[Significance of collaterals in protection of resting myocardial function in coronary heart disease (author's transl)].

The significance of collaterals for left ventricular function at rest was studied on the basis of 345 consecutive angiographies of patients with coronary heart disease. According to the severity of coronary stenosis, patients were assigned to groups with one-, two-, and three-vessel disease. Subgroups were formed based on the extent of narrowing in percent. All angiograms were examined for the presence and absence of collaterals. The significance of the collaterals in evidence was quantified in terms of a collateral score. To assess left ventricular function, global (left ventricular enddiastolic pressure, left ventricular enddiastolic volume, left ventricular ejection fraction) and regional (percentage hemiaxis shortening) parameters were employed. Within the groups with the same degree of coronary stenosis, no differences in left ventricular function were observed even when regrouping was carried out according to the presence or absence of collaterals. The collateral score, however, suggested that left ventricular function was better in patients with good collaterals than in those with poor collaterals. Regional parameters of left ventricular function underscore the protective effect of collaterals for left ventricular function at rest particularly clearly. Global parameters of left ventricular function do not demonstrate this relationship quite as decisively, since regional disturbances of contractile function may be compensated for by hypercontraction of other wall areas.