Evaluation of the effects of different cardioplegic techniques on left ventricular function during coronary artery bypass surgery using transesophageal echocardiography.

Fifty consecutive patients undergoing coronary artery bypass grafting surgery were studied to evaluate the effect of intermittent anterograde cold cardioplegia (IACCH) and intermittent combined anterograde-retrograde cold cardioplegia (IRCCN) on left ventricular function using transesophageal echocardiography. Global function did not significantly change in both groups, but significantly more inotropes were required in IACCH. Newly developed abnormalities of regional wall motion after cardiopulmonary bypass, which were indicative of ischemic myocardium, were detected in the segments supplied by the right coronary artery in both groups (IACCH, 20%; IRCCN, 16%), by the left circumflex coronary artery only in IACCH (12%) and by the left anterior descending coronary artery only in IRCCN (12%). It is concluded that although global evaluation of left ventricular function did not show any significant change after IACCH and IRCCN under routine management, analysis of abnormalities of regional wall motion provided specific information. In both groups, complete protection of the myocardium was not achieved, and the characteristics of poorly protected areas were dependent on the difference in the two methods. Myocardium supplied by the right coronary artery seemed to be particularly vulnerable, and a special effort to protect these segments is mandatory for a successful outcome.

Is use of the intraaortic balloon pump in octogenarians justified?

Increasing numbers of octogenarians are seen in the operating room or critical care unit with circumstances for which intraaortic balloon pump (IABP) assistance is appropriate, but it has been suggested that the complication rate for IABP use in octogenarians is excessive. From 1980 to 1990, 25 octogenarians needed an IABP in our institution, as an adjunct to operation in 20 patients (1 had repair of a ventricular rupture and 19 underwent coronary grafting); 5 patients did not have operation. The indications for IABP use were unstable angina, 12 (48%); cardiogenic shock, 10 (40%); and difficulty weaning off cardiopulmonary bypass, 3 (12%)--these 3 were the only ones who had insertion through a femoral cut-down. No serious insertion difficulties were noticed with the percutaneous route in the other 22 patients. Without operation, 4 of 5 patients died in the hospital (80%), and the 5th died 2 years 8 months after discharge. After operation, there were two hospital deaths (10%) and two late deaths, neither from cardiac causes. A fatal outcome occurred in 6 of 9 patients with cardiogenic shock. Intraaortic balloon pump-related complications were rare, minor, and unrelated to IABP assistance duration, which ranged from 24 to 146 hours (mean, 49.9 hours). No long-term vascular complications resulted. Hospital stay averaged 22.2 days. At follow-up from 9 to 81 months (mean, 51.8 months), of the 16 survivors, 12 (75%) were in New York Heart Association class I/II and 2 each were in classes III and IV.(ABSTRACT TRUNCATED AT 250 WORDS)

Early detection of coronary artery graft dysfunction with intraoperative 2-dimensional transesophageal echocardiography.

We report 5 cases in which intraoperative transesophageal echocardiography was instrumental in the early detection of a left ventricular wall-motion abnormality caused by acute dysfunction of a coronary artery bypass graft. The appearance of a wall-motion abnormality on transesophageal echocardiography preceded signs of myocardial ischemia when such signs were detectable with routine monitoring. By facilitating prompt, appropriate correction of technical problems, transesophageal echocardiography enabled the blood flow to be restored and the ischemic insult to be resolved without further complication.

Transesophageal echocardiography for the evaluation of mitral valve prostheses in the weanling sheep.

The sheep model has been widely accepted for evaluating the in vivo performance of artificial valves. Introduction of transthoracic echocardiography revolutionized the evaluation of human cardiac valves, but in many cases, resolution of transthoracic studies in sheep is inadequate. The authors used transesophageal echocardiography to follow the performance of chronically implanted mitral prostheses. The technique has proven feasible and safe, requiring sedation only and being done in the spontaneously breathing animal without endotracheal intubation in the left lateral position. The HP 77020A, equipped with a standard HP 5 mHz transesophageal transducer probe, is used. The authors have had to modify the probe to allow for automatic cooling. Standard insertion techniques are used and the probe is positioned in the stomach, close to the gastroesophageal junction. They were able to assess leaflet motion, vegetations, and calcification and use color flow doppler to evaluate stenosis and regurgitation. The technique is convenient and permits a complete assessment of valve function in 10 minutes. Reproducibility has been confirmed. Validation of quantitative data will require further study.

The anatomical location of the transesophageal echocardiographic transducer during a short-axis view of the left ventricle.

This study was performed to clarify the location of a transesophageal echocardiographic (TEE) transducer when obtaining the short-axis view of the left ventricle (S-LV). The depth of the probe tip from the incisors when obtaining a S-LV, the relationship to the diaphragm, and the location of the cardia of the stomach using a gastroscope attached to the TEE probe were measured in 24 patients undergoing coronary artery bypass grafting. The location of the transducer relative to the cardia and diaphragm was determined. The study demonstrated that when obtaining a S-LV, the transducer was in the stomach in 72.7%, at the cardia in 13.6%, and in the esophagus in 13.6% of the patients. The predominantly intragastric position of the transducer suggests that gastric diseases should be included as contraindications to TEE. When the probe was advanced about 40 cm from the incisors, some resistance was often encountered by the TEE operator at about the level of the diaphragm. Careful manipulation is mandatory to avoid tissue damage by the probe. Visualization of the S-LV can be disturbed by gas in the stomach. This is a specific problem in anesthetized patients because gas is often pushed into the stomach at the time of induction.

A technique for donor lung procurement and preservation for transplantation after completion of cardiac donation.

The scarcity of donor lungs for transplantation has been caused, in part, by the belief that a single donor cannot provide usable lungs if it serves as a heart donor. However, the appropriate division of the left atrial wall provides sufficient cuffs for individual transplantation of the heart and each lung into three separate recipients. With the described technique, the results of the present studies demonstrate the feasibility of donor lung procurement and preservation for transplantation after cardiac donation. Use of this method will allow the most effective and efficient use of the limited supply of donor organs and thereby permit therapeutic single lung transplantation in selected patients. Cardiac donation should no longer preclude lung donation as it has in the past.

The preoperative bleeding time as a predictor of postoperative hemorrhage after cardiopulmonary bypass.

To determine whether the preoperative bleeding time, the most reliable indicator of in vivo platelet dysfunction, can prognosticate excessive postoperative hemorrhage and, hence, the need for infusion of platelet concentrations, we studied blood loss versus bleeding time in 43 patients undergoing coronary bypass grafting. There was no correlation between bleeding time and either fall in hemoglobin level (r = 0.04) or chest tube drainage (r = 0.004). In addition, bleeding time did not correlate with the number of units of platelet concentrate (r = 0.12) or packed red cells (r = 0.2) infused. The bleeding time, which has been recommended as an essential screening test before all cardiopulmonary bypass procedures, need not be performed as a preoperative screen in otherwise healthy patients with no history of bleeding abnormalities and a normal coagulation profile.

Retained intracardiac air. Transesophageal echocardiography for definition of incidence and monitoring removal by improved techniques.

Retained intracardiac air is a continuing hazard for cardiopulmonary bypass. M-mode transesophageal echocardiography of the left atrium, left ventricle, and aorta is a highly sensitive method for detecting retained intracardiac air bubbles. In 15 patients having valve operations and 18 having coronary bypass, M-mode transesophageal echocardiography was used to record air bubbles during and for 15 minutes after bypass. Routine air clearing methods were used: needle aspiration of the ascending aorta (combined coronary and valve operations) and left atrial, left ventricular, and aortic aspiration after careful passive chamber filling (valve operations). Air was detected in 12 of 15 (79%) patients having valve operations and two of 18 (11%) patients having coronary bypass. One with air in the aorta had visible right coronary air embolism. Three patients with positive echograms had transient central nervous system disturbances. In a further 11 patients having valve operations, an ascending aorta-venous shunt was created before bypass was discontinued, but air continued to be present in the left atrium. Finally, in seven patients, we added the following maneuvers to our routine: positive chamber filling with echocardiographic demonstration of left atrial stretching, vigorous chamber ballottement, specific echo-directed chamber aspiration, and maintenance of cardiopulmonary bypass until transesophageal echocardiography showed no retained air. Although small amounts of atrial air could still be detected for a minute or two in some patients, this technique appears finally to have eliminated significant retained air and its consequences. A sensitive technique for intracardiac air detection reveals retained air surprisingly often after cardiopulmonary bypass. There are both possible and probable adverse consequences of this air. After valve operations, it is most difficult to eliminate air from the left atrium. There are three essential elements of air removal: First is mobilization of the air; positive chamber filling, stretching of the atrial wall, and ballottement are critical. Second is removal of mobilized air; continuous ascending aorta-venous shunting and nonsuction venting of the left atrium are very important. Third is proof of elimination of air before cardiopulmonary bypass is terminated; transesophageal echocardiography is vital for this.

Immediate tricuspid valve replacement for endocarditis. Indications and results.

Tricuspid valve excision for tricuspid endocarditis in addicts is recommended to avoid early reinfection, continued sepsis, and late reinfection because of the resumption of intravenous drug abuse. Valvectomy is allegedly well tolerated hemodynamically by some, but it leads to heart failure in at least a third of patients. In our experience in 10 addicts with staphylococcal endocarditis who had failed to respond to antibiotic therapy, tricuspid valve replacement allowed all 10 to leave the hospital free of infection and free of heart failure. Resumption of drug addiction in three led to septic death, but not necessarily to tricuspid reinfection. Two returned to jobs requiring a high level of physical labor and tolerated this without difficulty. We find no need to follow the practice of tricuspid valve excision for tricuspid endocarditis in addicts. Those who refrain from drug abuse are well served by valve replacement. Those who do not are doomed with or without a tricuspid valve.

Multiple organ procurement from one donor.

To maximize organ utilization, we assessed the feasibility of retrieving the heart and two single lungs or the heart and a separate bilateral lung block for transplantation into multiple recipients. In eight dogs the excision of the heart-lung block or of the left lung was followed by six hours of lung preservation. Four of these lungs and all eight hearts were transplanted successfully. In addition, satisfactory retrieval of the three separate organs or of the heart and a separate bilateral lung block was done in six human cadavers. An appropriate division of the left atrial wall provided suitable cuffs for individual transplantation of the three organs or for the heart and bilateral lung block. This study demonstrates the feasibility of multiple organ donation from a single donor followed by separate organ transplantation.

Metabolic and immune effects of arginine in postinjury hyperalimentation.

Nitrogen balance and thymic immune function studies were carried out in rats subjected to anesthesia, jugular vein catheterization, and bilateral femoral fractures, who were then given for 5 days: A) D5W; B) D20 FreAmine II (total arginine 1.55 gm/L); or C) D20 FreAmine III (4.05 gm of arginine/L). Administration of hypercaloric amino acid mixtures had strong positive effects on nitrogen retention and thymic function when compared to isotonic dextrose infusion. The administration of solution C had the most positive effect on nitrogen balance and on thymic immune function. The data suggest that increased arginine administration may prove beneficial to injured patients.

Arginine stimulates thymic immune function and ameliorates the obesity and the hyperglycemia of genetically obese mice.

The effect of 6-day dietary arginine supplementation on the weight gain, blood glucose, thymus weight, thymic lymphocyte content, and in vitro thymic lymphocyte immune reactivity was studied in obese (C57BL/6J-OB/)B) and heterozygous lean mice. Control mice were fed a commercial laboratory chow (1.8% arginine content) and drank tap water, while supplemented mice were given 0.5% arginine in the chow and 0.5% arginine solution for drinking. All mice ate and drank ad libitum. Supplemental arginine significantly decreased the weight gain (1.2 g vs. 2.2 g, p less than 0.01) and blood glucose levels (303 mg% vs 236 mg%, p less than 0.02) of the OB/OB mice; no such effects were noted in the lean heterozygotes, all of which had normal blood glucose levels. OB/OB mice had thymus glands which weighed less and contained significantly fewer lymphocytes than their lean littermates. In vitro mitogen-stimulated thymic lymphocyte protein synthetic rates were equal in chow-fed lean and OB/OB mice. In both groups, supplemental arginine significantly increased thymus weight, the number of thymic lymphocytes per gland, and thymic lymphocyte immunoreactivity in vitro. The hormonal secretagogue activity of arginine on the pituitary may explain its beneficial effects on the rate of weight gain, hyperglycemia, and depressed thymic immune function of OB/OB mice.

Arginine stimulates lymphocyte immune response in healthy human beings.

The effect of daily dietary supplements of 30 gm of arginine HCl for 7 days on peripheral blood lymphocyte (PBL) mitogenic reactivity in vitro was measured in 21 healthy human volunteers. Arginine significantly increased stimulation indices of PBL following concanavalin A (Con A) (57.9 +/- 11.4 versus 216.9 +/- 46.6, P less than 0.01) and phytohemagglutinin (PHA) (84.1 +/- 12.8 versus 307.0 +/- 59.4, P less than 0.001) stimulation in a microculture assay utilizing RPMI 1640 medium supplemented with 10% heat-inactivated autologous serum. Similar enhanced blastogenesis was observed using medium supplemented with 10% heat-inactivated pooled AB normal human serum. In six volunteers studied following 3 days of similar arginine supplementation, blastogenic responses of their peripheral blood lymphocytes were already significantly enhanced, although not as greatly as after 7 days. Arginine had no effect on total peripheral blood lymphocyte counts and on T- and B-cell ratios. The effects of supplemental dietary arginine could not be duplicated in vitro by increasing the arginine concentration in the culture medium. Furthermore, dietary arginine supplementation did not increase cell viability in culture. Minimal side effects were noted, such as nausea or diarrhea, which responded to lowering the dose ingested at one time. No deleterious effects were noted on liver function test results. We conclude that supplemental dietary arginine is a safe nutritional stimulator of lymphocyte immune reactivity in healthy human beings.

Thymic stimulatory actions of arginine.

Various arginine HCl supplements (0.5-3%), half added to a basal commercial rodent chow (1.8% arginine) and half to the drinking water, were given to 8- to 9-week-old male CBA/J mice for 6 days. Control animals were fed the basal chow and drank tap water. All mice ate and drank ad libitum. Weight gain and food intake were similar in all groups. All arginine supplements increased significantly: thymic weight (average 22%), thymic lymphocyte content (average 45%), and the in vitro reactivity of thymic lymphocytes judged by the incorporation of 3H-leucine into the TCA-precipitable protein fraction in response to stimulation by phytohemagglutinin and concanavalin A. All these thymic effects resulted from the 0.5% arginine hydrochloride supplement; further increases in arginine supplementation did not increase these effects. These data suggest that supplemental arginine may improve host defence mechanisms and thereby may play an important role in the care of severely injured or ill patients, since it is well established that their defense mechanisms are reduced.