Differentiates between normal and abnormal cardiac rhythms and uses deductive reasoning with ambiguous arrhypthmias which includes sinus mechanism, sinus tachycardia, sinus bradycardia, sinus pause and arrest, sinus arrhythmia , SA block, wandering atrial pacemaker, supraventricular extra systoles (atrial and junctional) atrial and junctional tachycardia, conducted and nonconducted impulses, aberrant conduction, atrial flutter, artrial fibrillation, ventricular extrasystoles (unifocal , multifocal) ventricular bigeminy, interpolated VPCs R on T, late cycle complexes, fusion complexes, ventricular couplets and triplets, ventricular tachycardia, indioventricular rhythms, parasystolic rhythms, ventricular escape rhythms, ventricular flutter or fibrillation, first degree AV block, 2nd degree AV block (type I and II), 3rd degree AV block, high grade AV block, AV dissociation, ST elevation, ST depression, T wave changes, and interventricular conduction defect. Utilizes techniques of high speed scanning including recognizing the effects of arrhythmias on various portions of the cardiac cycle during superimposition and using the ECG audio-reproduction in conjunction with visual inspection.