Biomedical subjects

W L Sugg

Publications and source records attributed to W L Sugg.

At least 19 recordsLinked to original sources

PubMed1976

Technetium stannous pyrophosphate myocardial scintigrams in the recognition of myocardial infarction in patients undergoing coronary artery revascularization.

Myocardial imaging using technetium 99m stannous pyrophosphate (99mTc-PYP) has been utilized preoperatively and three to five days postoperatively to detect myocardial infarction in 48 patients undergoing aortocoronary bypass grafting, including 7 having valve replacement (5 aortic, 2 mitral) in addition to revascularization. In the total group of patients operated on there were 3 deaths (6%). Preoperatively, 26 patients had unstable angina and 10 had severe left main coronary artery disease. Eleven of the 48 (23%) were women. ECG and enzyme-proved infarctions occurred in 6 of the 48 patients (12%), but the addition of 99mTc-PYP myocardial imaging demonstrated scintigraphic evidence of infarction in 15 patients (31%), including 2 who died in the operating room. The 99mTc-PYP myocardial imaging technique, which has proved safe, simple, and relatively inexpensive in these patients, suggests that the incidence of infarction after coronary bypass operations is somewhat higher than has been previously recognized from just ECG and enzyme changes. This technique also has been of value in helping to exclude myocardial infarction in difficult clinical situations such as postoperative arrhythmias and the postpericardiotomy syndrome.

Adult↗

PubMed1976

Similarities in coronary flow between external counterpulsation and intra-aortic balloon pumping.

The ability of external counterpulsation (Cardiassist) and intra-aortic balloon pumping (AVCO) to influence collateral coronary blood flow in ischemic myocardium was measured in anesthetized dogs. Cardiac output and heart rate (atrial pacing) were held constant on right-heart bypass. Both external counterpulsation and balloon pumping augmented peak diastolic pressure (30 mmHg and 38 mmHg, respectively), while mean aortic pressure, peak left-ventricular pressure, left-ventricular end-diastolic pressure, maximum left-ventricular dp/dt, hematocrit, and osmolality remained unchanged. Regional coronary blood flow was measured using 9-mum radioactive microspheres. External counterpulsation and balloon pumping begun immediately following ligation of the left-anterior descending coronary artery significantly increased collateral coronary blood flow 29 +/- 7.5% (SE, P is less than .01) and 20 +/- 8% (P is less than .05), respectively, to ischemic myocardium. This redistribution of collateral coronary blood flow produced by both methods of counterpulsation was primarily to the subepicardial region of the ischemic myocardium. The mechanism responsible for the measured increases in collateral coronary blood flow appears most likely to be an increased pressure gradient produced by diastolic augmentation.

Animals↗

PubMed1976

Perioperative myocardial infarction diagnosed by technetium 99m stannous pyrophosphate myocardial scintigrams.

Two groups of patients have been studied using 99mTc stannous pyrophosphate myocardial imaging prior to and 3-5 days after myocardial revascularization. The first group consisted of 48 patients undergoing revascularization, including 26 with unstable angina and seven with concomitant valve replacement. There were 3 deaths (6%), and the incidence of perioperative infarction by electrocardiogram (ECG) and enzyme analysis was 6/48 (12%), while 15 of 48 (31%) had positive myocardial scintigrams. The second group of 29 patients included one nonischemic death (3%) that was excluded. The operative technique was changed (optical magnification used, silastic tapes avoided, venting avoided, while aortic cross clamping was used frequently). In this latter group two of 29 (7%) had ECG evidence of infarction while four of 28 (14%) had positive scintigrams, compared to the pervious incidence of 31%. The imaging technique is simple, reliable, and probably more sensitive in the postoperative setting than ECG and enzyme analysis. It appears useful in evaluating the influence of changes in operative technique on myocardial preservation.

Female↗

PubMed1975

Intraaortic balloon counterpulsation in patients in cardiogenic shock, medically refractory left ventricular failure and/or recurrent ventricular tachycardia.

Of the 27 patients described, 23 were in cardiogenic shock, 2 had severe left ventricular failure, and 2 had medically refractory ventricular tachycardia. Utilizing intraaortic counterpulsation, adequate systemic blood pressure was initially restored in 19 patients. Nine of these were subsequently weaned from circulatory assistance, but only three were discharged from the hospital and are currently alive. The remaining 10 patients who derived initial benefit from circulatory assistance were balloon-dependent in that they could not be weaned from circulatory assistance. Eight of these patients subsequently underwent cardiac catheterization; four had inoperable disease. The remaining four patients underwent surgery for either resection of the area of infarction and/or for myocardial revascularization; only one survived to subsequently leave the hospital. Ventricular volumes were abnormal and ejection fractions were below 30 per cent in all the patients in cardiogenic shock except one who underwent cardiac catheterization and ultimately died. Ejection fractions were greater than 30 per cent in the two patients with cardiogenic shock who were weaned from balloon support and survived to leave the hospital without surgery. Both of these patients had inferior myocardial infarction. The data obtained from this experience suggest that intraaortic counterpulsation is a very useful adjunct to currently existing medical measures to treat both cardiogenic shock and medically refractory left ventricular failure but that most patients have such extensive disease that they can neither be weaned from balloon support nor undergo successful infarctectomy or myocardial revascularization.

Adult↗

PubMed1975

Five-day partial bypass using a membrane oxygenator without systemic heparinzation.

These studies indicate that a heparin bound membrane oxygenator can be used in venovenous bypass circuit in dogs for a period of 5 days without systemic heparinization. The plasma SGOT, plasma hemoglobin, and MLW of the animals increased after initiation of bypass but returned to control levels. Oxygen transfer did not deteriorate in the membrane oxygenator, eliminating the necessity of membrane exchange during the 5-day bypass.

Animals↗

PubMed1974