Diagnostic significance of some accessory systems of electrocardiographic leads in early diagnosis of myocardial infarction on the basis of vector analysis.

With a view to facilitating early diagnosis of myocardial infarction, the diagnostic significance was studied of 12 standard electrocardiographic leads and of accessory leads according to Nehb, Gurevich, and Slapak-Partilla. Attention was paid to the deflexion of the pathological vector from the positions of active electrodes in the above systems on the basis of vectorcardiographic findings. There were examined 300 patients with extensive myocardial infarction [84.7% of them already within 24 h after infarction] and 80 healthy control persons. Vectorcardiographic analysis showed that the Gurevich leads CKL, and the Slapak-Partilla leads S2(-4), and partially also S1, reflected lesions in posterobasal, and the Nehb leads, in lateral and posterolateral segments of left ventricular myocardium. Application of Gurevich leads and of Slapak-Partilla leads in combination with standard leads makes possible the recognition of lesions in both basal and septal segments of the posterior wall. Extensive necroses of this type should be termed extensive infractions of left ventricular posterior wall.