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Biomedical subjects

T L Spray

Publications and source records attributed to T L Spray.

At least 127 records · Page 7Linked to original sources
PubMed1990

Rejection and infection after pediatric cardiac transplantation.

Cardiac transplantation has only recently become an accepted therapeutic modality for children and adolescents with end-stage cardiomyopathy. Long-term survival, the incidence of rejection, and the incidence of infection are still being defined. From 1985 to 1989, 21 children aged 6 months to 19 years (average age, 11.2 years) underwent cardiac transplantation at our institutions. Eighteen survived the operative period and have been followed for 5 to 49 months (average follow-up, 24 months). All operative survivors have received triple-drug immunosuppression consisting of cyclosporine, azathioprine, and prednisone. During follow-up, 7 patients have been treated on 12 occasions for rejection as documented by endomyocardial biopsy. Eight (67%) of the 12 episodes of rejection occurred in the presence of subtherapeutic cyclosporine levels. Two of the 7 patients treated for rejection have subsequently died of ongoing cardiac rejection and arrhythmia. There have been no perioperative or late deaths from infection. Bacterial sepsis was identified and treated twice during follow-up, viral infections on five occasions, and fungal infection once. Actuarial 1-year survival and 3-year survival of the 18 operative survivors are 94% and 78%, respectively. In the first 7 months after cardiac transplantation, 73% of patients were free from rejection and 83% were free from serious bloodborne infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Extracorporeal membrane oxygenation for circulatory support after repair of congenital heart defects.

Extracorporeal membrane oxygenation was used for cardiovascular support in 13 infants and children with complex congenital heart disease and 1 premature neonate treated in preparation for pericardial patch tracheoplasty for long-segment tracheal stenosis. Nine patients were weaned from extracorporeal membrane oxygenation. There were five (36%) early deaths and four (29%) late deaths. Cannulation sites included right carotid/jugular vessels, femoral artery and vein, and right atrium and aorta. In 4 patients, the neck vessels were repaired at decannulation. Five survivors had normal growth and neurodevelopmental evaluations at follow-up. Extracorporeal membrane oxygenation can be successfully used as biventricular support in patients with intractable low cardiac output syndrome after repair of congenital heart disease. Best results are obtained in patients who have several hours of stability after operation before initiation of support. Hemorrhagic complications are reduced and long-term neurodevelopmental outcomes appear promising with right neck vessel cannulation and repair. No bleeding complications were observed in patients cannulated through the neck vessels.

Carotid Arteries↗
PubMed1989

Circulatory support with a centrifugal pump as a bridge to cardiac transplantation.

Since January 1985, the Heart Transplant Program at Washington University Medical Center, St. Louis, has performed 89 heart transplantations in 86 patients. Twenty patients (23%) have required preoperative mechanical support of circulation or respiration prior to transplantation. The Bio-Medicus centrifugal pump (Bio-Pump) formed the basis of our circulatory support system during the period of this report. Nine patients were placed on the Bio-Pump with the intention of bridging them to transplantation. Six patients required left ventricular assistance; in 2, the device was inserted because they could not be weaned from cardiopulmonary bypass. Two patients required biventricular assistance, 1 because she could not be weaned from cardiopulmonary bypass at the end of a cardiac operation. Extracorporeal membrane oxygenation was necessary in 1 patient for right ventricular decompensation and cardiac arrest four hours after orthotopic cardiac transplantation. One of these 9 patients died on circulatory support, and in another, a complication developed that precluded transplantation. The remaining 7 patients (78%) underwent a successful transplant procedure after an average of 1.6 days of circulatory support (range, 0.5 to three days), and all are long-term survivors of transplantation. There has been 1 late death at 17 months from a cerebrovascular hemorrhage. In summary, the centrifugal pump provides excellent short-term circulatory support for individuals who would otherwise die before cardiac transplantation.

Adolescent↗
PubMed1989

Intraoperative evaluation of atrioventricular septal defect repair by color flow mapping echocardiography.

Despite improving survival rates after repair of atrioventricular septal defect, many patients require reoperation because of postoperative heart failure. We used intraoperative color flow mapping echocardiography to assess the results of surgical repair of atrioventricular septal defect in 19 consecutive patients and compared those findings with results three to five days and 3 to 11 months after repair. There was close correlation between intraoperative and postoperative color flow mapping echocardiography in estimating the presence and severity of left atrioventricular valve regurgitation. All patients survived surgical repair, but in 4 (21%), postoperative congestive heart failure due to left atrioventricular valve regurgitation developed. The need for reoperation was significantly correlated with the severity of left atrioventricular valve regurgitation (r = 0.68) as estimated by intraoperative echocardiography and preoperative aberrancies in the atrioventricular valve (r = 0.68). Age, weight, additional congenital heart disease, preoperative pulmonary vascular resistance, preoperative atrioventricular valve regurgitation, and postoperative mean pulmonary arterial or left atrial pressure were not significantly correlated with the need for reoperation. Intraoperative color flow mapping echocardiography can accurately predict the development of early postoperative heart failure and subsequent reoperation after surgical repair of atrioventricular septal defect.

Child↗
PubMed1988

Dilated cardiomyopathy in infants and children.

The outcome of medical treatment of dilated cardiomyopathy in infants and children was reviewed to develop a predictive index for selection of patients likely to benefit from cardiac transplantation. The clinical findings, laboratory investigations, treatment and outcome of 20 patients (Group 1) less than 2 years of age at presentation and 12 patients (Group 2) greater than 2 years of age at onset were compared. Of 20 Group 1 patients, 5 (25%) died. Available autopsies (four patients) showed endocardial fibroelastosis. Of 15 survivors, 10 showed improvement in cardiac status and 5 remained unchanged. Ninety-three percent of survivors had dilated cardiomyopathy consistent with endocardial fibroelastosis by angiocardiography. All 12 Group 2 patients died. In addition to age at presentation and poor outcome, Group 2 differed from Group 1 in having a higher incidence of other family members with cardiomyopathy, more significant rhythm disturbances at presentation and a more rapid course to death. Risk factors of poor outcome in both groups included persistent cardiomegaly and the development of significant arrhythmias by Holter electrocardiographic monitoring. Cardiac transplantation is recommended for children with dilated cardiomyopathy presenting after age 2 years who survive 1 month. Those patients less than 2 years old at presentation whose condition has not improved after 1 year and who have persistent cardiomegaly or complex ventricular arrhythmias may also benefit from transplantation.

Actuarial Analysis↗
PubMed1988

Preoperative three-dimensional reconstruction of the heart and great vessels in patients with congenital heart disease. Technique and initial results.

Magnetic resonance images have been obtained preoperatively in six patients with congenital heart disease. Contiguous sequences of electrocardiogram-triggered spin-echo images have been reconstructed in three-dimensional form to define the size and anatomic relationships to the great vessels and internal cardiac structures. Findings of magnetic resonance imaging were corroborated by angiographic and sector-scan echocardiographic studies and at operation. Individual scan slices were manually edited to separate the heart and great vessels from the blood within them and from extracardiac structures. Surface reconstruction software originally developed for craniofacial and orthopedic surgical planning was adapted for processing of cardiac magnetic resonance image sequences. Preoperative three-dimensional magnetic resonance imaging reconstructions were obtained in patients with aortic coarctation with ventricular septal defect, hypoplastic left ventricle, pulmonary artery atresia with ventricular septal defect, atrial septal defect, partial atrioventricular canal defect with anomalous pulmonary venous drainage, and tetralogy of Fallot with peripheral pulmonary artery stenosis. The reconstructions showed anatomic findings consistent with two-dimensional magnetic resonance imaging, echocardiography, cineangiography, and intraoperative findings. The three-dimensional images have a format that is familiar and consistent with the gross intraoperative appearance of the heart and great vessels. These three-dimensional images can facilitate the interpretation of magnetic resonance scan findings for cardiac surgeons without the sacrifice of significant clinical information.

Adolescent↗
PubMed1984

Myocardial depression by anesthetic agents (halothane, enflurane and nitrous oxide): quantitation based on end-systolic pressure-dimension relations.

The end-systolic pressure-diameter relation of the left ventricle was used to examine the effect of halothane, enflurane and nitrous oxide on left ventricular (LV) contractility in 10 dogs chronically instrumented with dimension transducers to measure LV diameter and micromanometers to measure LV transmural pressure. Contractility was assessed by the slope (EES) of the end-systolic pressure-diameter relation. A new index that identifies the dose of anesthetic necessary to depress the inotropic state by 20% (ID20) was calculated to be 0.63% for halothane and 1.55% for enflurane, indicating a greater apparent myocardial depressant effect of halothane than enflurane. However, when these agents were compared at equi-anesthetic concentrations by normalizing the ID20 to the minimal alveolar concentration of each drug, they had comparable degrees of myocardial depressant effects. This measurement technique was used in 7 patients undergoing coronary artery bypass grafting conducted under narcotic anesthesia showing that halothane induced a similar depression of contractility. The use of ID20 should allow reclassification of anesthetic agents according to their myocardial depressant effects.

Anesthesia↗
PubMed1984

Anesthesia-induced myocardial depression: quantitation of effects on systolic and diastolic function.

The effect of general anesthesia induced with halothane and nitrous oxide on left ventricular (LV) contractility and diastolic mechanics was directly assessed in the chronically instrumented canine model. Seven dogs were instrumented with ultrasonic dimension transducers to measure LV diameter and micromanometers to measure LV transmural pressure. Contractility was assessed by the slope (EES) of the end-systolic pressure-diameter relationship PES = EES (LES - LD). Diastolic compliance was assessed by fitting end-diastolic pressure-dimension data to the exponential P = alpha (e beta epsilon L-1), where alpha and beta are nonlinear elastic coefficients. A new index (ID20) that identifies the dose of anesthetic necessary to depress the inotropic state by 20% was calculated to be 0.63% for halothane. Contractility was progressively decreased by halothane, with EES falling from 10.1 +/- 0.6 at control to 6.7 +/- 0.4 at 1% halothane and to 4.2 +/- 0.5 at 2% halothane (p less than 0.05 at each halothane level). However, similar levels of halothane did not significantly alter alpha and beta, nor did they significantly shift the exponential diastolic compliance curve from control. Seven patients who underwent coronary artery bypass grafting conducted under narcotic anesthesia showed a similar halothane-induced depression of contractility; 0.5% halothane decreased EES from 11.5 +/- 2.0 to 8.0 +/- 2.4 (p less than 0.01). Use of ID20 allows reclassification of anesthetic agents in accord with their myocardial depressant effects, which with halothane appears to be caused by decreased inotropism without alterations in diastolic chamber mechanics.

Animals↗
PubMed1984

The comparative effects of dopamine and dobutamine on ventricular mechanics after coronary artery bypass grafting: a pressure-dimension analysis.

To compare the contractile response to dopamine and dobutamine after coronary artery bypass grafting, 20 patients were instrumented with ultrasonic dimension transducers to measure left ventricular anterior/posterior minor-axis diameter and equatorial wall thickness. Micromanometers were placed to measure left ventricular transmural pressure. Pressure-dimension data were recorded and computer analyzed during dopamine and dobutamine infusions in each patient at 0, 2.5, 5.0, and 10.0 micrograms/kg/min 16 to 20 hr after surgery. Contractility was measured by determination of maximal velocity of shortening of the ventricular diameter (mm/sec) and wall excursion (mm). Preload was assessed with end-diastolic diameter and peak left ventricular wall stress (dynes-cm-2) was calculated at each dose. End-diastolic diameter was unchanged at equal doses of dopamine and dobutamine. However, ejection phase indexes of contractility were significantly higher with dobutamine than dopamine, and were associated with lower levels of peak wall stress and peripheral vascular resistance. These data indicate that use of dobutamine results in greater enhancement of left ventricular contractility without the disadvantage of excess demand on myocardial oxygen reserve produced by higher levels of myocardial wall tension. Furthermore, the decreased peripheral vascular resistance induced by dobutamine accounts for some of the differences in drug response, and is beneficial in optimizing myocardial oxygen balance during pharmacologic inotropic support of the bypass graft patient or other patients in whom there is a potential for development of myocardial ischemia.

Angina Pectoris↗
PubMed1983

The influence of time on the response to dopamine after coronary artery bypass grafting: assessment of left ventricular performance and contractility using pressure/dimension analyses.

Pressure and dimension analyses were used to quantitate the changing cardiac response to dopamine over a 24-hour interval after coronary artery bypass grafting (CABG). Ultrasonic dimension transducers were utilized to measure the minor-axis diameter of the left ventricle, and matched micromanometers were inserted to measure intracavitary left ventricular pressure and intrathoracic pressure. Pressure and dimension data were recorded and analysed by computer during dopamine infusion at 0, 2.5, 5.0, and 10.0 micrograms per kilogram per minute, at periods designated as early (2 to 4 hours after CABG) and late (18 to 24 hours after CABG). Myocardial contractile responses to dopamine (peak velocity of minor-axis shortening, maximal excursion) were similar at each dose in the early and late studies. However, overall hydraulic performance, as reflected by cardiac outputs and the areas of the pressure/diameter work loops, had augmented late dose responses. This study suggests a major change in the relationship between the heart and peripheral control mechanisms that may partially explain diminishing inotropic requirements over time, in addition to the generally accepted occurrence of improvement in contractile state and functional reserve following cardiac operation.

Angina Pectoris↗
PubMed1983

The mechanism of halothane-induced myocardial depression. Altered diastolic mechanics versus impaired contractility.

Although halothane has been shown to depress left ventricular function, it remains a common alternative to narcotic anesthesia in cardiac operations. To clarify the mechanism by which this functional depression occurs (direct decrease in contractility versus altered diastolic compliance), we studied seven dogs in the closed-chest state following instrumentation with ultrasonic dimension transducers to measure left ventricular anteroposterior diameter and micromanometers to measure transmural left ventricular pressure. Ventricular volumes were varied with transient vena caval occlusions in the awake state and following general anesthesia with halothane at 1% and 2% end-tidal concentrations. Ventricular contractility was assessed by the slope of the end-systolic pressure-diameter relationship (EES). Following normalization of end-diastolic diameters with a Lagrangian strain definition (E), diastolic compliance was assessed by fitting end-diastolic pressure-strain data to the exponential: P = alpha (e beta E -1), where alpha and beta are nonlinear elastic coefficients. Halothane was found to produce a significant, dose-dependent decrease in EES from 10.6 +/- 0.6 control to 6.7 +/- 0.4 at 1% halothane and 4.2 +/- 0.5 at 2% halothane (p less than 0.05, control versus both 1% and 2% halothane). Furthermore, halothane at the concentrations studied did not significantly alter alpha and beta nor significantly shift the exponential end-diastolic pressure-strain curve from control. These data indicate that halothane produces a direct, severe depression of left ventricular contractility without primarily altering the diastolic mechanical properties of the myocardium.

Animals↗
PubMed1982

Hemophilus influenzae pericarditis.

Although Hemophilus influenzae infections have long been considered to be a disease of childhood, recent reports have demonstrated an increasing frequency of serious Hemophilus influenzae infections in adults. A case of purulent H. influenzae pericarditis in a previously healthy adult without evidence of concurrent H. influenzae infection is reported.

Adult↗
PubMed1982

The effect of PEEP on left ventricular diastolic dimensions and systolic performance following myocardial revascularization.

To quantitate the alterations in left ventricular (LV) dimensions and performance at successive levels of positive end-expiratory pressure (PEEP), 16 patients undergoing coronary artery bypass grafting (CABG) underwent instrumentation with ultrasonic dimension transducers to measure the minor-axis diameter of the left ventricle. Matched micromanometers were placed to measure intracavitary LV pressure and intrathoracic pressure. LV pressure and dimension data were recorded and computer analyzed during continuous positive-pressure ventilation at 0, 5, 10, and 15 cm H2O of PEEP 4 to 8 hours postoperatively. Preload was determined by the end-diastolic minor-axis diameter, cardiac output was measured by thermodilution, and indices of LV contractility assessed included the maximal velocity of minor-axis shortening and the slope of the end-systolic pressure-diameter relationship. PEEP produced a progressive increase in intrathoracic pressure associated with a fall in cardiac output; this was associated with a decrease in LV end-diastolic diameter and no significant change in the maximal velocity of minor-axis shortening or the slope of the end-systolic pressure-diameter relationship. Our results indicate that PEEP of 10 cm H2O or greater will produce a significant fall in cardiac output in patients following CABG, due to a decrease in preload rather than impaired LV contractility.

Angina Pectoris↗
PubMed1982

Subvalvular thrombotic obstruction of an aortic porcine heterograft.

A 48-year-old man had angina pectoris and symptoms of heart failure. Cardiac catheterization showed severe aortic stenosis and regurgitation, and he underwent aortic valve replacement in 1976 with a 23-mm Carpentier-Edwards aortic porcine heterograft. Initially there was symptomatic improvement, but one year later the patient had the onset of dyspnea and exertional chest pain that became progressively more severe over the next three years. Repeat cardiac catheterization was performed 45 months after valve implantation, and a 76 mm Hg peak to peak and a 44 mm Hg mean systolic gradient across the aortic bioprosthesis were recorded. The porcine heterograft was surgically explanted and found to be obstructed by a subvalvular thrombus that appeared to arise from the junction of the aortic and mitral valve annuli.

Aortic Valve↗