The Electrocardiogram of Myocardial Infarction : PART VII. NEHB'S LEADS

Abstract

Nehb's leabs, leads D, A and J, which was proposed by W. Nehb in 1938 were hardly regarded in the American and British literature. But in Germany Nehb's leads were appraised as considerably valuable in the diagnosis of myocardial infarction and some of the Japanese investigators also supported Nehb's opinion.In this paper, the value of the Nehb's leads in the diagnosis of infarction has been examined by the correlation between the electrocardiographic and post-mortem findings of 30 cases in the series of 35 cases of myocardial infarction. Of these 30 cases, in the majority the Wilson precordial leads, the Goldberger unipolar limb leads and the standard limb leads, and in few cases from two to five CF leads and the standard limb leads were taken together with the Nehb's leads.The author considered that in the diagnosis of infarction in the Nehb's leads one should also attach importance first to the appearance of an abnormal Q wave and in addition refer to the typical RS-T variations of infarction, similarly in the other leads.In 6 of 22 cases, in which the infarct was revealed in the posterior wall of the left ventricle at autopsy, lead D showed a deep Q wave which is more than one-third of the amplitude of R wave, and in 5 of these 6 cases, this change was accompanied by the elevation of RS-T segment and/or a inverted or flat T wave. This pattern was considered as the diagnostic change of posterior infarction. In 13 of the remaining 16 cases, lead D showed RS-T variations without a deep Q wave. The lesion in the posterior wall of these cases, in which an abnormal Q wave was recorded in lead D, was extensive in general. In only one of the cases, in which posterior infarct was confined to less than apical one-third of the posterior wall of the left ventricle at autopsy and the pattern of posterior infarct could not be found in the standard and unipolar limb leads, an abnormal Q wave was found in lead D in the acute stage of infarction. However, it is worthy of note in the diagnosis of posterior infarction that lead D displayed signs of infarction in 3 cases, in which signs of posterior infarction could not be found in leads _aV_F, III and II.In 8 of 13 cases with anterior or anterolateral infarction, leads A and J showed an abnormal Q wave and/or typical elevation of the RS-T segment and a coronary T wave. Consequently, these 8 cases were dignostic of anterior infarction in a broad sense. But, in all of these 13 cases, the multiple unipolar precordial leads could not only diagnose the infarction in all cases, but also were far more excellent than the Nehb's leads in the localization diagnosis of infarction. Lead A and J were of little value, when the multiple unipolar precordial leads were employed.