Biomedical subjects

W J Kostuk

Publications and source records attributed to W J Kostuk.

At least 37 records · Page 2Linked to original sources

PubMed1992

Normalization of upright exercise hemodynamics and improved exercise capacity one year after orthotopic cardiac transplantation.

The mechanisms of improved functional capacity over the first year after cardiac transplantation are not well studied. To assess the contribution of cardiac changes to this improvement, the serial evolution of upright rest and exercise hemodynamics during graded upright bicycle exercise was studied in 17 patients at 3 and 12 months after heart transplantation. Heart rate responsiveness, reflected by rapid heart rate acceleration on sitting and rapid deceleration after exercise, developed in the first year. Pulmonary capillary wedge pressure was lower at 1 year, both at rest and at peak exercise (10 +/- 3 vs 13 +/- 5 mm Hg at rest supine and 14 +/- 6 vs 18 +/- 8 mm Hg at peak exercise, p less than 0.05). Similarly, right atrial pressures were also significantly lower at 1 year (4 +/- 2 vs 6 +/- 3 mm Hg at rest supine and 6 +/- 5 vs 11 +/- 5 mm Hg at peak exercise, p less than 0.05). Cardiac index at peak exercise was greater at 12 months (6.4 +/- 1.3 vs 5.8 +/- 0.8 liters/min/m2, p less than 0.05), mediated primarily by higher exercise heart rate (135 +/- 16 vs 125 +/- 12 beats/min, p less than 0.05). In the first year after heart transplantation, improved rest and exercise hemodynamics and heart rate responsiveness contribute significantly to the improved functional capacity observed in these patients.

Adult↗

PubMed1992

Hemodynamic observations following orthotopic cardiac transplantation: hemodynamic responses to upright exercise at 1 year.

Central hemodynamic responses during upright exercise were studied at 1 year in 40 orthotopic cardiac transplant recipients. Hemodynamic responses were characterized by slow rise in heart rate and blunted peak exercise heart rate response, a significant early increase in stroke index followed by a plateau phase, and a steady increase in ventricular filling pressures and pulmonary artery pressure. In spite of exclusive utilization of the Frank-Starling mechanism to augment cardiac output during early exercise, the pressure responses were comparable to those reported in normal subjects. Our observations also indicate that similarly to normal subjects, the heart rate response plays an important role in the cardiac output achieved at maximum exercise. Although patients with younger donor hearts achieved a more favorable maximum heart rate, the other hemodynamic parameters showed no correlation with the donor heart age. Thus, no hemodynamic disadvantage of older donor hearts could be demonstrated. These data provide further enlightenment regarding the mechanisms of the well-preserved functional capacity noted in these patients.

Adult↗

PubMed1992

Hemodynamic observations following orthotopic cardiac transplantation: evolution of rest hemodynamics in the first year.

The evolution of resting hemodynamics was studied at 1 week and 1 year in 40 patients following orthotopic cardiac transplantation. Abnormal hemodynamics after transplantation, characterized by elevated ventricular filling pressures (indicating diastolic dysfunction) and also by pulmonary hypertension, showed normalization by 1 year. In the absence of innervation, the resting heart rate of heart transplant recipients should theoretically be close to the intrinsic heart rate predicted by the age of the donor heart. In this study, a high incidence of relative sinus bradycardia (an indicator of sinus node dysfunction) was noted in the first post-operative week, although again there was a tendency to normalization by 1 year. These beneficial changes help to explain the dramatic and sustained improvement in the functional capacity of these patients late after transplantation.

Adult↗

PubMed1992

Vasodepressor syncope in a cardiac transplant recipient: a case of vagal re-innervation?

At the time of hemodynamic assessment three years after cardiac transplantation, a patient developed symptoms and signs of a vasodepressor reaction. In addition to sudden deceleration of heart rate, a 26% fall in mean blood pressure and a 36% fall in cardiac output was observed. Subsequent investigations revealed the presence of respiratory sinus arrhythmia, profound heart rate acceleration on standing and an approximately normal heart rate response during the following exercise. Contrary to current thinking, these observations suggest that certain individuals may develop autonomic re-innervation following orthotopic cardiac transplantation.

Adult↗

PubMed1991

Evolution of heart rate responsiveness after orthotopic cardiac transplantation.

Although anatomic reinnervation of the donor heart is unlikely after transplantation, individual subjects have been noted to show near physiologic heart rate (HR) responses to exercise. To assess development of this phenomenon, we studied HR changes in response to orthostasis and treadmill exercise in 52 orthotopic cardiac transplant recipients grouped according to time after transplantation. In group 1 (2.0 +/- 0.9 months), no significant increase in HR was seen up to 100 cardiac cycles after standing. A maximal acceleration of 4.0 +/- 3.8 beats was seen within 100 cardiac cycles after standing in group 2 (15.8 +/- 5.6 months). Patients in group 3 (42.4 +/- 12.4 months) showed significant cardioacceleration by 5 cardiac cycles after standing to a maximum of 10.7 +/- 5.8 beats/min within the first 100 cardiac cycles. During exercise, HR increased more rapidly during the first minute in group 3 compared with group 1 (p less than 0.01). After exercise, HR continued to increase in group 1 but decreased rapidly in the other groups, most notably group 3 (-26.5 +/- 16.5 by 2 minutes, p less than 0.0001 vs groups 1 and 2). These data indicate development of functional reinnervation after orthotopic heart transplantation. The phenomenon of early acceleration of the HR after orthostasis and rapid deceleration after exercise in transplant recipients implies a local cardiac mechanism rather than response to circulating catecholamines.

Adolescent↗

PubMed1991

The safety of low-dose prednisone before and immediately after heart-lung transplantation.

Preoperative steroid use has been considered a contraindication to heart-lung as well as lung transplantation. Moreover, most centers delay prednisone administration until 2 to 3 weeks postoperatively until airway healing is secure. We have performed 19 heart-lung transplantations and four single-lung transplantations since 1983. Five recipients (4 heart-lung, 1 single lung) had received prednisone, 5 to 40 mg daily, for 2 to 10 years preoperatively. All recipients were administered prednisone, 0.5 mg/kg daily, starting on postoperative day 1, with a taper to 0.2 mg/kg daily by 4 weeks. Minnesota antilymphocyte globulin (for 10 days), cyclosporine, and azathioprine were also employed. Bronchoscopy, lavage, and transbronchial biopsies were performed every 2 weeks for 3 months postoperatively. No patient had a serious airway complication; 2 heart-lung recipients, not on prednisone preoperatively, had a minor tracheal slough detected on bronchoscopy that resolved spontaneously. Actuarial survival after heart-lung transplantation is 84% +/- 8% and 69% +/- 16% at 1 year and 2 years, respectively. We conclude that prednisone commencing at a dose of 0.5 mg/kg daily from the first postoperative day is a safe practice after heart-lung transplantation. The long-term use of low-dose prednisone before heart-lung transplantation does not preclude normal tracheal healing. The safety of prednisone before and immediately after single-lung transplantation awaits confirmation by further experience.

Adolescent↗

PubMed1991

Expanding applicability of transplantation after multiple prior palliative procedures. The Paediatric Heart Transplant Group.

The number of heart transplantations performed over the past 3 years has plateaued. However, the number of pediatric transplantations continues to slowly increase. Unlike adult heart transplantation, for which cardiomyopathy remains the most frequent indication, structural congenital heart disease is the primary indication in children. This report reviews our experience with orthotopic heart transplantation in the presence of structural congenital heart disease with and without prior palliative repair. The diagnoses included transposition of the great arteries, common atrium, left superior vena cava with and without a bridging innominate vein, dextrocardia, and univentricular configurations. The palliative repairs included Blalock-Taussig shunt, bilateral Glenn shunt, Fontan repair, and Mustard and Rastelli procedure. There were no early deaths. Two rejection-related late deaths have occurred at 8 months and at 3 years postoperatively. Extended use of donor tissue and modifications to surgical technique allowed for successful orthotopic heart transplantation in these patients who had structural congenital heart disease with and without prior surgical palliation.

Child↗

PubMed1991

Large artery function in patients with chronic heart failure. Studies of brachial artery diameter and hemodynamics.

BACKGROUND: Although progressive chronic congestive heart failure (CHF) is associated with elevated systemic vascular resistance and increased impedance to ventricular outflow, the contribution of changes in large artery function has not been well documented in humans. METHODS AND RESULTS: We studied 45 patients with a broad range of clinical severity of CHF and compared noninvasive measurements of brachial artery diameter, flow, and pulse wave velocity with 22 normal controls of similar age. In CHF, mean arterial pressure was lower than in controls (85 +/- 1 versus 93 +/- 2 mm Hg, p less than 0.001), as were brachial artery diameter (4.07 +/- 0.10 versus 4.53 +/- 0.09 mm, p less than 0.001), flow (40.9 +/- 4.1 versus 70.9 +/- 11.5 ml.min-1, p less than 0.02), compliance (1.29 +/- 0.12 versus 2.00 +/- 0.18 cm4.dyne-1.10(-7), p less than 0.002), and conductance (0.49 +/- 0.05 versus 0.76 +/- 0.13 units, p = 0.06). Limb vascular resistance (40.2 +/- 5.0 versus 20.5 +/- 3.1 units, p less than 0.001) and pulse wave velocity (10.6 +/- 0.5 versus 9.2 +/- 0.4 m.sec-1, p less than 0.03) were higher than in controls. Brachial artery diameter was progressively lower than in controls as severity of CHF increased (New York Heart Association class II, 4.47 +/- 0.23 mm, p = NS; class III, 4.05 +/- 0.10 mm, p less than 0.05; class IV, 3.71 +/- 0.28 mm, p less than 0.05). Similar changes were observed for arterial compliance (class II, 1.76 +/- 0.32 cm4.dyne-1.10(-7), p = NS; class III, 1.21 +/- 0.13 cm4.dyne-1.10(-7), p less than 0.05; class IV, 0.95 +/- 0.10 cm4.dyne-1.10(-7), p less than 0.05). While the lower arterial pressure and flow might be expected to passively reduce arterial diameter, this would be associated with a reduced pulse wave velocity and improved arterial compliance, yet the opposite was observed. Differences in large artery function were not likely caused by underlying atherosclerosis alone, because patients with dilated cardiomyopathy and patients with ischemic heart disease of the same sex, age, left ventricular ejection fraction, and exercise treadmill duration had similar changes in large artery function. CONCLUSIONS: We conclude that alterations in brachial artery function are present in patients with moderate and severe CHF. The observed reduction in arterial compliance, if present diffusely throughout the arterial tree, could increase left ventricular end-systolic stress directly and through increased velocity of reflected pressure waves from the periphery.

Adult↗

PubMed1991

The importance of acquired diffuse bronchomalacia in heart-lung transplant recipients with obliterative bronchiolitis.

The results of heart-lung transplantation are improving with increasing experience in postoperative management, but obliterative bronchiolitis may still develop late postoperatively. We have performed 19 heart-lung transplants, with 1-month, 1-year, and 2-year actuarial survival rates of 95% +/- 5%, 84% +/- 8%, and 69% +/- 16%, respectively. Three early recipients died of bronchiolitis, and four patients who were operated on more than 2 years ago are currently being followed up with bronchiolitis. Since August 1988, 13 surviving recipients have undergone serial postoperative bronchoscopies and transbronchial biopsies with topical analgesia. Diffuse bronchomalacia, involving the main bronchi down to the fifth-order bronchi bilaterally, has developed in four patients with bronchiolitis 9 +/- 2 months after the diagnosis of bronchiolitis was confirmed. Pulmonary function tests have revealed a lower ratio of forced expiratory volume in 1 second to forced vital capacity, lower specific airway conductance, and higher airway resistance in heart-lung recipients with bronchomalacia than in patients with bronchiolitis alone. We conclude that diffuse bronchomalacia occurs frequently in heart-lung transplant recipients who have obliterative bronchiolitis. Bronchomalacia worsens the functional airflow obstruction caused by bronchiolitis and may play an important role clinically in the declining respiratory status of heart-lung transplant recipients.

Adolescent↗

PubMed1991

Clinical response and effects on left ventricular function of isosorbide dinitrate added to propranolol or diltiazem monotherapy in patients with chronic stable angina.

Twenty-four patients were randomized to a double-blind, triple placebo controlled, latin square protocol to examine the relative efficacy of propranolol or diltiazem given as monotherapy or in combination with isosorbide dinitrate. Treatment phases were preceded and followed by placebo control periods. At the end of each phase, symptom-limited treadmill exercise stress tests were performed, as well as rest and exercise radionuclide ventriculography. Both forms of monotherapy were effective in reducing episodes of angina and nitroglycerin use, and in improving exercise tolerance. Diltiazem monotherapy was associated with slightly higher treadmill times (509.9 +/- 123 s) compared to propranolol (462.7 +/- 131 s, P less than 0.05). The addition of isosorbide dinitrate to either form of monotherapy allowed no further improvement in any of the measured clinical responses. Radionuclide ventriculography showed no significant difference in resting left ventricular function. The addition of isosorbide dinitrate to propranolol showed a reduction in end diastolic volume in keeping with a reduction in preload. In response to exercise, stress-induced left ventricular dysfunction was equal in all groups except for the diltiazem-nitrate combination, which was associated with a higher ejection fraction (56.2 +/- 8.6%) compared to monotherapy (52.6 +/- 10.9%, P less than 0.01). A higher cardiac output could be achieved in the groups treated with diltiazem; this was related to increased heart rate and maintenance of stroke volume. It was concluded that diltiazem is equally effective as propranolol for the treatment of chronic stable angina and, in terms of exercise capacity and cardiac output, superior to beta-blockade. The addition of isosorbide dinitrate appears to impart no overt benefits, but some evidence suggests a reduction in left ventricular decompensation in the face of stress.

Adult↗

PubMed1990

Serial evaluation of lipid profiles and risk factors for development of hyperlipidemia after cardiac transplantation.

To determine the prevalence, time course and factors responsible for hyperlipidemia after heart transplantation, 83 consecutive 1-year survivors were studied. By 1 year, 83% of patients had serum total cholesterol levels greater than 5.2 mmol/liter (200 mg/dl) and 28% of the patients had serum total cholesterol higher than the age- and sex-matched ninety-fifth percentile. At the end of 1-year follow-up, serum total cholesterol correlated with the recipient age (p less than 0.0001), the preoperative cholesterol level (p less than 0.001), the actual dose of maintenance prednisone at 1 year (p less than 0.02) and the cumulative 1-year steroid dose (p less than 0.03). Similarly, the serum triglyceride level at 1 year correlated with the pretransplant level of serum triglycerides (p less than 0.0001), recipient age (p less than 0.03) and cumulative 1-year steroid dose (p less than 0.03). Patients with a pretransplant diagnosis of coronary artery disease had a significantly higher level of serum total cholesterol and triglyceride levels at 1 year (p less than 0.02 and p less than 0.03, respectively). Heart transplant recipients with body mass index greater than or equal to 25 kg/m2 also presented with significantly elevated serum total cholesterol and triglyceride levels at 1 year compared with nonobese patients (p less than 0.01 and p less than 0.002, respectively). Hyperlipidemia occurs frequently and is detected within the first month after heart transplantation. Optimal management of this problem requires further study.

Adolescent↗

PubMed1990

Importance of chronic aspiration in recipients of heart-lung transplants.

In a series of eleven recipients of heart-lung transplants (HLT), five have obliterative bronchiolitis. Five of the eleven patients have chronic cough as well as slower than normal gastric emptying and/or oesophageal dysmotility; all five have evidence of bronchiectasis and three have obliterative bronchiolitis. Three of the patients improved after the introduction of treatment to prevent reflux, and another, who had a large phytobezoar, improved after pyloroplasty. In patients with chronic cough after HLT, with or without dyspeptic symptoms or recurring pulmonary sepsis, investigation of oesophageal motility and gastric emptying should be undertaken.

Adult↗

PubMed1990

Comparison of hemodynamic responses during dynamic exercise in the upright and supine postures after orthotopic cardiac transplantation.

Abnormal hemodynamic responses during supine exercise have been well documented in orthotopic cardiac transplant recipients. To determine the effect of posture, central hemodynamics were studied in 20 patients during a change from supine to sitting and during graded upright bicycle exercise (group U) and were compared with those of 20 patients matched for age, gender and time from transplantation who were studied after passive leg elevation and during exercise in the supine posture (group S). Passive leg elevation resulted in a 9% increase in stroke index (34 +/- 6 to 37 +/- 6 ml/m2, p less than 0.001) and a 10% increase in cardiac index (3.1 +/- 0.4 to 3.4 +/- 0.5 liters/min per m2, p less than 0.001) in group S patients compared with a 15% reduction in stroke index (34 +/- 7 to 29 +/- 6 ml/m2, p less than 0.001) and a 9% decrease in cardiac index (3.2 +/- 0.6 to 2.9 +/- 0.5 liters/min per m2, p less than 0.001) in group U patients on assuming the sitting posture. Likewise, both the pulmonary capillary wedge pressure and right atrial pressure increased significantly (13 +/- 4 to 17 +/- 8 mm Hg, p less than 0.001 and 5 +/- 3 to 7 +/- 3 mm Hg, p less than 0.001) with passive leg elevation in group S and decreased on sitting (12 +/- 6 to 8 +/- 5 mm Hg, p less than 0.001 and 5 +/- 3 to 3 +/- 2, p less than 0.001) in group U.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Hemodynamic effects of intravenous procainamide during ventricular tachycardia.

Radionuclide angiography was used to study the hemodynamic effects of intravenous procainamide during stable monomorphic ventricular tachycardia. In four patients studied without procainamide, the ejection fraction was 25% +/- 2.4% during normal sinus rhythm, dropped to 11.3% +/- 2.2% (p less than 0.05) at the onset of ventricular tachycardia, increased to 16.7% +/- 1.7% after remaining in ventricular tachycardia for 10 minutes, and returned to 25.3% +/- 3.7% in sinus rhythm. In the 10 study patients, ejection fraction dropped from 36% +/- 5.8% in sinus rhythm to 25% +/- 5.1% in ventricular tachycardia (p less than 0.2). Ejection fraction decreased further (23% +/- 5.0%) following low doses of procainamide (140 +/- 52 mg) despite cycle length prolongation (354 +/- 18 msec versus 373 +/- 21 msec, p less than 0.5). In 8 of 10 patients, there was a progressive increase in the ejection fraction (28.8% +/- 4.1%). Ventricular tachycardia onset also resulted in a decrease in cardiac output and end-diastolic and end-systolic volumes. Two patients who tolerated procainamide in sinus rhythm showed hemodynamic collapse secondary to procainamide during ventricular tachycardia. We conclude that in some patients hemodynamic intolerance to an antiarrhythmic drug may only become evident during ventricular tachycardia.

Adult↗

PubMed1990

Atrial and ventricular arrhythmias in asymptomatic active elderly subjects: correlation with left atrial size and left ventricular mass.

Elderly normal subjects have an increased prevalence of cardiac arrhythmias compared with young and middle-aged subjects. The objective of this study was to test the hypothesis that the incidence and complexity of atrial and ventricular arrhythmias may be related to either left atrial enlargement or to increased left ventricular mass, respectively. From 146 asymptomatic volunteers older than 60 years, 86 subjects were considered to be free of cardiovascular abnormalities and had adequate M-mode echocardiograms and 24-hour ambulatory electrocardiograms. The mean age was 72 +/- 7 years, with a range of 60 to 96 years. There were 37 men and 49 women. During 1415 +/- 73 minutes of ambulatory electrocardiography, the average heart rate was 72 +/- 8 beats/min in men and 76 +/- 6 beats/min in women (p less than 0.05). Atrial arrhythmias were present in 64 subjects (74%); the frequency and complexity of these arrhythmias correlated with left atrial size (p less than 0.01). Ventricular arrhythmias were present in 55 subjects (64%); the frequency and complexity of ventricular arrhythmias did not correlate with left ventricular mass index. These results suggest that left atrial dilatation, a normal development in healthy elderly subjects, plays a significant role in the pathophysiology of the increased incidence of atrial arrhythmias. Increased left ventricular mass, which also occurs normally in the aging heart, is not, on the other hand, associated with an increased frequency and/or complexity of ventricular arrhythmias.

Aged↗

PubMed1990

Psychosocial adjustment and quality of life following heart transplantation.

This article describes the pre-operative psychosocial and quality-of-life adjustment of a consecutive series of 27 heart transplant recipients and the adjustment of the 24 survivors at 12 months follow-up. Pre-operatively, 14 had a psychiatric diagnosis and this figure had dropped to five at 12 months follow-up. Those patients without a psychiatric diagnosis preoperatively had not developed one at follow-up. There was a significant correlation between pre-operative psychiatric diagnosis and a rating of poor medical compliance. Ratings of physical activity, employment and questionnaire ratings of psychological adjustment also showed highly significant improvement at follow-up and the majority of patients were active sexually. It is concluded that heart transplantation in selected subjects with terminal heart disease results in a substantial improvement in psychosocial adjustment and quality-of-life 12 months following surgery.

Activities of Daily Living↗

PubMed1990

Reduction in bleeding after heart-lung transplantation. The importance of posterior mediastinal hemostasis.

To reduce perioperative hemorrhage following heart-lung transplantation, several technical modifications were introduced in June 1988 to secure better posterior mediastinal hemostasis. The intraoperative and postoperative use of blood and blood products, as well as the chest tube drainage in the first 24 hours postoperatively, were compared in the seven patients operated on since June 1988 with the nine patients operated on before that date. Significant (p less than 0.05) reductions were demonstrated in the intraoperative and postoperative transfusion of packed cells, in the postoperative administration of fresh frozen plasma, and in the chest tube drainage within the first 24 hours postoperatively. The one-month and total hospital mortality rates were 6 percent and 12.5 percent, respectively. It is concluded that newer techniques to obtain optimal posterior mediastinal hemostasis have significantly reduced blood loss following heart-lung transplantation in our experience and have contributed to our excellent early postoperative results.

Adolescent↗

PubMed1989

Usefulness of sustained-release diltiazem for stable angina pectoris.

Sustained-release diltiazem, 120 and 180 mg twice daily, was assessed in a multicenter, double-blind, randomized, placebo-controlled trial in 65 stable angina patients with exercise-induced ST depression. Exercise testing was performed 12 +/- 1 hours after the last dose at the end of each of the 3 treatment weeks. Both dose levels of drug reduced spontaneous angina (p less than 0.001) and increased exercise duration (p less than 0.01) and time to 1-mm ST depression (p less than 0.001). No differences were noted between the 2 dose levels. Rate-pressure product at maximal exercise was similar for the 3 groups. Only 1 patient terminated the study because of adverse drug effects; severe adverse effects occurred in 1 placebo and 1 low-dose period. Sustained-release diltiazem is safe and efficacious monotherapy for patients with stable angina.

Adult↗