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Biomedical subjects

W Bleifeld

Publications and source records attributed to W Bleifeld.

At least 91 records · Page 5Linked to original sources
PubMed1987

[Thrombi in the left atrial appendage in mitral defects despite adequate anticoagulation. The advantages of transesophageal echocardiography].

Thrombi in the left atrium are a frequent complication of mitral valve disease accompanied by left atrial enlargement. It is often difficult to recognize abnormal structures in this area with sufficient reliability by conventional transthoracic cross-sectional (2-D) echocardiography. Diagnosis is almost impossible with thrombi in the left atrial appendage. Transesophageal echocardiography presents a useful alternative. By this means thrombi in the left atrial appendage were diagnosed in seven of 24 patients with mitral stenosis on adequate anticoagulation, transthoracic 2-D echocardiography having given negative results. At subsequent valve replacement the results of transthoracic echocardiography were confirmed in all cases.

Adult↗
PubMed1987

[Heart surgery in acute bacterial endocarditis without preoperative heart catheterization. Long-term observation of 40 patients].

In 40 patients with acute bacterial endocarditis, the indication for cardiac valve replacement was established exclusively on the basis of the echocardiographic and clinical findings. The patients had an average age of 42 years and were under followup observation for an average of 2.2 years. The endocarditis involved the aortic valve 32 times, the mitral valve once, the tricuspid valve in two cases and the aortic and mitral valve together in five cases. In addition to the valve replacement, a ventricular septum defect and aneurysm of the ascending aorta had to be dealt with surgically in two cases each. The intraoperative and perioperative lethality was 2.5% (n = 1). The postoperative lethality was 12.5% (n = 5). In the surviving 34 patients, a recurrence of the endocarditis has not occurred up to now in any case. According to the NYHA classification, six of the surviving patients were to be classified as stage II and 28 as stage I, whereas stage III or IV had been present preoperatively in all cases. The postoperative echocardiographic investigation revealed a significant decrease of the left ventricular enddiastolic diameter (from 61 +/- 8 mm to 51 +/- 5 mm; P less than 0.001). In four cases, a slight insufficiency of the artificial valve could be detected. Reoperation was not necessary in any of these patients.

Adult↗
PubMed1987

Usefulness of anatomic parameters derived from two-dimensional echocardiography for estimating magnitude of left to right shunt in patients with atrial septal defect.

The ability of two-dimensional echocardiography (2DE) to quantitate the atrial septal defect size and left-to-right shunt magnitude was examined in 75 adult patients with simple ostium secundum atrial septal defect (ASD) with left-to-right shunts of 19-92% of systemic flow as determined by oximetry. The ASD was visualized in 71 of 75 (95%) patients utilizing subcostal 2DE, and the end-systolic atrial septal defect diameters in subcostal 2DE (ASDe) were measured. The maximal diameters of ASD measured during operation (ASDop) were obtained in 45 of these patients, who then underwent surgical ASD repair. The correlation between ASDe and ASDop was high (r = 0.91, p less than 0.001), indicating accuracy of quantitating defect size via subcostal 2DE approach. However, the correlation between the left-to-right shunt magnitude and ASDe was only fair (r = 0.76, p less than 0.01). In large ASDe the shunts varied greatly, while in small ASDe the shunts increased proportionally with increasing sizes of ASD. In addition, the ratio of left-to-right ventricular diameter (RVD/LVD) was determined. The RVD/LVD correlated relatively well with the shunt magnitudes (r = 0.83, p less than 0.001). Using the two new echocardiographic parameters of ASDe and RVD/LVD, a high percentage (85%) of patients with a large left-to-right shunt requiring surgical closure can be identified. All 43 patients with ASDe greater than 2.0 cm and RVD/LVD greater than 1.1 had a left-to-right shunt greater than 40%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

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↗
PubMed1987

Biochemical evidence of platelet activation in patients with persistent unstable angina.

Thromboxane released from activated platelets and prostacyclin of the vessel wall may act as potent antagonistic modulators of platelet aggregability and coronary vascular tone. Therefore, urinary excretion of their major metabolites, 2,3-dinor-thromboxane B2 and 2,3-dinor-6-ketoprostaglandin F1 alpha, was studied in 16 patients presenting with prolonged angina at rest. The 10 patients whose condition did not improve under vigorous antianginal treatment within 48 hours exhibited higher thromboxane metabolite excretion than did the 6 patients who responded to therapy (2,208 +/- 1,542 versus 609 +/- 312 ng/g creatinine; p less than 0.001). Elevated values were also found in four of eight patients with sustained postinfarction angina. Enhanced thromboxane metabolite excretion was frequently associated with angiographic evidence of thrombus formation. When nine patients were restudied in a stable phase after 11 +/- 5 months, thromboxane metabolite excretion was consistently normal or high normal. Excretion of prostacyclin metabolites was not depressed in any patient but correlated weakly with thromboxane (r = 0.41). Thus, enhanced thromboxane production as an index of platelet activation may identify patients with active thrombus formation who could benefit most from platelet inhibitory treatment.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

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↗
PubMed1987

Right ventricular ejection fraction from equilibrium krypton-81m blood pool scans: a noninvasive predictor of pulmonary arterial hypertension.

Based on the relation between the impedance to right ventricular ejection and ejection fraction of the right ventricle (RVEF) we tested the hypothesis that radionuclide RVEF correlates inversely with pulmonary artery pressure and allows the noninvasive prediction of pulmonary hypertension. A recently developed improved equilibrium right ventricular blood pool imaging technique using ultrashort-lived krypton-81m and simultaneous right heart catheterization were combined for assessment of right ventricular systolic performance in relation to right ventricular loading in a heterogeneous group of cardiopulmonary disorders. The study group included 9 patients with pulmonary artery hypertension secondary to left ventricular dysfunction, 5 with primary pulmonary hypertension, 5 with corrected tetralogy of Fallot, and 10 normal subjects. Linear regression analysis between radionuclide RVEF and simultaneously recorded hemodynamic measurements of right ventricular loading revealed a significant inverse correlation with mean PA pressure (r = -0.87; P less than 0.001), with total pulmonary resistance index (r = -0.81; P less than 0.001) and with pulmonary vascular resistance index (r = -0.78, P less than 0.01). The sensitivity and specificity of a resting RVEF less than 40% to indicate pulmonary hypertension (mean PA pressure greater than 20 mmHg) were 71% and 100%, respectively; positive and negative predictive values were 100% and 80%, respectively. Thus, radionuclide RVEF as a parameter of right ventricular systolic performance is predominantly dependent on right ventricular afterload and has the potential for the noninvasive prediction of pulmonary hypertension in a heterogeneous group of cardiopulmonary disorders.

Humans↗
PubMed1987

[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↗
PubMed1987

[Noninvasive identification of collateralized myocardium by 201 thallium tomography in vasodilation and redistribution].

Coronary arteriolar vasodilatation may provoke the redistribution of flow to collateral-dependent jeopardized myocardium. To assess the physiologic significance of collateral channels, 80 consecutive postinfarction patients (aged: 58 +/- 8 years) underwent vasodilatation/redistribution thallium-201 tomographic (SPECT) imaging using 0.56 mg dipyridamole/kg body weight. Circumferential profile analysis of redistribution and slow washout in representative left ventricular tomograms provided quantitative evaluation of transient and persistent defects and a separation between a periinfarctional and distant inducible hypoperfusion. Tomographic perfusion data were correlated to subsequent cineangiographic analysis of wall motion and to the extent of collateral circulation between two distinct anatomic perfusion areas, one of which involved the infarct zone. Patients were grouped according to the presence (59%) or absence (41%) of angiographically visible collateral channels to the jeopardized myocardium. In the presence of collaterals, distant reversible defects were larger than in the absence of collaterals (p less than 0.05); the extent of combined periinfarctional and distant redistribution was also larger in collateralized patients (p less than 0.025), whereas the size of the persistent perfusion defect was similar in both groups. In a prospective analysis, the tomographic perfusion pattern of combined periinfarctional and distant ischemia revealed a sensitivity of 85% and a specificity of 78% for the detection of significant collateral circulation in this group of patients. Thus, using the limited collateral flow reserve as a diagnostic tool, vasodilatation/redistribution thallium-201 tomography has some potential for identifying and quantifying collateral-dependent myocardium and may guide diagnostic and therapeutic decision-making.

Aged↗
PubMed1987

[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↗
PubMed1986

[Percutaneous transluminal angioplasty of coronary bypass vessels. Quantitative findings and long-term results].

Computer-assisted quantitative angiographic analysis was undertaken of 17 stenoses in aortocoronary bypass vessels in 14 patients. Angioplasty was successful in 13 of 17 haemodynamically significant bypass stenoses, with a reduction in the degree of stenosis (cross-sectional reduction) from 82 +/- 9% to 44 +/- 9% (P less than 0.001) and a significant reduction in flow-related stenosis resistance. This method revealed significant bypass restenoses in 38% within 9 +/- 6 months, successfully treated by a second angioplasty. These patients make up a group which--in contrast to the natural progression of vascular sclerosis--is characterized by an early development of bypass stenoses and restenoses. Transluminal angioplasty after stenoses and restenoses in bypass vessels is an effective and safe alternative to reoperation.

Angioplasty, Balloon↗
PubMed1986

[Tolerance development during a 1-week course of dobutamine treatment].

UNLABELLED: Eleven patients with chronic heart failure (NYHA stage III or IV) were given dobutamine infusions over 7 days, mean dose 6.2 +/- 2.2 micrograms/kg X min. The patients were pretreated with digitalis, diuretics, and vasodilators. Haemodynamic parameters were measured prior to infusion, 30 minutes and 7 days thereafter as well as 24 hours after the end of therapy. Before and after the 7-day therapy a two-dimensional echocardiogram was taken. In four patients, the protocol had to be discontinued prematurely for technical or medical reasons. RESULTS: Arterial blood pressure, body weight, fractional shortening and end-diastolic diameter of the left ventricle were not changed significantly. Cardiac index rose acutely and returned to initial values after 7 days. Total peripheral resistance, which was initially significantly reduced, again rose after infusion over 7 days. Permanent reduction in pulmonary artery wedge pressure, even one day after the end of therapy, was observed in three patients showing a left-ventricular end-diastolic wall thickness greater than 7 mm. However, in patients whose wall thickness was less than 7 mm, there was a rise in pulmonary artery wedge pressure accompanied by a fall in cardiac index even below initial values.

Adult↗