Faculty Bibliography

A 67-yr-old female patient with accelerated hypertension, severe peripheral vascular disease, diabetes mellitus, and coronary artery disease had an abnormal renal scan, renal angiogram, and renal vein renin determination with lateralization to the left kidney. Angiography demonstrated a very tight, eccentric plaque obstructing the left renal artery of approximately 99%. Because of the anatomy of the plaque, balloon dilatation was deemed inadvisable. Subsequently, a Simpson 7F graft DCA atherocath through a four-curved 10F right bypass graft guiding catheter was used to successfully debulk the left renal artery. After debulking, the artery was dilated with a 5 mm Meditech balloon on a wire through a Cobra guiding catheter. The patient's blood pressure responded immediately and there were no complications. A large amount of atherosclerotic plaque was removed from the renal artery.

Thallium-201 redistribution pattern after exercise was related to rest and exercise left ventricular regional and global function, measured by radionuclide ventriculography, in 61 patients, 50 with coronary artery disease (CAD). Sixteen patients had exclusively transient thallium defects, suggesting ischemia: in this group, mean left ventricular ejection fraction (LVEF) was 65% at rest, falling to 58% during exercise (p less than 0.01). Eight patients had exclusively persistent thallium defects, suggesting scar: LVEF was unchanged during exercise, 58% to 59%. LVEF increased during exercise in the 17 patients without exercise thallium defects, seven with CAD: 66% to 73% (p less than 0.05). Individual LV wall segments which exhibited transient or persistent thallium defects contracted abnormally both at rest and during exercise; (2) both transient and persistent thallium defects can be associated with resting dyssynergy; and (3) in some CAD patients, apparent hypoperfusion does not necessarily predict left ventricular dysfunction during exercise.

We have constructed a bifocal diverging collimator (BDC), capable of simultaneously recording two views of the heart 50 degrees apart on each half of a standard imaging field. In this study, simultaneous two-view blood-pool scans using the BDC were compared with the same two separate views obtained using an all-purpose parallel-hole collimator (PHC), assessing left-ventricular ejection fraction and regional wall motion in 20 patients undergoing contrast left ventriculography (CV). Ejection fraction by BDC correlated closely with PHC (r = 0.94) and with CV (r = 0.88). Regional wall motion was scored qualitatively on a five-point scale from 3 (normal) to--1 (dyskinesis) with an 88% agreement between BDC and PHC and PHC for segment scores. The percentages for agreement between BDC and CV, and between PHC and CV, were identical, 79%. A single blood-pool scan acquisition using a new BDC provides information about global and regional left-ventricular function in two planes, comparable with that of a PHC.

To assess the clinical usefulness of radionuclide-determined changes in pulmonary blood volume in patients with or without substantial coronary-artery disease, we determined the ratio of pulmonary blood volume at rest as compared with that during exercise. We used multigated blood-pool images obtained at rest and during supine exercise to determine the blood-volume ratio in patients subsequently undergoing coronary arteriography for evaluation of chest pain. Exercise tests were performed by use of a submaximal-workload protocol, although all tests were limited according to each patient's symptoms. The mean exercise/rest pulmonary-blood-volume ratios were lower for persons without coronary-artery disease (0.94 +/- 0.06 [S.D.], 10 patients) and for those with disease confined to the right coronary artery (0.99 +/- 0.12, five patients), as compared with all others with coronary-artery disease (1.14 +/- 0.15, 37 patients) (P less than 0.01). A pulmonary-blood-volume ratio equal to or greater than 1.06 had a sensitivity of 79 per cent. Patients with coronary-artery disease not confined to the right coronary artery usually show an increase in pulmonary blood volume during supine exercise. No such change occurs in persons without coronary-artery disease.