RATE OF CHANGE OF LEFT-VENTRICULAR EJECTION FRACTION DURING EXERCISE IS SUPERIOR TO THE PEAK EJECTION FRACTION FOR PREDICTING FUNCTIONALLY SIGNIFICANT CORONARY-ARTERY DISEASE
Bs. Sridhara et al., RATE OF CHANGE OF LEFT-VENTRICULAR EJECTION FRACTION DURING EXERCISE IS SUPERIOR TO THE PEAK EJECTION FRACTION FOR PREDICTING FUNCTIONALLY SIGNIFICANT CORONARY-ARTERY DISEASE, British Heart Journal, 70(6), 1993, pp. 507-512
Objective-To detect and characterise rapid temporal changes in the lef
t ventricular response to exercise in patients with ischaemic heart di
sease and to relate these changes to the functional severity of corona
ry artery disease. Background-The gamma camera does not allow the dete
ction of rapid changes in cardiac function during exercise radionuclid
e ventriculography, the monitoring of which may improve the assessment
of patients with ischaemic heart disease. Methods-A miniature nuclear
probe (Cardioscint) was used to monitor continuously left ventricular
function during exercise in 31 patients who had coronary angiography
for suspected coronary artery disease. A coronary angiographic jeopard
y score was calculated for each patient. Results-The coronary jeopardy
score ranged from 0 to 12 (median 4). Ejection fraction fell signific
antly during exercise from 46% to 34%. Patients were divided into two
groups based on the response of their ejection fraction to exercise. I
n 14 patients (group I), the peak change in ejection fi action coincid
ed with the end of exercise, whereas in the other 17 patients (group I
I) the peak change in ejection fraction occurred before the end of exe
rcise, resulting in a brief plateau. The peak change in ejection fract
ion and the time to its occurrence were independent predictors of coro
nary jeopardy (r = -0.59, p < 0.001 for peak change and r = -0.69, p <
0.001 for time to that change). The rate of change in ejection fracti
on was the strongest predictor of coronary jeopardy (r = -0.81, p < 0.
001). In group I the peak change in ejection fraction was a poor predi
ctor severity of coronary disease (r = -0.28, NS), whereas the time to
peak and the rate of change in ejection fraction were good predictors
(r = -0.65 and r = -0.73, p < 0.01). In group II the peak, the time t
o the peak, and the rate of change in ejection fraction were good pred
ictors of coronary jeopardy (r = -0.75, r = -0.61, and r = -0.83, p <
0.01). Conclusion-The rate of change of ejection fraction during exerc
ise can be assessed by continuous monitoring of left ventricular funct
ion with the nuclear probe, and is the best predictor of functionally
significant coronary artery disease.