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Biomedical subjects

W Bleifeld

Publications and source records attributed to W Bleifeld.

At least 163 records · Page 9Linked to original sources
PubMed1981

Transesophageal echocardiographic evaluation of left ventricular function at rest and during dynamic exercise in aortic insufficiency.

Transthoracic echocardiography is often of limited value for the evaluation of left ventricular (LV) performance during dynamic exercise (E). Therefore, we studied LV function during maximal E by supine ergometry in 10 normal subjects (N) and 15 patients of aortic regurgitation (AR) with (8) and without (7) symptoms with transesophageal M-mode echocardiography. With this transesophageal approach, where an esophageal transducer is incorporated at the tip of a commercially available gastroscope, good continuous recordings of LV diameter were obtained without being disturbed by respiration or thoracic movement during E. Systolic blood pressure was measured by cuff method and echocardiographic indices such as heart rate, enddiastolic dimension (ED), and fractional shortening (FS) were determined at rest (R) and during maximal E. In N the following significant changes were observed during maximal E; pressure rate product (13 +/- 2 mmHg . min-1 . 10(3) leads to 20 +/0 3 mmHg . min-1 . 10(3), p less than 0.001), ED (51 +/0 5 mm leads to 48 +/- 6 mm, p less than 0.05), and FS (37 +/- 4% leads to 43 +/- 5%, p less than 0.001). In AR no significant change was observed between pressure-rate products in symptomatic and asymptomatic groups at R and during E, respectively. Significant changes in ED during E was observed only in asymptomatic AR (55 +/- 4 mm leads to 51 +/- 6, p less than 0.05). FS was within a normal range in both groups of AR at R. During maximal E, however, symptomatic group exhibited a decrease of FS (33 +/- 7% leads to 28 +/- 5, p less than 0.05), whereas the asymptomatic group showed a significant increase (34 +/- 5% leads to 37 +/- 6%, p less than 0.01). Thus the present study revealed the different response of LV in symptomatic and asymptomatic AR to E in terms of ED and FS.

Adult↗
PubMed1980

[Prazosin long-term treatment in severe chronic cardiac failure (author's transl)].

In addition to digitalis and diuretics, 10 patients with chronic cardiac failure were treated with prazosin (15 mg/d) over a period of 6 months. It was shown that the mean pulmonary artery pressure decreased significantly, on average by 30%, during both rest and exercise. Despite significant decrease of arterio-central venous oxygen difference no improvement of cardiac output was measured after 6 months on prazosin. Cardiac output increased clearly in only 4 patients, particularly during exercise. Heart rate and arterial blood pressure remained statistically unchanged. Eight patients reported subjective improvement of dyspnoea after 6 months. Prazosin plasma levels were between 9.4 and 58.6 ng/ml. Side effects such as orthostatic hypotension, urinary incontinence and disturbances of potency occurred in 4 patients. Antinuclear factors could not be demonstrated after 6 months. These data show that after 6 months of prazosin therapy haemodynamically significant improvement of pulmonary congestion can be demonstrated without concurrent increase of cardiac output. Prazosin is indicated in treatment of chronic cardiac insufficiency with predominant pulmonary congestion an an adjunct to digitalis and diuretic baseline treatment.

Adult↗
PubMed1980

[Significance of myocardial blood flow and metabolism in valvular aortic stenosis for the indication for operation (author's transl)].

Coronary venous blood flow measured by continuous thermodilution, myocardial oxygen consumption and lactate extraction rate were estimated at rest and during graded heart rate exercise in 21 patients with compensated aortic valve stenosis and in 10 patients without heart disease. Significant differences between the groups were found only in coronary sinus flow, however not in coronary perfusion related to 100 g of left ventricular muscle mass. As regards indication for operation patients with aortic valve stenosis were differentiated according to transvalvular pressure differences. Pressure gradients of more than 90 mm Hg (n = 5) were associated with significant lowering of weight-related myocardial perfusion and oxygen consumption and high lactate production during stimulation. This evidence of myocardial ischaemia was also seen in 3 out of 11 patients with a pressure gradient between 51 and 90 mm Hg. The rest of the patients showed no significantly different measurements in comparison with the control group. Thus insufficient myocardial perfusion during exercise is likely in patients with transvalvular pressure differences of more than 90 mm/Hg and possible when the difference is more than 50 mm Hg.

Adult↗
PubMed1980

[Non-invasive method for recognition of coronary artery spasm: 201thallium sequential scintigraphy of the myocardium after ergotamine provocation (author's transl)].

For evaluation of coronary artery spasm 201thallium sequential scintigraphy of the myocardium after ergotamine provocation was performed in 10 patients with recurrent angina pectoris at rest and normal exercise ECG. In 9 out of the 10 patients ergotamine administration in the same dosage was repeated during the coronary angiography. A reversible defect in the 201thallium scintigram representative of regional myocardial ischaemia developed in 9 patients after ergotamine. Only in 4 out of the 9 patients angina pectoris and ST elevation were present at the same time. In all cases coronary spasm after ergotamine was demonstrable in the coronary angiogram; in the 4 patients with ergotamine-induced Prinzmetal angina pectoris it consisted of complete vascular occlusion, in the asymptomatic patients of incomplete vascular narrowing of a higher degree. In all cases the spasm could be relieved by ergotamine antidotes within a few minutes.

Adult↗
PubMed1980

[Correlation between myocardial Thallium-201 kinetics, myocardial lactate metabolism and coronary angiographic findings in hypertrophic cardiomyopathy (author's transl)].

In 20 patients with idiopathic hypertrophic obstructive and nonobstructive cardiomyopathy (IHSS), biphasic Thallium-201 myocardial scintigraphy was performed. Regional myocardial Thallium-201 kinetics of these patients were analysed by a semiquantitative computerized method and compared with those of 6 normal subjects. In 12 of 18 with IHSS and no coronary artery disease 26 regions of interest with irreversible and 6 regions of interest with reversible Thallium-201 defects could be detected. Most of the Thallium-201 defects were localized in the interventricular septum. The defects were not related to the age of the patients and there was no relationship between the occurrence of reversible Thallium-201 defects and pathological myocardial lactate extraction rate during maximal atrial pacing measured in 14 patients. The percentage (6.8%) of irreversible defect regions in patients with LV outflow obstruction at rest (n = 13) was more than twice higher compared to those (n = 5, 3.2%) without LV outflow obstruction or no provocative pressure gradient, resp. These data suggest that IHSS is often associated with regional ischemic myocardial fibrosis despite normal coronary arteries. Therefore in these patients Thallium scintigraphy cannot be used as a noninvasive screening method to exclude or prove coronary artery disease.

Adult↗
PubMed1980

[Left ventricular hemodynamics at rest and during exercise in patients with idiopathic mitral valve prolapse syndrome (author's transl)].

Idiopathic Mitral Valve Prolapse has been regarded by some authors as a primary cardiomyopathy. To determine, if left ventricular hemodynamics at rest and during exercise are impaired, 20 young symptomatic patients with idiopathic mitral valve prolapse, proven by echo- and phonocardiography, without coronary artery disease or severe mitral regurgitation, underwent supine bicycle exercise stress testing. Pulmonary artery pressure, central venous oxygen saturation and cardiac index as well as heart rate were measured with a Swan-Ganz thermodilution catheter and the results compared with those of 10 voluntary normal subjects. Variance analysis showed no significant differences in global left ventricular hemodynamics between patients with idiopathic mitral valve prolapse and normal subjects at rest as well as during exercise. In addition no significant differences were found between patients with echocardiographical holosystolic or mesosystolic mitral valve prolapse. In patients with idiopathic mitral valve prolapse, global left ventricular hemodynamics are not impaired neither at rest nor during exercise.

Adolescent↗
PubMed1979

[Anti-arrhythmic effect of tocainide (lidocaine congener) on ventricular arrhythmias (author's transl)].

The antiarrhythmic effect of tocainide, an amine analogue of lidocaine, was tested in the course of a double-blind trial on 12 patients with ventricular arrhythmias. Daily dose was 400 or 600 mg every eight hours. In all tested patients the frequency of ventricular extrasystoles, analysed by means of ambulatory 24-hour ECG monitoring, decreased by an average of 70%. In four of nine patients the severity of the ventricular extrasystoles (Lown's classification) was improved by at least one functional class. There was no correlation between the anti-arrhythmic effect and the plasma level of tocainide, which was between 4.1 and 9.7 micrograms/ml. Four patients had side effects in the form of CNS symptoms, but the drug did not have to be discontinued. Tocainide is an orally effective antiarrhythmic drug, an alternative in the treatment of ventricular arrhythmias.

Adult↗
PubMed1979

[Ventricular arrhythmias in mitral valve prolapse syndrome (author's transl)].

Long-term ECG monitoring over 22 hours and exercise ECGs were performed in 72 patients with mitral valve prolapse syndrome. 70% of the patients had ventricular arrhythmias. In 28% severe arrhythmias in the form of multifocal atopic beats and ventricular runs were demonstrated. Long-term ECG monitoring was a suitable method for detection of these arrhythmias and superior to exercise ECG. Clinical, electrocardiographic and echocardiographic findings could not be correlated to the severity of ventricular arrhythmias.

Adolescent↗