George E. Reed

Release of adenosine from human hearts during angina induced by rapid atrial pacing.

This study was designed to determine whether human hearts release adenosine, a possible regulator of coronary flow, during temporary myocardial ischemia and, if so, to examine the mechanisms involved. Release of adenosine from canine hearts had been reported during reactive hyperemia following brief coronary occlusion, and we initially confirmed this observation in six dogs hearts. Angina was then produced in 15 patients with anginal syndrome and severe coronary atherosclerosis by rapid atrial pacing during diagnostic studies. In 13 of these patients, adenosine appeared in coronary sinus blood, at a mean level of 40 nmol/100 ml blood (SE = +/-9). In 11 of these 13, adenosine was not detectable in control or recovery samples; when measured, there was concomitant production of lactate and minimal leakage of K(+), but no significant release of creatine phosphokinase, lactic acid dehydrogenase, creatine, or Na(+). THERE WAS NO DETECTABLE RELEASE OF ADENOSINE BY HEARTS DURING PACING OR EXERCISE IN THREE CONTROL GROUPS OF PATIENTS: nine with anginal syndrome and severe coronary atherosclerosis who did not develop angina or produce lactate during rapid pacing, five with normal coronaries and no myocardial disease, and three with normal coronaries but with left ventricular failure. The results indicate that human hearts release significant amounts of adenosine during severe regional myocardial ischemia and anaerobic metabolism. Adenosine release might provide a useful supplementary index of the early effects of ischemia on myocardial metabolism, and might influence regional coronary flow during or after angina pectoris.

Release of nucleosides from canine and human hearts as an index of prior ischemia.

During ischemia, myocardial adenosine triphosphate is degraded to adenosine, inosine and hypoxanthine. These nucleosides are released into coronary venous blood and may provide an index of ischemia; adenosine may also participate in the autoregulation of coronary flow. In dogs, the temporal relations between reactive hyperemic flow and nucleoside concentrations in regional venous blood were correlated after brief occlusions of a segmental coronary artery. Reactive hyperemia and adenosine release peaked together in 10 seconds, persisted for 10 to 30 seconds and then decreased in a pattern consistent with the hypothesis that they are related. During initial reflow after 45 seconds of ischemia, mean concentrations of adenosine, inosine and hypoxanthine increased, respectively, to 52, 67 and 114 nmol/100 ml plasma; after 5 minutes of ischemia, the respective levels increased to 58, 1,570 and 1,134 nmol and fell quickly. In nine patients there was a similar release of nucleosides into coronary sinus blood during reperfusion after 59 to 80 minutes of ischemic arrest during cardiac surgery. With initial reflow, adenosine, inosine and hypoxanthine levels reached 65, 655 and 917 nmol/100 ml of blood, respectively. Inosine and hypoxanthine concentrations remained high for 5 to 10 minutes after cardiac beating resumed, often when production of lactate had decreased. The results indicate that postischemic release of nucleosides reaches significant levels in man as well as animals, is parallel with the duration of ischemia, is temporary and may be a useful supplement to measurement of lactate as an index of prior myocardial ischemia.

LYMPH DRAINAGE IN PATIENTS WITH CONGESTIVE HEART FAILURE. COMPARISON WITH FINDINGS IN HEPATIC CIRRHOSIS.

UNDERSTANDING of the physiologic alterations present in patients with congestive heart failure is limited in part by incomplete knowledge concerning pathogenesis of elevated venous pressure and cir...

Hemodynamic comparison of albumin and hydroxyethyl starch in postoperative cardiac surgery patients.

The hemodynamic effects of 2 plasma volume expanders were compared in postoperative open heart surgery patients. Albumin 5% (A) or hydroxyethyl starch 6% (HES) solutions were infused according to indications based on cardiac index (CI) and pulmonary wedge pressure (WP), and their effects evaluated by physiologic profile measurements.Both groups demonstrated significant increases with volume infusion in CI (A from 2.37 to 2.84; HES from 1.97 to 2.49 L/min-m2) and WP (A from 9.4 to 13.7 mm Hg; HES from 11.9 to 13.2 mm Hg). Stroke index and stroke work increased similarly. Mean systemic arterial pressure (MAP) and mean pulmonary arterial pressure (MPAP) remained unchanged. No significant difference for any variable was demonstrated between the A and HES groups. In the volume used, from 250 to 750 ml, HES caused no bleeding abnormalities. HES is as effective as A as a plasma volume expander in postoperative cardiac surgery patients.

Cardiac Tamponade Following Open-Heart Surgery

A review of 310 consecutive cardiac operations with cardiopulmonary bypass for acquired valvular and congenital heart disease found eight cases of late tamponade, 8 to 30 days after operation, and four cases of early tamponade, within 36 hours after operation. Early tamponade, associated with postoperative bleeding, was easily recognized and treated, but late tamponade was often misdiagnosed as cardiac failure or pulmonary embolism. In the eight late cases, six were associated with anticoagulation and hemorrhage, while two developed a bloody effusion with a pericardiotomy syndrome. Tamponade produced an elevated right atrial pressure, low central or mixed venous oxygen tension, oliguria, hypotension, and tachycardia. A severe metabolic acidosis was a late finding. Treatment in the presence of bleeding was uniformly effective if thoracotomy and drainage were promptly instituted. Pericardiocentesis sufficed only in the patients with a pericardiotomy syndrome. Three deaths occurred in the late group from a delay in diagnosis (37.5% mortality).

The Long-term Influence of Coronary Bypass Grafts on Myocardial Infarction and Survival

Approximately 1,000 coronary bypass procedures were performed at New York University between February 1968 and December 1973. This report reviews all elective operations performed for angina between 1968 and 1972, a total of 448 patients. In this five-year period the percentage of diseased arteries bypassed rose from 40% to 84%, and operative mortality decreased from 28% to less than 3%. There were a total of 28 operative deaths, mostly from myocardial infarction and low cardiac output. Operability was nearly 95%. The only fixed contraindication was chronic congestive failure. Over one-half of the patients had an abnormal ventriculogram, and there was some history of mild congestive failure in nearly 20%. Elevation of left ventricular end-diastolic pressure above 20 mm before operation was associated with a higher operative mortality, but the late mortality was similar to those with a normal preoperative end-diastolic pressure. In 383 surviving patients, angina was eliminated or greatly improved in 86%, unimproved in 12% and worse in 2%. Late angiograms were performed on 201 patients, studying a total of 445 venous grafts with an overall patency rate of 71%. Graft occlusion was sporadic and unpredictable, but over 90% of patients with multiple grafts remained with at least one patent graft. A late myocardial infarction occurred in 32 out of 420 patients surviving operation, and was fatal in eight. The cumulative incidence over a period of five years was 17%. Twenty-three deaths occurred following discharge from the hospital. Life-table analyses showed a five-year survival of 77% when all deaths were included, and a five-year cardiac survival of 81% when non-cardiac deaths were withdrawn alive at the time of death. The expected survival in a comparable population group without coronary disease was 92%, while data published by Sones of patients treated without operation showed a five-year cardiac survival of 66%. Current operative techniques have an operative mortality of 2-3% and a subclinical infarction rate of 5-10%. The ideal graft is yet evolving, but data with internal mammary artery grafts are most encouraging. A future goal should be a five-year graft patency of at least 80%. Because many infarcts probably develop from a relatively small decrease in coronary blood flow, either during rest or mild activity, the likelihood that future data will demonstrate a marked increase in longevity with bypass grafting is great.

Factors in the Mortality and Morbidity Associated with Surgical Treatment of Cerebrovascular Insufficiency

The mortality and morbidity associated with 267 surgical procedures for cerebrovascular insufficiency carried out over a 5-year period are reviewed. Patients with marked intracranial arterial disease on angiogram, with completed strokes, over 70 years old or who required continuous nursing care are identified as the highest surgical risks. The introduction of monitoring of the oxygen saturation of lateral sinus venous blood has reduced the incidence of intra-operative new neurological deficit during general anesthesia from 9.1 to 4.4%. Episodes of hypotension occurred in 27% of patients but were associated with 48% of grave complications. The occurrence of hypotension is related to diabetes, preoperative hypertension, and to the extent of the operative procedure. Evidence is presented that hypotension is due to abnormal circulatory reflexes and may best be prevented by careful maintenance of intravascular volume.

Long-term results in 1375 patients undergoing valve replacement with the Starr-Edwards cloth-covered steel ball prosthesis.

The two principal considerations with prosthetic valves are durability and thromboembolism. With the widespread interest in recently developed prosthetic valves (porcine, tilting dise, Cooley), the long-term results at one institution with a single prosthesis were considered of particular importance. Accordingly, a 97% follow-up has been completed on 1375 patients (pts) undergoing prosthetic valve replacement with the Starr-Edwards cloth-covered steel ball prosthesis at New York University between October 1967 and December 1975. Operative procedures were as follows: aortic valve replacement (AVR): 470 pts; mitral valve replacement (MVR): 362 pts; combined AYR and MVR: 129 pts; other combined procedures: 414 pts. Overall operative deaths were 13.7%, 9% for AVR, 10.8% for MVR, and 18.6% for combined AVR and MVR. At seven years, AVR survival was 64%, and MVR survival 64.5%. There has been widespread pessimism, usually without significant data, about the cloth-covered prosthesis, because of concern of cloth wear, hemolysis and other complications. Therefore, a particularly significant finding by actuarial analysis was that 85% of surviving patients with isolated AVR remained free of emboli for five years. In pts surviving isolated MVR, 80% remained free of emboli for five years. Of those having embolie episodes, 33% were not on anticoagulants. Fatal hemorrhage from anticoagulants occurred in 0.8% of pts. Endocarditis occurred in 5.7% of the entire group, with 1.3% requiring reoperation. Clinically significant hemolysis occurred in 5.1% of the group, with only 0.2% requiring reoperation. Hence, the total frequency of clinically significant cloth-wear was less than 0.5%. These data indicate both the reliability and the limitations of the Starr-Edwards cloth-covered steel ball valve and can be used in comparing experiences with the more recently developed prostheses.

Coexisting carotid stenosis in patients undergoing cardiac surgery: Indications and guidelines for simultaneous operations

The coexistence of critical carotid stenosis with coronary artery or valvular heart disease occurs in a small percentage of patients requiring open heart surgical procedures. Recognition of such combined lesions by noninvasive carotid testing identifies patients at risk for neurologic events. Our experience with 62 patients having combined simultaneous carotid and cardiac operations among 2,400 open heart surgery patients was compared with the results in 110 patients with only carotid endarterectomy operations. The outcomes indicated that carotid endarterectomy can be performed simultaneously with open heart surgical procedures with morbidity and mortality rates similar to those of isolated cervical artery operations. Thus, patients with significant coexisting carotid artery disease defined with specific criteria and coronary artery disease need not be exposed to cerebral ischemic events or to myocardial infarctions that often accompany staged operations.

Roof patch repair of an aortoduodenal fistula resulting from suture line failure in an aortic prosthesis

Abstract A unique method of managing aortoduodenal fistula due to proximal suture line failure eight years after resection of an aortic aneurysm is presented. A roof patch of woven Dacron was employed in the repair rather than resection and replacement of the entire prosthesis. Immediate operation is recommended for the patient presenting with the “herald bleed” of aortointestinal fistula after prosthetic aortic replacement.