K. Alvin Merendino

Experience with surgical management of primary infective endocarditis: A collected review of 139 patients

Abstract One hundred thirty-nine patients with primary infective endocarditis who under-went open-heart surgery are analyzed; of these, 24 patients were operated upon at the University of Washington while the rest have been collected from the English literature. One hundred five patients were operated during the active stage and 34 patients in the healed stage. Seventy patients had pre-existent cardiac lesions before the onset of endocarditis. As a group, Streptococcus was the commonest infective organism followed by Staphylococcus. Congestive heart failure alone or with other conditions was the indication for surgery in 96 per cent of patients. Left-heart valves were involved in 135 patients, the aortic valve being the commonest site of infection. Prosthetic valve replacement alone or along with other procedures was done in 113 patients; in the remaining patients reconstructive procedures or homograft valve replacement was done. Over-all early and late mortality rates in the entire series were 25 and 8.6 per cent, respectively. The early mortality rate in the active stage was about 26.6 per cent while in the healed stage it was 11.7 per cent. Of 130 patients who left the operating room, 32 were reported to develop murmurs of regurgitation; of these 32 patients, 3 died of congestive heart failure and/or septicemia, 9 were reoperated upon, while the rest are stable. Two patients had residual infection with the original organism while an-other 2 patients developed reinfection with a new organism. Hemodynamic status is the most important determinant of timing of the operation in this disease. Once congestive heart failure starts due to tear or perforation of a leaflet during the course of active endocarditis, particularly of the aortic valve, surgery should be undertaken at an early date. It is suggested that an aggressive attitude with regard to early surgical intervention in these patients should further reduce the early mortality rate.

Deep Hypothermia in Cardiovascular Surgery

Abstract Recent experimental studies and clinical application of deep hypothermia for cardiovascular surgery are reviewed. At most institutions, surface hypothermia alone or in combination with limited cardiopulmonary bypass has been employed. Circulatory dynamics were well maintained following prolonged cardiac arrest at 20°C. Some degree of acidosis usually developed after the arrest period but was gradually corrected during rewarming. Total circulatory occlusion could be maintained for at least one hour at 20°C. without evidence of cerebral damage in infants. Many complex congenital cardiac anomalies, including transposition of the great arteries, total anomalous pulmonary venous return, ventricular septal defect, and tetralogy of Fallot, have been successfully corrected in the first few weeks of life. Less encouraging results have been achieved in patients with infradiaphragmatic total anomalous pulmonary venous return, complete atrioventricular canal, or pulmonary atresia.

An Anatomical Comparison of Human, Pig, Calf, and Sheep Aortic Valves

he limited availability of aortic valves for transplantation has stimulated efforts to establish easily obtainable sources of suitT able valve grafts. T o this end, several groups have investigated the clinical use of heterografts. Some of these heterografts have functioned at least two years [ l , 51. It has been noted, however, that certain animal aortic valves vary in configuration from the human valve. This study is presented in the interest of defining certain aspects of the comparative anatomies of human, pig, calf, and sheep aortic valves so as to facilitate the selection of the most favorable heterograft donor species.

Correction of Total Anomalous Pulmonary Venous Drainage in Infancy Utilizing Deep Hypothermia with Total Circulatory Arrest

Four critically ill infants aged 3, 5, 5, and 13 months; weighing 3.7, 4.6, 5.3, and 6.5 kg, respectively; with total anomalous pulmonary venous drainage, underwent complete correction of their lesions with the utilization of surface-induced deep hypothermia. Although this series is small, we are not aware of any other consecutive series in this age group with a comparable mortality rate. Rectal temperatures of 17.5 to 20.2 C were utilized, with periods of cardiac arrest and total circulatory interruption of 32 to 41 minutes. Important aspects of the technique are surface cooling, deep ether anesthesia, intravenous low-molecular-weight dextran, induced respiratory alkalosis during cooling, and electrical pacing during resuscitation. This method works well in the infant, in contrast with perfusion techniques in which surgical mortality is excessively high.

Morphological Alterations in Vital Organs After Prolonged Cardiac Arrest at Low Body Temperature

Abstract Surface-induced deep hypothermia was carried out in 34 adult mongrel dogs using ether anesthesia, Rheomacrodex, and respiratory alkalosis. Cardiac arrest was instituted for 30, 60, or 90 minutes at a temperature of 18° to 20°C. All animals were resuscitated, rewarmed, and sacrificed up to two and one-half years postoperatively. One other group was only cooled and rewarmed without cardiac arrest. Myocardial sections showed focal areas of cell necrosis with cytoplasmic band formation, and in the later specimens calcification and interstitial fibrosis had developed. These changes were more severe in the animals subjected to cardiac arrest. The alterations in pulmonary tissue consisted only of patchy atelectasis and alveolar hemorrhage in the early specimens. The kidney and spleen were unaltered. Some liver sections showed widening of centrilobular sinusoids and vacuolization of hepatic cells. All the brains examined had slight anoxic changes; however, it was not possible to differentiate normal from hypothermic brains. There was no correlation between morphological changes and duration of total circulatory arrest.

The deep epigastric artery: rectus muscle syndrome.

Abstract 1. 1. Hemorrhage into the rectus muscle, with or without muscle rupture, is an uncommon but not a rare condition. In some cases, the muscle is torn; in others, branches of the deep epigastric artery or vein have ruptured; in still others, there has been both rupture of the muscle and laceration of one or more of the blood vessels. 2. 2. The signs and symptoms can simulate those of any acute abdominal or pelvic condition. An elevation in temperature, pulse, respiration and white blood cell count is not unusual. There may be a tender palpable mass. Ecchymosis of the skin is usually not present until the third or fourth day or unless the continuity of the anterior sheath of the rectus has been interrupted. Roentgenogram may demonstrate an abnormal mass of soft tissue. Diagnostic needle aspiration may be useful when a localized hematoma is present. 3. 3. The common sites of occurrence for rectus muscle hematoma are, in descending order, right lower quadrant, left lower quadrant, right upper quadrant, bilateral lower quadrants, and both upper and lower quadrants on either side. 4. 4. Prognosis is favorable if there is no other serious associated underlying condition. The general mortality is 4 to 5 per cent; however, during pregnancy and labor, maternal and fetal mortality of 2 to 15 per cent and 25 to 50 per cent, respectively, have been reported. 5. 5. Surgical treatment is required to establish the diagnosis, control the hemorrhage, evacuate the hematoma and repair the defect if possible. 6. 6. Four additional cases of this condition are presented with their clinical and operative findings, making a total of approximately 250 cases reported in the world literature.

Open Heart Surgery in Infective Endocarditis

Fourteen patients with bacterial endocarditis had open heart surgery. Thirteen were operated upon because of congestive heart failure, and in one the indication for surgery was persistent infection. The aortic valve alone was involved in six patients; two patients had both aortic and mitral valve endocarditis. Five patients had infection of the mitral valve, and one patient had tricuspid valve involvement. All the patients received preoperative antibiotics for a variable period.Ten patients left the hospital and four died in the hospital. Of the 10 patients discharged, one died 9 months later of congestive heart failure. Seven patients developed valvular leaks either through the suture line or the homograft, and two deaths resulted. Nine patients are alive and in good functional status. Antibiotics were given for 5 to 10 days postoperatively; one patient, however, received antibiotics for 49 days.Early open heart surgery is recommended in bacterial endocarditis if heart failure is progressive. Shorter postoperative antibiotic therapy is proposed once the source of residual infection is removed.

Repair of Mitral Incompetence Secondary to Ruptured Chordae Tendineae

Twenty-two patients with ruptured chordae tendineae are presented. Etiology was rheumatic heart disease in seven patients, bacterial endocarditis in four patients, both rheumatic heart disease and endocarditis in two patients, trauma in one patient, and aortic regurgitation in one patient. Exact cause of rupture was unknown in seven patients. Plastic repair of the leaflet and/or posteromedial annuloplasty was done in all the patients. In two patients the annuloplasty broke down soon after the operation and necessitated valve replacement. There was one hospital death. One patient died two years after operation probably because of cerebral embolism; a large thrombus was found in the left atrium at autopsy. All survivors have been followed for 7 months to 8 years and, except for two, are either working full-time or leading an active life.In ruptured chordae early and five-year results after repair of the leaflet and/or posteromedial annuloplasty are very good irrespective of the left atrial enlargement and “V” wave size. Results were better in the rheumatic group than in the nonrheumatic group. In our opinion this method of treatment is superior to prosthetic valve replacement for this condition, except if the annulus is thin and attenuated.

Effects of Isoproterenol on Carbohydrate Metabolism of Isolated Canine Heart

Chronotropic and inotropic effects of intraarterial infusion of isoproterenol were monitored in the isolated, metabolically supported preparations of the canine heart. The time-dosage relationship was found to be hyperbolic over a narrow range of concentration of isoproterenol. Increasing concentration beyond the optimal range by a factor of about two produced arrhythmias and A-V conduction defects. Oxidative metabolism increased significantly and proportionally to heart rate. Since utilization of glucose remained the same, pyruvate utilization increased slightly and lactate was excreted; the augmented oxidative metabolism could not be accounted for by the observed changes in carbohydrate substrates. Myocardial glycogen concentrations were insignificantly changed during this inotropic stimulation.

Evaluation of Mitral Annuloplasty for Mitral Regurgitation: Clinical and Hemodynamic Status Four to Forty-one Months after Surgery

Eleven patients seriously disabled by mitral regurgitation were re-evaluated 4 to 41 months following mitral annuloplasty (average 19.4 months). Preoperative and postoperative comparative data are presented. One patient was unimproved or worse. The rest were subjectively better. Mean changes were transverse cardiac diameter −17.8 mm. (median 15 mm.) (p < .005); resting stroke index +9 ml./beat/M.2 (median 9 ml./beat/M.2, p < .05); resting cardiac index +0.5 L./min./M.2 (p = .20); mean pulmonary artery pressure −7.2 mm. Hg, or 29 per cent (median 8 mm. Hg, p < .03); and arteriovenous oxygen difference −12 ml./L. (median 13 ml./L., p < .005).Abnormally prolonged mixing, as shown by indicator-dilution curves, was decreased in all patients (p < .05). Exercise testing showed varying degrees of improvement in six of the nine so studied. In six patients mitral regurgitation by angiocardiographic measurements postoperatively represented 0, 0, 21, 24, 35, and 46 per cent of the total left ventricular stroke volume. Two patients had increased end-systolic left ventricular volume as evidence for postoperative left ventricular failure. The other four were probably normal. Ten of the 11 patients showed postoperative improvement that was felt to be significant in two or more of the above objective measures. Striking x-ray improvement in heart size occurred in two patients, eight others showed decreases in transverse diameter of up to 17 mm. One developed an increase in heart size. Although probably improved over their preoperative status, two patients had significant mitral stenosis at the time of re-evaluation. Another showed evidences of progressive mitral regurgitation after an initial period of improvement. Mitral annuloplasty is a palliative procedure with considerable potential for effecting a reduction in regurgitant volume and improving the clinical status of carefully selected patients.