ONLINE QUANTITATIVE ASSESSMENT OF LEFT-VENTRICULAR FILLING DURING DOBUTAMINE STRESS ECHOCARDIOGRAPHY - A USEFUL ADDITION TO CONVENTIONAL WALL-MOTION SCORING

In order to determine whether the diastolic rate of ventricular volume change obtained on-line with an automatic border detection (ABD) syst em during dobutamine stress echocardiography (DSE) would provide an in terpretation of the diastolic ventricular response to the drug in quan titative terms in the assessment of coronary artery disease, we studie d, with ABD and DSE, 59 patients who underwent coronary arteriography within 2 months of the stress test. Eleven patients had normal coronar y findings or non-significant coronary lesions. Significant (greater t han or equal to 70% diameter stenosis) coronary artery disease (CAD) w as present in 48 patients (81%). Dobutamine stress echocardiography (D SE) to a maximal dose of 50 mu g/kg per min was performed in all patie nts. ABD images were acquired at rest and at the peak of infusion alon g with conventional two-dimensional images. The following measurements were evaluated: left ventricular end-diastolic volume (LVEDV), left v entricular end-systolic volume (LVESV), left ventricular ejection frac tion (LVEF), slope of rapid filling segment (RFS), peak filling rate ( PFR), rapid filling phase fractional change (RFFC). Patients with non- significant Coronary artery lesions exhibited a hyperdynamic response with an LVEF increment of at least 20% from baseline to peak drug infu sion. In these patients the effect of dobutamine produced an increase of RFS from 35.5+/-5.6 to 86.51+/-0.5 ml/s, an increase of PFR from 4. 4+/-0.6 to 6.8+/-0.6 EDV/s, and an increase of RFFC from 74+/-8 to 92/-5% (P<0.001). Of the 48 patients with coronary artery disease, 27 ha d <20% LVEF increase at peak dobutamine infusion. Four of 22 patients with single vessel disease and 23 of 26 patients with multivessel dise ase had an abnormal systolic response. After dobutamine infusion singl e vessel CAD patients showed a decrease of RFS from 33.4+/-5.3 to 26.7 +/-5.9 ml/s, a decrease of PFR from 3.8+/-0.7 to 3.0+/-0.7 EDV/s, and a decrease of RFFC from 73+/-6 to 59+/-4% (P<0.001). Multivessel CAD p atients showed a decrease of RFS from 32.0+/-5.9 to 23.1+/-4.1 ml/s, a decrease of PFR form 3.8+/-0.6 to 2.8+/-0.6 EDV/s, and a decrease of RFFC from 71+/-5 to 54+/-8% (P<0.001). The overall sensitivity of dete cting CAD was 85% for conventional DSE and 90% for ABD-DSE (P=NS). The sensitivities of detecting patients with single vessel and multivesse l CAD with conventional DSE were 68 and 92%, respectively, and with AB D-DSE were 91% (P<0.01) and 96% (P=NS), respectively. Our results show that an abnormal diastolic as well as systolic response during on-lin e quantitative assessment of dobutamine stress echocardiography is a s ensitive marker of coronary artery disease and is predictive for the d etection of extensive lesions. The described measurements can be utili zed to improve the DSE sensitivity in identifying coronary artery dise ase. On-line quantitation of diastolic indexes with ABD can represent another step toward obtaining uniform results after stress echocardiog raphy. (C) 1997 Elsevier Science Ireland Ltd.