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Biomedical subjects

N A Stolf

Publications and source records attributed to N A Stolf.

At least 19 recordsLinked to original sources
PubMed1998

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.

Adult↗
PubMed1998

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.

Cardiomyopathy, Dilated↗
PubMed1998

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.

Acute Disease↗
PubMed1998

[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.

Adult↗
PubMed1997

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.

Adult↗
PubMed1997

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.

Adult↗
PubMed1997

[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.

Adult↗
PubMed1996

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.

Adult↗
PubMed1996

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.

Actuarial Analysis↗
PubMed1996

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.

Adult↗
PubMed1996

[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.

Adult↗
PubMed1995

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.

Actuarial Analysis↗
PubMed1995

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.

Adolescent↗
PubMed1995

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.

Animals↗
PubMed1995

[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.

Adult↗
PubMed1994

Unsuspected rheumatic fever carditis ending in heart transplantation.

A 25-year-old female patient with presumed peripartum cardiomyopathy was submitted after two years to orthotopic heart transplantation. Pathological examination of the excised heart revealed acute rheumatic fever. Five days after the transplantation persistent fever developed. The patient's condition deteriorated until death after six weeks, which was attributed to cytomegalovirus disease.

Adult↗
PubMed1994

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%.

Cardiomyopathy, Dilated↗