Tests for ischaemia and left ventricular function in young patients with effort-induced chest pain.

The type of angina pectoris was determined in 47 women and 27 men aged 40 or less who then underwent quantitative left cineventriculography, coronary arteriography and atrial pacing test with determination of lactate concentrations from arterial and coronary sinus blood samples. The 29/74 patients with atypical angina and no narrowings on coronary arteriography (Group I) gave no pathological atrial pacing tests but 9 had pathological lactate tests. Group II consisted of 27/74 patients with typical angina but normal coronary arteriography. In these the atrial pacing test was pathological in 20 and the lactate test in 11. Coronary narrowings of 50% or more were found in 18/74 patients (Group III), who all had pathological pacing tests but only 9 pathological lactate tests. No statistical differences could be elicited between diagnostic groups in the quantitative evaluation of left ventricular function and it could be regarded as normal in 42/74 patients. The left ventricular mass index exceeded the control level in 6 patients in Group I and in 10 patients in Group II who all had a net lactate production upon pacing. The end-diastolic volume index was above control level in 11 patients in Group II, in whom the ST depression in pacing test was the only finding indicating ischemia. The hoop stress values exceeded the control level in both of these subgroups. In Group III 7 patients had a high left ventricular mass index and 4 a billowing mitral leaflet. The changes observed suggest disturbed functioning of left ventricle.