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Biomedical subjects

S Effert

Publications and source records attributed to S Effert.

At least 73 records · Page 4Linked to original sources
PubMed1982

[Apical two-dimensional echocardiography: normal values for single- and bi-plane determination of left ventricular volume and ejection fraction].

A difference was obtained between cineventriculography and 2-D echocardiography in the determination of left ventricular volume and ejection fraction. Normal values obtained by the former could not be used for the latter. The authors, therefore, determined their own normal values. Apical 2-D echocardiography was used for the normal group (35 males, mean age 30.2 years; 20 females, mean age 26.2 years). In addition to mean values and standard deviations, one-sided tolerance limits (T) were calculated, separating the normal range from abnormal within 95% confidence limits for 90% of the total group. End-diastolic and end-systolic volume index in males was 66.8 +/- 8.8 ml/m2 compared with 26.9 +/- 5.2 ml/m2 on biplane evaluation. Tolerance limits were calculated at 82.0 and 35.9 ml/m2, respectively. Stroke volume index was 39.9 +/- 7.0 ml/m2, T = 27.8 ml/m2, ejection fraction 59.2 +/- 6.0%, T = 48.8%. End-diastolic and -systolic volume index for females had a mean of 60.7 +/- 12.5 ml/m2, T = 85.0 ml/m2, and 25.7 +/- 7.4 ml/m2, T = 40.1 ml/m2, respectively. Stroke volume index was 56.5 +/- 10.6 ml/m2, T = 35.9 ml/m2, the ejection fraction 58.1 +/- 6.5%, T = 45.5%. Between monoplane and biplane measurements of apical 2-D echocardiograms there was no significant difference. Normal values for volume and ejection fraction of the left ventricle, determined from apical four-chamber and RAO-equivalent cuts make it possible to categorize the function of the heart and to provide the basis for further studies of the sensitivity and specificity of the method.

Adolescent↗
PubMed1982

[Treatment of acute cardiac arrest. Observations in a cardiological intensive-care unit].

Between 1976 and 1980, 301 of 3106 patients in the cardiological intensive-care unit were treated for acute cardiac arrest (9.7%). As a result of better methods of prevention and the emergency doctor system, there has since 1968 been a 50% reduction in the number of cardiac arrests. Two-thirds of the patients were male, resuscitation was successful in 34% ("successful" means that the patient was transferred to a general ward from the intensive-care unit in a clinically and haemodynamically stable condition). The prognosis was better in those with posterior-wall myocardial infarction than in those with unstable angina, mitral-valve disease with congestive heart failure, and those with anterior-wall infarction, the latter generally being more extensive and thus in principle more dangerous than posterior-wall infarction. Cardiac arrest as part of cardiogenic shock proved irreversible in every instance. After three months the survival rate was 72%, after six months 66%, after one year 62% of all patients who had required resuscitation. They would not have been alive without intensive-care treatment. These figures contradict negative comments on the purpose and usefulness of cardiological intensive-care units.

Adult↗
PubMed1982

[Ventricular septal defect in acute myocardial infarction].

Ventricular septal rupture is the fourth-common cause of death after cardiac arrhythmia, acute congestive failure and rupture of the cardiac wall in acute myocardial infarction. Generally it can be easily diagnosed by a systolic jet sound in the 4th and 5th intercostal space parasternally on the left side. Differential diagnostic difficulties occur in the acute phase of infarction regarding papillary muscle rupture. Myocardial rupture does not occur immediately after the onset of the pectanginous state and not within the first day of illness, but generally within the first week. Vasodilatory treatment permits only short-term stabilisation of vascular problems, however, time is made available for diagnostic measures, usually catheterisation of both sides of the heart and coronary angiography. Immediate operation and occlusion of the defect, if necessary accompanied by a saphenous vein bypass, is presently considered treatment of choice. Out of the three patients with this complication the ruptured site could be occluded surgically in two, one of whom had severe cardiogenic shock. Shock symptoms regressed immediately and the postoperative course was unremarkable. In the third patient no operation was performed due to his age of 77 years and general vascular sclerosis. He died of cardiogenic shock 11 hours after admission to hospital.

Aged↗
PubMed1982

[Right heart failure after infarction of the right ventricle (author's transl)].

The right ventricular filling pressure was raised above 10 mm Hg in 20 cases (12%) out of 175 patients haemodynamically monitored in the acute phase after cardiac infarction. The end-diastolic pulmonary arterial pressure was not above 18 mm Hg so that in these cases an extensive necrosis of the right ventricle must be assumed to be the cause of right heart failure. In 75% of these patients with predominantly right sided infarction there was a posterior wall infarct whereas in patients with left heart failure the anterior wall was significantly more often affected. Patients with posterior wall infarction and right heart failure had more commonly infarct signs in the right precordial chest leads Vr3 to Vr6 and an increased diameter of the right ventricle in the echocardiogram than patients with posterior wall infarction but without right heart failure. However, a definite separation of the two groups was not possible with these non-invasive techniques. Haemodynamic changes should thus be decisive for the diagnosis of predominantly right heart infarction as these dictate the treatment.

Adult↗
PubMed1982

Haemodynamic effects of prenalterol in patients with severe congestive heart failure--NYHA III-IV.

In 12 patients with severe congestive heart failure due to ischaemic heart disease (n = 6) and due to congestive cardiomyopathy (n = 6) the haemodynamic effects of a new beta 1-agonist, prenalterol, were studied. Left ventricular (LV) function was studied before and 20 min after infusion of 12 mg prenalterol. Heart rate was kept constant by atrial pacing at a rate of 100 min-1 unless intrinsic heart rate exceeded it. As a sign of positive inotropic support, prenalterol enhanced peak rate of LV pressure development (dP/dt) from 1160 +/- 100 mm Hg/s to 1590 +/- 190 mm Hg/s (p less than 0.005). In the mean LV end-diastolic and end-systolic volume determined by cineventriculography and two-dimensional echocardiography decreased. LV stroke work index measured with both methods increased with 4 ml/m and 5 ml/m, respectively (p less than 0.02). LV ejection fraction was improved by 6% and 8% (p less than 0.005). Increase of peak fall of left ventricular pressure (dP/dt) (1050 +/- 60 mm Hg/s to 1270 +/- 100 mm Hg/s, p less than 0.005) and shortening of time constant (T) of pressure fall from 64.5 +/- 5.0 ms to 44.5 +/- 6.0 ms (p less than 0.005) demonstrated the improved LV relaxation. Analysis of LV volume and myocardial compliance revealed decrease of left ventricular stiffness. Thus, LV filling pressure was reduced from 22.1 +/- 4 mm Hg to 14 +/- 3.5 mm Hg (p less than 0.001). Pressure volume analysis showed a significant increase of LV power and work, as well as a slight decrease of wall stress. Our study could demonstrate, even in patients with severe heart failure, a sustained positive inotropic effect of prenalterol leading to an improved left ventricular contractility, relaxation and compliance. LV power and work was enhanced. The increase of oxygen demand seemed to be counterbalanced by an improved perfusion of particularly subendocardial layers indicated by an increased transmyocardial pressure gradient.

Adrenergic beta-Agonists↗
PubMed1982

Morphometric investigations in mitral stenosis using two dimensional echocardiography.

A method is proposed for comparing the orifice size and the morphology of stenotic mitral valves, removed intact at the time of replacement, with the preoperative two dimensional echocardiographic cross-sections. The excised mitral valve apparatus is suspended on a specially constructed mounting. To avoid shrinkage the orifice is stabilised with an airfilled balloon. A radiography is taken directing the x-ray beam perpendicular to the valve orifice. In 40 of 51 patients this method provided the means of relating the echocardiographic cross-sections to the morphology of the valve. Planimetry of the valve area compared favourably with the postoperatively determined orifice size. Agreement was found in 34 of 40 patients in orifice shape between preoperative echocardiograms and x-rays of th excised valve. The relation between intraoperative estimation of size of the valve, using dilators with known diameters, and the postoperative results was less favourable. Areas of calcification were identified on echocardiography as dense conglomerate echoes. In 30 patients (75%) the localisation of calcium deposits and in 67% the degree of calcification was in agreement with the x-rays of the valve taken after operation. In addition to determination of the area, two dimensional echocardiography allows detailed studies of the stenotic valves, and is of particular importance for planning operative treatment.

Adult↗
PubMed1982

Percutaneous transluminal coronary angioplasty immediately after intracoronary streptolysis of transmural myocardial infarction.

Percutaneous transluminal coronary angioplasty (PTCA) was performed in 21 patients with acute myocardial infarction (AMI) treated by intracoronary infusion of streptokinase within 8 hours after the onset of symptoms. Streptolysis therapy began a mean of 3.6 +/- 1.2 hours (+/- SD) after the onset of symptoms. The vessel was occluded in 14 patients and highly stenosed in seven. After the infusion of 67,300 +/- 63,200 IU of streptokinase over 26.1 +/- 21.5 minutes, patency of the occluded vessels was reached. PTCA as performed 20-60 minutes after the end of streptokinase treatment in 19 patients and 24 and 31 hours after treatment in two patients. The dilation was successful in 17 patients (81%). The degree of vessel obstruction was reduced from 90.2 +/- 7.3% to 58.6 +/- 19.5% (area method) and from 71.4 +/- 12.4% to 39.2 +/- 19.7% (diameter method). The improvement was 31.5 +/- 18.4% and 32.2 +/- 19.3%, respectively. No reocclusion was induced by PTCA. Twenty patients were discharged. One died during hospitalization; at autopsy, the treated vessel was still patent. During the follow-up period, two reinfarctions and one asymptomatic reocclusion occurred. The clinical findings during the hospital course and the follow-up period were compared with those of a control group of 18 patients with AMI and comparable coronary stenoses who were treated only with streptokinase infusion. Four of these patients had a reinfarction during the hospital course, and three died during the follow-up period. PTCA can be performed safely and successfully immediately after intracoronary infusion of streptokinase in patients with AMI. By reducing the subtotal stenosis, this treatment contributes to the reperfusion of the ischemic myocardium, diminishes the risk of a reocclusion and seems to improve the prognosis.

Adult↗
PubMed1982

[Right ventricular volume determination by two-dimensional echocardiography and radiography in model hearts using a subtraction method].

The irregularity and complexity of the right ventricle is the reason why no accurate method for right ventricular volume determination exists. A new method for right ventricular volume determination particularly for two-dimensional echocardiography was developed-it is called subtraction method-and was compared with the pyramid and Simpson's methods. The partial volume of the left ventricle and septum was subtracted from total volume of right and left ventricle including interventricular septum. Thus right ventricular volume resulted. Total and partial volume were computer-assisted calculated by use of biplane methods, preferably Simpson's rule. The method was proved with thinwall silicon-rubber model hearts of the left and right ventricle. Two orthogonal planes in the long-axis were filmed by radiography or scanned in a water bath by two-dimensional echocardiography equivalent to RAO and LAO-projections of cineangiocardiograms or to four- and two-chamber views of apical two-dimensional echocardiograms. For calculation of the major axes of the elliptical sections, summed up by Simpson's rule, they were derived from the LAO-projection and the four-chamber view, respectively, the minor axis approximated from the RAO-projection and the two-chamber view. For comparison of direct-measured volume and two-dimensional echocardiographically determined volume, regression equation was given by y = 1.01 x -3.2, correlation-coefficient, r = 0.977, and standard error of estimate (SEE) +/- 10.5 ml. For radiography, regression equation was y = 0.909 x + 13.3,r = 0.983, SEE = +/- 8.0 ml. For pyramid method and Simpson's rule, higher standard errors and lower correlation coefficients were found. Between radiography and two-dimensional echocardiography a mean difference of 4.3 +/- 13.2 ml, using subtraction method, and -10.2 +/- 22.9 ml, using pyramid method, as well as -0,6 +/- 18.5 ml, using Simpson's rule, were calculated for right ventricular volume measurements. Differences were not significant. The subtraction method seems to be useful for calculation of right ventricular volume by radiography as well as two-dimensional echocardiography. Further studies in isolated hearts and patients are necessary for final judgment of the accuracy of this new method.

Blood Volume↗
PubMed1982

[Value of contrast echocardiography in the diagnosis of tricuspid insufficiency].

Contrast echocardiography utilizing peripheral saline injection was used for the detection of tricuspid regurgitation in 127 patients. In 36 patients prior to contrast echocardiography a tricuspid regurgitation was documented by angiography of the right ventricle. A V-wave synchronous pattern of contrast appearance in the inferior vena cava was detected by subcostal transducer position in 34 patients, and in 27 patients retrograde systolic flow lines across the tricuspid valve were documented by left parasternal transducer position. Correlated with angiographic data, the sensitivity of the method in the detection of a tricuspid regurgitation was 97% and the specificity 100%. False positive findings consisted in A-wave synchronous patterns and in heart-cycle-independent patterns of contrast appearance. Vena caval ultrasonography using size, pulsation, and inspiratory decrease in dimension was not helpful in predicting tricuspid regurgitation. A diameter of the inferior vena cava less than 10 mm/m2 BSA was indicative of normal right ventricular function.

Adult↗
PubMed1982

Biomedical engineering in cardiology.

There are numerous and quite controversial opinions on what should be covered by the term 'biomedical engineering'. Therefore, it seems necessary to define and reflect on what biomedical engineering really means. Our definition is: biomedical engineering is the application of engineering sciences in clinical medicine. Several examples of 10 years of cooperation between engineers and physicians in Aachen are presented under the confines of the above definition.

Animals↗