[Cardiac angioscintigraphy at equilibrium coupled with isoproterenol perfusion. Method of diagnosing chronic coronary insufficiency].

The effects of isoproterenol (IPNA) on global and regional left ventricular wall motion were studied by cardiac angioscintigraphy at equilibrium performed under basal conditions, during IPNA administration (per IPNA) and 10 minutes after (post IPNA) in 50 patients classified by coronary angiography as coronary (C) (n = 37) and non-coronary (NC) patients (n = 13), 5 reference subjects (REF) and 8 non-coronary pathology. The effects were assessed from variations of global LV function and from indices of regional wall function (12 regional ejection fractions - REF). The IPNA perfusion was well tolerated, even in patients with severe coronary lesions. 1. Diagnosis of myocardial dysfunction due to coronary artery disease: it was possible to separate the patients into C and NC groups according to the variations in EF, end systolic (ESV) and REF, especially post IPNA: NC group: per IPNA: 12/13 NC patients showed an increase in EF (+10.7%), a decrease in ESV (-41%) and increased or stable REFs. Post IPNA: 10/13 had raised EF (+4.6%), 9/13 had a reduced ESV (-17.4%) and 10/13 had stable or increased REF. C group: per IPNA: 15/37 C patients showed decreased EF, 12/37 had increased ESV and 15/37 had a decrease in at least two ref greater than or equal to 5%. Post IPNA: 25/37 had decreased EF, 21/37 increased ESV, 34/37 had at least two reduced REFs. These results show that decreased ref post IPNA (sensitivity 91.9%, specificity 66.9%) was a better indicator of coronary artery disease than VEF (sensitivity 68%, specificity 54%), increased ESV (sensitivity 57%, specificity 77%) or ECG changes (sensitivity 54%, p 0.05; specificity 91%, p less than 0.1). 2. Diagnosis of the extent of coronary artery disease: the post IPNA abnormal ref were situated in zones compatible with the coronary lesions: 10/13 single vessel disease (2 false negatives, 1 false localisation); 8/11 double vessel disease (1 false negative, 2 single vessel disease); 5/10 triple vessel disease (2 single vessel and 3 double vessel disease); 2/3 left main stem disease (1 single vessel disease). The study of REF demonstrated at least 2 diseased zones in 15/24 patients with multiple diseased vessels. Independently, the diagnosis of multivessel disease may be suspected by the fall in EF per IPNA (4/13 single vessel cases compared to 11/24 multivessel disease) and, more generally, by the fact that the EF and ZSV per and post IPNA appear more pathological with respect to the reference group when the coronary lesions are most diffuse.(ABSTRACT TRUNCATED AT 400 WORDS)