Reinaldo Wilson Vieira

Standardization of an isolated pig heart preparation with parabiotic circulation: methodological considerations

In the present study we standardized an experimental model of parabiotic circulation of isolated pig heart. The isolated heart was perfused with arterial blood from a second animal as support and submitted to regional ischemia for 30 min, followed by total ischemia for 90 min and reperfusion for 90 min. Parameters for measurement of ventricular performance using different indices measured directly or indirectly from intraventricular pressure were defined as: maximum peak pressure, final diastolic pressure, pressure developed, first derivative of maximum pressure (dP/dt max), first derivative of minimum pressure (dP/dt min), systolic stress of the left ventricle (sigmas), and maximum elastance of the left ventricle. Isolated hearts subjected to regional and global ischemia presented significant worsening of all measured parameters. Less discriminative parameters were dP/dt max and dP/dt min. Elastance was the most sensitive parameter during the reperfusion period, demonstrating an early loss of ventricular function during reperfusion. The model proved to be stable and reproducible and permitted the study of several variables in the isolated heart, such as ischemia and reperfusion phenomena, the effects of different drugs, surgical interventions, etc. The model introduces an advantage over the classical models which use crystalloid solutions as perfusate, because parabiotic circulation mimics heart surgery with extracorporeal circulation.

Inflamação sistêmica causada pela periodontite crônica em pacientes vítimas de ataque cardíaco isquêmico agudo

OBJECTIVE Infectious and inflammatory processes mediated by bacteria in distant sites have been described as a risk factor for acute ischemic heart disease (AIHD). METHODS One hundred one patients with AIHD with and without chronic periodontitis (CP) were included in this study. Patients were admitted to the HC UNICAMP and stratified into three groups: in group 1, we selected patients with severe chronic periodontitis (31 men and 19 women, mean age 55.1 +/- 11.29 years old); the group 2 with mild chronic periodontitis (40 men and 28 women, mean age 54.8 +/- 10.37 years old) and group 3 represented by the toothless (43 men and 20 women, mean age 67.5 +/- 8.55 years old). Blood samples were collected to measure the lipid profiles, hematological and blood glucose levels. In addition, biopsies of seventeen coronary arteries with atherosclerosis and an equal number of internal mammary arteries without atherosclerotic degeneration in group 1 were investigated. Statistical analysis by analysis of variance (ANOVA) and Scheffé test for multiple comparisons was performed. RESULTS Triglyceride and LDL levels were elevated in group 1 than in group 2. HDL were reduced by 20% in group 1 and remained reduced by 8% in toothless. Blood glucose was higher in group 1. DNA of periodontal bacteria was detected in 58.8% of the coronary arteries. CONCLUSIONS Patients with (AIHD) and severe chronic periodontitis may have altered lipid profile, as well as microorganisms associated with CP can permeate into coronary vessels.AbstractObjective: Infectious and inflammatory processesmediated by bacteria in distant sites have been described asa risk factor for acute ischemic heart disease (AIHD). Methods: One hundred one patients with AIHD with andwithout chronic periodontitis (CP) were included in thisstudy. Patients were admitted to the HC UNICAMP andstratified into three groups: in group 1, we selected patientswith severe chronic periodontitis (31 men and 19 women,mean age 55.1 ± 11.29 years old); the group 2 with mildchronic periodontitis (40 men and 28 women, mean age 54.8± 10.37 years old) and group 3 represented by the toothless(43 men and 20 women, mean age 67.5 ± 8.55 years old).Blood samples were collected to measure the lipid profiles,hematological and blood glucose levels. In addition, biopsiesof seventeen coronary arteries with atherosclerosis and anequal number of internal mammary arteries withoutatherosclerotic degeneration in group 1 were investigated.Statistical analysis by analysis of variance (ANOVA) andScheffe test for multiple comparisons was performed.

Mitral valve repair with a malleable bovine pericardium ring

OBJECTIVE To describe a surgical procedure utilizing a malleable bovine pericardium ring in mitral valve repair and clinical and Doppler echocardiographic results. METHODS Thirty-two (25 female and 7 male) patients, aged between 9 and 66 (M=36.4+/-17.2) years, were studied over a 16-month period, with 100% follow-up. In 23 (72%) of the patients, the mitral approach was the only one applied; 9 patients underwent associated operations. The technique applied consisted of measuring the perimeter of the anterior leaflet and implanting, according to this measurement, a flexible bovine pericardium prosthesis for reinforcement and conformation of the posterior mitral annulus, reducing it to the perimeter of the anterior leaflet with adjustment of the valve apparatus. RESULTS The patient survival ratio was 93.8%, with 2 (6.2%) fatal outcomes, one from unknown causes, the other due to left ventricular failure. Only one reoperation was performed. On Doppler echocardiography, 88% of the patients had functional recovery of the mitral valve (50% without and 38% with mild insufficiency and no hemodynamic repercussions). Of four (12%) of the remaining patients, 6% had moderate and 6% had accented insufficiency. Twenty-eight percent of class II patients and 72% of class III patients passed into classes I (65%), II (32%), and III (3%), according to NYHA classification criteria. CONCLUSION Being flexible, the bovine pericardium ring fit perfectly into the valve annulus, taking into account its geometry and contractility. Valve repair was shown to be reproducible, demonstrating significant advantages during patient evolution, which did not require anticoagulation measures.

Variáveis capnográficas pré e pós-tromboendarterectomias pulmonares

In these case report, the results of late dead space fraction (fDlate), end-tidal alveolar dead space fraction (AVDSf), arterial-alveolar gradient CO2 [P(a-et)CO2], and slope phase 3 of spirogram of two patients who underwent thromboendarterectomy for pulmonary embolism (PE) are shown. PE was diagnosed by pulmonary scintigraphy, helical tomography, and pulmonary angiography. The calculation of fDlate, AVDSf and P(a-et)CO2 was based on volumetric capnography associated with arterial blood gas analysis. The pre-operative fDlate of the first patient was 0.16 (cutoff 0.12) and AVDSf was 0.30 (cutoff 0.15). However, the fDlate of the second patient was false-negative (0.01) but, the AVDSf was positive (0.28). Postoperative fDlate of the first patient was -0.04 and AVDSf was 0.16; for the second patient, the values were 0.07 and 0.28, respectively. The association of these capnographic variables with image exams reinforces the importance of this noninvasive diagnosis method.

Fração tardia do espaço morto (fDlate) antes e após embolectomia pulmonar

This report presents data on the late dead space fraction (fDlate) of a patient submitted to surgical pulmonary embolectomy. Pulmonary thromboembolism (PTE) was diagnosed by echo-Doppler ultrasound of the lower limbs, lung scintigraphy, computerized helical tomography and angiography. The fDlate was calculated based on volumetric capnography as well as on arterial blood gases according to ERIKSSON et al. [1]. The preoperative fDlate value was 0.16, which was considered positive for the diagnosis of PTE, as it was higher than the cut-off point of 0.12. The postoperative fDlate value was - 0.04, which was below 0.12 and was characterized as negative. The agreement of fDlate with the imaging results confirms the validity of this new, noninvasive diagnostic tool. Descriptors: Pulmonary embolism. Pulmonary gas exchange. Capnography. Late dead space fraction (fDlate) before and after pulmonary embolectomy

Resultados tardios da plastia mitral em pacientes reumáticos

INTRODUCTION AND AIMS The long-term results after surgical repair of rheumatic mitral valve remain controversial in literature. Our aim was to determine the predictive factors which impact the long-term results after isolated rheumatic mitral valve repair and to evaluate the effect of those factors on reoperation and late mortality. METHODS One hundred and four patients with rheumatic valve disease who had undergone mitral valve repair with or without tricuspid valve annuloplasty were included. All patients with associated procedures were excluded. The predictive variables for reoperation were assessed with Cox regression and Kaplan Meier survival curves. RESULTS The mean follow-up time was 63 ± 39 months (CI 95% 36 to 74 months). The functional class III and IV was observed in 65.4% of all patients. The posterior ring annuloplasty was performed in 33 cases, comissutoromy in 21 cases, and comissurotomy with posterior ring annuloplasty in 50 patients. There was no operative mortality. The late mortality was 2.8% (three patients). The late reoperation was associated with residual mitral valve regurgitation after surgery (P<0.001), pulmonary hypertension at the pre-operative time (P<0.001), age (P<0.04) and functional class at the post-operative time (P<0.001). We observed freedom from reoperation rates at 5 and 10 years of 91.2 ± 3.4% and 71.1 ± 9.2%, respectively. CONCLUSION Repair of mitral valve in rheumatic valve disease is feasible with good long-term outcomes. Preoperative pulmonary hypertension, residual mitral valve regurgitation after surgery, age and functional class are predictors of late reoperation.

A bovine pericardium rigid prosthesis for left ventricle restoration: 12 years of follow-up

BACKGROUND Myocardial infarction might result in dilated left ventricle and numerous techniques have been described to restore the original left ventricle shape and identify tools for late survival assessment. The aim of this study is to compare our experience with a modified Dor procedure using a rigid prosthesis to the septal anterior ventricular exclusion procedure (SAVE) for left ventricle restoration. The EuroScore index for prediction of late follow up survival was evaluated. METHODS We evaluated 80 patients who underwent left ventricle restoration between 1999 to 2007 and eight patients were excluded with incomplete data. A modified Dor procedure with rigid prosthesis (MD group) was performed on 53 patients and 19 underwent the septal anterior ventricular exclusion procedure (SAVE group). The patients were classified according their left ventricle shape as type I, II or III. Kaplan-Meier and Cox proportional hazard ratio regressions analysis were performed to assess survival after both techniques and expected surgical mortality using EuroScore index ranking after 12 years of follow up. RESULTS The operative mortality was comparable in both groups ranked by EuroScore index. The groups were comparable for all clinical data, except the MD group had more patients using intra-aortic balloon pumps before surgery, (5.7% vs. 0; P<0.01). Kaplan Meier analysis by left ventricle shape showed comparable survival for all patients, with slightly higher survival for type I. Kaplan Meier analysis of all death showed equivalent survival curves for both techniques after 12 years of follow up (71.5 ± 12.3 vs. 46.6 ± 20.5 years; P=0.08). Kaplan Meier analysis of EuroScore index for all patients showed a difference between the three ranked categories, i.e., 0 to 10%, 11 to 49% and higher than 50% expected surgical mortality after 12 years of follow up (70.9 ± 16.2 vs. 67.5 ± 12.7 vs. 53.0 ± 15.5; P=0.003). CONCLUSION The MD procedure showed consistent ejection fraction improvements after long term follow up. Survival was comparable for all ventricular types and for the MD and SAVE procedures. The EuroScore index is a useful index for late survival assessment of ventricular restoration techniques.

The effects of modified ultrafiltration on pulmonary function and transfusion requirements in patients underwent coronary artery bypass graft surgery.

OBJECTIVE The inflammatory response after cardiac surgery increases vascular permeability leading to higher mortality and morbidity in the post operative time. The modified ultrafiltration (MUF) had shown benefits on respiratory, and hemodynamic in pediatric patients. This approach in adults is not well established yet. We hypothesize that modified ultrafiltration may improve respiratory, hemodynamic and coagulation function in adults after cardiac surgeries. METHODS A prospective randomized study was carried out with 37 patients who underwent coronary artery bypass graft surgery (CABG) were randomized either to MUF (n=20) at the end of bypass or to control (no MUF) (n=17). The anesthesia and ICU team were blinded for the group selection. The MUF were carried out for 15 minutes after the end of bypass. The patients data were taken at beginning of anesthesia, ending of bypass, ending MUF, 24 hours, and 48 hours after surgery. For clinical outcome the pulmonary, hemodynamic and coagulation function were evaluated. RESULTS We observed lower drain loss in the MUF group compared to control group after 48 hours (598 +/- 123 ml vs. 848 +/- 455 ml; P=0.04) and required less red blood cells units transfusion compared to control group (0.6 +/- 0.6 units/patient vs.1.6 +/- 1.1 units/patient; P=0.03). The MUF group showed lower airway resistance (9.3 +/- 0.4 cmH2O.L-1s-1 vs. 12.1 +/- 0.8 cmH2O.L-1s-1; P=0.04). There were no deaths in both groups. CONCLUSION The MUF reduces post operatory bleeding and red blood cells units transfusion, but with no differences on clinical outcome were observed. The routinely MUF employment was not associated with hemodynamic instability.

Analysis of the hydrodynamic profile in different roller pumps models used in cardiopulmonary bypass

OBJECTIVE Among the equipments used in cardiopulmonary bypass the roller pumps have great importance with various models available from several manufacturers. The calibration is an important factor in hemolysis rates and its potential is different in each. Researchers do not always approach details on the pump bed profiles assuming that the standardized calibration settings ensure equal and comparable values for all models of roller pumps. We have mainly two methods for calibration of pumps which also interferes on the hemolytic potential. In both of them, the characteristics of fluid impulsion defined by the pump bed design are not considered. The aim of this study is to compare the hydrodynamic profile of three models of roller pumps available in the Brazilian market. METHOD The rollers occlusion was performed by measures of drop and dynamic calibration. Two different silicone diameter tubes were used (3/8 x 1/16 and 1/2 x 3/32 inches). RESULTS The profiles showed differences in their variances, P<0.01 for drop rate measures and P<0.0001 for dynamic calibration. Different changes in pressure were found between the pumps analyzed (P<0.002). CONCLUSION The measures of occlusion are dependent on the design of the pump bed and comparisons involving roller pumps should be performed with caution. Blood tests should be performed to verify the influence of changes in hemolysis pressure.

Erythropoietin protects the systolic function of neonatal hearts against ischaemia/reperfusion injury

OBJECTIVES The effect of erythropoietin (EPO) on neonatal hearts is not well understood. The current hypothesis is that EPO has protective effects against ischaemia-reperfusion when administered prior to ischaemia induction. METHODS Systolic and diastolic indices, as well as the Akt and extracellular-regulated kinase (Erk) signalling pathways, were studied in vivo using a neonatal pig heart model. Regional ischaemia was induced for 45 min by the ligation of the left anterior descending artery, followed by 90 min of reperfusion. The treatment groups consisted of: (i) untreated controls, (ii) treatment with EPO 3 min prior to ischaemia and (iii) treatment with EPO 24 h before ischaemia. Sophisticated myocardial contractility indices were assessed by pressure/volume loops of the left ventricle. The Akt and Erk pathways were evaluated via a western blot. RESULTS Elastance was found to be higher in the group receiving EPO 3 min prior to ischaemia. In addition, preload recruitable stroke work was higher for both groups receiving EPO prior to ischaemia when compared with controls. The time constant of the isovolumic relaxation and end-diastolic pressure-volume relationship did not differ between the three groups after 90 min of reperfusion. Furthermore, EPO treatment enhanced phosphorylation of Akt, but not Erk, and EPO-treated animals showed lower levels of apoptosis-related proteins. CONCLUSIONS EPO had a protective effect on neonatal systolic function after ischaemia/reperfusion injury, but no effect on diastolic function. This cardioprotective effect might be mediated by the activation of the Akt pathway.