Electrophysiological and clinical characteristics of catheter ablation for isolated left side atrial tachycardia over a 10-year period.

AIMS: Most left atrial tachycardia (LAT) is associated with atrial fibrillation (AF). The clinical and electrophysiological characteristics and outcomes of LAT without AF have not been investigated. This study sought to determine the long-term ablation outcomes and predictors of recurrence of isolated LAT. METHODS: This is a single-center study of consecutive patients with isolated LAT. Atrial arrhythmia recurrence was determined from follow-up records of patients who underwent LAT ablation from 2008 to 2017. Clinical and electrophysiologic characteristics associated with atrial arrhythmia recurrence were identified. RESULTS: A total of 50 patients (53 ± 19 years, 46% male) with 59 LAT (1.16 ± 0.47 per patient) were enrolled. Over a mean follow-up of 37 ± 33 months, atrial arrhythmia recurrence occurred in 22 (44%) patients, 11 with atrial tachycardia (AT) only, five with AF only, and six with concurrent AT and AF. The incidence of pulmonary vein (PV) origins increased significantly in the repeat procedure (P = 0.036). Multivariate analysis identified left ventricular ejection fraction (LVEF) as the only predictor of any atrial arrhythmia recurrence and LAT recurrence, while smoking and identified macroreentrant LAT in the index procedure predicted AF recurrence. CONCLUSION: This study demonstrated a higher rate of atrial arrhythmia recurrence, including AF, among patients with initially isolated LAT. A lower LVEF predicted any atrial arrhythmia and LAT recurrence, whereas smoking and index macroreentrant AT mechanism predicted long-term AF. PV ATs were frequently observed in recurrent patients irrespective of index procedure origin.

Intermediate Pause at Daytime Is Associated With Increased Cardiovascular Risk and Mortality: An 8-Year Cohort Study.

BACKGROUND: Long-term cardiovascular risk in patients with intermediate pauses remains unclear. Whether asymptomatic patients with intermediate pauses have increased future cardiovascular events remains unknown. We hypothesize that intermediate pause is associated with increased cardiovascular risk and mortality. METHODS AND RESULTS: We retrospectively analyzed 5291 patients who have pauses of <3 seconds on 24-hour Holter monitoring. Patients with pauses of 2 to 3 seconds constitute the intermediate pause patients, who are further divided into daytime pause (8:00 am-8:00 pm), nighttime pause (8:00 pm-8:00 am), and daytime plus nighttime pause groups depending on the occurring time of the pauses. The rest of the patients (pause <2 seconds) are the no pause group. The multivariate Cox hazards regression model was used to assess the hazard ratio for mortality (primary outcome) and adverse cardiovascular events (secondary outcome). There were 4859 (91.8%) patients in no pause, 248 (4.7%) in nighttime pause, 103 (1.9%) in daytime pause, and 81 (1.5%) in daytime plus nighttime pause groups. After a follow-up of 8.8±1.7 years' follow-up, 343 (6.5%) patients died. The risk for adverse cardiovascular events, including all-cause hospitalization, cardiovascular-cause hospitalization, pacemaker implantation, new-onset atrial fibrillation/heart failure, and transient ischemic attack, were higher in daytime pause and nighttime pause patients than those in the no pause group. Daytime pause (hazard ratio, 2.35; P=0.008) and daytime plus nighttime pause (hazard ratio, 2.26; P=0.016) patients have a higher mortality rate than that in nighttime pause. CONCLUSIONS: Patients with intermediate pause are associated with increased cardiovascular risk. Intermediate pauses occurring at daytime have a higher mortality rate than that at nighttime during long-term follow-up.