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Biomedical subjects

W Merx

Publications and source records attributed to W Merx.

At least 19 recordsLinked to original sources
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↗
PubMed1979

[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↗
PubMed1979

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↗
PubMed1979

Circus movement in canine right ventricle.

The present study reports on the epicardial spread of excitation during premature beats and during the initial stages of ventricular fibrillation, both of which were induced by single-test stimuli during regional ischemia or local hypothermia. Simultaneous recording of the activity at 48 epicardial sites on the right ventricle of dog hearts enabled us in some instances to demonstrate a circus movement.

Animals↗
PubMed1979

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↗
PubMed1978

[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↗
PubMed1977

[Clinical value of multiple praecordial chest leads for evaluating the course of acute anterior myocardial infarction (author's transl)].

Percordial ST-segment mapping using an improved 48-lead system was evaluated 2-to-3-hourly in 322 single measurements on 24 patients with acute anterior myocardial infarction. Changes in the sum of ST-elevation (capital sigma ST) or in the number of leads with ST-elevation (NST) could be distinguished in two different phases: an initial rapid increase and decrease in capital sigmaST and NST was followed after 6 to 12 hours, by a more plateau-like course, which exhibited, especially in uncomplicated cases, only slight further changes. During the initial phase, marked differences in the maximal rate of decrease were observed for capital sigma ST and NST. In this phase, interpretation of therapeutical interventions using changes of capital sigma ST or NST as reference is therefore very critical. However, during the second plateau-like phase, extension of myocardial necroses is significantly associated with a new steep increase in capital sigma ST. Thus precordial mapping is suitable for rapid and sensitive detection of infarct extension in patients with anterior myocardial infarction. The development of pericarditis or bundle-branch block, which principally can disturb the evaluation of capital sigma ST and NST, occurred only sporadically in a few patients and therefore caused no major problems.

Acute Disease↗
PubMed1977

[Multiple chest leads to evaluate the course of acute myocardial infarction (author's transl)].

At present, precordial mapping is the only reliable method to define the course of myocardial ischemia in patients with acute myocardial infarction. To improve registration technique and evaluation an elastic synthetic plate with 48 electrodes and a computer program for calculation of the different ecg-changes have been developed. Registration and evaluation require an average period of 15 minutes (+/-3 minutes) thus allowing repeated application within time intervals.

Acute Disease↗