title: Advantages of high-speed simultaneous electrocardiography: re-evaluation of r waves in V1, the initial forces in V6 and abnormal Q waves.
abstract: The main aim of this study is to re-evaluate the r wave in V1 (rV1) and the initial forces in V6 with normal QRS duration. A total of 741 high-speed simultaneous electrocardiograms of V1 and V6 with either aVF or aVL as reference lead were recorded in patients with cardiac or noncardiac conditions. Patients with a QS pattern in V1 and/or a wide QRS complex were excluded. The peak of rV1 was beyond the nadir of the q wave in V6 (qV6) in 448 patients but coincided with the nadir of qV6 in 51 patients. The onset of the R wave in V6 (RV6) with absent qV6 was delayed in comparison with the onset of rV1 in 210 patients but coincided with the onset of rV1 in 30 patients. In this study, the nadir of a q wave either in aVL and/or aVF was never beyond the peak of an r wave in V1 except for high lateral and/or inferior infarction. In many cases rV1 appears to represent both septal activation and right ventricular activation. The absence of qV6 with some delay in the onset of RV6 in comparison with the onset of rV1 might indicate a nonpathologic absence of qV6 due to masked septal potential in the isoelectric line in V6, although the absence of qV6 with simultaneous onset of rV1 and RV6 may suggest septal abnormalities. An abnormal Q wave in aVL and/or aVF may be defined as that the nadir of q wave exceeded the peak of r wave in V1.
authors.affiliation: Department of Cardiology Ohfuna Central General Hospital, Kamakura, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016001:Confidence Intervals; D004562:Electrocardiography / Q000379:methods*; D006331:Heart Diseases / Q000175:diagnosis; D006801:Humans; D008875:Middle Aged