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Biomedical subjects

T D Fraker

Publications and source records attributed to T D Fraker.

At least 37 records · Page 2Linked to original sources
PubMed1988

Discrepant changes in plasminogen by two different assays in patients receiving streptokinase.

The fluorogenic synthetic substrate and radial immunodiffusion assays of plasma plasminogen were compared before and after administration of intravenous streptokinase in differing doses to 57 patients being treated for acute myocardial infarction. There was a moderate correlation (r = 0.73, slope = 0.221, intercept = 1.005, n = 57 pairs) in the two assays of plasma plasminogen before the administration of streptokinase. After streptokinase, however, the correlation of the two assays was poor (r = 0.28, slope = 0.03, y-intercept = 0.003, n = 57 pairs). The decrease in plasma plasminogen by the fluorogenic synthetic substrate assay after streptokinase averaged 95 +/- 5%, with little variation between doses. In contrast, the percentage decrease in plasma plasminogen after streptokinase by the radial immunodiffusion assay averaged only 30 +/- 11%. The percentage change in plasma plasminogen by the two assays is significantly different (P = 0.001). The discrepancy in the percentage change in plasma plasminogen after streptokinase as measured by the fluorogenic synthetic substrate assay and the radial immunodiffusion assay can be explained by a lack of specificity for the antibody to plasminogen in the radial immunodiffusion kit. Antigen-antibody precipitin rings were observed after incubation of antibody with a mixture presumed to contain plasmin, plasmin-alpha 2 antiplasmin complexes, and plasmin-fibrin/fibrinogen degradation products. Based on these data, the fluorogenic synthetic substrate assay for plasma plasminogen is a superior means of following plasminogen depletion in response to thrombolytic therapy after streptokinase treatment for acute myocardial infarction.

Dose-Response Relationship, Drug↗
PubMed1987

Pharmacokinetic implications of lorcainide therapy in patients with normal and depressed cardiac function.

The influence of cardiac function as measured by the left ventricular ejection fraction on the pharmacokinetic variables of a new antiarrhythmic drug, lorcainide, was investigated in 20 cardiac patients. Patients were divided into two groups: those with normal (ejection fraction greater than .40) or depressed (ejection fraction less than .40) left ventricular function. The elimination half-life, plasma clearance rates, or volume of distribution of lorcainide were not significantly different in patients with either normal or depressed cardiac function. A decrease in arrhythmia frequency could be correlated to plasma lorcainide concentration in the majority of patients, and it was noted that at least 0.1 mg/L of lorcainide was required for the presence of an antiarrhythmic effect. Three unusual cases are presented to illustrate the importance of measuring plasma drug concentrations and calculating the drug pharmacokinetics and to correlate these to the antiarrhythmic response in order to minimize the risk of plasma drug accumulation and side effects. A review of published data shows a three- to sixfold interpatient variation in the elimination half-life of lorcainide with practical implications in its use as an antiarrhythmic drug.

Adult↗
PubMed1987

Comparison of thrombolytic therapy for acute myocardial infarction in rural and urban settings.

In this study, a tertiary care hospital served as a registry and information source to rural hospitals in northwestern Ohio where thrombolytic therapy had not previously been used. The study was designed to compare the safety and efficacy of intravenous thrombolytic therapy for acute myocardial infarction in the two settings. Fifty-five patients in eight rural hospitals and 36 patients in the urban tertiary care center received intravenous streptokinase. Of the 87 patients whose symptoms first occurred out of the hospital, 63 percent were treated within three hours. There were no significant differences in rates of clinically determined coronary artery recanalization (63 percent versus 69 percent for rural and tertiary hospitals, respectively), in-hospital mortality (5.4 percent versus 11 percent), bleeding complications (3.6 percent versus 5.5 percent), or time from the onset of pain to infusion of streptokinase (3.4 hours versus 2.9 hours). There were also no differences in the completeness of collection of serial coagulation data and cardiac enzyme values, or in the documentation of chest pain onset and cessation. Major differences between rural centers and the tertiary care center involved the use of serial electrocardiography (58 percent versus 89 percent, respectively), subsequent cardiac catheterization (49 percent versus 86 percent), and the timing of catheterization, when performed (30.4 days versus 4.6 days) (p less than 0.005 for all values). Thrombolytic therapy for acute myocardial infarction can be administered quickly, safely, and effectively in rural hospital settings even by physicians previously unfamiliar with this form of treatment.

Cardiac Catheterization↗
PubMed1985

Relation of effectiveness of intracoronary thrombolysis in acute myocardial infarction to systemic thrombolytic state.

Twenty-nine patients received intracoronary thrombolytic therapy for acute myocardial infarction 3.5 +/- 1.4 hours (mean +/- standard deviation) after the onset of pain. Ten patients received urokinase (UK) and 19 patients received streptokinase (SK). Laboratory variables of the coagulation system were measured before and immediately after therapy. When comparing patients in whom coronary artery recanalization occurred vs those in whom the artery remained occluded, those in whom recanalization was achieved had greater alterations in fibrinogen, prothrombin time, activated partial thromboplastin time, fibrin/fibrinogen degradation products and plasminogen by thrombolytic therapy than did those in whom recanalization was not achieved (p less than 0.05 for all variables). Euglobulin lysis time showed a similar but nonsignificant trend (p = 0.114). Patients who received SK showed markedly greater alterations in coagulation parameters than did patients treated with UK (p less than 0.05 for 5 of 6 variables measured) and had a much higher incidence of successful thrombolysis (74% for SK, 20% for UK). These data indicate that the development of a systemic fibrinolytic state contributes to success when using intracoronary thrombolytic agents in acute myocardial infarction. Rather than being considered an adverse effect of therapy, a systemic lytic state may serve as a reasonable clinical goal in attempting to produce thrombolysis.

Adult↗
PubMed1985

Current status of valve prostheses.

The deterioration in cardiac function caused by a valvular lesion frequently can be halted or reversed by timely surgery. This article discusses the principles used to decide when surgery is beneficial and briefly reviews current indications for operation in the more common acquired and congenital valve lesions. The factors influencing the choice of a valve prosthesis are also discussed.

Age Factors↗
PubMed1984

Altered acoustic reflectance on two-dimensional echocardiography as an early predictor of myocardial infarct size.

P6 area of increased acoustic reflectance was readily observed by 2-dimensional echocardiography (2-D echo) in the acutely ischemic canine myocardium. Fifteen mongrel dogs subjected to closed-chest coronary artery occlusion were used to test the hypothesis that these areas of altered acoustic reflectance were predictors of subsequent myocardial infarction (MI). Each dog was studied by 2-D echo in short-axis views of the left ventricle at 4 levels before and after coronary artery occlusion. The dogs were killed after 48 hours and heart sections were stained with triphenyltetrazolium chloride to identify the areas of necrosis. Four sections were then selected, approximating the same location within the left ventricle as the short-axis views taken for 2-D echocardiographic analysis. The in vivo 2-D echocardiographic examination revealed alteration of acoustic reflectance immediately after coronary occlusion, which detected the presence of MI with a sensitivity of 92% and a specificity of 90%. The extent of altered acoustic reflectance seen by echo correlated closely (r = 0.81) with the extent of MI detected by triphenyltetrazolium staining of the excised heart. Altered acoustic reflectance seen by 2-D echo immediately after coronary artery occlusion reflects acute ischemic changes and may be an early predictor of MI size.

Animals↗
PubMed1984

Hyponatremia in patients treated with lorcainide, a new antiarrhythmic drug.

The effects of lorcainide, a new antiarrhythmic drug, on serum electrolytes and osmolality are described in a series of 33 patients with organic heart disease and complex ventricular arrhythmias treated with lorcainide. In eight patients, a mean decrease in serum Na+ of 8.25 +/- 3.2 mEq/L was observed after a single 200 mg intravenous dose of lorcainide. Sixteen of 33 patients developed significant hyponatremia and hypoosmolality during oral treatment with lorcainide. In all except two patients, serum Na+ returned to normal values within 3 to 12 months of continued lorcainide therapy. Low serum Na+ and hypoosmolality in the absence of volume depletion, clinically manifest edema, and unaltered renal, adrenal, cardiac, or thyroid function suggest that this antiarrhythmic drug produced the syndrome of inappropriate antidiuretic hormone secretion (SIADH). SIADH appeared to be transient and asymptomatic in our patients. One patient developed severe hyponatremia with serum Na+ of 108 mEq/L when hydrochlorothiazide was given to control hypertension. It is concluded that SIADH is an important side effect of lorcainide therapy. We recommend that serum Na+ be carefully monitored in patients started on lorcainide therapy, and extreme caution should be exercised in prescribing diuretics to patients with persistent hyponatremia.

Adult↗
PubMed1984

Who is normal?

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Coronary Disease↗
PubMed1981

Contrast M-mode ultrasonography of the inferior vena cava.

Contrast M-mode and two-dimensional ultrasonography of the inferior vena cava were performed in 65 patients with various acquired and congenital cardiac disorders. After saline was injected into a peripheral arm vein, the inferior vena cava was visualized by both methods in 60 patients (92%). The M-mode approach was better for correlating the appearance of contrast within the inferior vena cava with the ECG. This precise correlation served as the basis for differentiating patients with tricuspid insufficiency (visualization of contrast after the QRS) from those with impaired right ventricular filling (visualization of contrast before the QRS) or arrhythmia. Results with the M-mode approach suggest that conditions other than tricuspid insufficiency may cause the appearance of contrast within the inferior vena cava. M-mode echocardiography should be used to further investigate patients with impaired right ventricular filling.

Arrhythmias, Cardiac↗
PubMed1980

Echocardiographic documentation of vegetative lesions in infective endocarditis: clinical implications.

Eighty-seven patients with the clinical syndrome of infective endocarditis were examined by M-mode and two-dimensional echocardiography. Patients were divided into two groups based on the presence or absence of echocardiographically detected vegetative lesions. Group 1 consisted of 47 patients with one or more vegetations. Group 2 consisted of 40 patients without evidence of vegetations. Group 1 patients had a higher rate of complications: emboli, congestive heart failure and the need for surgical intervention. Analysis of morphologic characteristics of the vegetations in group 1 was of no predictive value for complications in individual patients. Two-thirds of the vegetations persisted unaltered well beyond the period of bacteriologic cure without significant complications. No characteristic alteration of the vegetations predicted the efficacy of medical therapy. Although the detection of vegetations by echocardiography in patients with the clinical syndrome of endocarditis clearly identifies a subgroup at risk for complications, decisions regarding clinical management made solely on the basis of the presence or absence of vegetative lesions are hazardous. Management of such patients must continue to be based on the clinical integration of multiple factors.

Adolescent↗
PubMed1979

Detection of persistent left superior vena cava by two-dimensional contrast echocardiography.

One hundred seventy adult patients with possible congenital or valvular heart disease underwent contrast two-dimensional echocardiographic examination as part of a precatheterization evaluation. Persistent left superior vena cava was detected in 5 patients, each of whom demonstrated an abnormally large coronary sinus. Injection of echocardiographic contrast material from a peripheral left arm vein resulted in early opacification of this structure before other right-side chambers, thus suggesting abnormal venous drainage. Persistent left superior vena cava was confirmed in all 5 patients at the time of catheterization and/or surgery.

Adolescent↗
PubMed1979

Detection and exclusion of interatrial shunts by two-dimensional echocardiography and peripheral venous injection.

Two-dimensional echocardiography (2-D echo) was used with peripherally injected contrast material to detect interatrial shunts in 33 patients. Group 1 consisted of 11 patients having classic clinical findings of atrial septal defect. Group 2 consisted of 12 patients with problems requiring that atrial shunting be excluded. Group 3 (control group) consisted of 10 patients undergoing cardiac catheterization for chest pain. Confirmation of the 2-D echo findings was provided by cardiac catheterization in 32 patients and postmortem examination in one. Right-to-left atrial shunts were detected in all 11 patients in group 1, although seven had no right-to-left shunt calculable by oximetry. Four patients in Group 2 had right-to-left atrial shunts. None of the patients in Group 3 had atrial shunts. In the 15 patients with atrial shunts, the degree of right-to-left shunting could be qualitatively assessed as small, moderate, or large. There were no false-negative or false-positive results by contrast 2-D echo.

Adolescent↗