NORMATIVE VALUES FOR DOBUTAMINE STRESS EC HOCARDIOGRAPHY

Dobutamine stress echocardiography having established itself as a sens itive method for diagnosing coronary heart disease, even in the absenc e of normative values, the physiological haemodynamics as well as the physiological values for global and regional left ventricular myocardi al function were measured. Test persons and methods: 14 healthy subjec ts (ten men, four women; median age 25 [range 21-32] years) underwent dobutamine stress echo-cardiography according to an internationally pr actised dosage steps protocol (5-40 mu g/kg/min with additonal 0.5 mg atropine at 40 mu g). Results: Maximal infusion rate achieved a serum dobutamine level of 1.67 mu g/ml with minimal quartiles; it did not in fluence serum electrolytes (especially potassium). Heart rate increase d from 64 to 150/min (P < 0.0001), blood pressure hem 111/66 to 158/88 mm Hg (systolic: P < 0.0001; diastolic P < 0.001) and the double prod uct of systolic pressure and heart rate from 6714 to 24571 (P < 0.001) . While the enddiastolic volume index decreased from 50 to 37 ml/m(2) (P < 0.05), the endsystolic volume index fell hom 20 to 7ml/m(2) (P < 0.0001). Regional wall motion analysis indicated an increase in left v entricular circumferential contractility with little scatter. Conclusi ons: The usual protocol for dobutamine stress echocardiography is a se nsible one, because the haemodynamic effect occurs already at low dosa ge and can then be increased significantly with further dosage steps. High serum dobutamine concentrations can be achieved without arrhythmo genic hypokalaemia. Volume index and ejection fraction are especially discriminatory variables. Quantitative analysis of wall motion is just ified because of the low scatter of values.