MORPHOLOGICAL EVALUATION OF IDIOPATHIC LEFTVENTRICULAR TACHYARRHYTHMIA FROM ANTERIORASPECTS OF MITRAL ANNULUS COMPARED WITH THOSEFROM AORTIC SINUS CUSPS

摘要

We previously reported that idiopathic left ventricular repetitive tachyarrhythmia can arise not only from LVOT but from the mitral annulus (MA-VT). Little is known about the morphology of MA-VT arising from anterior aspects of mitral annulus (anteriorMA-VT). This study was designed to confirm the electrocardiographic characteristics of anteriorMA-VT in comparison with VT arising from aortic sinus cusps (ASC-VT). Methods The site of the origin of MA-VT was in anterior aspect of mitral annulus in 11 out of 35 consecutive patients. The QRS morphology, the widest ventricular activation time(VAT) and the amplitude of each limb leads were compared with those of ASC-VT in 34 consecutive patients. Results Electrocardiographic analysis revealed that precordial R wave transition was almost always in lead VI and no S wave in V6 in both groups; however, QRS hi VI showed R wave in anteriorMA-VT and RS pattern in ASC-VT. VAT in anterior MA-VT was significantly wider than that of ASC-VT (95+-20 vs 75+-10ms, p<0.05), and the amplitude of lead aVF in anterior MA-VT were significantly smaller, compared with that in ASC-VT (1.7+-0.7 vs 2.2+-0.3mV, p<0.05). Conclusions Although the sites of the origin of those VTs are similar, there are clear differences of VAT and the amplitude of lead aVF in two groups.