McLeod, Christopher J.

Background: Recognition of rates and causes of hard, patient-centered outcomes of death and cerebrovascular events (CVEs) after heart rhythm disorder management (HRDM) procedures is an essential step for the development of quality improvement programs in electrophysiology laboratories. Our primary aim was to assess and characterize death and CVEs (stroke or transient ischemic attack) after HRDM procedures over a 17-year period. Methods: We performed a retrospective cohort study of all patients undergoing HRDM procedures between January 2000 and November 2016 at the Mayo Clinic. Patients from all 3 tertiary academic centers (Rochester, Phoenix, and Jacksonville) were included in the study. All in-hospital deaths and CVEs after HRDM procedures were identified and were further characterized as directly or indirectly related to the HRDM procedure. Subgroup analysis of death and CVE rates was performed for ablation, device implantation, electrophysiology study, lead extraction, and defibrillation threshold testing procedures. Results: A total of 48 913 patients (age, 65.7±6.6 years; 64% male) who underwent a total of 62 065 HRDM procedures were included in the study. The overall mortality and CVE rates in the cohort were 0.36% (95% confidence interval [CI], 0.31–0.42) and 0.12% (95% CI, 0.09–0.16), respectively. Patients undergoing lead extraction had the highest overall mortality rate at 1.9% (95% CI, 1.34–2.61) and CVE rate at 0.62% (95% CI, 0.32–1.07). Among patients undergoing HRDM procedures, 48% of deaths directly related to the HDRM procedure were among patients undergoing device implantation procedures. Overall, cardiac tamponade was the most frequent direct cause of death (40%), and infection was the most common indirect cause of death (29%). The overall 30-day mortality rate was 0.76%, with the highest being in lead extraction procedures (3.08%), followed by device implantation procedures (0.94%). Conclusions: Half of the deaths directly related to an HRDM procedure were among the patients undergoing device implantation procedures, with cardiac tamponade being the most common cause of death. This highlights the importance of the development of protocols for the quick identification and management of cardiac tamponade even in procedures typically believed to be lower risk such as device implantation.

AbstractIntroductionCardiac pacing from the right ventricular apex is associated with detrimental long‐term effects and nonapical pacing locations may be associated with improved outcomes. There is little data regarding complications with nonapical lead positions. The aim of this study was to assess long‐term outcomes and lead‐related complications associated with differing ventricular lead tip position.Methods and resultsAll adult patients who underwent dual‐chamber pacemaker implantation from 2004 to 2014 were included if they had postprocedure chest radiographs amenable to lead position determination. Long‐term outcomes and lead‐related complication rates were recorded. These were compared at 5 years between: (1) apical and septal leads, (2) apical and nonseptal nonapical (NSNA), and (3) apical and septal with >40% ventricular pacing. We retrospectively evaluated 3,450 patients, which included 238 with a septal position and 733 with NSNA lead positions. Septal lead position was associated with a lower mortality compared to apical leads (24% vs. 31%, P = 0.02). In patients with greater than 40% pacing, septal leads were associated with significantly higher rates of incident atrial fibrillation compared to apical leads (49% vs. 34%, P = 0.04). NSNA positions were associated with a significantly higher rate of lead dislodgement (4% vs. 2%, P = 0.005) and need for revision (8% vs. 5%, P = 0.005).ConclusionsSeptal pacemaker lead position is associated with a lower mortality compared to apically placed leads, but a higher incidence of atrial fibrillation with higher percentage ventricular pacing. NSNA lead locations are associated with more complications and should be avoided.

Background— Ventricular tachycardia and premature ventricular complexes (PVCs) most frequently occur in the context of structural heart disease. However, the burden of idiopathic ventricular arrhythmias (IVA) in the general population is unknown. Methods and Results— We identified incident cases of IVA between 2005 and 2013 from Olmsted County, Minnesota, using the Rochester Epidemiology Project database. For PVC cohorts, we included those with frequent (defined as ≥100 PVC/24 hours) symptomatic PVCs. We defined IVA-associated cardiomyopathy as a drop in ejection fraction of ≥10% from baseline. Between 2005 and 2013, we identified 614 individuals with incident IVA (229 [37.3%] were male; average age was 52.1±17.2 years). Of these, 177 (28.8%) had idiopathic ventricular tachycardia, 408 (66.5%) had symptomatic PVCs, and 29 (4.7%) had IVA-associated cardiomyopathy. The age- and sex-adjusted incidence rates in 2005 to 2007, 2008 to 2010, and 2011 to 2013 were 44.9 per 100 000 (95% confidence interval [CI], 38.0–51.8), 47.6 per 100 000 (95% CI, 40.8–54.5), and 62.0 per 100 000 (95% CI, 54.4–69.6), respectively. In idiopathic ventricular tachycardia, there was an increase in incidence rate with ages ( P <0.001) but not between sexes ( P =0.12). The age-adjusted incidence of symptomatic PVC was higher in females than in males (46.2 per 100 000 [95% CI, 40.9–51.6] versus 20.5 per 100 000 [95% CI, 16.8–24.3]; P <0.001). The small number of individuals with IVA-associated cardiomyopathy precluded any formal testing. Conclusions— The incidence of IVA is increasing. Furthermore, overall incidence increases with age. Although the rate of idiopathic ventricular tachycardia is similar across sexes, women have a higher incidence of symptomatic PVC.

Raghib defect and double-orifice tricuspid valve are two rare congenital heart defects. We report a case of a 42-year-old man with both Raghib defect and DOTV. The patient underwent reroofing of the coronary sinus with an intra-atrial baffle and annuloplasty of the tricuspid and mitral valves via median sternotomy.

Introduction: The therapeutic trough range for mexiletine (0.8–2 mcg/mL) was largely established in the setting of arrhythmia prophylaxis following myocardial infarction. Objective: Describe the usage patterns of serum mexiletine concentrations and the impact of these concentrations on mexiletine dosing in modern practice for ventricular arrhythmia treatment. Methods: A single-center, retrospective analysis was conducted using the electronic medical record to identify serum mexiletine concentrations drawn between December 2004 and December 2014. The primary endpoint was the incidence of mexiletine concentrations drawn as troughs. Secondary outcomes included the incidence of mexiletine concentrations that prompted a dose change, association between adverse events and elevated concentrations, and association between baseline characteristics and mexiletine concentrations. Results: A total of 237 individual concentrations were included for analysis with 109 (46.0%) drawn appropriately as trough concentrations. Only 31 (13.1%) of the 237 concentrations drawn prompted a dose change. Mexiletine was primarily used for the treatment of ventricular arrhythmias (96.2%), and 108 (45.6%) concentrations were drawn in an effort to assess efficacy. The median concentration was statistically different between patients with and without an adverse event (0.8 vs 0.7 mcg/mL, respectively; p = 0.017), but may not represent a clinical significance. Patients with hepatic dysfunction had higher median concentrations compared to those without hepatic dysfunction (1.30 vs 1.07 mcg/mL; p = 0.01). Conclusion: Mexiletine concentrations are often drawn at inappropriate times and seldom influence a dose change. This study suggests that routine monitoring of mexiletine concentrations may not be necessary; however, therapeutic drug monitoring may be considered in patients with hepatic dysfunction or to confirm mexiletine absorption in patients where this represents a concern.