Cardiovascular and metabolic strain of dynamic stress echocardiography in patients with coronary heart disease and healthy subjects

25 patients with coronary heart disease (CHD, 62 +/- 9 years) and 18 subjec ts free from cardiovascular disease (28 +/- 9 years) were tested on a cycle ergometer using a graded incremental test protocol: a) in the common uprig ht position, b) as dynamic stress echocardiography in a semi-supine positio n. Whereas no relevant differences could be detected between the two condit ions for the healthy subjects concerning heart rate, blood pressure, and ra te-pressure product (2x 3 ANOVA, t-tests with alpha-adjustment), the CHD pa tients showed both significantly higher heart rates as well as a significan tly higher rate-pressure product (50 W: 15 300 +/- 2973 mm Hg/min vs. 13 82 2 +/- 3042 mm Hg/min; 75 W: 18 028 +/- 3479 mm Hg/min vs. 16 337 +/- 2619 m m Hg/min) on equivalent stages during stress echocardiography if compared t o the sitting position. There were no differences for systolic blood pressu re in this group; the diastolic values were higher in the sitting position at rest and during 50 W. Lactate concentrations (determined only in the hea lthy subjects) were significantly higher on all stages during dynamic stres s echocardiography. The workload at the individual anaerobic threshold (IAT ) was significantly lower. In conclusion, we found a higher metabolic along with a similar cardiovascu lar strain at equivalent workloads in stress echocardiography compared to u pright bicycle ergometry for healthy subjects. However, CHD patients have a higher cardiocirculatory load in the semi-supine position. When investigat ing these patients with stress echocardiography, higher heart rates of abou t 8 beats/min have to be expected for equivalent workloads if compared to t he upright position.