Examination of the validity of the concept of vectorcardiography.

Full recognition must be given to the pioneers who have made what is known as vectorcardiography possible, and who have added a most useful tool to the armamentarium of the cardiologist, but it is pertinent to ask whether this newer method of recording the electrical activity of the heart has kept its early promise. Before one can attempt to answer this question it is necessary to ask another two, namely whether vectorcardiographers themselves agree that this is the case, and whether they agree among themselves upon the best way of recording vectorcardiograms. There certainly is unanimity among them that vectorcardiography is valuable, but they are not able to agree on the best electrode placements-and one obtains as many variations of the recordings as there are systems of electrode placement. Much work has been done and much time has been spent in attempting to correlate these variations mathematically, and even to equate them with the purely synthetic vectorcardiogram constructed graphically from the scalar electrocardiographic leads of the Einthoven system. A most complex terminology concerning lead vectors, vector images, lead field concepts, and so on, has arisen, which is confusing to the uninitiated and deters many a clinician from taking up this most rewarding method of investigation. The reason for the existence of these various electrode placements is that several different theories have been propounded for siting the electrodes in a particular way. Without, for the moment, considering their individual merits, it must be obvious that these cannot all be correct. Moreover, there is no positive and logical proof which is the correct oneor whether indeed any one of them is correct. In fact no proof is possible. If such proof existed, then all other theories and electrode placements would naturally fall away, and there would remain