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MCL 1 and MCL 6 Compared to V 1 and V 6 in Distinguishing Aberrant Supraventricular from Ventricular Ectopic Beats
Author(s) -
DREW BARBARA J.,
SCHEINMAN MELVIN M.,
DRACUP KATHLEEN
Publication year - 1991
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.1540-8159.1991.tb02883.x
Subject(s) - medicine , qrs complex , supraventricular arrhythmia , cardiology , precordial examination , electrocardiography , atrial fibrillation
Use of V 1 and V 6 has been suggested for distinguishing aberrant supraventricular from ventricular ectopy, For two decades, “modified” leads MCL 1 and MCL 6 have been widely used as V 1 and V 6 substitutes for bedside monitoring, but their use has never been validated. To determine the value of MCL 1 and MCL 6 , 81 morphologically distinct wide QRS ectopic beats were recorded from 46 patients during cardiac electrophysiological study. As determined by the His‐bundle electrogram, 31 of the ectopics were aberrant supraventricular, 50 were ventricular, A new criterion, measurement of QRS onset to the predominant peak or nadir of the complex, was valuable in diagnosing wide complexes in MCL 6 and V 6 . An interval of SO msec or less predicted aberrant Supraventricular ectopy; an interval of 70 msec or more predicted ventricular ectopy. There was agreement between the modified and conventional precordial leads regarding which QRS patterns were useful in distinguishing aberrant supraventricular from ventricular ectopy, A greater proportion of wide complexes in MCL 1 and V 1 exhibited patterns useful in making the diagnosis compared to MCL 6 and V 6 . Using well‐established criteria, the proportion of correct diagnoses that was made from individual leads was: MCL 1 —86%, V 1 = 85%, MCL 6 = 72%, V 6 = 67%. The bedside leads (MCL 1 and MCL 6 ) were not statistically different in diagnostic accuracy from their conventional lead counterparts (V 1 and V 6 ); however, MCL 1 and V 1 were superior to MCL 6 and V 6 , When the new criterion was added to make the diagnosis from MCL 6 and V 6 no difference in diagnostic accuracy was present between the four leads.