Sex differences in the origin of Purkinje ectopy-initiated idiopathic ventricular fibrillation

Abstract

BACKGROUND Purkinje ectopics (PurkEs) are major triggers of idiopathic ventricular fibrillation (VF). Identifying clinical factors associated with specific PurkE characteristics could yield insights into the mechanisms of Purkinje-mediated arrhythmogenicity. OBJECTIVE The purpose of this study was to examine the associations of clinical, environmental, and genetic factors with PurkE origin in patients with PurkE-initiated idiopathic VF.METHODS Consecutive patients with PurkE-initiated idiopathic VF from 4 arrhythmia referral centers were included. We evaluated demographic characteristics, medical history, clinical circumstances associated with index VF events, and electrophysiological characteristics of PurkEs. An electrophysiology study was performed in most patients to confirm the Purkinje origin.RESULTS Eighty-three patients were included (mean age 38 6 14 years; 44 [53%] women), of whom 32 had a history of syncope. Forty-four patients had VF at rest. PurkEs originated from the right ventricle (RV) in 41 patients (49%), from the left ventricle (LV) in 36 (44%), and from both ventricles in 6 (7%). Seasonal and circadian distributions of VF episodes were similar according to PurkE origin. The clinical characteristics of patients with RV vs LV PurkE origins were similar, except for sex. RV PurkEs were more frequent in men than in women (76% vs 24%), whereas LV and biventricular PurkEs were more frequent in women (81% vs 19% and 83% vs 17%, respectively) (P , .0001).CONCLUSION PurkEs triggering idiopathic VF originate dominantly from the RV in men and from the LV or both ventricles in women, adding to other sex-related arrhythmias such as Brugada syndrome or long QT syndrome. Sex-based factors influencing Purkinje arrhythmogenicity warrant investigation.

Idiopathic ventricular fibrillation associated with long‐coupled Purkinje ectopy

“…To further corroborate our findings with studies including patients with PVCs, we screened the references for eligible papers in two reviews 6,14 . We identified 19 examples of published figures 8,15–28 in which PVCs fall after the end of the T wave in patients with IVF.…”

Critical Requirements for the Initiation of a Cardiac Arrhythmia in Rat Ventricle: How Many Myocytes?

“…Furthermore, the ventricular wall structure contains sheets of cells that also could have a reduced dimensionality. The Purkinje fiber system and trabeculae have been identified as a source for arrhythmia [ 71 , 72 , 73 , 74 , 75 ]. These arrhythmias can arise as a result of ion channel dysfunction, for example through mutation.…”

Short or Long-Coupled Idiopathic Ventricular Fibrillation: Does the Coupling Interval Really Matter?

“…In a previous study involving 83 consecutive patients with Purkinje-initiated IVF from 4 arrhythmia referral centers, Surget and coworkers (9) found that Purkinje extrasystoles triggering idiopathic VF originate predominantly from the right ventricle in men and from the left ventricle or both ventricles in women. Although not specifically indicated, that study mainly included patients with SCIVF.…”

“…In the present study mainly dealing with LCPVC (n=12), 7 (64%) of the 11 patients with Purkinje ectopy triggering NSPVT were females and in all these 7 patients the left Purkinje system was involved. Triggered activities-as early afterdepolarization or delayed afterdepolarization-are the main mechanisms of Purkinje ectopy and well known to be increased by estradiol (9). This may explain some increase in female prevalence.…”