[Correlations between vectorcardiographic data and effect of myocardial infarction on global and regional left...

The object of this study was to identify vector-cardiographic parameters (VCG) dependant on the size of myocardial infarction and its consequences on segmental left ventricular wall motion. Forty-five patients were selected for study after a complete haemodynamic investigation including quantitative analysis of LV wall motion. They were divided into three groups: Group I, comprising 15 normal control subjects; Group II, comprising 16 patients with abnormal LV wall motion related to anterior wall infarction due to a solitary lesion of the left anterior descending artery; Group III, comprising 14 patients with abnormal LV wall motion related either to posterior wall infarction or inferior wall infarction due to a solitary lesion of the right coronary or left circumflex arteries. Segmental wall motion was analysed by a semi-automatic programme derived from the Standford method. This programme detects the number of pathological segments in a ventricle and their shortening, and also determines a coefficient of severity of the abnormal zone. The VCG was performed according to Frank's principle and exploited using the computerised Arnaud RUBEL system. The characteristics of the instantaneous vectors were determined every 10 ms up to 60 ms: X, Y and 2 coordinates, amplitude, azimuth and elevation. These coordinates were compared with the segmental wall motion in every patient. There was a close correlation between LV regional wall motion abnormalities and the deflection of the initial vectors (during the first 40 ms) in the horizontal and frontal planes. A ROC statistical analysis showed that VCG was an excellent method of detecting abnormal LV wall motion.(ABSTRACT TRUNCATED AT 250 WORDS)