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Biomedical subjects

F Loogen

Publications and source records attributed to F Loogen.

At least 91 records · Page 5Linked to original sources
PubMed1981

[Clinical and hemodynamic results in patients with left ventricular aneurysm after surgical therapy (author's transl)].

The clinical and hemodynamic results of 87 patients (average age 49 years, range 22 to 65 years) with left ventricular aneurysm were retrospectively investigated before and after (1-87 months) surgical treatment. 34 patients underwent aneurysmectomy only (group 1), 35 patients additionally underwent coronary revascularisation (group II), and 18 patients underwent--because of findings during operation--coronary revascularisation only (group III). The size of aneurysm was not significantly different in the three groups. Postoperatively it decreased only in groups I and II. The majority of the patients in group I (with predomination of one-vessel disease) had no angina pectoris. There was no significant change early and late (more than 12 months) after the operation. The patients in groups II and III (the majority with multi-vessel disease) showed an improvement of angina pectoris. Preoperatively most of all the patients claimed to have exertional dyspnea. On the whole, there was no significant change after operation. The majority of the patients showed an improvement in their angina pectoris and dyspnea when those symptoms were the major indications for the operation. Heart rate, systolic and end-diastolic pressure in the three groups did not significantly change after the operation. End-diastolic and end-systolic volumes decreased significantly in groups I and II. The ejection fraction increased significantly. In group III these parameters did not change. Circumferential fiber shortening velocity in the residual ventricle significantly increased only in group I. Hemodynamic studies during exercise were performed in total on 32 patients. In group I, there was a significant smaller increase of the mean pulmonary artery pressure, no significant change in groups II and III. At rest, only the patients with aneurysmectomy showed an improvement of the global and residual left ventricular function. The patients with an angiographically presumed aneurysm and viable myocardium found intraoperatively showed no improvement in function at rest or during exercise even after coronary revascularisation. The hospital mortality was 6%. Three patients died during the follow-up period because of ascertained cardiac reasons. The high mortality of non-operated patients with similar clinical and hemodynamic findings as in operated patients warrants an indication for aneurysmectomy without even taking into account the symptomatic and functional improvements.

Adult↗
PubMed1980

[Platelets and coronary artery disease (CAD) (author's transl)].

During recent years, platelets have been increasingly implicate in the pathogenesis of coronary artery disease and its complications. This is based on new knowledge of platelet physiology as well as on clinical observations. Experimentally, it can be demonstrated that platelet vessel wall interaction is important in atherogenesis. In animal, platelet aggregates in the arterial circulation may cause ischemic myocardial lesions. In patients who died suddenly platelet thrombi can often be found in the microcirculation at autopsy. Compounds released during platelet aggregation may cause a spasm of the coronary arteries. Hyperactive platelets can be demonstrated in patients with CAD as well as in patients with the known risk factors of CAD. In some clinical trials, platelet function inhibitors reduced death from cardiac causes. Here we review the theoretical and experimental basis of the "platelet hypothesis" of CAD and its complications as well as the rationale for treating patients with CAD with "'antiplatelet" drugs.

Animals↗
PubMed1980

[Hemodynamic effects of medical and surgical therapy of hypertrophic obstructive cardiomyopathy (author's transl)].

In order to assess the hemodynamic effects of medical (propranolol) and surgical (transaortal subvalvular myectomy) therapy, we determined in 20 patients with hypertrophic obstructive cardiomyopathy the following circulatory parameters at rest and during maximal exercise before and after therapy: heart rate, stroke volume, cardiac output, and pulmonary artery pressure. 9 patients were re-investigated after medical therapy of 3.5 weeks to 7 months (averaging 3 months) with a daily dose of 120 to 360 mg (mean 198 +/- 80 mg) propranolol, 11 patients 1 week to 28 months (averaging 7.5 months) after operation. Propranolol induced a significant reduction of heart rate and cardiac output averaging 20.9% and 20.3%, respectively (p in both cases < 0.0001) at equal exercise levels, no change in stroke volume, and a slight increase in the pathologically elevated exercise mean pulmonary artery pressure, with the pulmonary vascular resistance remaining unchanged. Although 3 of the 9 patients reported a slight subjective improvement, exercise capacity did not change significantly from a mean of 66.7 to 69.4 watts. Myectomy, on the other hand, induced no change in heart rate, but a significant increase in exercise stroke volume by 14.9% (p < 0.025) and a distinct increase in cardiac output by an average of 11.2% (not significant), whereas the pathologically elevated exercise mean pulmonary artery pressure fell significantly by 23.8% from a mean of 45.0 to 34.3 mm Hg (p < 0.025). 10 of the 11 surgically treated patients reported a usually marked subjective improvement, and the exercise capacity increased from an average of 61.4 to 81.8 watts (p < 0.01). Thus, the clinical and functional result of surgical therapy was significantly better than that of medical therapy and included, in contrast to medical therapy, a significant hemodynamic improvement and increase in exercise capacity.

Adult↗
PubMed1980

[Natural history of patients with severe mitral and double-valve disease under medical therapy (author's transl)].

55 patients with mitral valve disease (MV) and 30 patients with combined aortic and mitral valve lesions (DV) class III or IV (NYHA) were followed up to ten years on medical therapy. In all cases valve replacement was indicated but not done for different reasons. The prediction of late survival was analyzed by anamnestic, clinical and hemodynamic variables. The five-years survival rate in MV was 50% (stenosis 57%, incompetence 25%), in DV 28%. Those patients who refused operation had a high survival rate. Functional class IV, cardiothoracic ratio greater than 60%, mean pulmonary artery pressure greater than 30 mm Hg (MV) or greater than 25 mm Hg (DV), pulmonary vascular resistance greater than 400 dyn/s/cm5 (MV) or 300 dyn/s/cm5 (DV) were significantly negative factors influencing the survival curves. In addition, in patients with MV and incomplete right bundle branch block and a PEP/LVET ratio greater than 0.34 calculated from systolic time intervals indicated a serious prognosis. Comparing the survival curves after mitral valve replacement and conservative therapy, it is evident that in mitral and double valve disease class III or IV the operative therapy leads to life prolongation with the exception of mitral stenosis class III.

Adolescent↗
PubMed1980

[A 17-years follow-up study after closed mitral commissurotomy (author's transl)].

410 patients were operated upon by closed mitral commissurotomy in 1961-62. Of this group, 224 patients were followed up until 1978. The actuarial survival rate after 16 to 17 years postoperatively was 58%. Overall 43 patients were reoperated (second commissurotomy or mitral valve replacement). The cumulative reoperation rate of these patients was 1.5% per year. The mortality rate in patients with reoperation was 1.2% per year, without reoperation 2% per year. 87 patients are still alive 17 years after mitral commissurotomy without reoperation. 59% of this group belong to functional class II or I (NYHA). Most of them have combined mitral valve disease with predominant mitral stenosis. Atrial fibrillation was present in 33% (n = 29) preoperatively and in 58% (n = 50) postoperatively at the end of the study. Only 20% of all patients were on anticoagulant therapy. Nevertheless, the total embolic rate (5.7%) and the cumulative embolic rate (0.2% per year) remained low. The good long-term results show that mitral commissurotomy is an effective therapeutic approach in patients with mitral stenosis.

Adolescent↗
PubMed1980

[Thallium-201 myocardial scintigraphy in patients with normal coronary arteries and normal left ventriculogram - comparison with hemodynamics, metabolic and morphologic findings (author's transl)].

36 consecutive patients with chest pain and/or severe ventricular dysrhythmias, but normal coronary arteries and normal left ventriculogram, underwent thallium-201 myocardial imaging at rest and during exercise. The myocardial scintigram was abnormal in 27 patients (group A) and normal in only 9 patients patients (group B). To answer the question, whether the scintigram was false positive or a correct expression of a myocardial disorder not detectable with angiocardiographic methods, we compared the scintigraphic results with the findings of resting and exercise ECG (n = 36), mean pulmonary artery pressure during exercise (n = 27), myocardial lactate extraction during highrate atrial pacing (n = 14) and light- and electronmicropic examination of right ventricular endomyocardial biopsies (n = 14). The resting ECG was abnormal in 7 of 27 patients of group A and 1 of 9 patients of group B, the exercise ECG in 20 of 27 patients of group A and 1 of 9 patient B. An abnormally elevated exercise pulmonary artery pressure was measured in 10 of 21 patients of group A and 1 of 6 patients of group B. High rate atrial pacing induced an abnormal myocardial lactate extraction in 3 of 13 patients of group A, but not in the single investigated patient of group B. All 12 examined patients of group A and 1 of 2 patients of group B had abnormal biopsy findings. The high incidence of abnormal findings in group A compared to the rare incidence in group B suggests, that the abnormal myocardial scintigrams in patients with chest pain and normal coronary arteries is likely not false positive but reflects a myocardial disorder not being recognized on angiography.

Adult↗
PubMed1980

[Natural history of patients with severe aortic valve disease under medical therapy (author's transl)].

65 patients out of 420 with aortic valve lesions (class III and IV NYHA) who underwent cardiac catheterization in 1967-1976 were not operated upon for different reasons. The fate of these 65 patients was analyzed retrospectively to elucidate the natural history of severe aortic valve disease. The five years survival rate was 26% (aortic stenosis 17%, aortic incompetence 37%). Patients with angina pectoris and congestive heart failure, ventricular ectopic beats, mean pulmonary artery pressure greater than 30 mm Hg, mean left atrial pressure greater than 16 mm Hg and left ventricular enddiastolic pressure greater than 20 mm Hg had a significant worse prognosis than those without these parameters. Otherwise patients who refused the operation by personal reasons had a high survival rate. The results of the study indicate that patients with aortic valve disease class III or IV (NYHA) have a serious prognosis when treated medically. In comparison with our patients who underwent aortic valve replacement surgery has proven to be a life-prolonging procedure in these highly endangered cases.

Adolescent↗
PubMed1979

[Echocardiographic observations in malfunctioning heart valves due to thrombosis (author's transl)].

The study includes two patients with obstruction of prosthetic heart valves by thrombosis. In the first patient, a thrombus attached to the ventricular side of the cage of a Smeloff-Cutter mitral prosthesis caused incomplete excursion of the ball in most cardiac cycles, which was detected by echocardiography. In the second patient a thrombosis of the atrial and ventricular side of a Lillehei-Kaster mitral prosthesis delayed opening of the disc. The initial part of the opening movement was "rounded", the excursion of the disk diminished. The cases presented indicate that in patients whose condition deteriorates after prosthetic valve replacement, echocardiography can help identify the cause. In particular, the technique makes it possible to differentiate between valvular dysfunction and muscular insufficiency of the left ventricle. Comparison with recordings obtained in the early postoperative period facilitate the detection of a malfunctioning prosthesis.

Echocardiography↗
PubMed1979

[The applicability of systolic time intervals in patients before and after aortic valve replacement (author's transl)].

In order to evaluate the systolic time intervals (STI) for characterizing the left ventricular pump function and the clinical course in patients with aortic valve disease, 35 patients with aortic stenosis (AS) and 25 patients with aortic insufficiency (AI class III or IV (NYHA) were studied before and 1 year after valve replacement either with Björk-Shiley, Lillehie-Kaster or Starr-Edwards aortic prostheses. Left ventricular ejection time index (LVETI), preejection period index (PEPI) and PEP/LVET were determined and compared with cardiac index (CI), stroke volume index (SVI) and ejection fraction (EF). Prosthetic valve replacement leads to a high significant decrease of LVETI from preop. 468 +/- 31 ms to postop. 394 +/- 26 ms (mean normal values 415 ms) and an increase of PEPI from 100 +/- 26 ms to 136 +/- 25 ms (normal 132 ms) as of PEP/LVET from 0.21 +/- 0.09 to 0.41 +/- 0.12 (normal 0.31). Pre- as well as postop. there is no difference in STI between AS and AI. Also the groups with the three prosthetic valve types do not differ significantly. LVETI and PEPI correlate only postop. with CI and SVI, but PEP/LVET correlates well with EF (r = -0.73) before and after operation. The comparison of STI with the hemodynamic data suggest that preop. values of STI near normal and postop. LVETI below, PEPI and PEP/LVET above the mean values of the whole group with aortic valve replacement indicate left ventricular pump dysfunction. The STI are helpful in the pre-/postop. follow-op of patients with severe aortic valve disease to characterize the clinical and hemodynamic course.

Aortic Valve↗
PubMed1979

[Echocardiographic determination of the severity of mitral stenosis by the mitral valve closure index (author's transl)].

In 34 patients with mitral stenosis or combined mitral valve disease class II, III or IV (NYHA), the mitral valve closure index (MVCI, Shiu et al. 1977), based on the rate of diastolic apposition of the anterior and posterior mitral leaflet echos, and the diastolic closure rate (EF-slope) were determined and compared with hemodynamic data such as mean left atrial pressure (PLA), mean diastolic pressure gradient across the stenotic valve (DP) and mitral valve orifice area (Q), calculated by the Gorlin formula. MVCI and EF-slope correlated more favorably with DP (MVCIr = -0.71, EF-sloper = -0.53) than with Q and PLA. The results were not different in patients with sinus rhythm or atrial fibrillation. Using MVCI or EF-slope thie discrimination between severe and moderate or between moderate and light mitral stenosis was uncertain. Nevertheless, MVCI below 30 was associated with light, above 50 with severe mitral stenosis. In spite of the relationship between MVCI or EF-slope and the severity of mitral stenosis, in the individual case an exact quantification of mitral stenosis is not possible due to the great variability of echocardiographic data. For the assessment of the severity of mitral stenosis the mitral valve closure index is not superior to the EF-slope.

Adult↗