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Biomedical subjects

G C Kaiser

Publications and source records attributed to G C Kaiser.

At least 109 records · Page 6Linked to original sources
PubMed1979

Supraventricular tachyarrhythmias after myocardial revascularization: a randomized trial of prophylactic digitalization.

The success of prophylactic digitalization in reducing the incidence of supraventricular tachyarrhythmias (SVT) was studied in 140 randomly grouped, consecutive patients undergoing myocardial revascularization operations. The test group received either 1 or 1.5 mg. of digoxin the day before operation and were maintained postoperatively on 0.25 mg. of digoxin daily. There was a significant increase (p less than 0.05) in the incidence of SVT in the treated patients (17 of 61 or 27.8 percent) vs. the untreated patients (nine of 79 or 11.4 percent). There was no significant difference in SVT with the two digitalization dosage levels (31.6 percent with 1 mg. vs. 21.7 percent with 1.5 mg.). Prophylactic digitalization demonstrates no benefit in the prevention of SVT following myocardial revascularization and may, in fact, predispose the patient to these arrhythmias.

Coronary Artery Bypass↗
PubMed1978

Coronary revascularization under age 40 years. Risk factors and results of surgery.

Groups of patients such as the elderly, the diabetic and women have been studied to evaluate the effectiveness of coronary revascularization. In this report 77 patients under age 40 years undergoing coronary revascularization were studied. There was a high prevalence rate of predisposing factors. Sixty-eight percent reported a family history of heart disease and 27 percent a history of diabetes; 57 percent were hypertensive, 43 percent were overweight, 91 percent smoked, 5 percent were diabetic and 16 percent had abnormal glucose tolerance curves. Sixty-four percent had hypercholesterolemia (cholesterol 250 mg/100 ml) and 56 percent hyperlipidemia. Forty-four percent had had a previous myocardial infarction; 95 percent had angina pectoris, 12 percent preinfarction angina and 9 percent congestive cardiac failure. There were no operative deaths. The incidence rate of perioperative myocardial infarction (new Q waves in the electrocardiogram) was 4 percent. The mean length of of follow-up was 26 months (range 6 months to 5 years). The late mortality rate was 4 percent. Eight percent had a late myocardial infarction. Overall graft patency was 85 percent. Sixty-seven percent of patients were free of angina, and 17 percent were in improved condition. Seventy-one percent returned to work, while 29 percent remained unemployed. This study shows that in young patients, coronary revascularization is associated with low mortality and morbidity rates and that, despite the wide prevalence of predisposing factors, the prognosis and graft patency rate of these patients are similar to those of other groups.

Adult↗
PubMed1978

A simple method of cold coronary perfusion.

Hypothermic coronary perfusion lengthens the safe duration of anoxic arrest. Intermittent selective hypothermic coronary perfusion provides extended myocardial protection. We describe a method of achieving profound myocardial hypothermia by selective deep hypothermic coronary perfusion using a cooling coil without a separate pump head.

Adult↗
PubMed1978

Myocardial revascularization in women.

During the period January, 1970, through June, 1977, 1,541 patients underwent coronary artery bypass grafting; 241 of them were women (15.6%). Operative mortality rates for the entire study were 2.4% in men and 3.7% in women, but they showed a marked decline in women during 1975 to mid-1977, with only 2 deaths in 140 patients (1.4%). Women comprised a larger percentage of patients (16.7%) in these later years. Women were slightly older, received fewer grafts, had better preservation of ventricular function on preoperative studies, and had more severe anginal symptoms than men. Patency rates were significantly lower in women at 1 month, 1 year, and 3 years. Five-year survival was not significantly different between women (88.3%) and men (93.5%). Many of these findings may be explained on the basis of women having smaller coronary arteries than men. These favorable results differ from earlier reports of higher mortality rates in women and indicate that myocardial revascularization should not be withheld from female patients.

Age Factors↗
PubMed1978

Late sequelae of perioperative myocardial infarction.

The late suquelae of myocardial injury occurring at the time of direct myocardial revascularization are unknown. Fifty of 500 consecutive patients undergoing aortocoronary bypass grafting developed both electrocardiographic and enzymatic evidence of myocardial injury. They were matched with 50 patients of similar age, sex, history of previous infarction, severity of angina, degree of coronary arteriosclerosis, and level of ventricular function as determined by preoperative angiographic studies. The conduct of the operation was identical in each group except for prolongation of total cross-clamp time in those patients with myocardial injury. The total number of vessels grafted, the conduit used, and the operative mean graft flow were similar. Results of treadmill stress testing at 24 to 36 months were not significantly different between groups. Angina status, long-term survival, graft patency, and ventricular function were not adversely affected by intraoperative myocardial injury. However, postoperative ventricular function and stress test performance were related to graft patency.

Adult↗
PubMed1978

Myocardial revascularization: a rebuttal of the cooperative study.

From January 1972 through December 1974, at Saint Louis University Medical Center (SLU), 345 patients similar to those of the VA Cooperative Coronary Artery Study received CABG. Operative mortality was SLU 2.3%, VA 5.6% (p < 0.05). Perioperative myocardial infarction rate was SLU 8.4%, VA 18% (p < 0.005). One year graft patency was SLU 87%, VA 71%; all grafts patent SLU 76%, VA 54%; at least one graft patent SLU 96%, VA 89%. SLU angina pectoris relief at five years was 90%. SLU patients free of myocardial infarction five years postoperatively was 83%. Comparative cumulative four year survivals were: [Table: see text] Cumulative four-year survival in 272 SLU patients (79%) completely revascularized was 94%, compared to SLU entire group of 95%, VA medical 86% (p < 0.002) and VA surgical 85% (p < 0.002). Comparing 1972-74 SLU results to VA medical and surgical groups, CABG prolonged life in patients with double and triple vessel disease and in those completely revascularized.

Adult↗
PubMed1978

Atypical mycobacteria and the xenograft valve.

During a 4 month interval, cultures taken at the time of porcine xenograft valve implantation grew a fastidious atypical mycobacterium, Mycobacterium chelonei (Runyon's groups IV), in eight of 20 patients. Initial growth occurred at 2 to 3 weeks in thioglycollate broth only; detailed biochemical and bacteriologic evaluation demonstrates altered catalase activity accounting for its initial slow growth. Only one patient has manifested clinical evidence of infection 5 months after mitral valve replacement. A large pericardial effusion required pericardiectomy. Pericardial tissue and fluid have grown M. chelonei with the same growth characteristics as the initial valve culture. It is recommended that manufacturers of xenograft valve bioprostheses maintain a quarantine of 6 weeks until cultures, smears of culture broth, and microscopic evaluation of aortic wall coupons are negative. Users of these prostheses should keep cultures for a minimum of 3 weeks. Should positive cultures result, antimicrobial therapy should be considered only with clinical evidence of infection.

Animals↗
PubMed1977

Nonsyphilitic coronary ostial stenosis.

From October 1970 to June 1977, a total of 15 patients (12 women) were seen with atherosclerotic coronary ostial stenosis (14 left, one right). All patients had angina and two had aortic valve disease. Additional coronary arterial disease was present in nine. One patient declined surgery and died four months later after myocardial infarction. All patients had coronary bypass grafts and two had aortic valve replacement. One patient with valve replacement and one with preoperative cardiogenic shock died postoperatively. Angina recurred nine months postoperatively in one patient; the others (11) are free of angina. Postoperative catheterization from two weeks to 4.5 years in ten of 12 showed 11 of 13 vein grafts and eight of nine internal mammary artery grafts to be patent. In three patients, only a single left-sided coronary bypass was placed to the left anterior descending artery, because the circumflex branches were too small. Ideally, two left-sided bypass grafts should be placed for left ostial disease.

Adult↗
PubMed1977

Coronary venous arterialization: acute hemodynamic, metabolic, and chronic anatomical observations.

Nine dogs that had anastomosis of the internal mammary artery (IMA) to the left anterior descending coronary vein (LADV) were studied acutely on right-heart bypass. Occlusion of the left anterior descending coronary artery (LADA) and LADV without venous arterialization resulted in a significant decline in stroke work, total coronary flow, and myocardial oxygen uptake; with reactive hyperemia an increase in lactate and pyruvate consumption resulted. Occlusion of the LADA and LADV with VA did not change these variables greatly, except for a marked increase in total coronary flow with reactive hyperemia. Chronic venous arterialization in 14 dogs was associated with a 14% mortality, while 10 controls had a 40% mortality. Dogs were killed at six weeks, and prior angiography in 9 showed patency of the IMA to the heart without filling of cardiac veins. All dogs had infarcts in the distribution of the LADA; these infarcts were smaller in dogs with venous arterialization. The anastomoses were obliterated by mature or maturing fibrous tissue, with alteration of the vein so that it was frequently not discernible, while the IMA was well preserved. Distal veins had foci of intimal proliferation, subintimal fibrosis, and medial hypertrophy. Although venous arterialzaiton provides protection for the acutely ischemic myocardium, this effect does not persist, perhaps because of anastomotic occlusion due to fibrous proliferation.

Animals↗
PubMed1977

Myocardial injury following myocardial revascularization. Detection by isoenzyme analysis.

To clarify the value of isoenzymes in the detection of acute myocardial injury (AMI) associated with coronary artery bypass grafting, 350 consecutive patients (804 grafts) were evaluated with serial electrocardiograms (ECG) and serum levels of serum glutamic oxaloacetic transaminase (SGOT), total creatinine phosphokinase (CPK), and lactic dehydrogenase (LDH) on Days 0, 1,2,3,4,5, and 7. Graft patency 1 to 6 months postoperatively was 92%. Sixty patients (18%) had ECG evidence of AMI. Four patients died (1.1%) Of the 185 patients with serial LDH isoenzyme analysis, 46 had elevated cardiac fraction (LDH-1). Only 35 of these had AMI by ECG. The others had nonspecific ECG changes, but associated enzymatic andhemodynamic evidence of AMI. The CPK-MB band was elevated in all patients in the immediate postoperative period, but did not correlate with ECG, hemodynamic, or enzymatic evidence of AMI. The diagnosis of AMI following coronary artery bypass could not be substantiated by evaluation of total LDH, CPK, or CPK-MB. LDH-1 is specific in detecting AMI after a coronary artery bypass graft.

Adult↗
PubMed1976

Left ventricular aneurysmectomy.

Comparison of preoperative and postoperative studies in 81 patients undergoing left ventricular aneurysmectomy failed to show consistent hemodynamic trends. The most reliable prognostic indicator for survival (84% early, 71% late) was the function of the basilar ventricular segments. In 62 of the 81 patients, there was concomitant aortocoronary bypass grafting. Eighty-eight percent of the surviving patients are essentially free of symptoms. These findings support the continued surgical treatment of ventricular aneurysm in symptomatic patients, and suggest nonoperative treatment for patients who are asymptomatic.

Coronary Artery Bypass↗
PubMed1976

Intraaortic balloon assistance.

Intraaortic balloon (IAB) assistance in 64 patients over 2 1/2 years has resulted in a survival rate of 11% (1 patient) when used alone but 47% when utilized in patients treated surgically (long-term survival, 38% [21 patients]). Patients undergoing coronary artery bypass grafting or aortic valve replacement have a long-term survival of 50% (8 and 9 patients, respectively). The required duration of IAB support has a bearing on the clinical result. Complications have been minimal. Though it was originally developed to assist in the nonoperative management of complications of ischemic heart disease, IAB assistance offers significant promise as an adjuvant to operative therapy for both ischemic and valvular heart disease.

Aortic Valve↗
PubMed1976

In favor of the Y-graft for aortocoronary bypass.

The technique of multiple coronary artery bypass grafting has included separate conduits, snake grafts, and Y-grafts. Against the Y-graft have been reports of lesser patency and several theoretical objections. The theory is discussed and a laboratory model presented which demonstrates a flow difference of 2 ml/5 sec or less between Y-grafts and single grafts. In conjunction with this, 171 patients having aortocoronary bypass were analyzed and showed a combined one-year graft patency of 77% with no significant difference between single grafts and Y-grafts. It is concluded that the technical simplicity of Y-grafts is advantageous and that, if the operation is performed within the guidelines set forth, revascularization with Y-grafts is an acceptable method.

Animals↗
PubMed1976

A servocontrolled atrial-aortic assist device: experimental findings and clinical experience.

A servocontrol system was developed to regulate a single roller pump left atrial-aortic (La-A) assist device. Responsiveness of the servomechanism to blood volume changes, myocardial damage, and mitral regurgitation was evaluated in 5 sheep and 6 dogs. Myocardial damage was induced by occlusion of coronary arteries. and the hemodynamic effects of La-A assistance were evaluated. While La-A assistance reduced left atrial pressures to low levels, the left ventricular end-diastolic pressure remained elevated in the severely damaged heart. LaA-assistance was used in 3 patients. Two were weaned from cardiopulmonary bypass after failure of intraaortic balloon counterpulsation, and 1 is a long-term survivor. The third was supported for 48 hours after attempt repair of complex congenital heart disease. The servocontrol device added to the safety of prolonged La-A assistance. This mode of assistance should be considered when intraaortic balloon counterpulsation has failed.

Adolescent↗
PubMed1976

Aortic aneurysm in childhood: report of six instances.

Six instances of aortic aneurysm in children have been observed in the past 15 years. Four children with aortic stenosis and coarctation of the aorta had aneurysmal dilatation of the ascending aorta, and two children with coarctation of the aorta had ruptured post-stenotic dilatation of the descending aorta. Our observations suggest that aortic aneurysm can be the result of hemodynamic stress, although developmental anomaly of the aorta associated with aortic stenosis or coarctation could be responsible for the development of the aneurysm.

Adolescent↗
PubMed1976

Operative flow measurements and coronary bypass graft patency.

Early (one week) and late (one year) postoperative angiography was performed in 142 patients having 310 grafts (117 right coronary artery [RCA], 134 left anterior descending [LAD], and 59 circumflex coronary artery [CCA]) to assess the factors responsible for failure of aorta-coronary artery saphenous vein grafts. Early catheterization revealed an 85.5 per cent patency rate with similar rates for each artery (RCA 88 per cent, LAD 85 per cent, and CCA 81 per cent). At one year 238 grafts remained patent, for a cumulative patency rate of 76.8 per cent with a similar distribution for each vessel (RCA 75 per cent, LAD 78 per cent, and CCA 76 per cent). Intraoperative flow measurements were correlated with early and late patency. Grafts with a basal flow less than 20 ml. per minute have a 42 per cent early closure rate and a 21 per cent late closure rate (cumulative 63 per cent). A basal flow of less than 40 ml. per minute was associated with a 25 per cent early failure and an 11 per cent late failure rate (cumulative 36 per cent). Basal flow at levels greater than 40 ml. per minute was not associated with an increased probability of graft closure. Absence of reactive hyperemia (30 second graft occlusion) was associated with a 19 per cent probability of early closure and a 31 per cent probability of cumulative thrombosis. A papaverine-induced flow increase (15 mg. given into the graft) of less than 100 per cent over basal flow gave a 20 per cent probability of early failure and 30 per cent probability of cumulative closure. Thus intraoperative basal flow measurements are of predictive value in determining the fate of aorta-coronary artery vein bypass grafts, and vasodilatory maneuvers provide little additional information.

Coronary Artery Bypass↗