Related factors of tachycardia-induced cardiomyopathy caused by atrial tachycardia in children

Abstract

Objective To investigate the correlation between various types of atrial tachycardia(AT) and tachycardia-induced cardiomyopathy(TIC) in children and to assess the risk factors for the development of TIC. Methods Patients with AT were divided into 2 groups depending on whether complicated with TIC or not, defined as left ventricular ejection fraction(LVEF)<50% on echocardiography.The presence of atrial rhythm in Holter monitoring, ventricular rate of AT, and the type of AT onset were compared between the 2 groups; the risk factors associated with TIC were also analyzed. Results Totally 72 patients were enrolled in this study.The incidence of TIC was 23.6%.The incidence of TIC in patients presenting incessant tachycardia was significantly higher than that of patients presenting paroxysmal tachycardia(53.6% vs 4.5%, P<0.01). Patients with TIC had a higher mean atrial rhythm percent[(98±5)% vs (37±4)%, P<0.001] and faster mean ventricular rate [(134.25±19.24) beats/min vs(100.03±18.83) beats/min, P<0.05] compared with those without TIC.After successful control of tachycardia, LVEF in patients with TIC gradually recovered within 6 to 75 days [(29.44±21.62) days]. Conclusions An incessant AT with higher percent of atrial rhythm and faster mean ventricular rate is more frequently complicated by cardiomyopathy.Recovery of TIC can be achieved after successful control of AT.Early intervention and treatment should be performed for those with high risk factors for the development of TIC. Key words: Atrial tachycardia; Tachycardia-induced cardiomyopathy; Child