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The appearance of the ventricular myocardium in 6 patients electing coronary bypass operation was evaluated by electron microscope before and after aortic cross-clamping. Bypassing protocol included the induction of hypothermic cardioplegia by intermittent aortic root perfusion, with potassium chloride added to cold blood serving as the cardioplegic agent. Cross-clamp intervals ranged from 66 to 125 minutes. Ultrastructural alterations following bypass manipulations, and distinct from those observed before cross-clamping, were limited to the presence of extensive myocardiocytic pooling of glycogen. Scrutiny of the intramyocardial capillary bed following perfusion with the cardioplegic solution revealed no abnormalities attributable to, or intensified by, the bypass maneuver. These findings indicate that hypothermic potassium cardioplegia, as specified, is not injurious to human myocardial ultrastructure.

Three commercially available aortic vents have been evaluated as to effectiveness in removing small volumes of air introduced into a mock circulatory circuit. Without aspiration, Vent 2 was the most effective and removed 58 per cent of 0.1 ml., 90 per cent of 0.5 ml., and 74 per cent of 1.0 ml. boluses at a cardiac output of 2 L. At a cardiac output of 4 L., Vent 2 removed 42, 76, and 49 per cent, respectively. With aspiration (Vent 2 not designed for aspiration) and a 2 L. cardiac ouput, Vents 1 and 3 removed 84 to 98 per cent of 0.1 ml., 68 to 92 per cent of 0.5 ml., and 74 to 86 per cent of 1.0 ml. boluses. With aspiration and a 4 L. cardiac output. Vent 3 was significantly more effective than Vent 1 and removed 92 to 94 per cent of 0.1 ml., 82 to 86 per cent of 0.5 ml., and 77 to 80 per cent of 1.0 ml. boluses. One liter of canine blood was aspirated through Vents 1 and 3 at a flow rate of 250 ml. per minute. For Vent 1, serum hemoglobin levels increased from 40 to 249 mg. per 100 ml. and for Vent 3 from 49 to 212 mg. per 100 ml. There are significant differences in the ability of commercially available aortic vents to remove small air bubbles trapped in the heart after initial direct cardiac venting. Vents having the capability of aspiration are more effective and result in acceptable hemolysis.

Intraoperative beta blockade has been evaluated as an adjunct to hypothermic cold blood potassium cardioplegia by quantitating serum creatine kinase MB release. Randomization of 80 patients having coronary artery bypass grafting and 18 patients having valve replacement with or without bypass grafting resulted in 46 of the former and seven of the latter receiving propranolol 0.05 mg/kg 4 to 5 minutes before aortic cross-clamping. Among patients having bypass grafting, infarct size (in gram-equivalents) was 7.9 ± 0.7 gm-Eq for the propranolol group and 10.3 ± 0.8 (p

Of currently available methods for mechanical circulatory support, the Pierce-Donachy external pneumatic ventricular assist device has proved to be one of the most versatile and effective. Since 1981, 48 patients, aged 15 to 71 years (mean 43.0), with profound cardiogenic shock refractory to conventional therapy with drugs and intra-aortic balloon support, were supported with the Pierce-Donachy ventricular assist device. There were four patient groups. The largest group consisted of 30 patients with cardiogenic shock after cardiac operations. Nine required left ventricular support, six needed right ventricular support plus an intraaortic balloon pump, and 15 had biventricular support. Duration of support ranged from 3 hours to 22 days (mean 3.6 days). Eight of the first 11 patients died in the operating room of bleeding and/or biventricular failure. However, 16 patients, (53%) had improved cardiac function, 15 (50%) were weaned, and 11 (36%) were discharged. Of the last 19 patients, 47% survived. Frequent factors in nonsurvivors were myocardial infarction (75%) and renal failure (90%). Common complications in all patients were bleeding (52%) and infection (27%). The second group consisted of 11 patients with end-stage cardiomyopathy or acute myocardial infarction in whom the Pierce-Donachy ventricular assist device was used as a bridge to transplantation (left ventricular support, four patients; biventricular support, seven patients). Renal failure, infection, or coagulopathy that precluded transplantation developed in five patients. Five patients were supported for 8 hours to 75 days (mean 20.7 days) before undergoing successful transplantation, with one late death (six months) from rejection owing to noncompliance. One has subsequently undergone successful transplantation after 84 days of support. The third group consisted of four patients, aged 40 to 56 years (means 47.2), who had refractory cardiogenic shock after cardiac transplantation caused by pulmonary hypertension (two patients), hyperacute rejection (one patient), or graft failure (one patient). Despite biventricular support in all four (biventricular assist devices, two patients; right ventricular assist device plus intraaortic balloon pump, two patients), all died of infection and/or renal failure after 12 hours to 6 days (mean 3.4 days) of support. The final group consisted of three patients, aged 36 to 51 years (mean 45), with cardiogenic shock caused by acute myocardial infarction. One patient was supported with biventricular assist devices (3.5 days) and two patients were supported with a left ventricular assist device (8.5 and 15 days).(ABSTRACT TRUNCATED AT 400 WORDS)

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.

We compared moderate (29° C.) and profound (5° C.) (ice chips) cardiac hypothermia for myocardial preservation during aortic cross-clamping for 30 or 60 minutes in a canine right heart bypass preparation. Ventricular function deteriorated significantly at 29° C. but not at 5° C. Maximum dp/dt declined only after 60 minutes of ischemia at 29° C, and Vmax decreased after one hour at either temperature. Lactate and pyruvate washout were greater after 29° C., and pyruvate production persisted after 60 minutes of ischemia at 29° C. Reactive hyperemia was greater after 30 minutes of ischemia at 29° C. Reactive hyperemia was greater after 30 minutes of ischemia at 29° C., and total coronary flow remained elevated after 60 minutes of ischemia at 29° C. Coronary flow distribution was not altered by hypothermia. Ultrastructural changes were primarily time dependent and not temperature dependent. Ice-induced subepicardial injury was not evident in the ultrastructure or by flow distribution. Sixty minutes of profound topical cardiac hypothermia is moderately well tolerated by the canine heart, but functional and structural alterations are evident.

Between August 1980 and January 1986, 23 patients aged 80 years or older underwent coronary artery bypass grafting (CABG) operations. These patients had a higher incidence of severe left main coronary artery narrowing (p less than 0.0001), 3-vessel coronary artery disease (p less than 0.05) and moderate to severe left ventricular dysfunction (p less than 0.05) than patients in the Coronary Artery Surgery Study registry older than 65 years. Of 14 patients undergoing elective simple CABG procedures, none died; of 19 elective cases overall, 2 patients died (11%). Three of 4 patients undergoing emergency procedures (75%) and 4 of 6 patients (67%) requiring intraaortic balloon counterpulsation died. Significant complications occurred in 9 of 18 survivors (50%). All operative survivors improved at least 1 New York Heart Association class, with a mean classification improvement of 3.7 to 1.6 (p less than 0.0001); 13 of 16 long-term survivors were in class I or II. Actuarial survival at 1 and 2 years is 94% and 82%, respectively. CABG can be performed electively in octogenarian patients with increased but acceptable mortality and morbidity risks. Functional improvement and long-term survival are excellent.

It has been suggested that coronary artery bypass grafting (CABG) performed in the setting of emergent failure of percutaneous transluminal coronary angioplasty causes minimal increased risk compared with routine CABG. We reviewed the records of 103 patients undergoing emergency CABG for failed percutaneous transluminal coronary angioplasty (group 1) and compared them with an identical number of consecutive CABG patients from 1987 (group 2). Group 1 had a lower risk profile evidenced by lower mean age (p less than 0.01), fewer diseased vessels (p less than 0.0001), better ventricular function (p less than 0.001), fewer left main lesions (p less than 0.0001), and fewer patients with acute ischemia requiring intravenous administration of nitroglycerin (p less than 0.01). Despite these differences, the group 1 patients had a higher mortality rate (11% versus 1%; p less than 0.01) and a higher rate of perioperative infarctions (new Q wave) (22% versus 6%; p less than 0.01). An analysis of risk factors was performed in the group 1 patients using 36 preoperative and operative variables. Multivariate analysis revealed that left ventricular score (p less than 0.0001), preoperative (after percutaneous transluminal coronary angioplasty) need for inotropic support (p less than 0.005), and age (p less than 0.025) were independent predictors of operative mortality. In conclusion, emergency CABG after failed percutaneous transluminal coronary angioplasty carries a significantly greater risk of operative death and perioperative infarction than elective CABG.

A patient with von Willebrand's disease having aortic valve replacement was managed with cryoprecipitate infusions and monitoring of factor VIII levels. This disorder is associated with low factor VIII levels and abnormal platelet function. There may be no history of bleeding, as the severity of the bleeding tendency varies greatly and fluctuates temporally. The partial thromboplastin time is frequently prolonged, but more detailed studies are necessary to establish a diagnosis (bleeding time, platelet adhesiveness to glass beads and ristocetin, von Willebrand's antigen, ristocetin-von Willebrand's factor, and factor VIII clotting activity). Elevation of factor VIII levels to 50 to 100% of normal allows adequate clotting and is best accomplished with cryoprecipitate or fresh frozen plasma rather than commercial concentrates of factor VIII, whose activity is unpredictable.

Of 2,782 patients undergoing isolated coronary artery bypass grafting (CABG) from 1970 through 1979, 196 exhibited severe global impairment of left ventricular (LV) wall motion preoperatively (LV score, greater than or equal to 15; ejection fraction, less than 0.40 in all patients and less than 0.30 in 67%). The initial 89 patients (Group 1) underwent CABG without potassium chloride cardioplegia. The subsequent 107 patients (Group 2) were given potassium chloride cardioplegia intraoperatively. Group B patients received more grafts per patient (3.1 versus 2.5; p less than 0.001) and were completely revascularized more often (72.9% versus 58.4%; p less than 0.05). Operative mortality was lower in Group B (3.7% versus 12.4%; p less than 0.025), and 5-year cumulative survival was better in Group B (88.8% versus 63.9%; p less than 0.0001). Preoperative congestive heart failure resulted in higher operative mortality (14.3% versus 4.5%; p less than 0.05) and lower 5-year survival (65.0% versus 81.8%; p less than 0.02). Complete revascularization led to higher 5-year survival (82.2% versus 66.0%; p less than 0.02) but did not alter operative mortality significantly (6.9% versus 9.1%). Potassium chloride cardioplegia may influence operative survival favorably by reducing perioperative myocardial infarction in patients with severe LV dysfunction. Long-term survival relates to completeness of revascularization and severity of congestive heart failure as variables independent of methods of myocardial protection.

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.

The use of corticosteroids in the management of acute nonoperative myocardial infarction (MI) is controversial, but experimental evidence indicates reduction of infarct size with steroid treatment. Corticosteroids are also felt to be beneficial in low-flow states because of membrane stabilization. Methxlprednisolone (MP) effectiveness in limitation/prevention of perioperative Ml was assessed by serial ECG and serum LDH, SGOT, CPK, and CPK-MB measurements during the postoperative period in 150 patients. Of these, 75 randomly selected, received 2 Gm. of MP ½ hour prior to institution of cardiopulmonary bypass (CPB). There was no difference between the groups in operative technique, patient age, previous Ml, angina severity, graft number, CPB duration, myocardial ischemia duration, or graft patency. Four patients required ionotropic and intra-aortic balloon counterpulsation before removal from CPB could be accomplished. Three of these patients were in the treated group, and the only operative death occurred in the MP group. Analysis of enzymes did not further discriminate the incidence of MI or provide evidence of reduction of ischemic injury in the MP group. Nine patients in each group demonstrated ECG evidence of myocardial injury. New Q wave ST-T change, 48 nr. Total patients MP 6 3 9 No MP 5 4 9 Methylprednisolone did not reduce the incidence of perioperative myocardial injury during CABG.

Of 531 patients who underwent coronary artery bypass grafting during 1970 to 1973, 181 were restudied by ventriculography and by graft and coronary angiography at least 5 years following operation. Five patterns of postoperative ventricular function were identified: improved ventricular function resulting in normal left ventricular (LV) function; normal ventricular function that was unchanged; abnormal ventricular function that improved but did not reach normal; abnormal ventricular function that remained unchanged; and deterioration of LV function. Patients who regained (40) and those who retained normal ventricular function (49) comprise 49% of the series and patients with deterioration of ventricular function, only 20%. Graft patency and angina relief were significantly better in those with normal LV function than in those with LV deterioration. Progression of disease in grafted coronary arteries was similar in all groups, but was significantly higher in ungrafted coronary arteries (61.3%) in the patients showing deterioration than in either the improved patients or those with an unchanged normal LV (33.3% each) (p less than 0.05). The high incidence of progression of disease in ungrafted coronary arteries in the group with deterioration suggests that low graft patency and deterioration of ventricular function in this group might both be related to intrinsic acceleration of coronary atherosclerosis unrelated to operative intervention.

From January, 1972, through August, 1977, 472 patients had internal mammary artery (IMA) coronary bypass, of which 100 were double-IMA bypasses. We selected those patients having a widely patent IMA one year postoperatively who then had a second catheterization 49 to 105 (mean, 64) months following operation. None of the 93 patients who met these criteria was specifically recalled for this study; they all had follow-up catheterizations for multiple other reasons. All of the 91 left IMA and 22 right IMA bypasses (total, 113) were patent at late catheterization, but 1 right IMA was diffusely narrowed. One left IMA had acute angulation with 50% stenosis proximal to the distal anastomosis, which was unchanged over the follow-up interval. There were 100 patent saphenous vein bypasses at one year and 87 at late catheterization. Late closure of coronary bypass grafts is secondary to progression of coronary disease, atherosclerosis of the bypass conduit, or intimal proliferation. Because we have not encountered the latter two causes of conduit closure, IMA grafts remain our graft of choice for nonemergent operations in patients under 60 years of age having revascularization of the left anterior descending coronary artery system.

Potassium (34 mEq/L) cardioplegia was induced with cold blood (CBK) in three groups of six dogs undergoing 60 minutes of myocardial ischemia at a systemic temperature of 27 degrees +/- 2 degrees and a myocardial temperature of 7 degrees +/- 2 degrees C (crushed ice). Group 1 (CBK) animals were reperfused initially with 400 ml cold blood over 8 to 10 minutes at increasing pressures of up to 75 mm Hg. Group II (CBK-K) dogs were reperfused in the same manner as Group I with the addition of potassium chloride, 30 mEq/L. In Group III (CBKG-KG) glutathione, 30 mg/100 ml, was added to both the pre- and postischemic perfusions with CBK. After 30 minutes of reperfusion control studies were repeated. Heart rate, peak systolic pressure, rate of rise of left ventricular pressure, maximum velocity of contractile element, pressure-volume curves, coronary flow distribution, muscle stiffness, and heart water were not significantly different from control values. Total coronary flow and myocardial uptake of oxygen, lactate, and pyruvate did not serve to separate the three groups; the same was true for right ventricular creatine phosphate, adenosine triphosphate, and adenosine diphosphate during ischemia and recovery. Ultrastructural myofibrillar lesions were noted in all groups. thus, postischemic cardioplegia and use of a physiological reducing agent do not enhance CBK cardioplegia with topical and systemic hypothermia.

The calcium channel blocker, diltiazem, has been studied in the same model used for evaluation of cold blood-potassium cardioplegia. Six dogs (Group 1) had one hour of myocardial ischemia with topical ice (myocardial temperature, 7 degrees +/- 2 degrees C) after coronary perfusion with 200 ml of cold blood (5 degrees +/- 1 degree C) containing diltiazem, 400 micrograms per kilogram of body weight. Seven dogs (Group 2) had two hours of ischemia after perfusion with 200 ml of cold blood containing 200 micrograms/kg and reperfusion every 30 minutes with 100 ml of cold blood and diltiazem, 100 micrograms/kg. Baseline studies were repeated after rewarming and 40 minutes of reperfusion. No inotropic agents or calcium were used. Heart rate, peak systolic pressure, velocity of the contractile element, peak + rate of rise of left ventricular pressure (dP/dt), peak - dP/dt, dP/dt over common peak isovolumic pressure, left ventricular compliance and stiffness, and heart water were unchanged in Group 1. In Group 2, heart rate slowed (p less than 0.025) and compliance decreased (p less than 0.02). In both groups, coronary vascular resistance declined (p less than 0.001) and recovery of adenosine triphosphate (p less than 0.001), adenosine diphosphate (p less than 0.025), and the adenosine pool (p less than 0.001) was impaired. Ultrastructure was well preserved, but myofibrillar lesions were noted in Group 2. Diltiazem cardioplegia was associated with good functional recovery, but there was impairment of high-energy phosphate metabolism.

The technique of myocardial protection by means of a cardioplegic solution consisting of cold blood (10° C.) with potassium (30 mEq. per liter) is described. A disposable cooling coil is used and a separate pump head for coronary perfusion is avoided. The aortic perfusion cannula can be used for venting of the left ventricle and subsequently for venting of air. This method was used in 125 consecutive patients undergoing coronary revascularization and in 73 consecutive pediatric cardiac surgical procedures with excellent results.

Blood flow has been measured in 28 aortocoronary saphenous vein bypass grafts performed for chronic angina pectoris using the electromagnetic flowmeter. Nitroglycerin, 0.4 mg. intravenously or 0.1 mg. into the graft, and papaverine 30 mg. intravenously or 15 mg. into the graft, were studied. Intravenous nitroglycerin increased coronary flow a maximum of 4 per cent for 20 seconds followed by 23 per cent decline as mean arterial pressure fell 23 per cent. Intra-arterial nitroglycerin increased coronary flow 74 per cent in 15 seconds with return to control by 90 seconds. Intravenous papaverine elevated coronary flow 76 per cent at 30 seconds with stabilization of flow 15 to 20 per cent above control. Intra-arterial papaverine achieves a maximum flow of 215 per cent at 45 seconds with return to control at five minutes. Although nitroglycerin produces a small but significant rise in coronary flow it is doubtful whether this increase occurs with oral administration in the presence of coronary disease. Thus, the therapeutic effect of nitroglycerin lies in its systemic effects rather than in its coronary effect.

One hundred twenty-nine infants with esophageal atresia and tracheoesophageal fistula were reviewed from 1955 to 1978. The overall mortality was 38%. Factors associated with the increased mortality include prematurity, pneumonia, and congenital defects other than this anomaly. A classification based on these factors is introduced, which provides the clinician with a prognostic survival rate greater than 90% with only physical examination, chest and abdominal roentgenography, and intravenous pyelography. Postoperative mortality was reduced to 11% in the last five years of the study; this is attributed to the exclusive use of the retropleural approach to the esophagus, more intensive postoperative ventilatory support, and routine use of parenteral nutrition.

Cold blood with potassium, 34 mEq/L, was compared with cold blood and with a cardioplegic solution. Three groups of 6 dogs had 2 hours of aortic cross-clamp while on total bypass at 28 degrees C with the left ventricle vented. An initial 5-minute coronary perfusion was followed by 2 minutes of perfusion every 15 minutes for the cardioplegic solution (8 degrees C) and every 30 minutes for 3 minutes with cold blood or cold blood with potassium (8 degrees C). Hearts receiving cold blood or cold blood with potassium had topical cardiac hypothermia with crushed ice. Peak systolic pressure, rate of rise of left ventricular pressure, maximum velocity of the contractile element, pressure volume curves, coronary flow, coronary flow distribution, and myocardial uptake of oxygen, lactate, and pyruvate were measured prior to ischemia and 30 minutes after restoration of coronary flow. Myocardial creatine phosphate (CP), adenosine triphosphate (ATP), and adenosine diphosphate (ADP) were determined at the end of ischemia and after recovery. Changes in coronary flow, coronary flow distribution, and myocardial uptake of oxygen and pyruvate were not significant. Peak systolic pressure and lactate uptake declined significantly for hearts perfused with cold blood but not those with cold blood with potassium. ATP and ADP were lowest in hearts perfused with cardioplegic solution, and CP and ATP did not return to control in any group. Heart water increased with the use of cold blood and cardioplegic solution. Myocardial protection with cold blood with potassium and topical hypothermia has some advantages over cold blood and cardioplegic solution.

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.

Unstable angina pectoris is a broad, nonspecific diagnosis encompassing a wide variety of clinical syndromes. The intravenous administration of nitroglycerin preoperatively is indicative of a more acute clinical situation, and allows for selection and analysis of a more homogeneous patient population. We reviewed the results of coronary artery bypass grafting for unstable angina defined as angina necessitating intravenous administration of nitroglycerin preoperatively. There were 129 patients (83 men and 46 women) with a mean age of 63.2 years (range, 36 to 86 years). Complications included operative death in 6.2%, postoperative low cardiac output in 11%, and perioperative myocardial infarction in 9%. Twenty perioperative variables were analyzed to identify risk factors for these end points. For operative death, age (p less than 0.05), cross-clamp time (p less than 0.05), and cardiopulmonary bypass time (p less than 0.001) were significant in the univariate analysis, but only age (p less than 0.05, F = 4.6) was an independent predictor using multivariate analysis (stepwise linear regression). For low cardiac output, univariate analysis demonstrated that cross-clamp time (p less than 0.01), preoperative use of an intraaortic balloon for angina (p less than 0.05), left ventricular score (p less than 0.05), number of diseased coronary vessels (p less than 0.05), and cardiopulmonary bypass time (p less than 0.001) were significant variables. However, only use of an intraaortic balloon for angina (p less than 0.0001, F = 14.3) and left ventricular score (p less than 0.005, F = 11.1) were significant independent predictors in the multivariate model. For perioperative myocardial infarction, only diabetes requiring insulin (p less than 0.005) was a significant predictor.

Superior vena cava-right pulmonary artery anastomosis has been used to palliate cyanotic congenital heart disease in 42 patients with the following anomalies: tricuspid atresia, 19 cases; transposition of the great vessels, 11; pulmonary atresia, 6; truncus arteriosus, 3; Epstein’s malformation, 2; and atrioventricular canal with pulmonary stenosis, 1 case. Twelve of 13 operative deaths occurred in the 24 infants younger than 6 months of age. Five of 6 infants less than 1 month old died after the operation. Six late deaths were distributed among all age groups and all cardiac lesions. Although survivors were improved clinically, there is a gradual progression of cyanosis and rise of the hemoglobin level. It is clear that cava-pulmonary anastomosis should not be done in the first month of life. An ascending aorta-right pulmonary artery shunt is preferable, even in the first 6 months if the pulmonary artery is small. The cava-pulmonary anastomosis enlarges as the child grows, but increasing venous collateral may reduce its effectiveness. When complemented with a systemic-pulmonary shunt it has the potential for long-term palliation of uncorrectable congenital lesions.

Patients having coronary bypass for stable angina pectoris were grouped on the basis of the two hour plasma sugar of the glucose tolerance test: Group I, 120 mgs% (159 grafts); Group II, 120-150 (93 grafts); Group III, 150-200 (131 grafts) and Group IV, 200 (57 grafts) or patients receiving therapy for diabetes mellitus (10 patients, 21 grafts). Five of 10 diabetic patients had genetic evidence of diabetes and an average duration of therapy of 6.5 years. Blood flow was measured in 461 grafts with an electromagnetic flow probe after discontinuation of cardiopulmonary bypass in a stable state, after a 30 second graft occlusion and after injection of 15 mg of papaverine into the graft. Mean arterial pressure, graft flow and coronary resistance for each succeeding group did not vary significantly when compared with Group I. Analysis of phasic flow in 10 grafts to the left anterior descending indicates that the same proportion of flow occurs during systole and diastole in the basal state and after pappaverine. Coronary flow and resistance in patients with abnormal glucose metabolism and maturity onset diabetes do not provide evidence for the existence of myocardial microangiopathy.

This study retrospectively examines 447 patients with minimal or absent angina found to have significant coronary artery disease (CAD) by coronary arteriography. Patients with left main coronary stenosis, valvular heart disease, or ventricular aneurysm were excluded. Treatment choice was nonrandom—more medically treated patients had single-vessel disease, normal left ventricular contractility, or absence of angina. Isolated coronary artery bypass grafting (CABG) was performed in 284 patients; of 163 patients initially managed nonoperatively, 22 subsequently crossed over to surgical treatment because of increasing angina. Average followup is 38.6 months (range 18 to 64). There was an important, but not statistically significant, difference in the 3 year cumulative survival rate—surgical 98.3% (70% CL 97.6% to 100%) versus medical 94.1% (70% CL, 91.7% to 96.5%) p = 0.077. There was only one noncardiac death and there were three nonfatal myocardial infarctions in patients with single-vessel disease, regardless of therapy. In patients with multivessel disease, the 3 year cumulative survival rate was significantly better in the surgical (98.6%) than the medical group (91.5%) p = 0.031. Event-free 3 year survival rate (death, myocardial infarction, crossover to surgical therapy, or reoperation) was significantly better in surgically treated patients overall (90.4% versus 73.5%, p = 0.000041), as well as in surgically treated patients with double- or triple-vessel disease taken as separate subsets. Angina relief was also significantly better with surgical treatment (74.6% versus 44.3%, p

Impedance reduction with a continuous infusion of hydralazine was evaluated in 20 patients following cardiopulmonary bypass. Patients were selected for therapy when the cardiac index (CI) was less than 2.2 L/m2/min, when the systemic vascular resistance index (SVRI) was greater than 2,500 dyne sec cm-5, or when both conditions were present. No other vasoactive or cardiotonic drugs were used intraoperatively or postoperatively. Responses were measured at 15, 30, 60, 120, 180, and 240 minutes and compared with control measurements. Significant responses appeared by 15 minutes in the mean arterial pressure, CI, and SVRI, which were maximal by 2 hours. At 4 hours, the SVRI was 1,520 +/- 276 dyne sec cm-5 (control, 3,235 +/- 222) and pulmonary vascular resistance index, 365 +/- 102 dyne sec cm-5 (control, 592 +/- 71). The CI was 3.20 +/- 0.29 L/m2/min (control, 1.96 +/- 0.16) and mean arterial pressure, 75 +/- 2.3 mm Hg (control, 92 +/- 2.4). Left atrial, pulmonary artery diastolic, and right atrial pressures increased from control but not significantly: 11.4 +/- 0.8 to 13.3 +/- 1.2 mm Hg, 13.6 +/- 1.6 to 17.2 +/- 1.5 mm Hg, and 6 +/- 1.6 to 9.4 +/- 1.7 mm Hg, respectively. In 16 patients, hydralazine was continued for 24 hours and in 11, the transition to oral therapy was made. Hydralazine by infusion effectively reduces after load, avoids the fluctuations of bolus therapy, and allows the transition to oral therapy if needed.

Advances in prosthetic devices led to our analysis of revascularization in patients presenting with gangrene of the lower extremity. Between 1966 and 1976, 99 grafts were performed on 96 of the 249 patients treated by lower extremity revascularization who presented with the above criteria. Their mean age was 66 years; 46 (48%) were diabetic, 53 (55%) were over the age of 65, and 38 (40%) had angiographically proven disease with one vessel runoff. Initial therapy consisted of intravenous antibiotics and local debridement to control sepsis, followed by detailed arteriography. Femoral-popliteal bypass was per formed in 87 patients, and a more distal vessel was utilized in 9. There were 5 in- hospital deaths. Of these, 4 patients had come to major amputation. Four died as a result of myocardial infarctions, and 1 as a result of a cerebrovascular accident. Immediate graft patency was achieved in 93 of 99 patients (93%). Minor amputations were required in 44 patients. Early graft failure resulted in major amputations in 7 patients. A late major amputation (mean 13 months) was required in an additional 28 patients, 15 because of graft failure and 13 because of nonhealing minor amputations. Extremity salvage at 2 years was achieved in 72 of the 99 patients (72%).

The late sequelae 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.

We compared 147 consecutive patients who had left coronary ostial stenosis with 254 consecutive patients who had left main coronary artery stenosis treated with coronary artery bypass grafting. Mean age for the left main group was 61.6 years versus 59.7 years for the left ostial group (p = not significant [NS]). In the left ostial group, 43.5% were female and in the left main group, 12% (p less than 0.005). Prior myocardial infarction had occurred in 53% of patients with left main stenosis and 36% of patients with left ostial stenosis (p less than 0.005). There were 2.45 +/- 1.00 diseased vessels in the left main group and 1.96 +/- 1.09 in the left ostial group (p less than 0.0005). Seven (3%) of the patients with left main stenosis had no associated coronary disease (greater than 50%) versus 24 (16%) of the left ostial group (p less than 0.005). The degree of left main stenosis was 90% or more in 28.3% of patients versus 42.8% with equivalent ostial narrowing (p less than 0.01). Left ventricular function was better in the left ostial group than in the left main group (1.61 +/- 0.93 versus 2.02 +/- 1.11, respectively; p less than 0.0005). One-month mortality was 10 patients (3.9%) in the left main group and 8 (5.4%) in the left ostial group (p = NS). Perioperative infarction occurred in 8.6% of patients with left main stenosis and 4.7% of patients with left ostial stenosis (p = NS). Mean follow-up was 6.1 years for the left main group and 5.4 years for the left ostial group.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

During an 8 year interval, 184 patients with symptomatic single-vessel disease underwent coronary artery bypass grafting (CABG). There were no operative deaths and only one late cardiac death (5 year cumulative survival 97.9%). At 48 months mean follow-up, 91% are angina free or improved. The low incidence of perioperative and late myocardial infarction (MI) and the preservation of ventricular function seen on follow-up catheterization suggest that coronary bypass operations yield significant benefits in severely symptomatic patients with single-vessel disease. Evidence is presented which supports the idea that single-vessel coronary artery disease may be a unique manifestation of coronary atherosclerosis and not one stage in a continuum.

Impedance reduction with hydralazine was evaluated in 23 patients 1 to 3 hours after aortic or mitral valve replacement. Patients were randomly assigned to Group 1 (0.25 mg/kg) or Group 2 (0.5 mg/kg) and responses at 20, 60, and 120 minutes compared with control (paired t test) and mean values for each group compared (t test). In Group 1 significant responses were the fall in mean arterial pressure (78.3 +/- 3.0 to 66.7 +/- 2.2 mm Hg) and systemic vascular resistance (2,808 +/- 264 to 1,823 +/- 164 dynes-sec/cm5); the increase in cardiac index (2.07 +/- 0.13 to 2.71 +/- 0.21 L/min/m2), stroke volume index (26.9 +/- 2.3 to 34.0 +/- 3.3 ml/beat), and heart rate (80.8 +/- 5.8 to 84.2 +/- 6.6 beats/min). Central venous pressure did not change and left atrial pressure decreased at 120 minutes. Group 2 responses were similar except for higher central venous pressure at 20 minutes, higher left atrial pressures at control, 20, and 60 minutes, and lower left ventricular stroke work at control, 20, and 60 minutes. By selectively dilating the arterial system, hydralazine reduces mean arterial pressure and systemic vascular resistance and increases cardiac output with suble filling pressures.

During a 4 month interval, cultures taken at the time of porcine xenograft valve implantation grew a fastidious atypical mycobacterium, Mycobacterium chelonei (Runyon’s group 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.

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 arterialization provides protection for the acutely ischemic myocardium, this effect does not persist, perhaps because of anastomotic occlusion due to fibrous proliferation.

This study was designed to investigate myocardial abnormalities in general, and the extent of capillary basal laminar thickening (CBLT) in particular, in experimentally induced diabetic rats. For this purpose, buffered streptozotocin (70 mg/kg) was administered to 34 rats; control groups consisted of 18 rats, uninjected or buffer-injected only. Animals were sacrificed at monthly intervals up to 12 months and at 15 months following induction of the diabetes. Myocardial, renal, and skeletal muscular tissues, prepared for ultrastructural examination, were subjected to quantitative procedures, in order to obtain an index of CBLT. The results indicated that abnormal CBLT was present and relatable to the length of exposure to the hyperglycemia. Six months following induction, the increments in laminar thickening in diabetic rats significantly differed from those in normal maturing rats. In the diabetic myocardium CBLT represented the single, specific, and clearly identifiable strucutural abnormality. Increased CBLT was also observed within renal glomeruli and quadriceps in diabetic rats, to a more marked extent than that seen in the myocardium. Parenchymal changes in the three tissues under study were most pronounced in the kidneys of diabetic rats. These findings, paralleling previously published observations in human diabetics, fail to reveal morphologic evidence of an intrinsic diabetic cardiomyopathy and suggest that CBLT in experimentally diabetic rats is associated with the altered metabolic state in these animals.

Twenty-five patients (11 men and 14 women) aged 80 to 88 years (mean age, 82 years) underwent valve replacement at St. Louis University from August 1980 to June 1988. Isolated valve replacement was performed in 11 patients. Combined procedures included valve replacement with myocardial revascularization (7 patients), multiple valve procedures (5 patients), and ascending aortic plication (2 patients). Fifteen patients (60%) were in New York Heart Association functional class III and 10 (40%) were in class IV preoperatively. The operative mortality was 20% and late mortality was 20% (mean follow-up, 36 months). Isolated valve replacement carried a 9% early and 0% late mortality, whereas combined procedures of any type had a 16% early and 20% late mortality. Only 7 patients (28%) had a completely uncomplicated postoperative hospitalization. Twenty patients were discharged after a mean hospital stay of 18 ± 16 days. Their mean New York Heart Association functional class was 1.6 ± 0.66. The 1-year and 2-year actuarial survival rate is 79% and 69%, respectively. A significant increase in operative mortality is seen when valve replacement is combined with myocardial revascularization or an additional valve procedure. Late clinical improvement, as judged by return to an independent life-style, justifies this approach for select patients.