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Electrocardiographic Characteristics of Left Ventricular Outflow Tract Tachycardia
Author(s) -
HACHIYA HITOSHI,
AONUMA KAZUTAKA,
YAMAUCHI YASUTERU,
HARADA TOMOO,
IGAWA MASAYUKI,
NOGAMI AKIHIKO,
IESAKA YOSHITO,
HIROE MICHIAKI,
MARUMO FUMIAKI
Publication year - 2000
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.2000.tb07055.x
Subject(s) - medicine , cardiology , ventricular outflow tract , ventricle , ventricular tachycardia , qrs complex , tachycardia , catheter ablation , ablation
Catheter ablation of idiopathic left ventricular outflow tract tachycardia (LVOT‐VT) is rare because a safe ablation technique at this site has not been described, and serious complications may occur. This study compared the QRS morphology of LVOT‐VT with that of idiopathic right ventricular outflow tract tachycardia. A comparison was made between the electrocardiographic characteristics of LVOT‐VT originating from the supravalvular region of a coronary cusp (Supra‐Ao group) with those of LVOT‐VT originating from the infravalvular endocardial region of a coronary cusp of the aortic valve within the LV (Infra‐Ao group). After precise mapping of the right ventricle, left ventricle, pulmonary artery, coronary cusps, and proximal portion of the anterior interventricular vein, there were 17 patients in whom VT was thought to be located at the LVOT by both activation and pace mapping. They were divided between a Supra‐Ao group (n = 8), and an Infra‐Ao group (n = 9). Analysis of the 12‐lead electrocardiogram (ECG) revealed an S wave in lead I in all 17 patients. A precordial R wave transition was also observed at V 1 or V 2 in 16 patients (94%). In 7 of 8 patients (88%) with Supra‐Ao LVOT‐VT, no S wave was observed in either V 5 or V 6 . In contrast, an Rs pattern was observed in both V 5 and V 6 , or in V 6 only, in 100% of the patients with Infra‐Ao LVOT‐VT. A LVOT‐VT should be suspected when the ECG shows an S wave in lead I and an R/S ratio greater than 1 in lead V 1 or V 2 , versus a coronary cusp location if there is no S wave in either lead V 5 or V 6 .