[Electrocardiographic changes in hypertensive emergencies. Their incidence and possible pathogenetic mechanisms]

The aim of the study was to analyse electrocardiographic alterations in 30 patients with slight to moderate essential arterial hypertension during the course of hypertensive attacks (DAP greater than 115 mmHg). Standard hematochemical tests were performed in basal conditions, together with 24-h ECG monitoring and an echocardiogram to measure the left ventricular mass index. Echographic monitoring was carried out during hypertensive attacks and for 2 h after the return to basal pressure values. In basal conditions patients showed slight hypopotassemia (23%), left ventricular echographic involvement (57%), left ventricular hypertrophy with or without systolic strain (43%), and ventricular extrasystole (VE) classified as Lown's 1st and 2nd class (17%). During the course of hypertensive attacks, there was a significant increase in systolic strain, the appearance of anterolateral subendocardial ischemia (10%), left anterior hemiblock (3%), lateral subepicardial ischemia (3%), and a marked increase in VE (67%) which were complex in 40% of cases (Lown's classes 3, 4 and 5). A significant correlation was found between the left ventricular mass index and VE/h. The authors stress the multifactorial pathogenesis of echographic alterations and underline left ventricular involvement, acute hemodynamic strain and consequent alterations of coronary perfusion, hypopotassemia, and increased levels of circulating catecholamines.