Prevalence and Electrocardiographic Characteristics of Idiopathic Ventricular Arrhythmia Originating in the Free Wall of the Right Ventricular Outflow Tract

Abstract

adiofrequency (RF) catheter ablation is an established curative therapy for ventricular tachycardias (VT) or symptomatic premature ventricular contractions (PVCs) originating from the outflow tract (OT-VT/PVCs) in structurally normal hearts. [1][2][3][4][5][6][7][8][9][10][11][12][13] Although most of these arrhythmias have their origin in the septal aspect of the right ventricular outflow tract (RVOT), [1][2][3][4][5][6][7][8][9]14 some originate from the free wall of the RVOT. 3,4,14 However, the prevalence and electrocardiographic (ECG) characteristics of idiopathic VT or PVC originating in the free wall of the RVOT have not been sufficiently clarified and the present study was undertaken to determine these. Methods Patient GroupThe study included 110 patients with symptomatic VT or PVCs who underwent successful RF catheter ablation at the RVOT: 41 men and 69 women, with a mean age of 50±16 years (± SD; range, 21-81 years). During the clinical arrhythmia, the surface ECG showed a left bundle branch block morphology with an inferior axis in all patients. Thirty-four patients had monomorphic VT, defined as 3 or Circulation Journal Vol. 68, October 2004 more consecutive PVCs; 76 had monomorphic PVCs. All patients had a normal ECG during sinus rhythm, and no structural abnormalities were found by physical examination or echocardiography. None had electrolyte abnormalities, metabolic disorders or advanced systemic disease. The selection criteria of the patients with a PVC included: (1) severe symptoms (including palpitations, asthenia and vertigo) for a period of months or years that were clearly related to frequent PVCs; and (2) inability of the patient to tolerate, or unsuccessful treatment with, at least one antiarrhythmic drug or the patient did not wish to take long-term antiarrhythmic medications because of special reasons (eg, young women who want to become pregnant). To determine the precise origin of the OT-VT/PVC and to evaluate the short-term effects of RF ablation, patients were enrolled in this study provided that the clinical arrhythmia occurred spontaneously or could be induced during the ablation procedure. These criteria excluded 8 patients prior to initiation of the study. In 1 patient, nearly identical ventricular activations were recorded from both the RVOT and left sinus of Valsalva, and RF applications at both sites could not ablate the OT-VT/PVC. In the remaining 7 excluded patients, the OT-VT/PVC could not be induced during the procedure. Mapping and RF AblationAfter informed consent was obtained and anti-arrhythmic drugs had been withdrawn, electrophysiologic evaluation and catheter ablation were performed as previously described. Under fluoroscopic guidance, catheters were introduced into the high right atrium, right ventricular (RV) Circ J 2004; 68: 909 -914

Electrophysiological Characteristics of Idiopathic Ventricular Tachycardia in Children

“…Organic heart disease was excluded by physical examination, chest radiography, and echocardiography. The 46 children (18 males, 28 females) with a mean age of 11.7± 3.4 years (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) were included in this study. Their mean body weight was 41.6±14.2 kg (17.9-71.6 kg), mean body length 147.1±18.3 cm (109.4-178.0 cm), and mean body surface area 1.30±0.30 m 2 (0.74-1.85 m 2 ).…”

Successful Catheter Ablation of Left Ventricular Epicardial Tachycardia Originating From the Great Cardiac Vein A Case Report and Review of the Literature

“…[1][2][3][4][5][6][7][8] It is well known that some I-VTs can be eliminated by RFCA at the endocardium of the left ventricular outflow tract (LVOT) or the left sinus of Valsalva (LSV). [1][2][3]8 However, some that arise from the epicardial portion of the LVOT are remote from the LSV or left ventricular (LV) endocardium and are not amenable to ablation at those sites.…”

Association of Human SCN5A Polymorphisms With Idiopathic Ventricular Arrhythmia in a Chinese Han Cohort

“…19,20 This case-control study investigated the association between IVA and SCN5A SNPs, in which overall 11 genetic variations including 5 novel and 6 previously identified ones were detected in 31 unrelated Chinese patients with IVA and 103 healthy controls. The study showed significant difference in distribution of c.87G>A and c.1673A>G between men and women in healthy subjects.…”