Robert E. Sonnemaker

Left ventricular performance during exercise in patients with left bundle branch block: Evaluation by gated radionuclide ventriculography

To investigate changes in left ventricular (LV) function during exercise in patients with left bundle branch block (LBBB), 22 patients without a history or physical findings of previous myocardial infarction or LV dysfunction were studied by gated radionuclide ventriculography (GRNV) at rest and during bicycle exercise. Coronary arteriography demonstrated greater than 75% diameter narrowing of at least one coronary artery in nine patients. Of the remaining 13 patients, GRNV demonstrated wall motion abnormalities in seven patients either at rest or with exercise. During exercise, mean ejection fraction (EF) did not increase in patients without coronary artery disease (CAD). Patients with CAD had a 12-point fall in mean EF with exercise. We conclude that LV reserve, as demonstrated by ability to increase EF with exercise, is impaired in patients with LBBB even in the absence of CAD or other underlying cardiac disease and that standard GRNV criteria to exclude the presence of CAD (a greater than five-point increase in EF with exercise and normal wall motion) are not strictly applicable in screening patients with LBBB.

99mTc-Human Albumin Microspheres (HAM) for Measuring the Rate of Gastric Emptying

The radiopharmaceutical HAM (99mTc-human albumin microspheres) was used to measure gastric emptying time in a series of 29 patients (normal, 9; duodenal ulcer, 7; gastric ulcer, 7; and gastric carcinoma, 6). The mean emptying rate in each group of patients was significantly different, as was the pattern of emptying. No overlap occurred in the T-50% results for one standard deviation. The physical properties of 99mTc-HAM permit the administration of relatively large amounts of the radionuclide, creating a high photon flux which results in excellent scintillation camera images. This technique is reproducible, and tests show less than 2% absorption of the radionuclide.

Single injection thallium-201 stress and redistribution myocardial perfusion imaging: comparison with stress electrocardiography and coronary arteriography.

The efficacy of single injection thallium-201 exercise stress and rest redistribution imaging in the evaluation of myocardiacl ischemia was compared with stress electrocardiography and coronary arteriography. Thallium-201 imaging was interpreted at two levels of sensitivity in order to define the circumstances under which it best serves as a screening modality for coronary arteriography. With the prevalence of coronary disease usually found in patients referred for coronary arteriography (75%), unprocessed thallium-201 imaging is as good as stress electrocardiography in identifying patients apt to show coronary artery abnormalities, but not much better than stress electrocardiography in delineating those patients unlikely to show coronary artery disease. In contrast, processed lesion enhanced images showing normal results virtually eliminate the possibility of significant arteriographic findings. With this screening technique, many patients may be spared unnecessary coronary arteriography.

Renal accumulation of 67Ga-citrate

A 52-year-old female was admitted after a twq-day history of diarrhea, crampy abdominal pain, fever (to 104~ drenching sweats, cough, nausea, vomiting, and general malaise. Admission laboratory data revealed an elevated white blood cell count (WBC) with a marked left shift and a urinalysis showing trace protein, 3-5 WBC/HPF and numerous bacteria. Blood and urine cultures were positive for group D streptococcus (enterococcus). The patient was placed on intravenous ampicillin. An IVP revealed nonfunction of a slightly enlarged left kidney that was subsequently confirmed by abdominal CT. A gallium scan (Fig. 1) demonstrated intense diffuse accumulation throughout the left kidney at 4 and 48 hr. Subsequently, a left retrograde pyelogram demonstrated marked hydronephrosis with tight ureteropelvic junction (UP J) obstruction. After a full course of ampicillin the patient underwent surgery and a left nephrectomy was performed. Pathologic examination revealed diffuse extensive acute and subacute pyelonephritis with focal papillary necrosis, hydronephrosis, and UPJ stenosis. The patient recovered uneventfully.

Effects of stress management training and dietary changes in treating ischemic heart disease

To evaluate the short-term effects of an intervention that consists of stress management training and dietary changes in patients with ischemic heart disease (IHD), we compared the cardiovascular status of 23 patients who received this intervention with a randomized control group of 23 patient who did not. After 24 days, patients in the experimental group demonstrated a 44% mean increase in duration of exercise, a 55% mean increase in total work performed, somewhat improved left ventricular regional wall motion during peak exercise, and a net change in the left ventricular ejection fraction from rest to maximum exercise of +6.4%. Also, we measured a 20.5% mean decrease in plasma cholesterol levels and a 91.0% mean reduction in frequency of anginal episodes. In this selected sample, short-term improvements in cardiovascular status seem to result from these adjuncts to conventional treatments of IHD.

Probe radiocardiography: validation of a technique to routinely determine left ventricular ejection fraction.

We investigated the probability of obtaining a valid radiocardiogram with the first commercially available cardiac probe and a peripheral injection of the radiopharmaceutical. Measurements of left ventricular ejection fraction (LVEF) were obtained in a series of 15 patients undergoing cardiac catheterization. Probe LVEF determinations using central, peripheral and rapid sequential injections correlated well with each other and with ventriculography (r = .88-.98). By documenting its accuracy and precision, this study confirms the validity of a new technique for measuring LVEF.