[Electrocardiographic diagnosis in atrioventricular discordance]

The ECG of 37 patients with atrioventricular discordance were studied and divided in two main groups: I) Situs solitus and II) situs inversus, either a) without associated defects or b) with associated defects. It was concluded: 1) The first vector of ventricular activation, oriented in the same sense of that of atrial activation is a fundamental diagnostic sign; 2) The preponderance of anatomical right ventricle, leads to the diagnosis of unassociated defects; 3) The recognition of biventricular hypertrophy obliges to the diagnosis of associated defects; 4) The AQRS deviation and the shortening in duration of the local electrical systole help to recognized the hypertrofied ventricle and its overload; 5) The presence of right bundle branch block is not in relation to the degree of overloading; 6) The primary alterations of ventricular repolarization are univocal signs of myocardial damage.