[Recent myocardial infarction: incidence of the ventricular arrhythmias and correlations with some ecgraphic and hemodynamic parameters at rest and during exercise (author's transl)].

UNLABELLED

To assess incidence of ventricular premature beats (VPB) and correlate ECGraphic and hemodynamic data of parameters at rest and during exercise, 176 oligo or asymptomatic patients (167 males and 9 females) with recent myocardial infarction (RMI) (20-60 days after AMI) underwent a maximal symptom limited exercise test in supine position during hemodynamic monitoring (Swan-Ganz cath. 7F placed in pulmonary artery) without medical therapy. During the following 24 hours the patients underwent a continuous ambulatory ECG. 71 patients (40%) had no VPB (class 0), 56 patients (32%) had less than 1 VPB/hour (class 1), 35 patients (20%) had less than 6 VPB/minute and less than 30 VPB/hour (class 2) and 14 patients (8%) had greater than 6 VPB/minute and greater than 30 VPB/hour (class 3). Patients with VPB were then divided into qualitative classes: class A: 57 patients (54%) with isolated and unifocal VPB; class B: 38 patients (36%) with polifocal, bigeminal and paired VPB; class C: 10 patients (10%) with R on T or consecutive beats (3 or more). 28% of the patients had complex VPB (class B and C). 20% of all the patients (36/176) had VPB during exercise, 8 patients had VPB only during exercise, increasing the percentage of arrhythmias from 60% to 64%. VPB were more frequent and complex in patients with inferior or anterior + inferior MI than in patients with anterior MI and patients aged more than 60. Patients with complex VPB had cardiac volume index higher (p less than 0.05) than patients without VPB or with isolated VPB. Patients of different classes showed work capacity of 75-80 watts with 75-80% of maximal theoretic heart rate. Infarct size (NQ) was not correlated with number of VPB. Arrhythmias were slightly more frequent in patients with exercise ST depression (66%) than in patients without exercise ST depression (57%) (NS). No significant difference was found between ST elevation at rest and during exercise and VPB. PWP was, on the average, normal at rest (10 mmHg in the different classes) and slightly pathological during exercise with no differences between patients without VPB (class 0 = 21.7 mmHg) and patients with VPB (class 1 = 22.4 mmHg, Class 2 = 24.4 mmHg, Class 3 = 20.8 mmHg).

IN CONCLUSION

in oligo or asymptomatic patients with RMI: a) exercise slightly increased the sensitivity of continuous ambulatory ECG to reveal VPB b) poor correlations were found between VPB and ECGraphic and hemodynamic parameters both at rest and during exercise.