Vector analysis of the electrocardiogram in hypertension before and immediately after bilateral lumbodorsal sympathectomy

0 NE OF the interesting results of the surgical treatment of essential hypertension has been improvement in the electrocardiogram. The contention that these changes indicate improvement in the heart itself, while plausible, may not be entirely without sophistry. A study of the electrocardiogram by means of vector analysis in cases of arterial hypertension was undertaken, therefore, in the hope of clarifying the mechanism of the electrocardiographic abnormalities in this disease; and especially in the hope of contributing to an understanding of the changes which may follow extensive lumbodorsal sympathectomy.‘J The concept of semiquantitative analysis of the electrocardiogram by means of measurement of the area beneath the depolarization waves (QRS) and the electrical record of repolarization (ST-T) as a means of studying the time course of these events as they are projected on the frontal plane in standard limb leads has possible advantages over empirical interpretation. A larger experience and greater familiarity with the empirical method is its chief claim to superiority. The credibility of the concept of vector analysis and the ventricular gradient, first advanced by Wilson and co-workers3 is not subject, at the moment, to a great deal of controversy, but the available methods of measuring these vectors are not beyond criticism. The sources of error are manifold, but, crude as the methods may be, the semiquantitative analysis may give useful information.