Unusual QRS alterations seen in continuous Electrocardiocorder recordings: Instances associated with myocarditis, bundle branch block, and angina pectoris

Abstract

Only 4 cases were found to show both striking and reversible alterations in the QRS portion of the electrocardiographic complex in our review of over 400 5-hour (or more) recordings from a miscellaneous group of 273 subjects, using the Holter Electrocardiocorder-AVSEP system to record continuous electrocardiograms. Snapshots of the basic pattern in each case are contrasted with the variations from that pattern to show the alteration in QRS. A case of myocarditis was associated with sudden reversals of polarity, both with and without changes in the ST-T segment. Two cases of bundle branch block showed changes in the pattern of the QRS associated with change of position and voiding. The fourth case showed three episodes of intraventricular block which coincided with expressions of anginal pain, the pain being proportional to the amount of block. These 4 instances of striking and reversible changes in the usually stable QRS portion of the whole electrocardiographic complex emphasize the unique utility of this system in capturing relatively infrequent variations in the continuous electrocardiogram. They suggest the potential value of this continuous electrocardiographic monitor system which is free of the previously necessary restrictions upon subject activity and/or subject locale. This system makes possible a new scope of electrocardiographic observations, and permits the development of some concept of how great a variation may occur in the electrocardiogram during the course of daily activity, or during illness.