Influence of ischemic preconditioning in myocardial protection in patients undergoing myocardial revascularization with intermittent crossclamping of the aorta. Analysis of ions and blood gases

OBJECTIVE

To test the hypothesis that short periods of ischemia may increase the myocardial protection obtained with intermittent crossclamping of the aorta.

METHODS

In the control group (18 patients), surgery was performed with systemic hypothermia at 32 degrees C and intermittent crossclamping of the aorta. Extracorporeal circulation was used. In the preconditioning group (17 patients), 2 crossclampings of the aorta lasting 3min each were added prior to the intermittent crossclamping of the conventional technique with an interval of 2min of reperfusion between them. Blood samples for analyses of pH, pCO2, pO2, sodium, potassium, calcium, and magnesium were obtained from the coronary sinus at the beginning of extracorporeal circulation (time 1), at the end of the first anastomosis (time 2), and at the end of extracorporeal circulation (time 3).

RESULTS

No difference was observed in the results of the 2 groups, except for a variation in the ionic values in the different times of blood withdrawal; sodium values, however, remained stable. All patients had a good clinical outcome.

CONCLUSION

The results of intermittent crossclamping of the aorta with moderate hypothermia were not altered by the use of ischemic preconditioning.

Dynamic cardiomyoplasty as a therapeutic alternative: current status

Dynamic cardiomyoplasty was proposed as an alternative surgical treatment for severe cardiomyopathies and has been performed worldwide in more than 1,000 patients. Patients indicated for this procedure are specifically those with dilated or ischemic cardiomyopathies. The ventricular function improvement observed after dynamic cardiomyoplasty derived from the direct action of synchronized skeletal muscle flap contraction and from a girdling effect that helps to reverse chamber remodeling and to decrease ventricular wall stress. Although long-term benefits of this procedure may be limited by skeletal muscle flap ischemic compromise, technological advances incorporated in the new myostimulators will possibly decrease this complication incidence. Clinical improvement has been reported as a consistent finding in cardiomyoplasty follow-up and the overall 5-year survival after this procedure ranges from 39 % to 54 %. On the other hand, the mortality after cardiomyoplasty has been significantly higher for patients in persistent New York Heart Association functional class IV, showing that this procedure needs to be indicated earlier than the heart transplantation. In this regard, only the results of an ongoing randomized trial will potentially define cardiomyoplasty influence on the survival of patients with severe heart failure. In the meantime, however, there are clearly several functional class III patients whose quality of life and exercise capacity have worsened despite the use of maximum medical therapy, justifying dynamic cardiomyoplasty indication.

Mini-sternotomy for the treatment of aortic valve lesions

OBJECTIVE

To compare inverted-L mini-sternotomy performed above the sternal furcula with conventional sternotomy in patients with aortic valve diseases who undergo surgical treatment.

METHODS

We operated upon 30 patients who had aortic valve lesions that had clinical and hemodynamic findings. All patients underwent inverted-L sternotomy, which extended from above the manubrium of the sternum to the 3rd right intercostal space, without opening the pleural cavity. Their ages ranged from 32 to 76 years, and 18 were males and 12 were females. We used negative pressure in a venous 1/4-inch cannula, and the patients were maintained in Trendelemburg's position. Twenty-seven patients received bioprostheses with diameters ranging from 23 to 29mm. Three patients underwent only removal of the calcifications of the aortic valve leaflets and aortic commissurotomy.

RESULTS

The mean duration of anoxic cardiac arrest was 63.11min. Access was considered good in all patients. One death was due to pulmonary and renal problems not related to the incision. All patients had a better recovery in the intensive care unit, got out of bed sooner, coughed more easily, and performed prophylactic physiotherapeutic maneuvers for respiratory problems more easily and with less pain in the incision. Early ambulation was more easily carried out by all patients.

CONCLUSION

Mini-sternotomy proved to be better than the conventional sternotomy because it provided more comfort for the patients in the early postoperative period, with less pain and greater desire for early ambulation and all its inherent advantages.

Laser assisted extraction of pacemaker and implantable defibrillator leads

OBJECTIVE

To analyze the results of laser-assisted extraction of permanent pacemaker and defibrillator leads.

METHODS

We operated upon 36 patients, whose mean age was 54.2 years, and extracted 56 leads. The reasons for extracting the leads were as follows: infection in 19 patients, elective replacement in 13, and other causes in 4 patients. The mean time of catheter placement was 7.5+/-5.5 years. Forty-seven leads were from pacemakers, and 9 were from defibrillators. Thirty-eight leads were in use, 14 had been abandoned in the pacemaker pocket, and 4 had been abandoned inside the venous system.

RESULTS

We successfully extracted 54 catheters, obtaining a 96.4% rate of success and an 82.1% rate for complete extraction. The 2 unsuccessful cases were due to the presence of calcium in the trajectory of the lead. The mean duration of laser light application was 123.0+/-104.5 s, using 5,215.2+/-4,924.0 pulses, in a total of 24.4+/-24.2 cycles of application. Thirty-four leads were extracted from the myocardium with countertraction after complete progression of the laser sheath, 12 leads came loose during the progression of the laser sheath, and the remaining 10 were extracted with other maneuvers. One patient experienced cardiac tamponade after extraction of the defibrillator lead, requiring open emergency surgery.

CONCLUSION

The use of the excimer laser allowed extraction of the leads with a 96% rate of success; it was not effective in 2 patients who had calcification on the lead. One patient (2.8%) had a complication that required cardiac surgery on an emergency basis.

Total inversion of the left lung circulation: morphologic and functional analyses

BACKGROUND

An experimental model for total inversion of left lung circulation was developed. With this model, the authors demonstrate that it is possible to reverse the pulmonary circulation and preserve the normal function and morphology of the lung.

METHODS

Eight dogs had their left pulmonary circulation reversed. The blood from the pulmonary artery trunk was diverted to the pulmonary veins, and returned from the pulmonary artery into the left atrium. In order to monitor the flow through the reversed system, color Doppler echocardiography was performed on the ninth postoperative day. The dogs were reoperated after 15 days for re-evaluation. Blood gas analyses from the aorta and the pulmonary artery were used to study the functional status of the lung in both operations. The morphology was studied by comparing biopsies of the lung performed before and after reversal of flow.

RESULTS

Blood gas analysis showed no significant difference between the samples of from the aorta and pulmonary artery. Color Doppler echocardiography was a reliable method for the study of the inverted circulation. The histological study showed no differences in the morphology of the lung after the reversed circulation.

CONCLUSIONS

Left pulmonary circulation was fully reversed. Pulmonary function and morphology remained normal.

Mitral valve repair in rheumatic patients

BACKGROUND

There is controversy regarding the role of reparative techniques for rheumatic-mitral valve disease. We have analyzed the late results of mitral valve repair in a group of patients with rheumatic mitral valve insufficiency.

METHODS

From March 1980 to December 1997, 201 patients with rheumatic fever underwent mitral valve repair at the Heart Institute, Hospital das Clínicas, Medical School, University of São Paulo. The mean age of patients was 26.9 +/- 15.4 years, with 59.7% of the patients being female. Other diagnoses were present in 67.7% of patients; the most common was tricuspid regurgitation (31.3%). Mitral valve repair techniques included: 1) Carpentier ring annuloplasty in 75 patients (37.3%); 2) posterior annuloplasty with bovine patch in 68 patients (33.8%); 3) posterior segmental annuloplasty in 16 patients (7.9%); 4) quadrangular resection of the posterior leaflet with ring plication in 11 patients (5.5%); 5) partial resection of the anterior leaflet in 6 patients (3%); 6) De Vega's annuloplasty in 6 patients (3%); 7) Kay's annuloplasty in 5 patients (2.5%); 8) Reed's annuloplasty in 4 patients (2%); and 9) miscellaneous techniques in 10 patients (4.9%). Combined techniques were used in 94 patients (46.8%), the most frequent of which was chordal shortening (48 patients, 23.9%). Other non-mitral cardiac procedures were performed in 113 patients (56.2%). Actuarial survival and event-free curves (Kaplan-Meier method) were compared by linear regression analysis.

RESULTS

The in-hospital mortality rate was 2.0% (four patients). The causes of death were multiorgan failure in two patients and low cardiac output in the other two patients. In the late postoperative period, 83.9% of the patients were in New York Heart Association (NYHA) functional class 1. The actuarial survival was 93.9% +/- 1.9% at a mean of 125 months. Twenty-three patients were reoperated in the postoperative period at a mean interval of 35.7 months. Survival free from reoperation was 43.3% +/- 13.7% at 125 months. When analyzing the patients according to age, actuarial survival was 91.3% +/- 3.8% in the group of patients younger than 16 years (Group 1), compared with 95.6% +/- 2.7% in the group older than 16 years (Group 2), with a statistically significant difference of p < 0.0001. Survival free from reoperation was 50.8% +/- 16.9% in Group 1 and 47.0% +/- 14.9% in Group 2 (p < 0.0001).

CONCLUSIONS

Late results obtained with mitral valve repair for rheumatic mitral valve insufficiency were satisfactory and exceeded those reported for mitral valve replacement in the same population.

Fisics-Incor bovine pericardial bioprostheses: 15 year results

BACKGROUND

From March 1982 to December 1995, 2,607 Fisics-Incor bovine pericardial bioprostheses were implanted in 2,259 patients. Mean age was 47.2 +/- 17.5 years, and 55% were male. Rheumatic fever was present in 1,301 (45.7%) patients.

METHODS

One thousand and seventy-three aortic valve replacements, 1,085 mitral replacements, 27 tricuspid replacements, 195 mitral-aortic replacements, and 16 other combined valve replacements were carried out. Combined procedures were performed in 788 (32.9%) patients, the most frequent being tricuspid valve repair (9.2%) and coronary artery bypass grafting (7.7%).

RESULTS

Hospital mortality was 8.6% (194 patients), 8.6% for the mitral group, 4.7% for the aortic group, and 12.8% for double-valve replacements. The linear rates for calcification, thromboembolism, rupture, leak and endocarditis were, respectively, 1.1%, 0.2%, 0.9%, 0.1% and 0.5% patient-year. The actuarial survival curve was 56.7 +/- 5.4% in 15 years. Survival free from endocarditis was 91.92%, survival free from thromboembolism was 95 +/- 1.7%, survival free from rupture was 43.7 +/- 9.8%, survival free from leak was 98.9 +/- 4.5%, and survival free from calcification was 48.8 +/- 7.9% in 15 years. In the late postoperative period, 1,614 (80.6%) patients were in New York Heart Association functional Class I.

CONCLUSIONS

We conclude that the results with the Fisics-Incor bovine pericardial prostheses were satisfactory in our group of patients.

Histopathological findings in skeletal muscle used in human dynamic cardiomyoplasty

Patients submitted to dynamic cardiomyoplasty had an initial clinical improvement followed by a decrease in cardiac failure indices. A histopathological study of the skeletal muscle was undertaken to explain this. Latissimus dorsi fragments from 15 patients submitted to dynamic cardiomyoplasty in a 1:1 (heart beat:muscle stimulation) conditioning were analysed by light microscopy. The interval between surgery and obtaining the specimens (13 from necropsies, two from heart transplants) ranged from 37 days to 6 years. Nuclear clumps and internalization, the presence of round fibres, inflammation, and fibrosis were analysed semi-quantitatively; the thickness of muscle fibres and the percentage of tissue fat were measured by image analysis. The quantitative data were also compared, in 12 cases, with gender- and age-matched necropsy controls. The mean thickness of muscle fibres in cases and controls was 27.21+/-5.33 and 40.84+/-9.42 microm, respectively (p=0.001). The percentage of tissue fat in cases and controls was 12.04+/-12.66% and 0.93+/-0.91%, respectively (p=0.008). The duration of grafts correlated positively with the quantity of nuclear clumps (R=0.80, p<0.001) and round fibres (R=0.53, p=0.04), as well as with the percentage of tissue fat (R=0.68, p=0.005). Accordingly, a negative correlation was found between the duration of grafts and the mean diameter of fibres, characterizing muscle atrophy (R=-0.66, p=0.01). The longer the post-surgical period, the more intense the degenerative lesions. This study shows that skeletal muscle used in human dynamic cardiomyoplasty may atrophy and be replaced by fat when stimulation is synchronized to every cardiac beat. These findings could play a role in explaining the long-term results of this surgical procedure.

Histoplasmosis as a late infectious complication following heart transplantation in a patient with Chagas' disease

Infectious complications following heart transplantation are an important cause of morbidity and mortality. Generally, bacterial infections are predominant; however, fungal infections can be responsible for up to 25% of infectious events. We report the case of a patient who presented with histoplasmosis as an infectious complication five years after heart transplantation due to a chagasic cardiopathy. This association has rarely been reported in the international literature.

Comparison between antigenemia and a quantitative-competitive polymerase chain reaction for the diagnosis of cytomegalovirus infection after heart transplantation

BACKGROUND

Antigenemia and quantitative polymerase chain reaction (PCR) are widely used for cytomegalovirus (CMV) diagnosis after heart transplantation due to their enhanced predictive values for disease detection when specific cut-off values are used. The purpose of this study was to compare, in the same patient setting, the predictive values of quantitative PCR and antigenemia for CMV disease detection, using specific cut-off values.

METHODS

Thirty heart transplant receptors were ch prospectively monitored for active CMV infection and disease detection, using quantitative PCR and anti- po genemia. Positive and negative predictive values for pr CMV disease detection were calculated using cut-off pr values for both antigenemia (5 and 10 positive cells/300,000 neutrophils) and quantitative-PCR (50,000 and 100,000 copies/10(6) leukocytes).

RESULTS

Active CMV infection was diagnosed in 93.3% of patients and CMV disease in 23.3%. The positive and negative predictive (%) values for CMV disease detection were 35/100 and 46.7/100, respectively, for quantitative PCR and antigenemia. Using 5 and 10 positive cells/300,000 neutrophils as cut-off values for antigenemia, the positive and negative predictive values (%) for disease detection were respectively 63.6/100 and 70/100. For quantitative PCR, the positive and th negative predictive values (%) for cut-off values of to 50,000 and 100,000 copies/10(6) leukocytes were 53.8/100 and 60/94.1, respectively.

CONCLUSION

In our series, antigenemia and quantitative-PCR had enhanced and similar predictive values for CMV disease detection when specific cut-off values were used. The choice between these two methods for disease detection may rely less on their efficiency and more on the experience and familiarity with them.

Current perspectives of partial left ventriculectomy in the treatment of dilated cardiomyopathy

OBJECTIVES

Partial left ventriculectomy has been performed as an alternative to heart transplantation in the treatment of severe cardiomyopathies. This investigation documents the clinical and left ventricular (LV) function effects of this procedure, associated, when necessary, with mitral insufficiency correction, in 43 patients with idiopathic dilated cardiomyopathy.

METHODS

Eighteen patients were in New York Heart Association class III and 25 in class IV. Seven of them were operated in cardiogenic shock. The procedure was associated with mitral annuloplasty in 32 patients and mitral replacement in three.

RESULTS

Nine patients (20.9%) died during the hospital period and the cause of death was associated with ventricular failure in seven patients. The other patients were followed up from 2 to 57 months (mean, 28.3 months). At 6 months of follow-up, eight patients were in functional class I, 13 in class II, three in class III and one patient was in class IV (P<0.001). On the other hand, nine patients died during the first 6 months and another six in the later postoperative period. The cause of late death was progressive heart failure in eight patients, and seven patients died because of arrhythmia related events. The actuarial survival was 58.1+/-7.5% at 1 year and 43.9+/-8.1% at 4 years of follow-up. Regarding ventricular function modifications, the LV diastolic volume decreased by around 25% and the LV ejection fraction increased from 17.8+/-4.7 to 22.3+/-7.9% (P<0.001), whereas significant changes in the cardiac index, stroke index and pulmonary pressures were also found 1 month after the operation. In the later follow-up, despite the maintenance of hemodynamic improvement, the LV diastolic volume tended to increase and returned to preoperative levels at 4 years, while a concomitant decrease in the LV ejection fraction was also observed.

CONCLUSION

Partial left ventriculectomy associated with mitral insufficiency correction improves LV function and ameliorates congestive heart failure in patients with idiopathic cardiomyopathy. Otherwise, the LV function benefits seem to be restricted by the possibility of progressive LV redilatation. Furthermore, the clinical application of this procedure is limited by the high mortality observed in the first postoperative months and by the possibility of heart failure progression and arrhythmia related events at late follow-up.

Noninvasive diagnosis of allograft vascular disease after heart transplantation

OBJECTIVE

To determine the predictive values of noninvasive tests for the detection of allograft vascular disease.

METHODS

We studied 39 patients with mean ages of 48+/-13 years and a follow-up period of 86+/-13 months. The diagnosis of allograft vascular disease was made by cine-coronary arteriography, and it was considered as positive if lesions existed that caused > or =50% obstruction of the lumen. Patients underwent 24h Holter monitoring, thallium scintigraphy, a treadmill stress test, and dobutamine stress echocardiography. Sensitivity, specificity, and positive and negative predictive values were determined in percentages for each method, as compared with the cine-coronary arteriography results.

RESULTS

Allograft vascular disease was found in 15 (38%) patients. The Holter test showed 15.4% sensitivity, 95.5% specificity. For the treadmill stress test, sensitivity was 10%, specificity was 100%. When thallium scintigraphy was used, sensitivity was 40%, specificity 95.8%. On echocardiography with dobutamine, we found a 63.6% sensitivity, 91.3% specificity. When the dobutamine echocardiogram was associated with scintigraphy, sensitivity was 71.4%, specificity was 87%.

CONCLUSION

In this group of patients, the combination of two noninvasive methods (dobutamine echocardiography and thallium scintigraphy) may be a good alternative for the detection of allograft vascular disease in asymptomatic patients with normal ventricular function.

Analysis of the risk factors for allograft vasculopathy in asymptomatic patients after cardiac transplantation

OBJECTIVE

To study the influence of immune and nonimmune risk factors on the development of allograft vasculopathy after cardiac transplantation.

METHODS

We studied 39 patients with a mean age of 46+/-12 years. The following variables were analyzed: weight (kg), body mass index (kg/m2), donor's age and sex, rejection episodes in the first and second years after transplantation, systolic and diastolic blood pressures (mmHg), total cholesterol and fractions (mg/dL), triglycerides (mg/dL), diabetes, and cytomegalovirus infection. The presence of allograft vasculopathy was established through coronary angiography.

RESULTS

Allograft vasculopathy was observed in 15 (38%) patients. No statistically significant difference was observed between the two groups in regard to hypertension, cytomegalovirus infection, diabetes, donor's sex and age, rejection episodes in the first and second years after transplantation, and cholesterol levels. We observed a tendency toward higher levels of triglycerides in the group with disease. Univariate and multivariate analyses showed statistically significant differences between the two groups when we analyzed the body mass index (24.53+/-4.3 versus 28.11+/-4.6; p=0.019).

CONCLUSION

Body mass index was an important marker of allograft vasculopathy in the population studied.

Angiographic evaluation of graft patency in minimally invasive direct coronary artery bypass grafting

BACKGROUND

The objective of this report is to describe our experience using minimally invasive direct coronary artery bypass grafting and to evaluate angiographic patency of anastomoses.

METHODS

A total of 120 patients (86 men) were operated on, with ages ranging from 30 to 83 years (mean = 61.2 years). Two access routes were used: for single left anterior descending coronary artery lesions an 8 cm anterior minithoracotomy was performed at the fourth left intercostal space. Extracorporeal circulation was not used. In the last 82 patients a restraining device was used for the regional reduction of heart beats. Coronary cineangiography was carried out between postoperative days 1 and 3 in 84 (70%) patients. Anastomoses were graded: grade A, no blocks; grade B, blocks of more than 50%; grade C, occlusion. This evaluation was performed for two different periods: in the first period a restraining device was not used and in the second period a restraining device was used.

RESULTS

In the first study period (38 anastomoses) coronary cineangiography showed grade A, 79%, grade B, 5.2%, and grade C, 15.8%. In the second study period (62 anastomoses), angiography showed grade A, 90.4%, grade B, 6.4%, and grade C, 3.2%. Early mortality was 1.6%.

CONCLUSIONS

Minimally invasive coronary artery bypass grafting is a good alternative for some groups of patients. Anastomotic results seem to be better when a restraining device is used.

Ischemic preconditioning in myocardial revascularization with intermittent aortic cross-clamping

BACKGROUND

This study tests the hypothesis that initial brief periods of ischemia can increase the protection obtained by intermittent aortic cross-clamping.

METHODS

In the control group (n = 18), the procedure was performed under intermittent aortic cross-clamping at 32 degrees C. Patients in the preconditioned gorup (n = 17) received a stimulus of two 3-minute periods of cross-clamping followed by 2 minutes of reperfusion prior to standard operation. CKMB, troponin 1, adenosine, and lactate were obtained from the great cardiac vein at the onset of cardiopulmonary bypass (CPB), at the end of the first anastomosis, and at the end of CPB.

RESULTS

CKMB and troponin I were slightly higher at the end of CPB in the control group, while there was no difference between adenosine and lactate levels. [table: see text].

CONCLUSION

There was no difference between groups in terms of myocardial protection.

Mediastinitis after cardiac transplantation

OBJECTIVE

Assessment of incidence and behavior of mediastinitis after cardiac transplantation.

METHODS

From 1985 to 1999, 214 cardiac transplantations were performed, 12 (5.6%) of the transplanted patients developed confirmed mediastinitis. Patient's ages ranged from 42 to 66 years (mean of 52.3 +/- 10.0 years) and 10 (83.3%) patients were males. Seven (58.3%) patients showed sternal stability on palpation, 4 (33.3%) patients had pleural empyema, and 2 (16.7%) patients did not show purulent secretion draining through the wound.

RESULTS

Staphylococcus aureus was the infectious agent identified in the wound secretion or in the mediastinum, or both, in 8 (66.7%) patients. Staphylococcus epidermidis was identified in 2 (16.7%) patients, Enterococcus faecalis in 1 (8.3%) patient, and the cause of mediastinitis could not be determined in 1 (8.3%) patient. Surgical treatment was performed on an emergency basis, and the extension of the débridement varied with local conditions. In 2 (16.7%) patients, we chose to leave the surgical wound open and performed daily dressings with granulated sugar. Total sternal resection was performed in only 1 (8.3%) patient. Out of this series, 5 (41.7%) patients died, and the causes of death were related to the infection. Autopsy revealed persistence of mediastinitis in 1 (8.3%) patient.

CONCLUSION

Promptness in diagnosing mediastinitis and precocious surgical drainage have changed the natural evolution of this disease. Nevertheless, observance of the basic precepts of prophylaxis of infection is still the best way to treat mediastinitis.

Autopsy findings in early and late postoperative death after partial left ventriculectomy

BACKGROUND

Partial left ventriculectomy (PLV) is an alternative to heart transplantation for patients with severe heart failure. However, this procedure is accompanied by high morbidity and mortality. Therefore, we studied the hearts of 12 patients who underwent this procedure to increase our understanding of the causes of bad outcome.

METHODS

We analyzed the autopsy hearts of 11 of 16 patients who died after PLV, and one heart from a patient who underwent heart transplantation.

RESULTS

Six patients died less than 30 days postoperatively, 4 of cardiogenic shock, 1 of arrhythmia, and 1 of coagulopathy. Five patients died from 36 to 120 days after the procedure, 4 of cardiogenic shock and 1 of arrhythmia. The patient who underwent heart transplantation had a cardiogenic shock 230 days after PLV. Ten hearts weighed more than 500 g and nine had myocardial infarction that extended to the papillary muscles. Four patients had infarction of both papillary muscles and 3 of them had episodes of arrhythmia, suggesting some relation between these events.

CONCLUSIONS

We found several important morphologic clues for bad outcome: infarction of both papillary muscles, which may be associated with the development of arrhythmia, and myocardial infarction and pericardial hemorrhage, which may contribute to the outcome of heart failure.

Chylomicron metabolism in patients submitted to cardiac transplantation

BACKGROUND

Development of coronary graft disease is the most important cause of late heart graft failure. Alterations in plasma lipid profile are frequent in heart transplant (HT) patients, but they seem not to be prominent. Currently, the metabolism of chylomicrons, the lipoproteins that carry dietary lipids absorbed by the intestine, was evaluated because chylomicron remnants are considered atherogenic.

METHODS

An emulsion labeled with 3H-triolein and 14C-cholesteryl oleate and known to mimic the metabolic behavior of chylomicrons was injected intravenously after a 12-hr fast into 34 HT patients, 24 patients with end-stage heart failure (ESHF), and 30 healthy normolipidemic subjects. The plasma disappearance curves of the radioisotopes were determined from blood samples collected over 1 hr. In some of the patients and in controls, in vitro postheparin lipolytic activity was measured and an oral fat load test with postprandial measurement of triglyceridemia was performed.

RESULTS

Fractional clearance rate (in m(-1), median [25%; 75%]) of both emulsion 3H-triolein and 14C-cholesteryl oleate was extremely diminished in HT patients (HT: 0.0114 [0.0114; 0.0179] and 0.2x10(-8) [0.2x10(-8); 0.0041, respectively]; ESHF: 0.0226 [0.0223; 0.0568] and 0.0160 [0.0055; 0.0189]; control subjects: 0.0270 [0.0226; 0.0392] and 0.0090 [0.0042; 0.0180], respectively, P<0.05). HT patients also had reduced postheparin lipolysis and marked elevation of postprandial triglyceridemia compared with the controls.

CONCLUSIONS

HT patients develop accumulation in the plasma of chylomicrons and their remnants. The observed alterations were so intense that they may suggest an important involvement of atherogenic chylomicron remnants in coronary graft disease.

Influence of biopump with and without intraaortic balloon on the coronary and carotid flow

BACKGROUND

The objective of this study was to evaluate the influence of biopump used for left ventricular assistance on the coronary and carotid flows in dogs with normal heart. The efficacy of the simultaneous use of an intraaortic balloon pump to compensate the possible deleterious effects of the circulatory assistance with continuous flow was also analyzed.

METHODS

Fifteen dogs were studied. The hemodynamic evaluation included serial measurements of the classic parameters. Carotid and coronary blood flows were obtained by electromagnetic transducers.

RESULTS

The hemodynamic evaluation did not show significant statistical changes. The use of circulatory-isolated assistance with biopump shows reduction (24.6% +/- 6.1%) in coronary flow, in relation to the control situation and the concomitant use of biopump and intraaortic balloon pump showed similar coronary flow. Regarding carotid flow, a similar trend was observed in relation to the positive influence of the pulsatile flow with an intraaortic balloon pump without statistical significance (p = 0.0582).

CONCLUSIONS

The biopump reduces the coronary flow in dogs. The use of intraaortic balloon pump with the biopump increases the coronary flow significantly, reaching similar values to those observed without the circulatory assistance.

Treatment of persistent rejection with methotrexate in stable patients submitted to heart transplantation

OBJECTIVE

To evaluate the use of methotrexate for the treatment of recurrent rejection in heart transplant recipients.

METHODS

We studied 6 patients submitted to heart transplantation that showed rejection grade >/= 3A (ISHLT) in two consecutive endomyocardial biopsy specimens. The dose was 11.26+/-3.75 mg/week. The evaluated data were: ventricular function, endomyocardial biopsy, white cell count and number of rejection episodes before and after methotrexate administration.

RESULTS

There was a reduction in the number of rejection episodes (5.17+/-1.47 before methotrexate; 2.33+/-1.75 after 6 months and 3.17+/-2.99 after 12 months of treatment, p=0. 0193). The ventricular function was normal with ejection fraction of 76.5+/-4.80 before and 75.6+/-4.59 after methotrexate (p=0.4859). One patient did not finish the treatment because he showed signs of rejection associated with severe pericardial effusion. Five patients had a reduction in the white cell count (8,108+/-23.72 before and 5650+/-1350 after methotrexate, p=0.0961). One pulmonary infection with complete resolution after antibiotic treatment was observed.

CONCLUSION

Methotrexate in low doses is an effective adjunct therapy in the treatment of recurrent rejection after heart transplantation.

Permanent and temporary pacemaker implantation after orthotopic heart transplantation

PURPOSE

To determine the indication for and incidence and evolution of temporary and permanent pacemaker implantation in cardiac transplant recipients.

METHODS

A retrospective review of 114 patients who underwent orthotopic heart transplantation InCor (Heart Institute USP BR) between March 1985 and May 1993. We studied the incidence of and indication for temporary pacing, the relationship between pacing and rejection, the need for permanent pacing and the clinical follow-up.

RESULTS

Fourteen of 114 (12%) heart transplant recipients required temporary pacing and 4 of 114 (3.5%) patients required permanent pacing. The indication for temporary pacing was sinus node dysfunction in 11 patients (78.5%) and atrioventricular (AV) block in 3 patients (21.4%). The indication for permanent pacemaker implantation was sinus node dysfunction in 3 patients (75%) and atrioventricular (AV) block in 1 patient (25%). We observed rejection in 3 patients (21.4%) who required temporary pacing and in 2 patients (50%) who required permanent pacing. The previous use of amiodarone was observed in 10 patients (71.4%) with temporary pacing. Seven of the 14 patients (50%) died during follow-up.

CONCLUSION

Sinus node dysfunction was the principal indication for temporary and permanent pacemaker implantation in cardiac transplant recipients. The need for pacing was related to worse prognosis after cardiac transplantation.

Immediate and long term evolution of valve replacement in children less than 12 years old

OBJECTIVE

The aim of this work was the follow-up and evaluation of valve replacement in children under 12 years of age.

METHODS

Forty-four children less than 12 years old were underwent valve replacement at INCOR-HCFMUSP between January 1986 and December 1992. Forty (91%) were rheumatic, 39 (88.7%) were in functional classes II or IV, 19 (43.2%) were operated upon on an emergency basis, and 6 (13.6%) had atrial fibrillation. Biological prostheses (BP) were employed in 26 patients (59.1%), and mechanical prostheses (MP) in 18 (40.9%). Mitral valves were replaced in 30 (68.7%), aortic valves in 8 (18.2%), a tricuspid valve in 1 (2.3%), and double (aortic and mitral) valves in 5 (11.4) of the patients.

RESULTS

Hospital mortality was of 4.5% (2 cases). The mean follow-up period was 5.8 years. Re-operations occurred in 63.3% of the patients with BP and in 12.5% of those with MP (p=0.002). Infectious endocarditis was present in 26.3% of the BP, but in none of the cases of MP (p=0.049). Thrombosis occurred in 2 (12.5%) and hemorrhage in one (6.5%) of the patients with a MP. Delayed mortality occurred in 5 (11.9%) of the patients over a mean period of 2.6 years; four had had BP and one had a MP (NS). Actuarial survival and re-operation-free curves after 10 years were respectively, 82.5+/-7.7 (SD)% and 20.6+/-15.9%.

CONCLUSION

Patients with MP required fewer re-operation, had less infectious endocarditis and lower late mortality rates compared with patients with bioprostheses. The former, therefore, appear to be the best valve replacement for pediatric patients.

Successful one-stage resection of intravenous leiomyomatosis of the uterus with extension into the heart

Intravenous leiomyomatosis of the uterus is a rare neoplasm characterized by nodular masses of benign smooth muscles with intraluminal growth to the inferior vena cava and, in some cases, to the heart. It may cause abdominal and cardiovascular symptoms and is a serious risk of death when it reaches the tricuspid valve. Surgery is the best treatment and must be applied as soon as possible using cardiopulmonary bypass. The authors report a new case that had cardiac involvement and was successfully resected. The symptoms, imaging diagnosis, pathological and histopathological findings, tumors that mismatched the intravenous leiomyomatosis (IVL), and the use of circulatory arrest and deep hypothermia are discussed. A review of the literature is included.

Mitral valve repair. Quadrangular resection of the posterior leaflet in patients with myxomatous degeneration

OBJECTIVE

To analyze the immediate and late results of mitral valve repair with quadrangular resection of the posterior leaflet without the use of a prosthetic ring annuloplasty.

METHODS

Using this technique, 118 patients with mitral valve prolapse who underwent mitral repair from January '84 through December '96 were studied. Age ranged from 30 to 86 (mean = 59.1 +/- 11.8) years and 62.7% were males. An associated surgery was performed in 22% of the patients, and coronary artery bypass graft was the most frequently performed surgery (15 patients--12.7%). In 20 (16.9%) patients other associated techniques of mitral valve repair were used and shortening of elongated chordae tendineae was the most frequent one (6 patients).

RESULTS

Immediate mortality was 0.9% (one patient). Long-term rates for thromboembolism, endocarditis, reoperation and death in the late postoperative period were 0.4%, 0.4%, 1.7% and 2.2% patients/year, respectively. The actuarial curve of survival was 83.8 +/- 8.6% over 12 years; survival free from re-operation was 91.8 +/- 4.3%, free from endocarditis was 99.2 +/- 0.8% and free from thromboembolism was 99.2 +/- 0.8%. In the late postoperative period, 93.8% of the patients were in functional class 1 (NYHA), with a complete follow-up in 89.7% of the patients.

CONCLUSION

Patients with mitral valve prolapse who undergo mitral valve repair using this technique have a satisfactory prognosis over 12 years.

Unusual abdominal tumors with intracardiac extension. Two cases with successful surgical resection

Abdominal tumors that can grow through vascular lumen and spread to the right heart are rare. Although these tumors have different histologic aspects, they may cause similar abdominal and cardiac symptoms and are a serious risk factor for pulmonary embolism and sudden death when they reach the right atrium and tricuspid valve. The best treatment is radical surgical resection of the entire tumor using cardiopulmonary bypass with or without deep hypothermia and total circulatory arrest. We report the cases of two patients, the first with leiomyosarcoma of the inferior vena cava and the other with intravenous leiomyomatosis of the uterus that showed intravascular growth up to right atrium and ventricle, who underwent successful radical resection in a one-stage procedure with the use of cardiopulmonary bypass. We discuss the clinical and histologic aspects and imaging diagnosis and review the literature.

Management of aortic dissection that involves the right coronary artery

A report on the follow-up of 11 patients who suffered from aortic dissection involving the right coronary artery and who underwent surgical treatment is reported. In two patients, the left coronary ostia was also affected. In seven patients, the dissection was acute and in four, chronic. The ascending aorta was substituted by a Dacron graft in all patients, and right coronary artery saphenous vein bypass or Gore-Tex graft to the coronary ostia or right coronary artery was performed in nine, and reimplantation of both dissected coronary in two. There were three early postoperative deaths (27.3%) caused by low-output syndrome and myocardial infarction. There were two late deaths. The six surviving patients were followed-up from 78 to 96 months (mean 83 months). This experience suggests that although carrying a high risk, the involvement of the coronary ostia in aortic dissection can be successfully managed if made before irreversible complications arise.

Paraplegia following intraaortic balloon circulatory assistance

Intraaortic balloon counterpulsation is frequently used in patients experiencing severe ventricular dysfunction following maximal drug therapy. However, even with the improvement of percutaneous insertion techniques, the procedure has always been followed by vascular; infectious, and neurological complications. This article describes a case of paraplegia due to intraaortic balloon counterpulsation in the postoperative period of cardiac surgery.

Self-expanding endovascular stent-graft implant for treatment of descending aortic diseases

BACKGROUND

Aneurysms and dissections involving the descending thoracic aorta and the distal portion of the aortic arch are difficult to resolve surgically. The introduction of endovascular self-expanding stent-grafts has simplified the operation. Given the complications associated with their peripheral placement, we explored the feasibility of surgical insertion.

METHODS

Thirteen patients underwent surgical insertion of a stent-graft into the aortic arch via longitudinal aortotomy. Six patients had aneurysms (ruptured in two, and seven dissections (acute in two, ruptured in one). Five patients also underwent associated procedures including aortic valve replacement (one), ascending aorta replacement (two), arch replacement (one), and coronary artery bypass (one).

RESULTS

There was one intraoperative death due to ascending aortic dissection, and two hospital deaths due to multiple complications. Of ten patients discharged, one died 3 months postoperatively. The remaining survivors are well, and imaging studies confirmed adequate correction of the aortic disease.

CONCLUSIONS

The use of this technique simplifies the operation and treatment of particular cases of aortic disease. The observed morbidity and mortality are due to factors independent of the technique.

Distribution of hyaluronan and dermatan/chondroitin sulfate proteoglycans in human aortic dissection

Aortic dissections (AD) are characterized by the separation of the artery into two sheets, possibly due to fragility of the vessel wall. A mucoid histological pattern, imparted to the tissues mainly by hyaluronan and proteoglycans, can be seen in "cysts" and, in chronic cases, in a band of repair tissue. We studied the localization of hyaluronan, versican, decorin and biglycan in situ in aortas of 21 patients with recent AD, 8 with chronic AD and in 15 control cases. None of these substances was increased in the areas of mucoid "cysts" that possibly contain anomalous material. Similar distributions were seen in normal and dissected aortas: versican and hyaluronan were more prominent in the external half of the medial layer where the dissection usually occurs. Since these molecules play a role in resistance to compression, disorders not detected by our method may be involved in aortic dissection. Hyaluronan was seen adjacent to fibrin at the dissection tear, probably as an early wound repair phenomenon. Biglycan, hyaluronan and mostly versican are seen during advanced repairing. The mucoid deposits may represent various compounds which reflect different disorders in vascular biology.

Determinants of midterm outcome of partial left ventriculectomy in dilated cardiomyopathy

BACKGROUND

Partial left ventriculectomy has been proposed for treatment of severe cardiomyopathies. This study reports midterm results of this procedure in 37 patients with dilated cardiomyopathy.

METHODS

All patients were in New York Heart Association class III (16) or IV (21). Partial ventriculectomy was associated with mitral annuloplasty in 27 patients and with mitral replacement in 2.

RESULTS

There were seven operative deaths (18.9%). During a mean follow-up of 18.2+/-9.3 months, 9 more patients died. Actuarial survival was 56.7%+/-8.1% at 6 and 24 months. Analysis of factors influencing outcome showed that midterm survival was significantly affected only by myocardial cell diameter. Otherwise, functional class improved from 3.5+/-0.5 to 1.8+/-0.9 in the survivors (p < 0.001). Furthermore, left ventricular diastolic volume decreased from 523+/-207 to 380+/-148 mL (p < 0.001), and left ventricular ejection fraction increased from 17.1%+/-4.6% to 23%+/-8% (p < 0.001), whereas significant changes in cardiac index, stroke index, and pulmonary pressures were found at 1 month of follow-up. Although left ventricular diastolic volume tended to increase in the late postoperative period, left ventricular ejection fraction and hemodynamic variables did not change significantly.

CONCLUSIONS

Partial ventriculectomy improves left ventricular function and congestive heart failure in patients with dilated cardiomyopathy for up to 24 months of follow-up. Nevertheless, this procedure's clinical application is limited by the high mortality observed in the first postoperative months. Otherwise, new perspectives may be advised by the identification that partial ventriculectomy results seem to be influenced by compromised myocardial cells.

[Heart valve surgery during pregnancy. Experience with eight cases]

PURPOSE

To analyze the results of the valve cardiac surgery in pregnant women and cardiopulmonary bypass consequences to the patients and their fetuses.

METHODS

Study of 8 pregnant women who underwent cardiac surgery between January of 1986 and December of 1996. Patients' average age was 31.4 +/- 8.9 years and the gestation age ranged from 12 to 31 (average of 26.6 +/- 7.1) weeks. Fetus monitorization was performed in all patients. The temperature was always higher than 34 degrees C, as well as high flow rates during the cardiopulmonary bypass. Four surgeries of aortic valve and four of mitral valve were performed, in which two were reoperations.

RESULTS

There was no mortality. There were two premature births and in one child there was neurological damage. The other children did not have growth problems.

CONCLUSION

Valve cardiac surgery in pregnant women may have good results as long as care in the cardiopulmonary bypass and fetus monitorization are undertaken.

Partial left ventriculectomy with mitral valve preservation in the treatment of patients with dilated cardiomyopathy

OBJECTIVE

This study reports initial results of partial left ventriculectomy performed with preservation of the mitral valve in the treatment of 27 patients with idiopathic dilated cardiomyopathy.

METHODS

Patients were in New York Heart Association class III or IV. Partial ventriculectomy was performed as an isolated procedure in four patients and associated with mitral annuloplasty in 23 patients. There were four hospital deaths (14.8%) and the remaining patients were followed for 11.2 +/- 6 months.

RESULTS

Decrease of left ventricular diastolic diameter (81.8 +/- 8.7 to 68.5 +/- 7.6 mm, p < 0.001) and improvement of left ventricular wall shortening (12% +/- 3.1% to 18.1% +/- 3.9%, p < 0.001) were demonstrated by echocardiography after the operation. Left ventricular radioisotopic angiography showed reduction of diastolic volume (495 +/- 124 ml to 352 +/- 108 ml, p < 0.001) and increase of ejection fraction (17.7% +/- 4.6% to 23.7% +/- 8.8%, p < 0.001). Right-sided heart catheterization demonstrated improvement of stroke index (24.3 +/- 7.7 ml/m2 to 28.3 +/- 7.6 ml/m2, p < 0.01) and decrease of pulmonary wedge pressure (23.2 +/- 8.8 mm Hg to 17 +/- 7 mm Hg, p < 0.01). Similar results were documented at 6 and 12 months of follow-up. Functional class improved from 3.6 +/- 0.5 to 1.4 +/- 0.6 (p < 0.001). However, seven patients died at midterm follow-up because of heart failure progression or arrhythmia-related events, and survival rate was 59.2% +/- 9.4% from 6 to 24 months of follow-up.

CONCLUSIONS

Partial left ventriculectomy performed with preservation of the mitral valve improves left ventricular function and congestive heart failure in patients with dilated cardiomyopathy. Nevertheless, the high incidences of heart failure progression and arrhythmia-related deaths observed after this procedure preclude its wide clinical application.

VATS for complete dissection of LIMA in minimally invasive coronary artery bypass grafting

BACKGROUND

The aim of this work is to report our initial experience with minimally invasive coronary artery bypass grafting, using video-assisted thoracic surgery (VATS) to facilitate the operation and provide complete dissection of the left internal mammary artery (LIMA).

METHODS

Of 44 scheduled patients, 43 patients, 30 (69.8%) male, ranging in age from 31 to 83 years (60.8 +/- 12.0 years), with a severe lesion in the anterior descending artery, were operated upon. An 8-cm left anterior minithoracotomy was performed at the fourth intercostal space. Through this incision the optical device for video-assisted thoracic surgery as well as the surgical instruments were placed to provide complete LIMA dissection. This permits dissection until the subclavian region, allowing for anastomosis without tension or distortion. Bypass circulation was not used, and the cardiac rate was decreased with the use of intravenous beta-blockers. For LIMA-to-anterior descending artery anastomosis, proximal and distal tourniquets were used and 1.5 mg/kg of heparin was administered intravenously.

RESULTS

Video-assisted thoracic surgery provided a complete dissection of LIMA. The 43 patients presented satisfactory postoperative progress, being released from the hospital between 2 and 12 days after their operation, with a mean of 4 days. The patients have remained asymptomatic during a period that ranged from 1 to 13 months (6.3 +/- 3.5 months). During the follow-up, there was one death as a result of stroke and pneumonia 2 months after the release from the hospital.

CONCLUSIONS

The use of video-assisted thoracic surgery through thoracotomy allows the LIMA dissection without the necessity of other incisions. The procedure also permitted more ample dissection of LIMA when compared with minithoracotomy without video-assisted thoracic surgery.

Diclofenac plasma protein binding: PK-PD modelling in cardiac patients submitted to cardiopulmonary bypass

Twenty-four surgical patients of both sexes without cardiac, hepatic, renal or endocrine dysfunctions were divided into two groups: 10 cardiac surgical patients submitted to myocardial revascularization and cardiopulmonary bypass (CPB), 3 females and 7 males aged 65 +/- 11 years, 74 +/- 16 kg body weight, 166 +/- 9 cm height and 1.80 +/- 0.21 m2 body surface area (BSA), and control, 14 surgical patients not submitted to CPB, 11 female and 3 males aged 41 +/- 14 years, 66 +/- 14 kg body weight, 159 +/- 9 cm height and 1.65 +/- 0.16 m2 BSA (mean +/- SD). Sodium diclofenac (1 mg/kg, im Voltaren 75 twice a day) was administered to patients in the Recovery Unit 48 h after surgery. Venous blood samples were collected during a period of 0-12 h and analgesia was measured by the visual analogue scale (VAS) during the same period. Plasma diclofenac levels were measured by high performance liquid chromatography. A two-compartment open model was applied to obtain the plasma decay curve and to estimate kinetic parameters. Plasma diclofenac protein binding decreased whereas free plasma diclofenac levels were increased five-fold in CPB patients. Data obtained for analgesia reported as the maximum effect (EMAX) were: 25% VAS (CPB) vs 10% VAS (control), P < 0.05, median measured by the visual analogue scale where 100% is equivalent to the highest level of pain. To correlate the effect versus plasma diclofenac levels, the EMAX sigmoid model was applied. A prolongation of the mean residence time for maximum effect (MRTEMAX) was observed without any change in lag-time in CPB in spite of the reduced analgesia reported for these patients, during the time-dose interval. In conclusion, the extent of plasma diclofenac protein binding was influenced by CPB with clinically relevant kinetic-dynamic consequences.

[Minimally invasive myocardial bypass surgery using video-assisted thoracoscopy]

PURPOSE

In order to associate the major benefits of the coronary artery bypass graft (CABG) with a less aggressive procedure minimally invasive coronary artery bypass graft (MICABG) has been utilized. The aim of the work is to report our initial experience with this technical approach, using video assisted thoracic surgery (VATS) to facilitate the operation.

METHODS

Twenty-six patients, 19 males with ages from 44 to 83 years old, and having isolated lesion of the anterior descending artery were operated upon. Left anterior minithoracotomy of 8-10 cm was performed at the fourth intercostal space. Through this incision the optical device for VATS as well as the surgical instruments were placed in order to provide the complete left internal mammary artery (LIMA) dissection. Bypass circulation was not used and cardiac rate was decreased with the use of intravenous betablockers. For LIMA--anterior descending artery anastomosis, proximal and distal tourniquets were used and 1.5 mg/kg of heparin was intravenously administered.

RESULTS

All patients presented satisfactory postoperative evolution, being discharged from the hospital at 72 h after surgery in the majority of the cases. There were delay in two patients healing of incisions and 25 patients have remained asymptomatic, with a mean in postoperative follow-up of four months. One patient died in the second postoperative month due to stroke.

CONCLUSION

MICABG makes the surgery possible with better esthetic effect, lower cost and enables faster recovery than the conventional one. The use of VATS through the thoracotomy itself, allows the LIMA dissection without other incisions. It also permitted more ample dissection of the LIMA when compared to minithoracotomy without VATS.

[Results of aortic stenosis surgery in patients with severe ventricular dysfunction]

PURPOSE

To study the short and long term clinical course of patients with severe aortic stenosis after surgical treatment of the valvular lesion.

METHODS

Thirty survivors among 31 consecutive patients with severe left ventricular dysfunction (LVD) due to aortic stenosis (AS) were submitted to clinical and echocardiographic follow-up during a mean of 30 months after surgical treatment of the valvular lesion. Twenty five (83.3%) patients were male with a mean age of 50 years (25 to 74). Before operation the following parameters were obtained: diastolic left ventricular diameter (DLVD), shortening fraction (SF), left ventricular ejection fraction (LVEF), aortic valve area (AVA), left ventricular-aortic pressure gradient (PG) and NYHA functional class (FC). During the follow up, after the surgical procedure, FC, DLVD, LVEF and SF could be analysed and compared with previous data.

RESULTS

A significant rise in SF (p = 0.001) and LVEF (p = 0.0001), as well as a decrease in DLVD (p = 0.001) were observed in the follow up. Symptoms lessened in severity in the majority of patients. Three of our patients died with progressive LVD and heart failure, after at least 36 months of follow-up. These results indicate that when operation is carried out in patients with AS and left ventricular failure, a significant improvement in left ventricular function and in symptoms takes place. Although the risk of surgical treatment is increased in this group of patients, LVD should not be considered a contraindication to the procedure.

CONCLUSION

The left ventricular dysfunction is not a contraindiction for the surgical treatment of the aortic stenosis.

Heart transplantation for chronic Chagas' heart disease

BACKGROUND

Chagas' disease has been considered a contraindication to heart transplantation as Trypanosoma cruzi infection could recur after immunosuppression.

METHODS

We report the follow-up of 22 patients who underwent orthotopic heart transplantation for treatment of end-stage chronic Chagas' heart disease, divided in two groups. Group 1 consisted of 9 patients operated on from September 1985 to June 1991, and group 2 patients underwent transplantation from July 1991 to June 1995. After our early experience with group 1, we attempted to use a lower cyclosporine dosage in group 2.

RESULTS

Total actuarial survival at 24 months was 60%, and it was better for group 2 (33% for group 1, 80% for group 2, p = 0.008). Parasitemia occurred similarly in both groups, but Chagas' disease reactivation was seen in 5 group 1 patients and in 1 group 2 member (p < 0.002). Neoplasia developed in 5 group 1 patients and 1 group 2 patient, and contributed to death in 3 of them.

CONCLUSIONS

These data demonstrate satisfactory outcome of cardiac transplantation in patients with end-stage Chagas' heart disease in the second phase of our experience. Further progress is necessary to improve the results and evaluate its proper role in the management of this disease.

Dynamic cardiomyoplasty in the treatment of dilated cardiomyopathy: current results and perspectives

BACKGROUND

The purpose of this article is to provide an overview of the current indications, results, and perspectives of dynamic cardiomyoplasty in the treatment of patients with dilated cardiomyopathy. Particular emphasis is placed on the clinical experience with 36 patients operated at the São Paulo Heart Institute between 1988 and 1995.

METHODS

Based on several clinical reports, the mechanisms of action of dynamic cardiomyoplasty in these patients include the enhancement of left ventricular systolic function, by the direct action of synchronized skeletal muscle flap contraction and the reversion of chamber remodeling. Moreover, both mechanisms seem to be responsible for improved diastolic function properties and for the decrease of ventricular wall stress. Besides the acceptable hospital mortality observed for patients with dilated cardiomyopathy ranging from 0% to 8% with this surgical procedure, clinical improvement after dynamic cardiomyoplasty has been demonstrated as a prevailing and significant outcome.

RESULTS

Nevertheless, the 1-year survival for these patients ranges from 82% to 86% and the 5-year survival on the order of 41% to 49%. In addition, the analysis of factors influencing the outcome showed that cardiomyoplasty long-term survival was significantly affected by the severity of preoperative clinical compromise and cardiac function impairment. On the other hand, patients with dilated cardiomyopathy who were operated in functional Class III or intermittent Class IV and with pulmonary vascular resistance below 4 Wood units, present survival rates on the order of 79% at 2 years and of 64% at 5 years of follow-up, which are similar to those reported after cardiac transplantation.

CONCLUSIONS

Furthermore, technological advances incorporated in the new cardiomyostimulators may ameliorate skeletal muscle flap performance at long term. Other developments are also discussed in this field.

Low doses of inhaled nitric oxide in heart transplant recipients

BACKGROUND

The purpose of this study was to assess the hemodynamic effects of low doses of inhaled nitric oxide in patients after orthotopic heart transplantation.

METHODS

Two hours after the operation 10 adult patients who were still under anesthetic effects and undergoing mechanical ventilation inhaled, during 60 minutes, a mixture of nitrogen, oxygen, and nitric oxide (20 ppm). A standard profile of hemodynamic data was collected at baseline, at 30 minutes, at 30 more minutes of inhalation, and at the same points after nitric oxide suspension.

RESULTS

A significant decrease was found from baseline to 60 minutes, immediately after nitric oxide inhalation in the following: systemic vascular resistance index 1268 +/- 409 to 1090 +/- 354 (p = 0.0161); pulmonary vascular resistance index 252 +/- 124 to 154 +/- 98 (p < 0.05); pulmonary vascular resistance index/systemic vascular resistance index ratio 0.21 +/- 0.09 to 0.14 +/- 0.08 (p = 0.0025); transpulmonary gradient 12 +/- 3 to 9 +/- 3 (p = 0.05). A significant increase was also found in cardiac index from 4.2 +/- 1.1 to 4.9 +/- 1.4 (p = 0.0007). Other parameters such as mean pulmonary, systemic, wedge and right atrial pressures, in addition to intrapulmonary shunting, heart rate, and oxygen extraction ratio, did not present any significant changes. The procedure was well tolerated by all patients, and no undesirable effects such as methemoglobin elevation or worsening of pulmonary hypertension after nitric oxide suspension were observed.

CONCLUSIONS

The beneficial effects observed by inhaled nitric oxide in the pulmonary vascular resistance index/systemic vascular resistance index ratio, transpulmonary gradient, and cardiac index suggest that nitric oxide acts mainly in pulmonary territory and could be a possible pulmonary vasodilator agent used to control central hemodynamics after heart transplantation.

Dynamic cardiomyoplasty in South America

BACKGROUND

Dynamic cardiomyoplasty has been proposed in the treatment of severe cardiomyopathies. However, few reports to date have shown significant numbers of patients collected on a multicenter basis.

METHODS

From July 1987 to June 1994, dynamic cardiomyoplasty was performed in 112 patients in South America. The indications were dilated cardiomyopathy in 96 patients, Chagas' disease cardiomyopathy in 13, and ischemic cardiomyopathy in 3. Left latissimus dorsi muscle was used in all patients.

RESULTS

The thirty-day mortality rate was 8.1%, and patients were followed up for 22.1 +/- 18.6 months. Data of surviving patients show that 47.3% were in New York Heart Association functional class I, 45.6% in class II, and 7% in class III or IV 1 year after the operation. The 1-year survival was 78.4%; 2-year, 59.7%; and 5-year, 41.7%. The survival at 1 year was 86.1% for patients with dilated cardiomyopathy and 40% for those with Chagas' disease. At 5 years, these values were 49.8% and 9.5%, respectively. Long-term survival was also significantly affected by preoperative functional class and pulmonary vascular resistance. However, patients operated on in class III or intermittent class IV and without elevated pulmonary vascular resistance had survival rates of 91.5% at 1 year and 76.7% at 5 years of follow-up.

CONCLUSIONS

Cardiomyoplasty improves the functional status of patients with severe cardiomyopathies. Otherwise, long-term survival after this procedure is limited in patients with Chagas' disease and by patients' condition before the operation.

[Evaluation of chronic morphological changes in the latissimus dorsi, after cardiomyoplasty, with magnetic resonance]

PURPOSE

Long term clinical and hemodynamic benefits of dynamic cardiomyoplasty (DC) have been reported. However, no information is available about long-term morphological changes in the wrapped latissimus dorsi (LD) muscle in humans.

METHODS

The latissimus dorsi muscle flap was evaluated by magnetic resonance imaging (MRI) in 5 patients submitted to DC for treatment of severe dilated cardiomyopathy. All patients were studied from 24 to 52 months after the surgical procedure at the time of the cardiomyostimulator replacement. In the interim, LD was stimulated with burst of 6 pulses (burst duration 185 msec, burst freq 30Hz) synchronized to every cardiac contraction with a maximum of 100 LD contractions/min. Images were acquired on a GE Sigma 1.5 T system (TE = 25ms, TR = R- Rx2, slice thickness 8mm).

RESULTS

The thickness of was 7.6 +/- 0.8mm. In addition, the signal intensity of the LD was compared with that of thoracic skeletal muscle and was found to be increased (2.19 +/- 0.42). The signal intensity was similar to that of subcutaneous fat in those images.

CONCLUSION

Morphologic changes in the wrapped LD muscle consistent with fatty degeneration occur after DC and can be detected by MRI. Further studies will be necessary to demonstrate the clinical significance of such LD muscle flap changes.

Present trends in clinical experience with dynamic cardiomyoplasty

Dynamic cardiomyoplasty has been performed to reinforce the myocardium in the treatment of patients with severe cardiomyopathies. At the Heart Institute of São Paulo University Medical School, 36 patients were submitted to cardiomyoplasty between May 1988 and December 1993. The indications were idiopathic dilated cardiomyopathy in 31, ischemic cardiomyopathy in 3, and Chagas' disease cardiomyopathy in 2 patients. Twenty-eight patients were categorized in New York Heart Association (NYHA) Class III and 8 in Class IV despite the use of maximal medical therapy. There were no hospital deaths, and patients were followed up from 2 to 70 months (mean, 24 months). Besides the improvement of NYHA functional class from 3.2 +/- 0.6 to 1.6 +/- 0.9 at 6 months of follow-up, patients also presented significant changes in the left ventricular systolic and diastolic functions. Nevertheless, 16 patients died, and 2 patients were submitted to heart transplantation during late follow-up. Actuarial survival rates were 82.3% at 1 year, 61.5% at 2 years, and 38.8% at 5 years of follow-up. Otherwise, the analysis of factors influencing the outcome showed that long-term survival was significantly affected by preoperative functional class and by pulmonary vascular resistance. The 26 patients operated in NYHA functional Class III and with pulmonary vascular resistance below 4 Wood units presented survival rates of 72.7% at 2 years and of 63% at 5 years of follow-up. In conclusion dynamic cardiomyoplasty improves functional class and left ventricular function in patients with severe cardiomyopathies. However, the long-term survival after this surgical procedure may be limited by the patients' condition before the operation.

Design, manufacturing, and testing of a paracorporeal pulsatile ventricular assist device: São Paulo Heart Institute VAD

This paper describes the design of a ventricular assist device (VAD), its manufacturing, and testing. The VAD presented is pulsatile, with a free-floating membrane, smooth internal surfaces, and pericardial valves. It comprehends also a pneumatic driving unit capable of operating in the "full to empty," EKG synchronized or asynchronous modes. In vitro tests were performed to assess its mechanical durability, hydrodynamic performance, and hemolysis. To optimize cannulas and implant techniques, we performed in vivo tests in 22 sheep and 8 calves. In these tests, we also evaluated hemolysis and the device's capacity to normalize hemodynamic parameters during induced cardiac failure. The VAD worked for 4,000 h without failure in a mock circulatory loop. In full to empty mode, it displayed a rate-mediated "Starling-like" performance. Optimum output was achieved with a systole duration of 40% of the cycle. The in vitro hemolysis index (IH) was 6.7 +/- 2.1. Hemolysis in animal experiments was clinically nonsignificant. In calves with induced cardiac failure, the VAD was able to normalize hemodynamic parameters within 120 min.

Clinical and left ventricular function outcomes up to five years after dynamic cardiomyoplasty

Improvement in congestive heart failure and left ventricular function after dynamic cardiomyoplasty has been reported in patients with severe cardiomyopathies, but the long-term effects of this procedure remain unclear. In this investigation 31 patients undergoing cardiomyoplasty for treatment of idiopathic dilated cardiomyopathy were annually investigated with radionuclide scintigraphy, Doppler echocardiography, and right-sided heart catheterization. They were in New York Heart Association functional class III or IV before the operation. No hospital deaths occurred, but one patient with progressive heart failure required urgent heart transplantation 42 days after cardiomyoplasty. The other patients were followed up from 6 to 70 months (mean 25.6 months) and 12 patients died at late follow-up. Actuarial survivals were 86% at 1 year, 61.4% at 2 years, and 42.5% at 3 to 5 years of follow-up. Multivariate analysis of factors influencing outcome showed that long-term survival was significantly affected by preoperative functional class and pulmonary vascular resistance. Functional class improved from 3.2 +/- 0.4 to 1.7 +/- 0.7 in the surviving patients (p < 0.01). Furthermore, left ventricular ejection fraction improved from 19.8% +/- 3% to 23.9% +/- 7.2% (p < 0.01), and significant changes in stroke index, arterial pressure, pulmonary wedge pressure, and left ventricular stroke work index were also found at 6 months of follow-up. In the late postoperative period, the left ventricular ejection fraction tended to decrease and returned to preoperative levels at 5 years, whereas hemodynamic variables did not change significantly. Thus, despite the tendency of the left ventricular ejection fraction to decrease at late follow-up, the long-term course of these patients seems to be characterized by the maintenance of hemodynamic improvement. However, long-term survival after cardiomyoplasty is limited by the severity of the patient's condition before the operation.

Geometric reconstruction in left ventricular aneurysm. Surgical aspects and early results

The early results of 79 patients who underwent left ventricular aneurysmectomy with geometric and circular reconstruction in a seven-year experience are analyzed. The most common indication for operation was congestive heart failure (78.4%), either isolated (25.3%) or with angina (53.1%). Sixty patients (76%) were in NYHA class III and 10 (12.6%) in NYHA class IV at the time of surgery. Fifty-eight (73.4%) underwent coronary artery by-pass graft surgery. Hospital mortality was 5.1%, in patients older than 60 (12%), in NYHA class IV (20%), with poor left ventricular function (EF < 0.30-20% and LVED > 25) (14%), and with extensive coronary artery disease (10%) were under increased risk. Low cardiac output and use of intra-aortic balloon pump were also associated risk factors. Other risk factors mentioned in the literature are discussed. There were no deaths from isolated left ventricular aneurysmectomy. The early results of this study and the early and late results of others using the same technique are better than the results obtained in previous studies of different types of correction, suggesting that this is the procedure of choice for treating left ventricular aneurysm.

Cardiomyoplasty review: physiological principles and characteristics of electrically stimulated skeletal muscle. II. A therapeutic option

Chronic heart failure continues unsolved as ever despite recent advances in cardiac surgery and pharmacological new armamentarium and remains a significant cause of death, regardless of etiology. Cardiomyoplasty (CMP), a new form of biomechanical ventricular support, has given new life to the field of mechanical circulatory support, providing a "bridge" to transplantation and serving as a possible alternative to surgical treatment. The geographic distribution of world experience in 401 patients shows that 80% were centralized in Europe (50%) and South America (30%). This review of the data analysis, documented improved changes in patients clinical status, further clarifies and appropriate patients population indications for DCMP as well as that more than 80% survival probability for NYHA class II & III and an early procedure related mortality of 8 to 10%.

Arrhythmias and sudden death after dynamic cardiomyoplasty

BACKGROUND

The main causes of death in patients with severe cardiomyopathy are progressive heart failure and sudden death. The influence of cardiomyoplasty on the incidence of sudden death and arrhythmias in patients with cardiomyopathy remains unclear. The aim of this study was to investigate the occurrence of arrhythmias and sudden death after cardiomyoplasty.

METHODS AND RESULTS

We studied 32 patients (26 male, 6 female; mean age, 48 +/- 12 years) who submitted to cardiomyoplasty for treatment of heart failure in New York Heart Association (NYHA) class III (n = 24) or class IV (n = 8). The etiology was idiopathic dilated cardiomyopathy in 27 patients, ischemic heart disease in 3 patients, and Chagas' heart disease in 2 patients. Patients were routinely studied before and every 6 months after cardiomyoplasty by means of radioisotopic angiography and 24-hour Holter monitor recordings. There were no operative or immediate postoperative deaths. During the postoperative period, 5 patients presented with acute atrial fibrillation and 1 had an episode of sustained ventricular tachycardia. All episodes were successfully treated with intravenous antiarrhythmic drugs or cardioversion. During follow-up (from 2 to 66 months), 15 patients died from sudden death (n = 5) or progressive heart failure (n = 10). Survival rates at 1, 2, and 4 years were 79.9 +/- 7%, 62.5 +/- 9.7% and 35 +/- 12.1%, respectively. At 6-month follow-up, NYHA functional class improved from 3.2 +/- 0.4 to 1.7 +/- 0.6 (P = .001) and left ventricular ejection fraction increased from 19.8 +/- 3.3% to 24 +/- 8.2% (P = .004). The mean values per day of premature ventricular complexes (PVCs) and episodes of nonsustained ventricular tachycardia (NSVT) did not change statistically. The mean number of PVCs per 24 hours before and at 6, 12, 24, 36, and 48 months after surgery were 126 +/- 44, 96 +/- 33, 90 +/- 29, 81 +/- 35, 71 +/- 35, and 59 +/- 48. The mean number of episodes of NSVT per 24 hours before and at 6, 12, 24, 36, and 48 months after surgery were 3.3 +/- 1.3, 1.9 +/- 0.5, 1.3 +/- 0.5, 1 +/- 0.5, 1.5 +/- 1.1, and 0.6 +/- 0.5, respectively. With respect to analysis of the idiopathic dilated cardiomyopathy subgroup, there also were no significant differences in the incidences of pre- and postoperative arrhythmias.

CONCLUSIONS

Despite NYHA functional class and left ventricular function improvements observed after cardiomyoplasty, the incidence of arrhythmias did not change, and sudden death was an important finding mainly in late follow-up. The problem of sudden death after cardiomyoplasty, the mechanism that produces it, and the means to prevent it remain critical areas for future research.

Magnetic resonance imaging evaluation of chronic changes in latissimus dorsi cardiomyoplasty

BACKGROUND

Long-term clinical and hemodynamic benefits of dynamic cardiomyoplasty (DC) have been reported. However, no information is available about long-term morphological changes in the wrapped latissimus dorsi (LD) muscle in humans.

METHODS AND RESULTS

The LD muscle flap was evaluated by magnetic resonance imaging (MRI) in 13 patients submitted to dynamic cardiomyoplasty for treatment of severe dilated cardiomyopathy. Eight patients were studied 15 days after the surgery (group 1) and 5 patients were studied from 24 to 52 months after the surgical procedure at the time of the cardiomyostimulator replacement (group 2). In the interim, LD was stimulated with burst of 6 pulses (duration, 185 milliseconds; burst frequency, 30 Hz) synchronized to every cardiac contraction, with a maximum of 100 LD contractions per minute. Images were acquired on a GE Sigma 1.5-T system (echo time, 25 milliseconds; repetition time, R-R x 2; slice thickness, 8 mm). The thickness of the LD decreased from 19.6 +/- 7.3 mm for group 1 to 7.6 +/- 0.8 mm for group 2 (P < .01). In addition, the signal intensity of the LD was compared with that of thoracic skeletal muscle and was found to be significantly increased in group 2 (2.19 +/- 0.42) compared with group 1 (1.04 +/- 0.07, P < .001). The signal intensity for group 2 on the T1-weighted images was similar to that of subcutaneous fat in those images.

CONCLUSIONS

Morphological changes in the wrapped LD muscle consistent with fatty degeneration occur after DC and can be detected by MRI. Further studies will be necessary to demonstrate the clinical significance of such LD muscle flap changes.