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Biomedical subjects

F Loogen

Publications and source records attributed to F Loogen.

At least 55 records · Page 3Linked to original sources
PubMed1983

Differential diagnosis of hypertrophic cardiomyopathies: typical (subaortic) hypertrophic obstructive cardiomyopathy, atypical (mid-ventricular) hypertrophic obstructive cardiomyopathy and hypertrophic non-obstructive cardiomyopathy.

Previous clinical studies in patients with hypertrophic cardiomyopathies predominantly comprised patients with typical subaortic HOCM and in many other studies patients with 'hypertrophic' cardiomyopathies were investigated; i.e. no distinction was made between patients with the typical obstructive, the atypical obstructive and the non-obstructive forms of hypertrophic cardiomyopathy. In addition, in the more differentiated studies, the differential diagnosis between HOCM and HNCM was based mainly on the presence and absence of the subaortic pressure gradient. This is also true for the clinical characterization of both types of hypertrophic cardiomyopathy. Finally, diagnostic descriptions of atypical (mid-ventricular) HOCM exist only in the form of case reports, i.e. they are not based on observations in a large number of patients. Therefore a comparative study in 353 patients with hypertrophic cardiomyopathies was designed to characterize the clinical picture of patients with HNCM and with atypical HOCM in relation to typical HOCM with special reference to the differential diagnosis. The study revealed a profoundly different diagnostic profile of the three subsets of hypertrophic cardiomyopathies. The distinction between the three subsets may serve as a more differentiated basis for clinical studies related to diagnosis, therapeutic approaches, long-term follow-up observations and prognostic evaluation of patients with hypertrophic cardiomyopathies.

Adolescent↗
PubMed1983

Results of surgical therapy in patients with left ventricular aneurysm.

The clinical, angiographic and haemodynamic findings in 87 patients with left ventricular aneurysm were investigated before and after different surgical interventions. Thirty-four patients underwent aneurysmectomy alone (group I), 35 patients had additional coronary revascularization (group II), and 18 patients had revascularization alone because of the findings during operation (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 (predominantly one-vessel disease) had no angina pectoris, with no significant change early and late (more than 12 months) after operation. The patients in groups II and III (with more two- and three-vessel diseases) showed an improvement in angina pectoris. Preoperatively, most patients had experienced exertional dyspnoea. Overall, there was no significant change after operation, but most patients showed an improvement in angina and dyspnoea when these symptoms had been the major indication for surgical therapy. Heart rate, systolic and end-diastolic pressures in the three groups did not change significantly after surgery. End-diastolic and end-systolic volumes decreased and ejection fraction increased significantly in groups I and II. In group III these variables did not change. Circumferential fibre shortening velocity in the residual ventricle increased significantly only in group I. Haemodynamic studies during exercise were performed in a total of 32 patients. In group I the increase of mean pulmonary pressure was significantly lower postoperatively; there was no significant change in groups II and III.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

[Clinical aspects, course and prognosis of various forms of hypertrophic cardiomyopathy].

To characterize the different types of hypertrophic cardiomyopathy [typical (subaortic) hypertrophic obstructive cardiomyopathy (HOCM) (n = 235), atypical (midventricular or apical) HOCM (n = 33), and hypertrophic nonobstructive cardiomyopathy (HNCM) (n = 85)], studies of the clinical picture, course, and prognosis were performed in 353 patients. Clinical picture. There were found to be distinct differences between the diseases in terms of incidence, symptoms, findings at auscultation, carotid pulse tracings, ECG (incidence of abnormal negative T-waves), and echocardiography. Echochardiography proved to be diagnostically less specific than invasive methods, however, and in particular often failed to distinguish between atypical HOCM and HNCM. Clinical course. There was no evidence of a change from one form of hypertrophic cardiomyopathy to the other. The Sokolow-Lyon index in the ECG did not increase in any group. The rate of complications (endocarditis, systemic emboli) varied between 0.61 and 1.28 events per 100 patient years. Only 7.4%-23.5% of patients with HOCM improved as a result of conservative treatment, compared to 83%-87.5% of surgical patients. In addition, the rate of postoperative syncope was reduced by 90%. Prognosis. 90 patients were operated on. Operative mortality in typical HOCM was 4.5% over the last 5 years. If this is disregarded, the cumulative survival rates are significantly higher in surgical patients with typical HOCM than in those treated conservatively. The data confirm surgical treatment to be the therapy of choice in patients with HOCM refractory to conservative treatment. The prognosis seems to be improved by operation.

Adult↗
PubMed1983

[Digital subtraction angiocardiography: accuracy of left ventricular volume determination using intravenous injection of contrast medium].

The usefulness and accuracy of intravenous digital subtraction angiography of the left ventricle was proved by comparison with conventional left ventricular angiocardiography. During heart catheterization two cineangiograms were performed in 20 patients at rest: one with direct injection of contrast medium into the left ventricle and the other with intravenous injection. The intravenous angiocardiograms were processed by a hardwired digital image-processing system designed by our own group. Image enhancement was obtained by subtracting a mask image from the contrasted image of the left ventricle. The utility of four different mask modes was examined by correlating end-diastolic and end-systolic volumes determined from conventional and intravenous digital subtraction angiocardiograms of the left ventricle respectively. Reliable quantitative results could only be achieved by obtaining mask and contrasted images from the same phase of the cardiac cycle. Using these special mask modes, the standard deviations of the residuals amounted to +/- 33 and +/- 36 ml respectively. The results show that intravenous digital subtraction angiocardiography allows a quantitative determination of left ventricular volumes at rest.

Angiocardiography↗
PubMed1983

[Reliability of digital subtraction angiocardiography for the evaluation of left ventricular function and physical stress].

The reliability of determinations of left ventricular dimensions from digital subtraction angiocardiographies during exercise using intravenous injection of contrast material was proved in 20 patients. All angiocardiograms could be analyzed qualitatively and quantitatively only by means of the time-interval-difference (TID-) mode. Compared with other mask modes the superiority of the TID-mode results from the close temporal relationship between mask and contrasted frame. Thus, changes in position and brightness of the background structures are small, and left ventricular contours can be determined accurately despite intense respiratory movements. The intra-observer variability of determinations of end-diastolic and end-systolic volumes was +/- 12 ml (i.e. 7.5% of the mean value), corresponding inter-observer variability was +/- 24 ml (i.e. 17% of the mean value), respectively. Intra-observer deviation in determining ejection fraction was 2.8% (i.e. 4.5% of the mean value). The intra-observer variability in determining left ventricular axes was basal +/- 0.40 cm (i.e. 7% of the mean value), equatorial +/- 0.73 cm (i.e. 13% of the mean value) and apical +/- 0.34 cm (i.e. 8% of the mean value). Deviations of corresponding circumferential fiber shortening rates were basal +/- 0.22 s-1 (i.e. 14% of the mean value), equatorial +/- 0.32 s-1 (i.e. 22% of the mean value), and apical +/- 0.18 s-1 (i.e. 13% of the mean value). The results show that left ventricular dimensions can be determined accurately from intravenous angiocardiograms during exercise using digital subtraction angiocardiography.

Adult↗
PubMed1983

[Cardiac valve replacement and simultaneous myocardial revascularization].

Between 1974 and 1981, 84 patients underwent cardiac valve replacement and simultaneous myocardial revascularization. 77 patients had rheumatic valve disease with coexisting coronary artery disease (group I). Single valve replacement was performed in 67 patients, double valve replacement in 9 patients, and triple valve replacement in 1 patient. A second group consisted of 7 patients with severe coronary artery disease: in 6 of them papillary muscle necrosis necessitated mitral valve replacement, and in 1 patient hemodynamic reasons made aortic valve replacement necessary. The mean number of coronary artery bypass grafts performed was 1.7 in group I and 2.4 in group II. 56 patients were classified as NYHA grade III, 28 as grade IV. 8 patients (9.4%) died within 32 days after operation (7 from group I, 1 from group II). Follow-up averaged 20 months. There were 3 late deaths; 35 of the survivors underwent clinical reexamination, and all 73 completed questionnaires. Symptomatic improvement was found to be excellent: 97% of the patients examined had improved at least by one functional class. It is our impression that simultaneously performed myocardial revascularization does not substantially increase the risk of cardiac valve replacement, and yields good late results.

Adult↗
PubMed1983

[Effect of prosthetic heart valve replacement on the natural course of isolated mitral and aortic as well as multivalvular diseases. Clinical results in 783 patients up to 8 years following implantation of the Björk-Shiley tilting disc prosthesis].

In order to establish the influence of prosthetic valve replacement on the natural course of mitral, aortic, and double-valve disease of NYHA class III and IV, the progress of 359 patients with Björk-Shiley mitral-valve prostheses (BSM), 317 with aortic valve prostheses, and 107 with double valve prostheses was compared with that of patients who had been treated medically. In this last group of patients, valve replacement had been recommended in the period 1968-1976, but for various reasons had not been carried out. Cumulative survival rates after 8 years were 77% for the BSM group, but only 32% for the medically treated group (p less than 0.0001). One year after operation, 70% of the BSM patients showed an improvement equivalent to one NYHA class, and in the majority this was still apparent after 5 years. In patients with aortic-valve incompetence, cumulative survival rates were 86% for the surgically treated group and 32% for the medically treated group (p less than 0.00001). In aortic-valve stenosis, these differences of cumulative survival rates were even more pronounced (p less than 0.000001), and were calculated to be 85% in surgically treated and 10% in medically treated patients. Clinical improvement in the BSA group averaged 1.5 NYHA classes. The 5-year survival rate for the patients with mitral and aortic-valve disease was 32%, while following doublevalve replacement it was 67% (p less than 0.005). Clinical improvement after double-valve replacement was similar to that following mitral-valve replacement. Prosthetic heart-valve replacement significantly prolongs life in patients with isolated mitral- or aortic-valve lesions as well as in patients with double-valve disease of NYHA classes III and IV. Even in the early years of the study, when the operative mortality was relatively high, the surgically treated groups had a significantly higher survival rate than the conservatively treated groups, and this was already apparent at an early stage in the follow-up period. Improvement of functional capacity and relief of symptoms amount to a difference of approximately one NYHA class in mitral and double-valve disease and of approximately 1.5 NYHA classes in aortic-valve disease.

Adolescent↗
PubMed1983

[Value of the floating catheter test in cardiologic diagnosis].

This study had two aims: a) to investigate the diagnostic value of right heart catheterization at rest and during exercise in patients with angina pectoris and dyspnea, and b) to find out whether right heart catheterization during exercise provides additional diagnostic information when the correct diagnosis has been established by invasive means. The findings in 109 patients with coronary or myocardial heart disease (average age 50 years) were investigated retrospectively. Right heart catheterization is a semiinvasive measure which permits the differentiation of normal ventricles from ventricles with impaired function during exercise; further diagnostic information cannot be obtained, however. In patients with angina pectoris, right heart catheterization has no greater diagnostic value than the ECG during exercise. The patients were divided into five groups according to the final diagnosis: 55 with coronary heart disease, 11 with dilatative and 6 with latent cardiomyopathy, 26 with systemic hypertension, and 11 without heart disease. The results show that right heart catheterization during exercise is absolutely necessary in addition to invasive measures in patients with normal function of the left ventricle at rest and without coronary heart disease, as these patients show either a normal (patients with systemic hypertension, patients without heart disease) or an abnormal increase in pulmonary artery pressure during exercise (patients with systemic hypertension, patients with latent cardiomyopathy). Patients without coronary heart disease but with impaired left ventricular function even at rest always show a pathological increase in pulmonary artery pressure during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

[Effect of systolic-diastolic displacement of the base of the heart on M-mode echocardiography].

M-mode-beam detects only structures moving in a direction parallel to them. The purpose of this study was to examine those movements of the heart which cannot be recorded by M-mode. We examined ten normals, ten patients with left ventricular volume overload, and ten patients with left ventricular pressure overload by M-mode and two-dimensional echocardiography (parasternal long axis view) simultaneously. We looked at the movement of particular structures during the cardiac cycle. A systolic movement of the base of the heart toward the apex is perpendicular to the M-mode beam and can therefore not be recorded. This shift is marked in patients with volume overload. End-diastolic diameter was measured too far apically in relation to the end-systolic diameter. We measured the amount of this dislocation of the end-diastolic diameter and corrected it. The new end-diastolic diameter was lower than the usual one. The difference was: -2.2 +/- 1.9 mm in normals (p less than 0.02); -6.9 +/- 2.6 mm in left ventricular volume overload (p less than 0.005); and -0.8 +/- 2.2 mm in pressure overload (n.s.). The overestimation of the fractional shortening was 12.4 +/- 13.3% in normals (p less than 0.02) and 21.4 +/- 7.4% in volume overload (p less than 0.005), expressed as a percentage. In conclusion, the static M-mode beam does not cross the same parts of the heart during systole and diastole because of movements of the base of the heart in relation to the beam. Misinterpretations of left ventricular function are the consequence. These depend on the extent of the movements and the configuration of the left ventricle.

Adolescent↗
PubMed1983

[Left bundle-branch block: inferences from ventricular septal motion in the echocardiogram concerning left ventricular function].

In left bundle branch block (LBBB) abnormal motions of the interventricular septum (IVS) are well known in echocardiography. We asked: (1) Is it possible to distinguish several kinds of IVS motion in the M-mode echocardiogram and (2) Is there any correlation with clinical data? We analyzed the M-mode echocardiograms of 100 patients in whom LBBB had been diagnosed, either alone or in connection with latent or dilatative cardiomyopathy. All showed a posterior motion of the IVS in early systole. Three kinds of motion could subsequently be identified: anterior (= paradox) (18%, type A), posterior (= normal) (58%, type B), and intermediate (24%, type AB). Group A had a more severe clinical stage of disease than group B (p less than 0.0005); ECG showed a longer QRS complex (p less than 0.0005), X-ray a bigger cardiac-thoracic ratio (p less than 0.0005), and M-mode-echocardiogram larger left ventricular end-diastolic diameters (p less than 0.025). Mean values of group AB fell between those of group A and those of group B. Moreover, ejection fraction at left ventricular angiography was lower in group A (52.0%) than in groups AB (58.0%) and B (62.9%) (A vs B p less than 0.005), and mean pulmonary artery pressure on exertion was higher in group A (43.3 mm Hg) than in groups AB (38.1 mm Hg) and B (28.7 mm Hg) (A vs. B p less than 0.0005). For types A and AB taken together, the likelihood of abnormal pulmonary artery pressure on exertion was 88%.(ABSTRACT TRUNCATED AT 250 WORDS)

Bundle-Branch Block↗
PubMed1983

[Effect of valve type and valve function on chronic intravascular hemolysis after alloprosthetic mitral and aortic valve replacement].

In 1091 patients with isolated Björk-Shiley, Lillehei-Kaster, Starr-Edwards, and St. Jude Medical mitral and aortic valve replacement, hemolysis parameters were determined (hemoglobin, LDH, haptoglobin, free plasma hemoglobin, reticulocyte count, serum bilirubin, transferrin, urine hemosiderin, schistocyte count). In 1006 of these patients no valve dysfunction was detected, while in 85 patients either paravalvular leakage or a thrombosis of the prosthetic valve was present. Haptoglobin was the most sensitive parameter for detecting even mild intravascular hemolysis, which was present in two-thirds of patients after alloprosthetic heart valve replacement. For quantifying red cell damage LDH was useful. Hemolysis was somewhat higher after Lillehei-Kaster and Starr-Edwards than after Björk-Shiley or St. Jude Medical implantation. The variance of LDH levels can be explained in a high percentage by correlating them with the hemodynamic findings at rest and exercise, which are indirect parameters of velocity profiles. Hemolysis is higher after aortic than after mitral valve replacement, with the exception of St. Jude valves. In patients with perivalvular leakage or valve thrombosis, red cell damage is more pronounced than in normally functioning prostheses (p less than 0.0005). When the hemolysis characteristics of the individual types of prosthesis are taken into account, the degree of hemolysis is a reliable indicator (p less than 0.05) of the functional integrity of the prosthesis. However, the degree of hemolysis does not correlate with the hemodynamic significance of perivalvular regurgitation.

Adolescent↗
PubMed1983

Central hemodynamics at rest and during exercise after mitral valve replacement with different prostheses.

To compare the hemodynamic features of different prosthetic heart valves that have equal tissue anulus diameter (29 mm or comparable), 75 patients with isolated mitral valve replacement (19 with Björk-Shiley Standard [BS], five with Hall-Kaster [HK], seven with Ionescu-Shiley [IS], 12 with Lillehei-Kaster [LK], 12 with Starr-Edwards [type 6120, SE], and 20 with St. Jude Medical [SJ] prostheses) were reexamined approximately 1 year after operation by right and left heart catheterization while they were at rest and during bicycle exercise. Mean pulmonary artery and mean left atrial pressure were reduced significantly in all the groups postoperatively. However, pulmonary artery and left atrial pressure were somewhat lower after BS and SJ implantation than the comparable pressures in the other groups. Normal values were reached only in a small number of patients, and the cardiac index remained at the lower limit of normal. Average diastolic pressure gradients in patients at rest were 2.3 +/- 0.6 mm Hg after SJ, 4.5 +/- 1.6 after BS, 5.2 +/- 3.3 after HK, 5.3 +/- 1.6 after IS, 7.1 +/- 1.3 after LK, and 6.3 +/- 2.0 after SE implantation. Effective valve orifice areas were calculated to be 3.1 +/- 0.8 cm2 in the SJ group and 2.2 +/- 0.5 cm2 in the BS group and even smaller in the other groups. Total volume loss does not seem to be significantly different among the valve types reexamined as determined by left ventricular angiography. For hemodynamic reasons, of all those prosthetic valves we compared, the SJ prosthesis appears to perform best in terms of lowest pressure gradients and largest effective orifice areas.

Adolescent↗
PubMed1983

Late complications in patients with Björk-Shiley and St. Jude Medical heart valve replacement.

Valve-related complications after Björk-Shiley mitral valve implantation (n = 475), aortic valve implantation (n = 424), or mitral-aortic valve implantation (n = 119) were compared with those after St. Jude Medical mitral valve replacement (n = 173), aortic valve replacement (n = 152), or mitral-aortic valve replacement (n = 69). All patients were placed on anticoagulant therapy with phenprocoumon early after operation. All patients had a comparable follow-up time of approximately 23 months, which showed that cumulative thromboembolic rates were significantly higher after St. Jude valve implantation than after Björk-Shiley valve implantation. Reoperations were necessary because of valve thrombosis (0.46%), perivalvular leakage (2.2%), or prosthetic valve endocarditis with perivalvular regurgitation (0.46%). One Björk-Shiley mitral valve prosthesis had to be replaced because of fracture of the outlet strut. Without significant intergroup differences, hemorrhage due to anticoagulant treatment was the most frequent complication. Thromboembolic complications were significantly more frequent after Björk-Shiley mitral, aortic, and double valve replacements than after St. Jude valve implantation. This may lead to consideration of changes in the prophylaxis of thrombus formations in the St. Jude valve, especially in aortic valve replacements, in patients with sinus rhythm.

Adolescent↗
PubMed1983

[Late complications following Björk-Shiley and St. Jude Medical heart valve replacement].

Valve-related complications after Björk-Shiley mitral (n = 475), aortic (n = 424), or mitral-aortic implantation (n = 119) were compared to complications after St. Jude mitral (n = 173), aortic (n = 152), and St. Jude mitral and aortic (n = 63) replacements. The 1,018 consecutive patients with Björk-Shiley valves had been operated upon between 1974 and 1982, those with St. Jude valves between 1978 and 1982. All patients were placed on anticoagulant therapy with phenprocoumon early after operation and no significant intergroup differences in the effectiveness of the anticoagulant therapy were found. At a comparable follow-up time of approximately 23 months, 24 major thromboembolic episodes were observed after Björk-Shiley mitral (BSM) and 3 after St. Jude mitral valve implantation (SJM), corresponding to a thromboembolic rate of 2.82/100 patient years with BSM and 0.93/100 patient years with SJM. After aortic valve replacements, 1.93 events in 100 patient years occurred after Björk-Shiley aortic (BSA) and 0.73 after St. Jude aortic implantation (SJA). In patients with double valve replacements, these rates were 3.2 (BSM + BSA) and 0.88 (SJM + SJA), respectively. The cerebral vessels were involved in 52% and the arteries of the extremities in 22% of these major events. Six Björk-Shiley prostheses had to be replaced because of valve thrombosis. The overall incidence of severe hemorrhagic complications was 2.94/100 patient years in BSM and 1.79 in SJM. After aortic valve replacement, we found rates of 1.80/100 patient years (BSA) and 2.57/100 patient years (SJA), respectively. Intravascular hemolysis no longer seems to be a significant clinical problem. However, indications of red cell damage after heart valve replacement were significantly greater in patients with perivalvular leakage, valve thrombosis, or dysfunction than in those with normally functioning prostheses. Reoperations were necessary because of valve thrombosis (0.46%), perivalvular leakage (2.2%), or prosthetic valve endocarditis with concomitant perivalvular regurgitation (0.46%). One valve had to be replaced because of fracture of the outlet strut of a BSM prosthesis. Hemorrhage due to the anticoagulant treatment was thus the most frequent complication, without significant intergroup differences, while thromboembolic complications were significantly more frequent after Björk-Shiley mitral, aortic, and double valve replacements than after St. Jude implantation. This may lead to the consideration of a change in the prophylaxis of thrombus formations with the St. Jude valve, especially in aortic valve replacements with sinus rhythm.

Adolescent↗