Decreased early diastolic dV/dt in ischemic heart disease observed by ECG-gated radiocardiography

Evaluation of regional myocardial systolic and diastolic function using ECG-gated Sestamibi scintigraphy. Preliminary results in patients with and without coronary artery disease

Sestamibi allows ECG-gated acquisition and similarly to radionuclide angiography a time-activity curve from a defined myocardial region can be derived and analysed. Diastolic (peak relaxation velocity) and systolic (per cent thickening) functional parameters from Sestamibi ECG-gated acquisition were obtained; this data were compared in 10 patients with radionuclide angiographic data (peak filling rate and ejection fraction, respectively). A high correlation was found between peak relaxation velocity and peak filling rate (r = 0.792), while no significant correlation was found between thickening and ejection fraction (r = 0.577). Sestamibi parameters were calculated in 15 patients with known or suspected coronary artery disease and compared with those obtained in 10 normal subjects. In regions supplied by stenotic vessels the average values of peak relaxation velocity and thickening were significantly lower than those obtained in control subjects in the corresponding vascular territory. The average regional values of the diastolic parameter were significantly lower than the corresponding normal range also in regions with preserved systolic function, i.e. with thickening values within 1SD from the mean value of normals. In conclusion, from the ECG-gated acquisition of Sestamibi regional diastolic and systolic functional parameter may be derived; this completes the spectrum of information that can be obtained by a single injection of tracer.

Asynchronous left ventricular diastolic filling in patients with isolated disease of the left anterior descending coronary artery: assessment with radionuclide ventriculography

To study the relationship between global and regional filling of the left ventricle, we conducted resting gated radionuclide ventriculographic studies in 15 control subjects (group 1) and 22 patients with isolated disease of the left anterior descending coronary artery (group 2). None had had a previous myocardial infarction. A computer program subdivided the image of the left ventricle into four regions. The time-activity and first-derivative curves of the global and regional left ventricles were computed. In the global left ventricle, the normalized peak filling rate (PFR) was decreased (p less than .01) and the ratio of the time to PFR (time interval from global end-systole to PFR) to the diastolic time, TPFR/DT, was greater (p less than .02) in group 2 than in group 1. In the regional left ventricle, in the side perfused by the stenosed vessel (septal and apical), PFR was slightly decreased in the apical (p less than .05), but not the septal region (p = NS); TPFR/DT was greater in the apical (p less than .02) and in the septal region (p less than .01) in group 2. In the normally perfused lateral side, there were no significant differences in PFR or in TPFR/DT between group 1 and group 2. Total delta t/DT, which was defined as the ratio of the sum of the absolute values of the time differences from global PFR to regional PFR (septal, apical, and lateral) to the diastolic time, was significantly greater in group 2 (0.09 +/- 0.05 vs 0.16 +/- 0.05; p less than .001). This indicates the existence of asynchronous diastolic filling in the different regions of the left ventricle in group 2. A negative correlation existed between total delta t/DT and global PFR (r = -.64, p less than .001). Thus, in patients with one-vessel disease, asynchronous diastolic filling occurs due to the filling disturbance in the affected regions, which may cause impairment of the filling of the global left ventricle.

Phase analysis of radionuclide ventriculograms for the detection of coronary artery disease

The value of phase analysis of multiple gated acquisition blood pool images for identifying wall motion abnormalities due to stress-induced ischemia was examined. Myocardial segments with an abnormal phase, i.e., delayed onset of wall motion, were localized on a phase distribution image of the LV and the synchrony of LV systolic wall motion was assessed from histograms of the LV phase distribution, i.e., the standard deviation (SD) from the mean of this peak, which was defined as SDP, its upper limits of normal at rest and exercise were established in seven normals as the mean +2 SD and were 12 degrees at rest and 10 degrees at maximum exercise. Of the 56 patients, 37 had coronary artery disease (CAD), 11 had valvular disease but normal coronary arteries, and eight had normal coronary arteries, no valvular disease, but had either cardiomyopathy or typical angina. In the CAD patients, SDP was abnormal in 95% during exercise while only 86% had an abnormal ejection fraction (EF) response and/Or exercise-induced wall motion abnormalities by visual interpretation. By contrast, in the 11 valvular heart disease patients, SDP was abnormal in only two despite exercise-induced wall motion abnormalities in five and an abnormal EF response in all 11. Thus, although an abnormal EF response to exercise is a sensitive indicator of cardiac disease, it is, however, like exercise-induced wall motion abnormalities, not specific for CAD. By contrast, phase analysis not only permitted separation of wall motion abnormalities induced by ischemia from those associated with valvular disease, but was also an objective, highly sensitive, and specific indicator of regional myocardial ischemia.