Detection of early systolic dysfunction in ischemia by sequential radionuclide imaging of ejection rates.

The effectiveness of sequential imaging of early regional left ventricular contraction in the detection of ischemic abnormalities was assessed in 47 patients (15 with previous infarction) with angiographically proven coronary artery disease, and 11 normal volunteers, undergoing first pass radionuclide angiography with a multielement gamma camera at rest and at peak exercise. Global left ventricular hemodynamic parameters, and functional images of regional ejection fraction and ejection rate were compared to 6 pairs of sequential rate images showing the decrease and the increase of regional left ventricular volume during a time-interval of 80-280 ms (at rest) and 50-175 ms (at stress) from end-diastole. Diagnostic accuracy of sequential images (67-91%) was higher than that of ejection rate image (71-72%), and of global hemodynamic parameters (33-60%), in the detection of coronary patients. Regional sensitivity of stress sequential increase and decrease image achieved 77% and 100%, respectively. During early systole sensitivity of stress sequential increase and decrease images approached 100% even at rest, subsequently decreasing because of normalizing contraction. Thus, the analysis of early systolic dysfunction provided by dynamic sequential functional images of ejection rates proved to be an effective diagnostic tool in the detection of myocardial ischemic dysfunction.