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Biomedical subjects

J Schofer

Publications and source records attributed to J Schofer.

At least 55 records · Page 3Linked to original sources

Recombinant single-chain urokinase-type plasminogen activator during acute myocardial infarction.

Recombinant single-chain urokinase-type plasminogen activator was intravenously administered in 2 different doses in 24 patients with acute myocardial infarction and angiographically proved occlusion of the infarct-related artery. Patients with first infarction without contraindications of thrombolysis were treated within the first 4 hours after the onset of symptoms. Group A (12 patients) received 20 mg of rscu-PA as a bolus followed by 60 mg infused over 1 hour and group B received 10 mg as a bolus and 30 mg as infusion. The 2 groups showed no significant difference in age, sex, height, weight, time between onset of symptoms and start of therapy, peak values and course of infarct-related enzymes. Time to reperfusion was 43 minutes in group A versus 67 minutes in group B (p less than 0.005). The rate of reperfusion 90 minutes after start of treatment was 91% in group A and 50% in group B (p less than 0.001). Plasma levels of fibrinogen, plasminogen and alpha-2-antiplasmin did not differ significantly in both groups. Systemic lytic state (fibrinogen less than 100 mg/dl) occurred in 33% of group A and in 9% of group B. Intravenous infusion of 80 mg (but not 40 mg) of rscu-PA led to reperfusion of the occluded coronary artery in nearly all patients. Approximately one-third of the patients treated with this dose demonstrated systemic lysis.

Adult↗

Limitations in the interpretation of rest-exercise ejection fraction changes after early thrombolytic therapy during acute myocardial infarction.

The effect of exercise on left ventricular wall motion in the infarct and noninfarct regions, and their contribution to the global ejection fraction response to exercise was evaluated in 24 patients studied at least 2 weeks following thrombolytic therapy for acute myocardial infarction. To achieve this goal, a nonstandard protocol was used: contrast ventriculography was performed at rest and immediately following 3 minutes of supine bicycle exercise at 50 watts. Wall motion in the infarct and noninfarct regions was measured using the centerline method. The global ejection fraction response to exercise correlated poorly with the exercise response of motion in the infarct region (r = 0.38). In 15 of the 24 patients, the function of the infarct and noninfarct regions changed in opposing directions, and in only 8 (53%) of these did the global ejection fraction response follow the exercise response of motion in the infarct region. The motion of the noninfarct region was the predominant influence on the ejection fraction response in the other 7 patients. Subgroup analysis revealed that the global ejection fraction response was more dependent on the response of motion in the anterior wall (r = 0.71, p less than 0.001) than in the inferior wall (r = 0.16), regardless of infarct location. The regional wall motion response to exercise also better distinguished reperfused from nonreperfused patients than did the ejection fraction response. These results indicate that the global ejection fraction response to exercise may be an unreliable indicator of the functional status of the infarct region.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗

Improved survival up to four years after early coronary thrombolysis.

The long-term prognosis after thrombolytic therapy in patients with acute myocardial infarction (AMI) is unknown. This question was investigated in a 4-year follow-up study of 227 patients. According to the status of reperfusion at the end of the acute catheterization, the patients were divided into a patent (n = 171) and an occluded (n = 56) group. Both hospital and 4-year mortality rates were significantly reduced in the patent group by 13 and 14%, respectively (p less than or equal to 0.005 for both). Baseline variables known to be important for prognosis did not differ between the 2 groups. Patients with a patent infarct artery who underwent early acute coronary artery bypass grafting (CABG) had a greater survival (p less than 0.10) and better left ventricular function (p less than 0.01) than did patients with a patent infarct artery who did not undergo CABG. This difference was associated with a lower frequency of fatal reinfarction and cardiogenic shock in the CABG group. Thus, survival is improved up to 4 years after successful thrombolysis and appears to be further enhanced by early CABG.

Cardiac Catheterization↗

Iodine-123 meta-iodobenzylguanidine scintigraphy: a noninvasive method to demonstrate myocardial adrenergic nervous system disintegrity in patients with idiopathic dilated cardiomyopathy.

Iodine-123 (I-123) meta-iodobenzylguanidine (MIBG) imaging was performed in 31 patients. Three patients were without cardiac disease and 28 had idiopathic dilated cardiomyopathy with various degrees of left ventricular dysfunction. The qualitatively assessed myocardial I-123 MIBG scintigrams and the myocardial versus mediastinal I-123 MIBG uptake ratio were related to I-123 MIBG activity and norepinephrine concentration determined from endomyocardial biopsy samples taken from the right side of the interventricular septum. Scintigrams and the MIBG uptake ratio were also related to plasma catecholamine concentrations, left ventricular ejection fraction and New York Heart Association functional class. Patients with distinct myocardial I-123 MIBG uptake (score 1) had a normal ejection fraction (58 +/- 16%). Patients with diffusely reduced uptake or scintigraphic defects (score 2) had a significantly lower ejection fraction (38 +/- 9%, p less than 0.05), whereas patients with shadowy or no visible myocardial uptake (score 3) had the lowest ejection fraction (23 +/- 6%, p less than 0.002 versus patients with score 2). The scintigraphically determined I-123 MIBG activity in the septal region correlated significantly with I-123 MIBG activity from the endomyocardial biopsy samples (r = 0.78, p less than 0.001, n = 9). The myocardial versus mediastinal I-123 MIBG activity ratio was significantly related to myocardial norepinephrine concentration (r = 0.63, n = 28) and to left ventricular ejection fraction (r = 0.74, n = 31). These data suggest that myocardial I-123 MIBG scintigraphy is a useful noninvasive method for the assessment of myocardial adrenergic nervous system disintegrity in patients with idiopathic dilated cardiomyopathy.

3-Iodobenzylguanidine↗

[Magnetic resonance tomography of a thoracic aortic aneurysm].

The results of magnetic resonance imaging in 16 patients with non-dissecting aneurysm of the thoracic aorta are presented. Scans with ECG-gated spin-echo sequences in transversal, coronal, and left anterior oblique views demonstrated the size and extent of the aneurysms. Measurements of the maximum aneurysmal diameter differed by less than 5 mm from measurements obtained with computed tomography. In 6 of 7 patients with presence of wall adherent intraluminal signal, phase images were able to differentiate accurately between mural thrombus and slow blood flow.

Adult↗

Recovery of left ventricular function after myocardial infarction can be predicted immediately after thrombolysis by semiquantitative intracoronary thallium and technetium pyrophosphate scintigraphy.

The accuracy with which intracoronary thallium and technetium pyrophosphate scintigraphy during intracoronary thrombolysis predicts myocardial salvage was studied in 58 patients with acute myocardial infarction by comparing the acute scintigraphic findings with subsequent left ventricular function. Scintigrams obtained before and immediately after thrombolysis were interpreted by three independent observers using a scoring system. Regional wall motion in the infarct area was determined from left ventricular (LV) cine angiograms using the center-line method. Patients with mild hypokinesis (hypokinesis less than or equal to -2 SD from normal) could be distinguished from those with severe hypokinesis (hypokinesis greater than -2 SD) using the prethrombolysis thallium score with an accuracy of 83%. Accuracy using the post-thrombolysis score was 76%. When the post-thrombolysis thallium and technetium pyrophosphate scores were combined, differentiation was possible in 91% of all patients studied, and in 100% of patients with anterior myocardial infarction. Thus, analysis of combined thallium and technetium pyrophosphate scintigraphy accurately predicts recovery of LV function after thrombolysis and may be helpful in deciding whether acute percutaneous transluminal coronary angioplasty or bypass surgery should be performed after thrombolysis.

Cardiac Output↗

[Randomized double-blind study comparing tissue-type plasminogen activator with placebo in acute myocardial infarct].

In a double-blind randomised trial 129 patients with first myocardial infarction of less than 6 h duration were allocated to treatment with human recombinant tissue-type plasminogen activator (rt-PA) given intravenously over 90 min, or to placebo infusion. Coronary angiography at the end of this infusion showed that the infarct-related vessel was patent in 61% of 62 assessable coronary angiograms in the rt-PA-treated group compared with 21% in the control group. Treatment with rt-PA was not accompanied by any major complications. In the rt-PA group the circulating fibrinogen level at the end of the catheterisation was 52 +/- 29% (mean +/- SD) of the starting value.

Adult↗

[Thallium single photon emission computed tomography following thrombolysis: missing relation to left ventricular function].

To address the question of whether infarct size after thrombolysis can comparably be estimated by thallium SPECT scintigraphy and contrast cineangiography, 32 patients in whom regional wall motion abnormality had been assessed by means of the "centerline" method, 10 to 21 days after infarction, underwent biphasic thallium SPECT scintigraphy with dipyridamole. There were no statistically significant correlations between left ventricular ejection fraction and the degree of hypokinesia in the infarct area on one hand, and thallium defect size in the early and late scintigram on the other. Hypokinesia was inversely correlated (r = -0.51) with the time interval from symptom onset to reperfusion, but no such correlation was found between thallium defect size and this parameter. In patients in whom reperfusion was achieved within 3 h of symptom onset, hypokinesia was significantly less (-1.11 +/- 0.6 standard deviations (SD] than in patients in whom reperfusion was achieved later (-2.16 +/- 0.8 SD; p less than 0.01). Thallium defect size, however, was not different in these two groups of patients. It is concluded that there is no close correlation between regional wall motion abnormality assessed subacutely after thrombolysis and infarct size determined by SPECT in the chronic state. Thus, impairment of left ventricular function may not be assessed from scintigraphic findings.

Adult↗

Coronary thrombolysis with intravenous urokinase in patients with acute myocardial infarction.

Regional left ventricular wall motion, about two to three weeks after acute myocardial infarction (MI), is perhaps the best clinical measure of myocardial salvage and limitation of infarct size by thrombolytic therapy. Normal or only slightly depressed wall motion at the site of infarction indicates significant limitation of infarct size, whereas markedly abnormal wall motion indicates irreversible myocardial damage. Early studies found significant improvement in regional wall motion in only 40 percent of patients undergoing successful intracoronary thrombolytic therapy after the onset of symptoms of acute MI. Why only 40 percent of these reperfused patients demonstrated salvage of ischemic myocardium could not be answered at that time. Animal experiments show that the duration of coronary occlusion is an important factor in determining myocardial salvage after reperfusion. To study whether this time dependency also exists under clinical circumstances in patients with coronary artery disease, the relationship between regional wall motion (as an index of infarct size) and the time to thrombolytic therapy after the onset of symptoms (as an index of duration of coronary occlusion) was examined. After showing that such time dependency does indeed exist in patients with acute MI, the efficacy and safety of intravenous bolus injections of urokinase were then demonstrated.

Coronary Disease↗

Sympathetic activity in idiopathic dilated cardiomyopathy. Influence of captopril and hydralazine.

To study the interrelationship between myocardial norepinephrine content, left ventricular (LV) and right ventricular (RV) function, morphological changes, and plasma catecholamine concentrations, 20 patients with idiopathic dilated cardiomyopathy underwent endomyocardial biopsy and ventricular angiography. The strongest correlation was found between LV ejection fraction (EF) and myocardial norepinephrine content (r = 0.87; p less than 0.001). Myocardial norepinephrine content was much weaker correlated to RV EF (r = .55; p less than 0.005), and no correlation was found to morphological changes or plasma norepinephrine concentration. The hemodynamic and neurohumoral effects of hydralazine versus captopril after the first dose were compared in a crossover trial including 15 patients with idiopathic dilated cardiomyopathy. Hydralazine induced increases in heart rate and cardiac index (p less than 0.01) and decreases in mean arterial pressure and pulmonary wedge pressure (p less than 0.01 and p less than 0.005, respectively). These hemodynamic effects were associated with increased plasma norepinephrine concentrations during upright exercise (p less than 0.05) and increased plasma renin activity (p less than 0.01). After captopril, norepinephrine plasma concentrations showed a tendency to lower levels during upright exercise, although mean arterial pressure decreased significantly (p less than 0.01). These data suggest that, in patients with idiopathic dilated cardiomyopathy, myocardial norepinephrine depletion strongly reflects left ventricular dysfunction. The different patterns of neurohumoral response to hydralazine versus captopril may be important for their long-term effect and for the prognosis of patients with idiopathic dilated cardiomyopathy. It remains to be established whether the myocardial catecholamine content is differently influenced by either drug, and whether this effect is related to the drug response after long-term treatment.

Adolescent↗

Relationship between myocardial norepinephrine content and left ventricular function--an endomyocardial biopsy study.

To analyze the relationships between left ventricular function, catecholamine concentrations in plasma and myocardium, and morphological alterations, 20 patients were studied. Fifteen patients had idiopathic dilated cardiomyopathy, and 5 had normal left ventricular function. All patients underwent right ventricular endomyocardial biopsy to determine muscle fibre thickness, percent volume fraction of interstitium, and myocardial catecholamine content. Blood was sampled to measure plasma catecholamine concentrations, and left ventricular cineangiography was performed to determine global ejection fraction. In a simple correlation analysis a significant correlation was found between left ventricular ejection fraction and myocardial norepinephrine content (r = 0.80, P less than 0.001). Left ventricular ejection fraction was negatively correlated with plasma epinephrine concentration (r- = 0.53, P less than 0.02), and with muscle fibre thickness (r = -0.50, P less than 0.03). Myocardial norepinephrine concentration was negatively correlated with plasma epinephrine (r = -0.62, P less than 0.01). Multiple linear regression analysis revealed a strong correlation between myocardial norepinephrine depletion and left ventricular dysfunction, which was independent of all other variables. These data suggest that myocardial norepinephrine depletion determined from right ventricular endomyocardial biopsies strongly correlates with left ventricular dysfunction in idiopathic dilated cardiomyopathy, and seems to be independent of the degree of muscle fibre hypertrophy, volume fraction of interstitium, and of the increased sympathetic tone.

Biopsy↗

Hemodynamic and neurohumoral response to hydralazine versus captopril: a controlled study in idiopathic dilated cardiomyopathy.

To study the hemodynamic and neurohumoral effects of hydralazine versus captopril after the first dose, 15 patients with idiopathic dilated cardiomyopathy (NYHA Class II and III) were included in a crossover trial with a washout period of three days. Hemodynamic parameters were measured by using a Swan-Ganz thermodilution catheter, and venous blood was sampled during supine rest and standardized upright exercise before (control) and 60 min after drug administration. Compared to the control phase, hydralazine induced an increase in heart rate and cardiac index (p less than 0.01), and a decrease in mean arterial pressure and pulmonary wedge pressure (p less than 0.01, p less than 0.05, respectively). The hemodynamic effects were associated with increased norepinephrine plasma concentration during upright exercise (p less than 0.05) and increased plasma renin activity (p less than 0.01). After administration of captopril, heart rate at rest (p less than 0.05), mean arterial pressure, and pulmonary wedge pressure decreased significantly (p less than 0.01). Cardiac index remained unchanged. Norepinephrine plasma concentrations were not significantly influenced despite a tendency to lower levels during upright exercise. Plasma renin activity increased (p less than 0.01) and aldosterone at rest decreased significantly (p less than 0.05). These differences in neurohumoral response between both drugs may be important for their long-term effects.

Adult↗

[Left ventricular diastolic function in PTCA: a Doppler echocardiographic study].

The measurement of left ventricular inflow by Doppler echocardiography provides a continuous, non-invasive assessment of parameters of diastolic function. We studied changes in left ventricular diastolic function during percutaneous transluminal coronary angioplasty (PTCA) of the left anterior descending coronary artery (LAD). In ten patients, the diastolic flow velocity profile across the mitral valve was measured by Doppler echocardiography, before and 60 s after inflation and 60 s after deflation of the balloon. The peak velocity of early diastolic filling (VE) significantly decreased during angioplasty, from 68 +/- 12 to 56 +/- 10 cm/s (p less than 0.001), while the peak velocity of late diastolic filling caused by atrial contraction (VA) showed no change. This resulted in a significant decline in the diastolic velocity ratio (VE/VA) from 1.11 +/- 0.47 to 0.92 +/- 0.35 (p less than 0.01). The total area under the diastolic flow velocity profile representing the total filling volume fell from 14.3 +/- 4.1 to 10.9 +/- 3.6 cm (p less than 0.001). The early diastolic filling fraction decreased from 68 +/- 5% to 64 +/- 7%, in favor of the filling fraction due to atrial contraction, which increased from 32 +/- 5%, to 36 +/- 7% (p less than 0.01). 60 s after deflation of the balloon, the parameters of diastolic filling returned to baseline values. We conclude from our results that diastolic dysfunction caused by angioplasty of the LAD results in a decrease in early diastolic left ventricular filling, which is completely reversible after 60 s.

Adult↗

[Lung hemorrhage as a sequela of heart catheterization study].

We report a case of pulmonary hemoptysis induced by a balloon-tipped catheter. The bleeding ceased spontaneously. Factors known to be associated with pulmonary artery rupture such as pulmonary hypertension, anticoagulant therapy, and advanced age were absent in our patient. Bleeding occurred despite careful consideration of the guidelines for right heart catheterization suggested by Swan and Ganz in 1974. We conclude that hemoptysis may be a complication of balloon-tipped right heart catheterization even in the absence of risk factors for this procedure. Therefore the indication for this intervention should be considered carefully.

Cardiac Catheterization↗