The monophasic action potential: a simple in vivo model to evaluate the effects of antiarrhythmic drugs at atrial level.
Monophasic action potential (MAP) represents an extracellular recording of electrical potentials variations produced simultaneously by several cells. Even if it does not represent the real cellular action potential, monophasic action potential generally reproduces with accuracy that aspect, being useful especially in the assessment of myocardial repolarisation phases. Monophasic action potential recording was performed with a quadripolar catheter designed by Franz; the quality of recordings was good and the procedure is safe. In clinical electrophysiology, monophasic action potential may be helpful in the study of certain aspects that cannot be evaluated adequately by standard electrophysiological techniques. The study was performed on six patients, in drug-free state. The duration of monophasic action potential at 90% of repolarisation and the atrial effective refractory period, at three basic cycle lengths (600, 500 and 400 msec) were determined. Both monophasic action potential duration at 90% of repolarisation and the atrial effective refractory period shortening at short cycle length and a linear correlation between these two parameters were seen. We conclude that the correlation between monophasic action potential duration and the effective atrial refractory period may be a simple and useful model to characterise in vivo the electrophysiologic profile of antiarrhythmic drugs.
Dobreanu
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D
Department of Physiology, University of Medicine and Pharmacy, Târgu-Mureş, Romania.
Caraşca
E
E
Cotoi
S
S
D000200:Action Potentials / Q000187:drug effects; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000503:physiopathology; D001282:Atrial Flutter / Q000188:drug therapy / Q000503:physiopathology; D006328:Cardiac Catheterization / Q000295:instrumentation / Q000379:methods; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004562:Electrocardiography / Q000295:instrumentation / Q000379:methods; D004566:Electrodes; D006321:Heart / Q000187:drug effects* / Q000503:physiopathology*; D006325:Heart Atria / Q000187:drug effects / Q000503:physiopathology; D006801:Humans; D008955:Models, Cardiovascular; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation
D000889:Anti-Arrhythmia Agents