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Biomedical subjects

S Effert

Publications and source records attributed to S Effert.

At least 19 recordsLinked to original sources

[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

[A new method of pericardiocentesis and quantification of pericardial effusions by echocardiography (author's transl)].

With a new method for safe and complete evacuation of pericardial effusions it was possible to check the quantification of pericardial fluid is was possible to check the quantification of pericardial fluid by echocardiography. Using a formula based on the assumption that in systole the pericardial fluid is distributed equally around the contracting heart (like a coat enveloping a sphere), it was demonstrated that pericardial effusions ranging from 250 to 600 ml could be fairly accurately measured. Smaller effusions were not so readily determined. Effusions over 600 ml could be only roughly measured, usually being underestimated.

Echocardiography

The vulnerability of the right atrium. III. Electrophysiologic correlates of atrial vulnerability.

70 patients were investigated by means of the atrial extrastimulus method at three different driving rates: 80, 100 and 120/min. At each rate the effective, the relative, the total and the functional refractory periods were measured. 30 patients who showed signs of atrial vulnerability at least one of the tested rates were included in the so called vulnerability group. The remaining 40 patients, who did not fulfill the criteria for atrial vulnerability, were included in the nonvulnerability group. When the two groups were compared to each other there were significant larger P waves (p less than 0.005), shorter effective refractory periods (p less than 0.001) and longer relative refractory periods (p less than 0.001) in the vulnerability group. With increasing driving rate there was an increased tendency to repletitive firing in the vulnerability group. The phenomenon of vulnerability correlated well with the rate-induced shortening of the effective and the lengthening of the relative refractory period. The above described phenomena are compatible with the concept of re-entry as the electrophysiologic mechanism of atrial vulnerability in man.

Atrial Fibrillation

Left ventricular ejection power in coronary artery disease during atrial pacing.

Peak and mean left ventricular ejection power were measured during atrial pacing in 6 normal subjects (group I), 6 patients with coronary artery disease without myocardial infarction (group IIa), and 10 patients with coronary artery disease after myocardial infarction (group IIb). Pacing rates were 80 and 120/min. Power was determined by computer analysis of pressure, volume, and time. Data were normalised by end-diastolic volume and left ventricular muscle mass. Peak left ventricular ejection power normalised by end-diastolic volume values at a pacing rate of 120 min were significantly lower in group IIa and IIb than in normal subjects. Mean muscle mass in normal subjects was 179 g and in group IIa 216 g (P smaller than 0.05). Peak power normalised by muscle mass in normal subjects tended to increase at 120/min whereas in group IIa it declined by 26 per cent (P less than 0.001). These data indicate that the energy output of the left ventricle at rest may be the same in patients with significant coronary artery disease as in normal subjects. Increasing the heart rate from 80 to 120/min in a normal myocardium augments power but in coronary artery disease it remains static or falls.

Adult

Spontaneous course of ST-segment elevation in acute anterior myocardial infarction.

The spontaneous course of ST-segment elevation (sigmaST) in 24 patients with acute anterior myocardial infarction (AMI) was studied by precordial ST-segment mapping, which was recorded at 2-hour intervals during the first 48 hours after admission. Change of sigmaST between two registrations was expressed as mV/hr, and was compared with clinical and hemodynamic parameters, course of MB-CK curve, calculated infarct mass and arrhythmias. After an initial rapid increase, there was a decrease of sigmaST, which reaches a plateau-like curve approximately 12 hours after the onset of chest pain. A second new increase of sigmaST exceeding a value of 0.6 mV/hr correlates well with extension of necrosis, verified by re-elevation of MB-CK. During the first 2 days, extension of necrosis could be detected in 50% of our patients. As new ischemic episodes and extension of necrosis in AMI occur frequently and are promptly indicated by an increase of sigmaST, the physician should, while monitoring therapeutic interventions, concentrate on such a second increase rather than on a decrease of sigmaST (which may occur spontaneously), as has been suggested in most previous reports.

Adult

Efficacy of propranolol versus placebo in long-term treatment in patients with mitral valve prolapse.

In 60 patients with mitral valve prolapse syndrome a randomized controlled interindividual double-blind study of propranolol (p) was performed. Patients received p 80 mg (A), 160 mg (B) and placebo (C) orally for 4 weeks. Prior to and after treatment, heart rate (HR) and blood pressure (RR) as well as systolic time intervals (STI) were measured and corrected for heart rate--electromechanical systole (QS2I), left ventricular ejection time (LVETI), and preejection period (PEPI). The ratio PEP/LVET was calculated. Plasma levels were measured by an optimized fluorimetric method. 1. STI lay in the upper part of the normal range, indicating that some patients had a hyperkinetic cardiac function. 2. P had no influence on QS2I and LVETI in A and B. PEPI was prolonged (A: +13.2 ms, B: +14.2 ms) and PEP/LVET was increased (A: +0.040, B: +0.050). 3. As indicated by the changes in HR, RR, PEPI, and PEP/LVET p showed in B compared to A only minor additional effects. 4. Plasma levels of p were in B three times higher than in A (A: 89.2 +/- 10.0 nmol/l B: 246.7 +/- 30.5 nmol/l). With a dose of 80 mg propranolol a point close to the plateau of maximum efficacy was reached, where a higher dose resulted only in small additional negative inotropic effects.

Clinical Trials as Topic

[Pharmacodynamic studies in suicidal digoxin poisoning (author's transl)].

In two patients with suicidal digoxin poisoning the correlations between serum digoxin concentration and changes in the duration of QTc and the flattening of the T-waves were studied. The digoxin serum half-life following suicidal digoxin poisoning was in the first patient (10 mg beta-acetyl derivative of digoxin) 77 h, prolonged cause of renal insufficiency, and in the second patient 39.6 h. (20 mg beta-acetyl derivative of digoxin). In both patients the digoxin induced flattening of the T-wave reached a plateau of maximum efficacy at a serum level of 2-3 ng/ml with no further change up to a serum level of 13.2 ng/ml and 9.6 ng/ml respectively. A linear correlation, however, was found between the digoxin serum concentration and the digoxin induced shortening of QTc, r = 0.88 and r = 0.92 respectively. A plateau maximum efficacy was not found. The regression equations were y = -12.0 chi + 430.8 and y = -8.0 chi + 391.9 respectively. The shortening of QTc is therefore an important parameter for the diagnosis of digoxin poisoning. It can be determined very quick with no methodical problems.

Digoxin

[Special diagnostic procedures in atrial tumours of the heart (author's transl)].

A vascular myxoma which prolapsed into the mitral valve was found in the left atrium of a 47-year old man. Two-dimensional ultrasonic tomography yielded relevant non-invasive diagnostic information on the pattern of movement of the pedunculated tumour. Highly accurate determination of the tumour volume was achieved via angiocardiography and videometry. Coronography of the tumour vessels allowed identification of an unusual point of insertion of the myxoma. The risk of obstruction of the mitral orifice was documented haemodynamically by a steep gradient above the mitral valve when holding breath during the expiratory phase.

Angiocardiography

[Haemodynamic effects of nefopam (author's transl)].

The haemodynamic effects of nefopam (0.3 mg/kg i.v.) were measured for 45 minutes in ten patients with coronary heart disease. The drug is a new and highly potent analgesic without any respiratory depressant effect. Arterial blood pressure and cardiac output rose moderately, while left ventricular enddiastolic pressure remained unchanged. Heart rate did not exceed 91/min. Max dp/dt, min dp/dt, Vpm and V40 rose by a maximum of 16% above control. Thus nefopam differs from other potent analgesics in having a slight inotropic effect.

Adult

[Evaluation of infarct size using serum concentration of the CK-MB isoenzyme (author's transl)].

The size of infarction was determined in 21 patients with acute myocardial infarction aged 42 to 76 years using serial analyses of the serum concentrations of the total creatine kinase (CK) and of the CK-MB isoenzyme. CK-MB isoenzyme concentrations reached their maximum in serum three hours earlier on average and returned to the initial value 10 to 12 hours before the total CK. CK-MB isoenzyme concentrations reached a maximum of 12.4% of maximum total CK activity. In 17 uncomplicated cases the infarct weight determined from total CK (40 +/- 23 g) and from CK-MB isoenzyme (35 +/- 23 g) was only different by 5 g (r = 0.92). In 4 patients with infarction and defibrillation or reanimation use of total CK led to an overestimation of the infarct size by more than double. The determination of the infarct size from CK-MB isoenzyme values proves that without extracardial CK release, estimation of the infarct size can also be done sufficiently exactly from the total CK concentrations. In complicated cases, however, the specific myocardial CK isoenzyme makes determination of the infarct size possible

Acute Disease

[Incidence of spontaneous rhythm after pacemaker implantation for total A-V block (author's transl)].

Follow-up investigation over 12--84 months (mean 30 months) of 86 patients with the primary diagnosis of permanent total atrioventricular block revealed that spontaneous rhythm could be demonstrated in all but 17 patients. A-V conduction was re-established in 13, but in most of them it was on the basis of ventricular ectopic beats. These findings prove that in the described type of patient spontaneous rhythm after pacemaker implantation is common. Therefore, fixed-rate pacemakers are not indicated in these patients.

Atrioventricular Node

[Computer system for the automatic analysis of cath-lab data. Reliability of pattern-recognition and measurements (author's transl)].

The computer-system for the on-line-analysis of hemodynamic data developed in Aachen enables the clinical user to perform the immediate on-line analysis of ECG, pressure-curves and thermo- or dye-dilution-curves in a dialog mode. The procedure of pressure analysis as well as the calculations by the computer for the individual haemodynamic parameters are described. The comparison of the medical-manual evaluation of the pressure curves on paper-registration and the computer results of the same measurement shows a very good correlation for wave-recognitions and wave-measurements for this system, integrated in the daily routine since 24 months. As well in the application of various fluid-filled catheters used in praxis as in tip-manometers it could be proved for the pressure-analysis in the different positions of the heart, that the computer-system produced reliable evaluations for all catheter materials used. The flexible conception of the computer program with its fast adaption to new problems allows its use not only in the clinical routine, but also and especially in the handling of scientific questions in the frame-work of haemodynamic analysis.

Cardiac Catheterization

[Infleunce of heart cycle length on left ventricular ejection fraction in normals and patients with coronary artery disease].

The ejection fraction is a clinically valuable index of left ventricular pump function. We investigated the influence of a change in heart cycle length in normals (gr. I) and in patients with coronary artery disease without (gr. IIa) and after myocardial infarction (gr. IIb) (atrial pacing 80 and 120 min-1). In all subjects ejection time decreased by ca. 17%. There was no statistical difference between the groups. Ejection fraction (mean absolute values): gr. I (n = 7): - 3.4% (n. s.), gr. IIa (n = 8): - 8.4% (p is less than 0.01), gr. IIb (n = 12): - 6.5% (p is less than 0.01), Gr. IIa + IIb: - 7.2% (p is less than 0.001), gr. I +IIA + IIb: - 6.1% (p is less than 0.001). Compared to the control value the relative decrease for all subjects was -12.3 +/- 12.0% (n = 27). When left ventricular performance is evaluated by ejection fraction using invasive and noninvasive methods (contrast medium ventriculography, echocardiography and scintigraphy) heart cycle length has to be taken into account. The data cannot be normalized by a simple mathematical procedure.

Cardiac Output

[Evaluation of regional myocardial dysfunction by echocardiographic pressure-dimension analysis (author's transl)].

Ecg, left ventricular pressure measured by micromanometer-tipped catheter, and dimension measured by echocardiography were simultaneously recorded in 24 patients with coronary artery disease and 9 normal subjects. In analogy to pressure-volume diagrams, pressure-dimension diagrams were constructed, the area in systole and diastole and the cycle efficiency calculated. In patients with coronary artery disease the normal rectangular shape of the pressure-dimension diagram shows two typical deviations: 1. a dimension decrease during isovolumetric contraction and dimension increase during isovolumic relaxation in 42% of the patients, in 31% in patients with stenosis of the right coronary artery, in 56% in patients with stenosis of the left anterior descending coronary artery, in 85% in patients with a reduced ejection fraction. 2. An exact reflected image was found only in patients with stenosis of the right coronary artery and reduced ventricular function in 23%. The abnormal dimension changes are the result of an asynchronized contraction and relaxation with inward movement of one part and outward movement of another part of the left ventricle. These changes are caused by ischemic or fibrous areas of the ventricle. Independent of left ventricular pressure and dimension changes we found that the cycle efficiency was useful to study regional myocardial work. It ranged from 81.7 +/- 2.5% in the normal subjects to 74.8 +/- 1.8% in patients with reduced ventricular function. From the diastolic part of the pressure-dimension diagram the regional compliance was calculated. Dependent on coronary artery disease the regional compliance was decreased even at rest.

Adult