<0.001). After adjustment, significant progression of CAC was observed in patients with higher baseline levels of anti-HSP60 (estimate 31.73, p=0.016) and IL-2 (estimate 34.39, p=0.024). CONCLUSIONS: Increased concentrations of inflammatory markers (IL-2 and anti-HSP60) are associated with an increased CAC at baseline and follow-up in healthy asymptomatic adults. Future studies should be carried out to assess its association with early development of atherosclerosis.

Ultrasound probe with integrated ECG lead: feasibility study.

We integrated electrocardiogram (ECG) leads onto the face of a cardiac ultrasound transducer and the exterior chassis of a simulated small, portable scanner to minimize the number of devices needed to collect cardiac information. Since the ECG leads were not placed on their standard locations, a precordial ECG was recorded.