Defining the distance between the His bundle and first septal perforator: implications for left bundle branch pacing.

BACKGROUND: Left bundle branch pacing (LBBP) is a developing method of native conduction pacing, but cases of injury to the septal perforator arteries during implantation have been reported. Knowing the distance between the His bundle and the first septal perforator artery can help operators implant LBBP leads more safely. METHODS: Using previously performed coronary CT angiography (CCTA) studies, the distance between the His bundle and the first septal perforator was measured. RESULTS: A total of 50 CCTA studies were included. The mean distance from the His bundle to the first septal perforator (His-SP) along the line connecting the His bundle to the RV apex (His-RV apex) was 27.17 ± 7.7 mm with a range of 13.0 to 44.7 mm. The distance was greater than 2.0 cm in 84% of patients. To standardize this distance among patients with varying cardiac structures, the ratio between the His-SP distance and the His-RV Apex distance was also measured. The mean His-SP:His-RV Apex was 0.302 and the median was 0.298. Eighty-six percent of patients had a ratio of greater than 0.20. CONCLUSION: Using this information, operators can aim to implant LBBP leads within 2.0 cm of the His bundle or 20% of the distance between the His bundle and the RV apex with minimal risk of causing vascular injury.

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.).

Cardiac implantable device interrogation in left ventricular systolic dysfunction reveals physiologic abnormalities prior to symptom onset in COVID-19: a case series.

Background: COVID-19 has affected individuals across the globe, and those with cardiac implantable electronic devices (CIEDs) likely represent a high-risk group. These devices can be interrogated to reveal information about the patient activity, heart rate parameters, and respiratory rate. Case summary: Four patients with CIEDs and left ventricular dysfunction were admitted to a single institution for COVID-19 infection. Each patient survived hospitalization, and none required intensive care. Retrospectively, CIED interrogation revealed each patient had decreased activity level prior to their reporting COVID-19 symptoms. Similarly, respiratory rate increased before symptom onset for three of the patients, while one did not have these data available. Of the three patients with heart rate variability (HRV) available, two had decreased HRV before they developed symptoms. After hospital discharge, these parameters returned to their baseline. Discussion: This case series suggests physiologic changes identifiable through interrogation of CIEDs may occur prior to the reported onset of COVID-19 symptoms. These data may provide objective evidence on which to base more sensitive assessments of infectious risk when performing contact tracing in communities.

Impact of Racial Disparities in Preoperative Cardiovascular Evaluation and Surgical Outcomes in Patients Undergoing Metabolic and Bariatric Surgery: A Retrospective Cohort Analysis.

Background We investigated preoperative referral patterns, rates of cardiovascular testing, surgical wait times, and postoperative outcomes in White versus Black, Hispanic, or other racial or ethnic groups of patients undergoing metabolic and bariatric surgery. Methods and Results This was a single center retrospective cohort analysis of 797 consecutive patients undergoing metabolic and bariatric surgery from January 2014 to December 2018; 86% (n=682) were Black, Hispanic, or other racial or ethnic groups. White versus Black, Hispanic, or other racial or ethnic groups had similar baseline comorbidities and were referred for preoperative cardiovascular evaluation in similar proportion (65% versus 68%, P=0.529). Black, Hispanic, or other racial or ethnic groups of patients were less likely to undergo preoperative cardiovascular testing (unadjusted odds ratio [OR], 0.56; 95% CI, 0.33-0.95; P=0.031; adjusted for Revised Cardiac Risk Index OR, 0.59; 95% CI, 0.35-0.996; P=0.049). White patients had a shorter wait time for surgery (unadjusted hazard ratio [HR], 0.7; 95% CI, 0.58-0.87; P=0.001; adjusted HR, 0.7; 95% CI, 0.56-0.95; P=0.018). Reduction in body mass index at 6 months was greater in White patients (12.9 kg/m2 versus 12.0 kg/m2, P=0.0289), but equivalent at 1 year (14.9 kg/m2 versus 14.3 kg/m2, P=0.330). Conclusions White versus Black, Hispanic, or other racial or ethnic groups of patients were referred for preoperative cardiovascular evaluation in similar proportion. White patients underwent more preoperative cardiac testing yet had a shorter wait time for surgery. Early weight loss was greater in White patients, but equivalent between groups at 12 months.

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.

Prospective arrhythmia surveillance after a COVID-19 diagnosis.

BACKGROUND: Cardiac arrhythmias have been observed among patients hospitalised with acute COVID-19 infection, and palpitations remain a common symptom among the much larger outpatient population of COVID-19 survivors in the convalescent stage of the disease. OBJECTIVE: To determine arrhythmia prevalence among outpatients after a COVID-19 diagnosis. METHODS: Adults with a positive COVID-19 test and without a history of arrhythmia were prospectively evaluated with 14-day ambulatory electrocardiographic monitoring. Participants were instructed to trigger the monitor for palpitations. RESULTS: A total of 51 individuals (mean age 42±11 years, 65% women) underwent monitoring at a median 75 (IQR 34-126) days after a positive COVID-19 test. Median monitoring duration was 13.2 (IQR 10.5-13.8) days. No participant demonstrated atrial fibrillation, atrial flutter, sustained supraventricular tachycardia (SVT), sustained ventricular tachycardia or infranodal atrioventricular block. Nearly all participants (96%) had an ectopic burden of <1%; one participant had a 2.8% supraventricular ectopic burden and one had a 15.4% ventricular ectopic burden. While 47 (92%) participants triggered their monitor for palpitation symptoms, 78% of these triggers were for either sinus rhythm or sinus tachycardia. CONCLUSIONS: We did not find evidence of malignant or sustained arrhythmias in outpatients after a positive COVID-19 diagnosis. While palpitations were common, symptoms frequently corresponded to sinus rhythm/sinus tachycardia or non-malignant arrhythmias such as isolated ectopy or non-sustained SVT. While these findings cannot exclude the possibility of serious arrhythmias in select individuals, they do not support a strong or widespread proarrhythmic effect of COVID-19 infection after resolution of acute illness.

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.

Acute Consumption of Alcohol and Discrete Atrial Fibrillation Events.

BACKGROUND: Patients' self-reports suggest that acute alcohol consumption may trigger a discrete atrial fibrillation (AF) event. OBJECTIVE: To objectively ascertain whether alcohol consumption heightens risk for an AF episode. DESIGN: A prospective, case-crossover analysis. SETTING: Ambulatory persons in their natural environments. PARTICIPANTS: Consenting patients with paroxysmal AF. MEASUREMENTS: Participants were fitted with a continuous electrocardiogram (ECG) monitor and an ankle-worn transdermal ethanol sensor for 4 weeks. Real-time documentation of each alcoholic drink consumed was self-recorded using a button on the ECG recording device. Fingerstick blood tests for phosphatidylethanol (PEth) were used to corroborate ascertainments of drinking events. RESULTS: Of 100 participants (mean age, 64 years [SD, 15]; 79% male; 85% White), 56 had at least 1 episode of AF. Results of PEth testing correlated with the number of real-time recorded drinks and with events detected by the transdermal alcohol sensor. An AF episode was associated with 2-fold higher odds of 1 alcoholic drink (odds ratio [OR], 2.02 [95% CI, 1.38 to 3.17]) and greater than 3-fold higher odds of at least 2 drinks (OR, 3.58 [CI, 1.63 to 7.89]) in the preceding 4 hours. Episodes of AF were also associated with higher odds of peak blood alcohol concentration (OR, 1.38 [CI, 1.04 to 1.83] per 0.1% increase in blood alcohol concentration) and the total area under the curve of alcohol exposure (OR, 1.14 [CI, 1.06 to 1.22] per 4.7% increase in alcohol exposure) inferred from the transdermal ethanol sensor in the preceding 12 hours. LIMITATION: Confounding by other time-varying exposures that may accompany alcohol consumption cannot be excluded, and the findings from the current study of patients with AF consuming alcohol may not apply to the general population. CONCLUSION: Individual AF episodes were associated with higher odds of recent alcohol consumption, providing objective evidence that a modifiable behavior may influence the probability that a discrete AF event will occur. PRIMARY FUNDING SOURCE: National Institute on Alcohol Abuse and Alcoholism.

The Longer the Block, the Harder You Fall: Extrinsic Idiopathic Atrioventricular Block Masquerading as Seizures.

History and physical examination are the diagnostic cornerstones of transient loss of consciousness (TLOC). However, details can be scarce and examination unrevealing, thus making the diagnosis elusive. In a case of convulsive TLOC, the initial diagnosis was incorrect, but a fortuitously captured event on telemetry yielded the diagnosis: extrinsic idiopathic atrioventricular block. (Level of Difficulty: Beginner.).

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.

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.

Atrial Fibrillation Triggered by Premature Ventricular Complexes: An Under-Recognized Trigger.

Atrial fibrillation (AF) is a triggered rhythm, and ablation of the trigger is a common strategy for rhythm control. We describe a patient with symptomatic AF who was found to have episodes of AF triggered by premature ventricular complexes, likely by retrograde atrioventricular nodal conduction. (Level of Difficulty: Beginner.).

Reported mortality with rotating sheaths vs. laser sheaths for transvenous lead extraction.

AIMS: Rotating sheaths and laser sheaths are commonly used for transvenous lead extraction. This study aims to compare observed mortality between both approaches. METHODS AND RESULTS: The Manufacturer and User Facility Device Experience database was searched from 2011 to 2016 to determine number of deaths associated with each sheath. An independent analytics firm provided estimates for number of cases done, allowing calculation of market share. A sensitivity analysis was performed to determine relative risk (RR) of mortality at the calculated market share (36% rotating/64% laser) and two others. Additional sensitivity analyses assumed underreporting of deaths associated with rotating sheaths. An estimated 50 545 extractions were performed. Thirteen deaths were associated with rotating sheaths compared to 167 with laser sheaths. Of these, 92% (rotating) and 95% (laser) were due to cardiovascular injury. At the calculated market share, the RR of death was 7.2 times greater with laser sheaths [95% confidence interval (CI) 4.1-12.7, P < 0.0001]. At market share estimates of 25% rotating/75% laser and 45% rotating/55% laser, the RR of death with laser sheaths was 4.3 (95% CI 2.4-7.5, P < 0.0001) and 10.5 times greater (95% CI 6.0-18.5, P < 0.0001), respectively. The RR of death remained significant when assuming deaths with rotating sheaths were underreported and when deaths using both sheaths were attributed to the rotating sheath. CONCLUSIONS: Lead extraction with laser sheaths appears to be associated with a higher risk of mortality compared to rotating sheaths. Further studies are warranted to confirm this finding.

NT -pro BNP as a Mediator of the Racial Difference in Incident Atrial Fibrillation and Heart Failure.

Background Blacks harbor more cardiovascular risk factors than whites, but experience less atrial fibrillation ( AF ). Conversely, whites may have a lower risk of heart failure ( CHF ). N-terminal pro-B-type natriuretic peptide ( NT -pro BNP) levels are higher in whites, predict incident AF , and have diuretic effects in the setting of increased ventricular diastolic pressures, potentially providing a unifying explanation for these racial differences. Methods and Results We used data from the CHS (Cardiovascular Health Study) to determine the degree to which baseline NT -pro BNP levels mediate the relationships between race and incident AF and CHF by comparing beta estimates between models with and without NT -pro BNP . The ARIC (Atherosclerosis Risk in Communities) study was used to assess reproducibility. Among 4731 CHS (770 black) and 12 418 ARIC (3091 black) participants, there were 1277 and 1253 incident AF events, respectively. Whites had higher baseline NT -pro BNP ( CHS : 40% higher than blacks; 95% CI , 29-53; ARIC : 39% higher; 95% CI , 33-46) and had a greater risk of incident AF compared with blacks ( CHS : adjusted hazard ratio, 1.60; 95% CI , 1.31-1.93; ARIC : hazard ratio, 1.93; 95% CI , 1.57-2.27). NT -pro BNP levels explained a significant proportion of the racial difference in AF risk ( CHS : 36.2%; 95% CI , 23.2-69.2%; ARIC : 24.6%; 95% CI , 14.8-39.6%). Contrary to our hypothesis, given an increased risk of CHF among whites in CHS (adjusted hazard ratio, 1.20; 95% CI , 1.05-1.47) and the absence of a significant association between race and CHF in ARIC (adjusted hazard ratio, 1.07; 95% CI , 0.94-1.23), CHF -related mediation analyses were not performed. Conclusions A substantial portion of the relationship between race and AF was statistically explained by baseline NT -pro BNP levels. No consistent relationship between race and CHF was observed.