Eldred D. Mundth

Clinical and Hemodynamic Results of Intraaortic Balloon Pumping and Surgery for Cardiogenic Shock

The AVCO balloon pump has been employed in treating 40 patients with cardiogenic shock from acute myocardial infarction (CS-MI). All patients were given a trial of medical therapy with hemodynamic monitoring. The time from the development of shock to institution of intraaortic balloon pumping (IABP) was less than 24 hours in all but nine patients. Prior to IABP the mean hemodynamic values were: cardiac index (CI) 1.7 liters/min/m2; mean arterial pressure (MAP) 66 mm Hg; pulmonary artery wedge pressure (PAW) 22 mm Hg. After 24-48 hours of IABP the CI and MAP had increased 0.8 liters/min/m2 and 8 mm Hg, respectively, and the PAW had decreased 4.8 mm Hg. During IABP the shock syndrome was reversed in 31 patients. Four of 25 patients treated with IABP alone survived to be discharged, but two have died from subsequent infarctions. Because of the persistent high mortality, 15 patients judged unable to survive off IABP have undergone emergency surgical procedures with IABP continuing during preoperative angiography and postoperatively. Six were long-term survivors. It is concluded: (1) IABP is a safe, effective means of supporting the circulation in CS-MI; (2) IABP alone will improve survival in some patients; (3) IABP can provide circulatory support during angiography and the perioperative period in patients requiring revascularization for survival; and (4) some patients with CS-MI have myocardial necrosis too extensive to permit survival without permanent circulatory assistance or total cardiac replacement.

Surgery for post-myocardial infarct ventricular septal defect.

Forty-three patients (mean age 62 ± 1 years) were treated for ventricular septal defect (VSD) secondary to myocardial infarction. Whenever possible, operation was postponed until six weeks post-onset chest pain. However, hemodynamic instability, evidenced by cardiogenic shock, refractory pulmonary edema, or a rising blood urea nitrogen (BUN) forced operation in 21 patients within 21 days post-infarct (Group I). In seven patients operation was performed three to six weeks post-infarct (Group II). In only eight patients could operation be delayed beyond six weeks post-infarct (Group III). Clinical deterioration, once begun, progressed rapidly, and could be reversed only temporarily by intra-aortic balloon pumping, used in 26 patients for safe conduct of cardiac catheterization and for peri-operative hemodynamic support. Hospital survival was achieved in 24 of the 36 operated patients (66%). In Group I patients, ten of 21 survived. In Group II, six of seven survived. In Group III, eight of eight patients survived. There have been five late deaths with a mean follow-up of 41 months in survivors. Improved survival has been achieved recently by the greater use of prosthetic material to replace necrotic muscle and by a transinfarct incision regardless of infarct location. Operative mortality before 1973 was 47%; mortality after 1973 was only 18%, with a concomitant reduction of mortality (30%) even in Group I patients.

Intraaortic balloon pumping for ventricular septal defect or mitral regurgitation complicating acute myocardial infarction.

The intraaortic balloon pump (IABP) has been employed in the management of five patients with ventricular septal rupture (VSD) and six patients with acute mitral regurgitation (AMR) following myocardial infarction. All patients were in cardiogenic shock which responded poorly to medical therapy including pressor and inotropic agents. IABP resulted in significant clinical and hemodynamic improvement in all cases.In patients with VSD, IABP produced a fall in wedge (PCW) pressure from 17 ± 4 (SD) to 13 ± 4 mm Hg (P < 0.01) while mean arterial pressure increased from 68 to 73 mm Hg. Systemic A-V O2 difference fell from 9.7 ± 2.4 to 8.1 ± 2.4 vol % (P < 0.05) while pulmonary A-V O2 difference was unchanged. Thus the pulmonic/systemic flow ratio (P/S) declined in all patients. In patients with AMR, PCW fell from 25 ± 4 to 20 ± 4 mm Hg (P < 0.02) with a significant diminution in “V”-wave amplitude. Cardiac output (CO) rose from 3.1 ± 0.9 to 3.7 ± 1.0 liters/min (P < 0.01). All patients underwent coronary angiography without complication in preparation for emergency surgery.IABP reduces AMR following acute myocardial infarction and reduces the P/S in VSD by a selective augmentation of systemic CO. Such direct therapy acutely stabilizes these severely ill patients. Detailed angiography may then be performed safely.

Surgical management of mycotic aneurysms and the complications of infection in vascular reconstructive surgery

Abstract A series of seventeen mycotic aneurysms treated over the past fifteen years at this institution has been reported. Thirteen of these involved the abdominal aorta and four involved peripheral vessels. Rupture of the aneurysm occurred in ten. There were no survivors in the seven patients with ruptured aneurysms that involved the aorta, four of whom underwent emergency surgery. There were two survivors among the three patients with peripheral ruptured mycotic aneurysms. There were five survivors of the seven with nonruptured aneurysms treated surgically. Four of the six patients with mycotic nonruptured aneurysms of the aorta treated surgically survived and are well at periods of nineteen months to nine years. Three additional successfully managed cases of infection complicating vascular reconstructive procedures have been presented, emphasizing the technics of management. The following factors appear to be of importance to the successful management of mycotic aneurysms or infection complicating vascular reconstructive surgery: (1) early diagnosis and prompt surgery; (2) appropriate pre- and intraoperative antibiotic therapy and postoperative intravenous antibiotic therapy for a period of at least six weeks; (3) resection of infected tissue, foreign material, and adequate drainage; (4) placement of the new graft reconstruction through clean tissue planes; (5) use of wide drainage and local antibiotic irrigation in addition to systemic antibiotics in rare situations in which resection and reconstruction does not seem possible; (6) careful long-term follow-up study.

Surgical Measures for Coronary Heart Disease

(First of Three Parts) Indirect Myocardial Revascularization ON the basis of the myocardial sinusoidal circulation demonstrated by the detailed pathological studies of Wearn and his associates,1 Vi...

Variant angina pectoris: Clinical and anatomic spectrum and results of coronary bypass surgery

Twenty patients are described with the variant angina syndrome (recurrent angina at rest with S-T segment elevations occurring only during pain and no evolution of infarction). In contrast to patients previously reported on, all but one had progressive unstable angina before hospitalization. Angina was frequently associated with arrhythmias, including ventricular fibrillation (2 instances), ventricular tachycardia (4), frequent ventricular premature beats (5), atrioventricular block (4), sinus bradycardia (2), sinoatrial exit block (1) and supraventricular tachycardia (1). Seventeen patients had significant proximal stenosis of one or more coronary arteries with good distal vessels. Bypass surgery in 15 of these patients resulted in one noncardiac postoperative death, one perioperative infarction and relief of pain in all 14 survivors. After a 17 month mean follow-up period (range 4 to 38 months), all survivors are pain-free. Three patients had no significant coronary disease; one of these became asymptomatic with medical therapy, one continues to have angina and one died suddenly. Patients with normal coronary arteries could not be distinguished clinically or by electrocardiogram from those with severe obstructive lesions. This experience suggests that all patients with the variant angina syndrome should be studied by coronary angiography, and that most patients with significant fixed coronary lesions will do well after coronary bypass surgery.

Unstable angina pectoris: National cooperative study group to compare medical and surgical therapy. I. Report of protocol and patient population

A preliminary report is presented of a prospective randomized trial conducted by eight cooperative institutions under the auspices of the National Heart and Lung Institute to compare the effectiveness of medical and surgical therapy in the management of the acute stages of unstable angina pectoris. To date 150 patients have been included in the randomized trial, 80 assigned to medical and 70 to surgical therapy; the clinical presentation, coronary arterial anatomy and left ventricular function in the two groups are similar. Some physicians have been reluctant to prescribe medical or surgical therapy by a random process, and the eithical basis of the trial has been questioned. Since there are no hard data regarding the natural history and outcome of therapy for unstable angina pectoris, randomization appears to provide a rational way of selecting therapy. Furthermore, subsets of patients at high risk may emerge during the process of randomization. The design of this randomized trial is compared with that of another reported trial. Thus far, the study has shown that it is possible to conduct a randomized trial in patients with unstable angina pectoris, and that the medical and surgical groups have been similar in relation to the variables examined. The group as a whole presented with severe angina pectoris, either as a crescendo pattern or as new onset of angina at rest, and 84 percent had recurrence of pain while in the coronary care unit and receiving vigorous medical therapy. It is anticipated that sufficient patients will have been entered into the trial within the next 12 months to determine whether medical or surgical therapy is superior in the acute stages of unstable angina pectoris.Abstract A preliminary report is presented of a prospective randomized trial conducted by eight cooperative institutions under the auspices of the National Heart and Lung Institute to compare the effectiveness of medical and surgical therapy in the management of the acute stages of unstable angina pectoris. To date 150 patients have been included in the randomized trial, 80 assigned to medical and 70 to surgical therapy; the clinical presentation, coronary arterial anatomy and left ventricular function in the two groups are similar. Some physicians have been reluctant to prescribe medical or surgical therapy by a random process, and the ethical basis of the trial has been questioned. Since there are no hard data regarding the natural history and outcome of therapy for unstable angina pectoris, randomization appears to provide a rational way of selecting therapy. Furthermore, subsets of patients at high risk may emerge during the process of randomization. The design of this randomized trial is compared with that of another reported trial. Thus far, the study has shown that it is possible to conduct a randomized trial in patients with unstable angina pectoris, and that the medical and surgical groups have been similar in relation to the variables examined. The group as a whole presented with severe angina pectoris, either as a crescendo pattern or as new onset of angina at rest, and 84 percent had recurrence of pain while in the coronary care unit and receiving vigorous medical therapy. It is anticipated that sufficient patients will have been entered into the trial within the next 12 months to determine whether medical or surgical therapy is superior in the acute stages of unstable angina pectoris.

Intra-aortic Balloon Pump Assist for Cardiogenic Shock After Cardiopulmonary Bypass

Intra-aortic balloon pump assist (IABP) was applied to 26 patients who could not be with-drawn from total cardiopulmonary bypass (CB) subsequent to elective surgery for multiple cardiac procedures. Eighty-eight per cent were able to separate from CB with IABP and were assisted for 36 to 168 hours. Seventeen were withdrawn from the balloon. Eleven (42%) are hospital survivors. Ten (38%) are alive at the time of this report.IABP was most effective when applied early to patients who had recognizable acute ischemic injury to the myocardium at the time of operation and/or presence of hypertrophied left ventricular myocardium with small chamber volume. Support in these conditions gave 50% survival. Poorest results were in patients with either extensive acute infarction or severe chronic irreversible myocardial damage.

Intraaortic Balloon Pumping for Control of Recurrent Myocardial Ischemia

Eleven patients were studied because of recurrent angina at rest. In five cases ischemic pain developed 3-10 days after acute myocardial infarction. Pain recurred in all cases despite therapy with bedrest, oxygen, heparin anticoagulation, nitrates, and whenever possible, beta blockade. Intraaortic balloon pumping with a 30-cc balloon prevented ischemia in nine patients and markedly reduced the frequency of ischemic attacks in two. Coronary angiograms were obtained during circulatory assistance without complication and confirmed proximal coronary artery obstructions in all patients. Saphenous vein aortocoronary bypass grafting was then performed. Intraaortic balloon pumping will effectively control myocardial ischemia resistant to medical therapy.

Survival After Starr-Edwards Aortic Valve Replacement

A series of 507 patients who underwent Starr-Edwards aortic valve replacement is reported. Four hundred fifty-five of these patients were adequately followed an average of 36 months. Of this number, 339 patients (75%) are alive, and 116 (25%) have died. There was an operative mortality of 10.8% and a late mortality of 13.4%. Patients with mixed aortic stenosis and regurgitation had a significantly lower cumulative mortality than patients with pure stenosis or regurgitation. Complications related to the valvular prosthesis itself were frequent. Although the great majority were minor, prosthetic complications caused a significant number of deaths and considerable morbidity. Myocardial disease was the other significant limiting factor in survival. Preoperative cardiac index and functional classification were valuable in predicting long-term survival, but age at time of surgery and type of preoperative symptoms were of lesser prognostic value.