[Electrocardiogram in interstitial pneumonia. Electrocardiographic-hemodynamic correlation].

Twenty four patients with interstitial pulmonary disease from the Cardiopulmonary Service of the Instituto Nacional de Cardiología were studied. Surface electrocardiograms and pulmonary hemodynamic studies were registered to all patients in order to obtain the pulmonary vascular resistances and pressures to find out the electrocardiographic-hemodynamic correlation. Three groups were made according to the pulmonary artery sistolic pressure: Group I, 30 to 45 mm Hg (6 patients); Group II, 46 to 70 mm Hg (12 patients) and Group III more of 60 mm Hg (6 patients). Also, arterial gaseous partial pressures were determined, among other pulmonary test parameters. Electrocardiographically, the rhythm, A=V node conduction, AQRSF, APF, atrial and ventricular hypertrophy, intraventricular conduction and ventricular repolarization were studied in leads II, III, aVF, aVR, V1, V2, V3 and V6. The characteristics of the ventricular repolarization and depolarization processes of each group are described, in order to discuss the mechanism of the anormalities. Finally, the electrocardiographic findings were correlated with the different degrees of pulmonary arterial hypertension; the conclusions are: I. The electrocardiogram allows us to differenciate the patients with III degree of arterial pulmonary hypertension, from those of I and II degrees. II. Patients with I and II degrees of pulmonary arterial hypertension determine nearly the same electrocardiographic alterations; the mean differences to establish the differential diagnosis is the AQRSF, shifted to the right and upwards, in the II degree of pulmonary arterial hypertension.