Clinical characteristics and therapeutic strategy of frequent accelerated idioventricular rhythm

Abstract

Background: Accelerated idioventricular rhythm (AIVR) is often transient, considered benign and requires no treatment. This observational study aims to investigate the clinical manifestations, treatment, and prognosis of frequent AIVR.

Methods: Twenty-seven patients (20 male; mean age 32.2 ± 17.0 years) diagnosed with frequent AIVR were enrolled in our study. Inclusion criteria were as follows: (1) at least three recordings of AIVR on 24-h Holter monitoring with an interval of over one month between each recording; and (2) resting ectopic ventricular rate between 50 to 110 bpm on ECG. Electrophysiological study (EPS) and catheter ablation were performed in patients with distinct indications.

Results: All 27 patients experienced palpitation or chest discomfort, and two had syncope or presyncope on exertion. Impaired left ventricular ejection fraction (LVEF) was identified in 5 patients, and LVEF was negatively correlated with AIVR burden (P < 0.001). AIVR burden of over 73.8%/day could predict impaired LVEF with a sensitivity of 100% and specificity of 94.1%. Seventeen patients received EPS and ablation, five of whom had decreased LVEF. During a median follow-up of 60 (32, 84) months, LVEF of patients with impaired LV function returned to normal levels 6 months post-discharge, except one with dilated cardiomyopathy (DCM). Two patients died during follow-up. The DCM patient died due to late stage of heart failure, and another patient who refused ablation died of AIVR over-acceleration under fever.

Conclusions: Frequent AIVR has unique clinical manifestations. AIVR patients with burden of over 70%, impaired LVEF, and/or symptoms of syncope or presyncope due to over-response to sympathetic tone should be considered for catheter ablation.

Keywords: Accelerated idioventricular rhythm; Catheter ablation; Electrophysiology; Ventricular arrhythmia.

Fig. 1

A representative ECG recording of AIVR originating from the left HPS (a left panel, left anterior fascicular), right HPS (a right panel), left ventricular working myocardium (b left panel), and right ventricular working myocardium (b right panel). Note that it is competitive with the sinus rhythm. AIVR, accelerated idioventricular rhythm; ECG, electrocardiography; HPS, His-Purkinje system

Fig. 2

The phenomenon of AIVR competing with the sinus rhythm. AIVR, accelerated idioventricular rhythm

Fig. 3

ROC curve of AIVR burden for predicting impaired LVEF. The AUC was 0.971. AIVR burden was negatively correlated with LVEF (P < 0.001). An AIVR burden of over 73.8%/day was predictive of impaired LVEF (< 50%), with a sensitivity of 100% and a specificity of 94.1%. AIVR, accelerated idioventricular rhythm; LVEF, left ventricular ejection fraction

Fig. 4

Schematic diagram of the distribution of frequent AIVR foci. A, aortic annulus; AIVR, accelerated idioventricular rhythm; LAF, left anterior fascicular; LCC, left coronary cusp; LPF, left posterior fascicular; MB, moderator band; MV, mitral valve; NCC, noncoronary cusp; P, pulmonary annulus; RBB, right bundle branch; RCC, right coronary cusp; TV, tricuspid valve

Fig. 5

Ablation of AIVR with an RBB focus (Patient 27). A decapolar catheter was placed along the HIS-RBB axis. Upper panel: The activation of HIS-RBB went from proximal to distal (green arrow), but was reversed during AIVR (red arrow). Lower panel: The ablation target on the endocardial electrogram and three-dimensional mapping. Please note the advanced Purkinje potential on ablation catheter. ABL, ablation catheter; AIVR, accelerated idioventricular rhythm; CS, coronary sinus; HRA, high right atrium; RBB, right bundle branch

Fig. 6

Flowchart depicting frequent AIVR management. BEST is the abbreviation of the following criteria: over 70% Burden, impaired LVEF, or Syncope or presyncope due to over-response to sympathetic Tone. AIVR, accelerated idioventricular rhythm