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The lack of adequate myocardial preservation because of maldistribution of cardioplegic solution in coronary artery disease remains a perplexing problem. We compared two methods of cardioplegic delivery in dogs: antegrade aortic root perfusion (Group I) and retrograde coronary sinus perfusion (Group II). Metabolic changes and regional function in the coronary occlusion model, in which the left anterior descending artery was occluded at its prediagonal portion, were studied. In the distribution of the occluded coronary artery, adenosine triphosphate and total adenine nucleotides at the end of 120 minutes of ischemia were preserved better in Group II (16.80 and 22.94 mumol/gm dry weight) than in Group I (11.06 and 16.19 mumol/gm dry weight, p less than 0.05). Lactate accumulation tended to be higher in Group I than in Group II (114.0 and 87.2 mumol/gm dry weight, respectively; not significant). Percent recovery of segmental shortening was also better in Group II than in Group I (100% and 22.3% at the same left atrial pressure, 4 mm Hg; p less than 0.01). In the region supplied by the intact coronary artery, there were no significant differences between the two groups with regard to metabolic changes and regional function. These observations suggest that retrograde cardioplegic perfusion via the coronary sinus is preferable for surgically treatment of severe coronary artery disease.

1. 1. Minimal surface tension of the lungs of dogs was estimated in terms of surfactant activity before, during, and after cardiopulmonary bypass. 2. 2. Surfactant values of normal lungs sampled before the operation ranged from 1.8–11.8 dynes per cm. 2 , averaging 5.1 dynes per cm. 2 3. 3. Animals perfused one or two hours with 50% hemodilution showed little change in surfactant values immediately after the perfusion was completed. However, in those that survived more than fifteen hours the values rose an average of 11.1 dynes per cm. 2 4. 4. 60% of animals perfused with whole blood for one hour had rises in surface tension (average 8.5 dynes/cm. 2 ) both at the completion of bypass and at the time of death. None of these dogs survived more than eight hours. 5. 5. No rise in minimal surface tension was observed in animals placed on controlled ventilation without cardiopulmonary by pass; only one of 6 animals with thoracotomy and heparin showed a persistent rise. 6. 6. Possible explanations for the temporary protection to lung surface afforded by hemodilution as compared to whole blood perfusion are discussed.

Summary Total cardiopulmonary bypass at a flow rate of 50 ml. per kilogram of body weight per minute consistently produced metabolic acidosis in adult mongrel dogs. The acidosis was partially inhibited by pretreatment of the animals with large doses of corticosteroids. The pretreated animals showed a greater survival rate and a better postoperative clinical condition. Possible explanations for the effect of the steroids are discussed.

Kay's mitral valve repair was performed in six consecutive patients with symptomatic mitral regurgitation due to ruptured chordae tendineae of the posterior leaflet. All patients including one with mild residual murmur showed a marked decrease in the heart size and significant clinical improvement. Postoperative hemodynamic studies, performed in four patients, showed restoration of normal or near-normal dynamics. The medium-term follow-up, 15 to 30 months after the operation, revealed continuing asymptomatic states in all. The function of the repaired valves was significantly better than that of the Hancock mitral bioprostheses. The advantages of this procedure compared with mitral valve replacement for the same condition were stressed.

A series of 62 consecutive patients with an ejection fraction of 0.4 or less (mean 0.28 with a range from 0.10 to 0.40; 22 between 0.10 and 0.20, 18 between 0.21 and 0.30, and 22 between 0.31 and 0.40) who underwent aortic valve replacement from January 18, 1972 to December 20, 1976 was reviewed. Preoperatively two patients were in Class II, 35 in Class III and 25 in Class IV of the New York Heart Association functional classification (N.Y.H.A.). Thirty-nine patients (Group 1) underwent isolated aortic valve replacement and 23 patients (Group 2) underwent aortic valve replacement with associated procedures including aortocoronary bypass in 15. The operative mortality was 8 percent in Group 1, 17 percent in Group 2, and 11 percent overall. In the group of 15 patients with coronary artery disease, the operative mortality of aortic valve replacement and aorto-coronary bypass was 27 percent. Since January 1974, isolated aortic valve replacement was performed with no operative deaths in the 25 consecutive patients in Group 1 including 10 patients with an ejection fraction of 0.2 or less. Five-year survival rates were 70 percent in Group 1, 64 percent in Group 2 and 68 percent overall. In the 38 currently living patients, 32 showed clinical improvement and 27 are in Class I or II of N.Y.H.A. In conclusion, isolated aortic valve replacement can be performed with a low mortality and a high survival rate in patients with impaired left ventricular function.

dine, procainamide, and disopyramide.6 Torsades de pointes was not observed in our patient, although it might be potentially manifested in the presence of significant flecainide-induced QT, prolongation. In our current controlled study of 14 patients with ventricular ectopy taking flecainide versus quinidine, four patients randomized to quinidine had clinical side efl’ects such as diarrhea, causing them to discontinue treatment. It appears that flecainide results in less frequency of similar side effects and possesses potent suppression (> 85 % ) of VPCs. While the single patient presented herein manifeste,d the unusual response of VT with flecainide, a number of studies including our own L* have shown no other or similar adverse effects. F’lecainide remains a promising new antiarrhythmic agent that warrants further clinical investigation.

Myocardial distribution of the retrograde flow through the coronary sinus in the canine heart was evaluated by observing the corrosion casts of the myocardial vessels after coronary sinus injection of a low-viscosity resin, Mercox, a compound that passes through capillaries. The apex and the left ventricular free wall were well perfused at the microvascular level, even in the presence of complete left main coronary artery occlusion, whereas the right ventricular free wall was not perfused effectively at this level in any heart. Although there was considerable variation in the perfusion of the ventricular septum from heart to heart, the entire septum was not perfused in some of the hearts. We considered this poor perfusion of the septum to be due to the presence of well-developed thebesian veins in the septum. Retrograde coronary sinus perfusion of cardioplegic solution may be a valuable alternative to protect the left ventricular free wall, especially in cases of critical coronary artery stenosis or occlusion. However, antegrade perfusion should be used also, whenever possible, for adequate protection of the septum and the right ventricular free wall.

Using a method of our own design, we evaluated intraoperatively the function of prosthetic heart valves. The changing hemodynamics induced by a stress test were assessed by simultaneously measuring the mean transvalvular pressure gradient and the stroke volume. The effective orifice area (EOA) of the valves was determined for each stroke by computer analysis, and this value was compared with the actual orifice area. Data were collected from 19 patients undergoing aortic or mitral valve replacement or both with 17 St. Jude Medical and 12 Ionescu-Shiley valves. The mean pressure gradient increased with tachycardia and an increase in mean left atrial pressure in the mitral position, but decreased with a decrease in cardiac output and peak left ventricular pressure in the aortic position. The St. Jude Medical valve had a smaller mean pressure gradient than the Ionescu-Shiley bioprosthesis. For both valves, the EOA increased with valve size. The St. Jude Medical valve had a greater EOA than the Ionescu-Shiley bioprosthesis, regardless of the valve size (p less than 0.005). However, the performance of prosthetic leaflets was better with the Ionescu-Shiley bioprosthesis than with the St. Jude Medical mechanical valve (p less than 0.001). This method involving computer analysis of each cardiac cycle proved to be useful for evaluating prosthetic heart valve function in the presence of changing hemodynamics.

The protective effects of the glutathione peroxidase system against functional damage induced by perfusion of isolated hearts with adriamycin, an anthracycline antibiotic, were studied. We used selenium deficient rats, in which cardiac glutathione peroxidase activity was only 3% of control rats. Both contractile tension and coronary flow decreased during perfusion with the antibiotic. The degree of decline was significantly greater in the selenium deficient hearts than in the control hearts. The increase in malondialdehyde, a product of lipid peroxidation, induced by adriamycin perfusion was more evident in selenium deficient hearts, though the level of reduced glutathione was well maintained. Isolated mitochondrial function also decreased after aerobic adriamycin perfusion and the decrease was greater in selenium deficient rats. These observations indirectly suggest that the decrease in cardiac function induced by adriamycin is protected by the glutathione peroxidase system and that the decrease may be due, at least in part, to damage to the mitochondria caused by oxygen radicals generated by adriamycin.

Computer aided systems for performance evaluation of functional devices for passenger cars, such as engines or transmissions, have been applied for ten years. These systems generally consist of a large main frame computer or minicomputers for conducting a large number of complicated analyses. In the past, these computer aided systems were used for vehicle research and development since they were too expensive and sophisticated for use on the production line. Today, microcomputers with mass memory or personal computers are available at very low cost in comparison to conventional minicomputers. With many distributed microcomputers, we have developed a new test and control system for the engine production line. This system consists of (1) a microcomputer with a disk system for test data storage, (2) five personal computers for the man-machine system and data processing, and (3) microcomputers for real time control and data acquisition. These distributed micro and personal computers have been connected with standard interfaces. With this system we have achieved higher efficiency of inspection such as performance testing, quality control, and higher levels of the test analyses.

Treadmill exercise electrocardiography (TE) was recorded in 50 patients to evaluate the incidence of exercise-induced ventricular arrhythmias (VAs) in a group of patients who underwent corrective surgery of tetralogy of Fallot (TF) more than four years previously. The results of rhythm evaluation were correlated with cardiac catheterization data as well as clinical information such as the age at surgery and the interval from surgery. Of the 50 patients tested, ventricular premature contraction (VPC) was confirmed in 12 patients (24%) on TE, while five patients (10%) demonstrated VPC on the standard ECG. The interval from surgery was significantly longer in those patients with VA (Group 1) than those without VA (Group II) on TE (p less than 0.05). There was no significant difference of the age at corrective surgery between the two groups. In group I, the preoperative hemoglobin level was higher (p less than 0.05) and the right ventricular ejection fraction was lower (p less than 0.01). Exercise-induced VAs are closely related to the length of period after surgery and the depressed right ventricular function.

A ten-year-old Japanese boy with tricuspid atresia type IB was treated by direct anastomosis from the right atrium (RA) to the right ventricle (RV), entirely with autogenous material. An incision of the RA anterior wall was designed for a flap of RA appendage. A valveless conduit was created, with this flap and a large piece of pericardium. Atrial septal defect (ASD) and ventricular septal defect (VSD) were closed with a patch. Cardiac catheterization and angiocardiography two months postoperatively, showed good results of the surgery.

A 16-year-old Japanese girl with a persistent left superior vena cava draining into the coronary sinus was surgically treated. Both coronary sinus and left superior vena cava were totally unroofed in the posterior wall of the left atrium, but the routes were recognized as a deep ditch. Both preoperative diagnosis and the ensuing successful correction were performed only after the third cardiac catheterization and the third operation, respectively. The importance of preoperative diagnosis and the surgical procedures to correct this anomaly were discussed.

A 57-year-old man who was in end stage renal failure underwent an aortic and mitral valve replacement for the progression of cardiac dysfunction, secondary to Staphylococcus aureus infective endocarditis. Cardiac surgery was performed using a Hemo-Concentrator during cardiopulmonary bypass, 82 months following the initiation of hemodialysis. This is the second report in the literature of a successful double valve replacement for infective endocarditis and congestive heart failure in a chronic hemodialysis patient.

A 40-year-old man developed cardiomegaly with protrusion of the right heart border following staphylococcal endocarditis. Computed tomography of the chest revealed a large anterior mediastinal mass. Hemodynamic pressure curves presented features similar to those of constrictive pericarditis. At operation, 150 ml of purulent fluid was encapsulated within the thickened pericardium and separated from the rest of the pericardial sac. The encapsulated abscess was resected.

In a 10-year-old girl being treated for ventricular septal defect, the tip of a Polystan venous return catheter broke away when the catheter was being removed at the time of bypass disconnection. Following fluoroscopic identification of the tip in the left peripheral pulmonary artery, it was removed via arteriotomy.