Tachycardiomyopathy Complicated by Focal Atrial Tachycardia: Incidence, Risk Factors, and Long‐Term Outcome

AT‐Induced Cardiomyopathy Objective Focal atrial tachycardias (ATs) are known to have the potential to develop tachycardiomyopathy (TCM). The aim of the study was to investigate the incidence, risk factors, and long‐term outcome of TCM patients complicated by focal ATs. Methods and Results A total of 237 patients undergoing electrophysiological studies were enrolled, among which 216 patients were diagnosed as focal ATs. In total, 18 patients (8.3%, 13 males) were identified to have TCM. The TCM patients were younger (29.8 ± 20.1 vs. 45.9 ± 17.3; P < 0.000) and were more frequently males (13/18 vs. 80/198; P = 0.014). The ATs were more likely to be persistent (11/18 vs. 32/198; P < 0.001). There was no difference between the 2 groups in terms of the tachycardia cycle length (392 milliseconds vs. 380 milliseconds; P = 0.56) and heart rate (144 bpm vs. 156 bpm; P = 0.15). The persistence and incidence of symptoms and prevalence of structural heart disease were comparable between the groups. In a multivariable analysis, the younger age and persistent nature were independently associated with TCM. In a 56 ± 21‐month follow‐up, all TCM patients had improved left ventricle ejection fraction after successful catheter ablation or medical therapy (43.9 ± 5.8% vs. 61.1 ± 3.5%; P ＜ 0.05). However, 1 patient suffered sudden cardiac death due to unauthorized withdrawal of the drug and progressive heart failure. Conclusions The incidence of TCM in focal ATs patients was 8.3%. Younger age and persistent nature were the independent risk factors of TCM. Most TCM patients had a benign outcome; however, long‐term risk of sudden death does exist.