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Biomedical subjects

W Ganz

Publications and source records attributed to W Ganz.

At least 109 records · Page 6Linked to original sources
PubMed1975

Abnormal regional metabolism and mechanical function in patients with ischemic heart diseases: improvement after successful regional revascularization by aortocoronary bypass.

Left ventricular anterior wall metabolism was investigated concurrently with global myocardail metabolism by simultaneous preoperation sampling of anterior interventricular venous (AIV) and coronary sinus (CS) as well as arterial bloods in seven patients with severe obstructive lesions of the major coronary arteries, including left anterior descending. Postoperative study was performed two weeks to six months following successful aortocoronary artery bypass surgery. All grafts including the aorto-left anterior descending artery grafts were patent. Preoperatively in three of the seven patients, anterior wall lactate extraction (R%L) was negative at rest. The average R%L at rest (7 +/- 14%) was abnormal and was negative (-49 +/- 26%) at a maximum supraventricular pacing rate (MPR) of 137 +/- 4.6 beats/min. Postoperatively, not only was resting R%L (39 +/- 4;4%) normal but also it remained normal during atrial pacing (32 +/- 8.5%) even though the postoperative MPR (164 +/- 4.4 beats/min) was much higher than the preoperative MPR; Postoperatively AIV pO2 both at rest (21 +/- 1.1 mm Hg) and at MPR (22 +/- 1.3 mm Hg) and directly determined O2 saturations (resting: 34 +/- 3.0%; MPR:35 +/- 2.1%) tended to be higher than the preoperative values (AIV pO2, resting: 18 +/- 1.7; MPR: 19 +/- 1.7 mm Hg; AIV O2 saturation resting: 30 +/- 2.7; MPR: 33 +/- 3.3%), although only differences in pO2 were statistically significant. In five of the seven patients in whom the pre and postoperative left ventricular angiograms could be compared, systolic wall motion of the left ventricular anterior wall improved markedly postoperatively. Average global myocardial lactate extraction (G%L) preoperatively was normal (19 +/- 4.8%) at rest but was negative (-22 +/- 12%) at MPR. Postoperatively however, G%L both at rest (44 +/- 5.5%) and at MPR (34 +/- 7.9%) were normal. Coronary sinus pO2 and O2 saturation were also higher postoperatively compared to the preoperative values. Over-all left ventricular performance indicated by increase in ejection fraction also improved postoperatively. This improvement was not caused by increased coronary blood flow. Postoperative coronary sinus blood flow both at rest (114 +/- 19 ml/min) and at MPR (199 +/- 27 ml/min) however were less than the preoperative values (resting 136 +/- 24, MPR 261 +/- 40 ml/min), There was also no increase in global O2 delivery and O2 consumption despite higher heart rate and rate-pressure product achieved during postoperative pacing stress and the patients did not develop angina. These findings suggest that improved regional and global metabolism and mechanical functions observed postoperatively in these patients may be due to redistribution of blood flow to the ischemic and nonischemic myocardium following successful aortocoronary artery bypass surgery.

Adult↗
PubMed1975

Improved angina threshold and coronary reserve following direct myocardial revascularization.

Angina threshold, coronary reserve, and global myocardial lactate metabolism were studied by atrial pacing in 18 patients with obstructive coronary artery disease before and after aortocoronary artery bypass (ACB) surgery. In 3 of these 18 patients, regional (anterior wall) metabolism was also studied. Following ACB, 16 of the 18 patients did not develop angina at the maximum pacing rate (MPR). One patient developed angina postoperatively at a similar rate as before surgery. In the other patient, postoperative angina threshold was much higher. In the group as a whole, postoperative MPR (159 +/- 3.5 beats/min) was much higher than the preoperative angina rate (124.9 +/- 4.9 beats/min; P less than 0.001). Rate-pressure product (RP) at MPR postoperatively (21.5 +/- 0.89 mm Hg/min X 10(-3)) was also higher than RP at angina rate preoperatively (18.8 +/- 0.92 mm Hg/min X 10(-3); P less than 0.01). Although coronary sinus blood flow (CSBF) both at rest (152 +/- 16.2 ml/min) and at MRP (266 +/- 27.5 ml/min) postoperatively was higher than preoperative CSBF at rest (111 +/- 10.7 ml/min; P less than 0.05) and at angina rate (202 +/- 19.9 ml/min; P less than 0.05), arterial-coronary sinus O2 content (Art.-CSO2) difference was significantly lower postoperatively both at rest (8.9 +/- 0.37 ml/min) and at MPR (9.1 +/- 0.44 ml/min) compared with the preoperative Art.-CSO2 at the rest (12.7 +/- 0.40 ml/min; P less than 0.01) and at angina rate (12.4 +/- 3.8 ml/min; P less than 0.01)...

Adult↗
PubMedDate not supplied

99mTc-HMPAO SPECT of the brain in mild to moderate traumatic brain injury patients: compared with CT--a prospective study.

Single photon emission computed tomography (SPECT) with Technetium-99m hexamethyl propylenamine oxime (Tc-99m-HMPAO) was used in 20 patients with mild to moderate traumatic brain injury (TBI) to evaluate the effects of brain trauma on regional cerebral blood flow (rCBF). SPECT scan was compared with CT scan in 16 patients. SPECT showed intraparenchymal differences in rCBF more often than lesions diagnosed with CT scans (87.5% vs. 37.5%). In five of six patients with lesions in both modalities, the area of involvement was relatively larger on SPECT scans than on CT scans. Contrecoup changes were seen in five patients on SPECT alone, two patients with CT alone and one patient had contrecoup lesions on CT and SPECT. Of the eight patients (50%) with skull fractures, seven (43.7%) had rCBF findings on SPECT scan and five (31.3%) demonstrated decrease in rCBF in brain underlying the fracture. All these patients with fractures had normal brain on CT scans. Conversely, extra-axial lesions and fractures evident on CT did not visualize on SPECT, but SPECT demonstrated associated changes in rCBF. Although there is still lack of clinical and pathological correlation, SPECT appears to be a promising method for a more sensitive evaluation of axial lesions in patients with mild to moderate TBI.

Adolescent↗