Biomedical subjects

E Gymoese

Publications and source records attributed to E Gymoese.

4 recordsLinked to original sources

PubMed1991

Comparison of different orthogonal systems in high resolution ECGs and the significance of the number of averaged beats in detecting late potentials.

For non-invasive detection of late potentials in the signal-averaged electrocardiogram (SAECG) most studies use modified orthogonal leads. In the present study the significance of three different lead systems for the detection of late potentials was examined. SAECGs were recorded at five different (32, 64, 128, 256, and 512) numbers of averaged beats in 24 patients with ventricular tachycardia after myocardial infarction and in 76 normal subjects. The original Frank leads and two different modified orthogonal vector lead systems were used. There was no clinical difference between the three orthogonal systems in sensitivity and the difference in specificity (P less than 0.01) seemed to be primarily related to differences in noise content. When the vector systems were compared at equally low noise levels of 0.47-0.50 microV, the apparent differences in specificity between the vector systems disappeared. At decreasing noise levels the sensitivity increased, at the cost of a loss in specificity which at very low noise levels was out of proportion with the gain in sensitivity. A modified approach with a fixed threshold noise level to determine the QRS endpoint is suggested.

Adult↗

PubMed1978

Long-term ECG monitoring in suspected Adams-Stokes disease.

Long-term ECG recording techniques have facilitated the diagnosis in atypical cases of Adams-Stockes syndrome. In the use of ambulatory ECG monitoring, new and mainly technical problems have been arisen. In 200 ECG recordings on cassette tape, 78% was considered sufficient for an accurate diagnosis. More than 50% of the unsuccessful recordings were unreadable due to electrode problems. The use of ambulatory monitoring demands that electrode fixation and placement be handled carefully and that the mechanical and electronic equipment be serviced frequently. Patients with third-degree atrioventricular block and syncopes of fainting spells run a high risk of sudden death. It is therefore not recommended to use ambulatory monitoring techniques on these patients.

Adams-Stokes Syndrome↗

PubMed1976

Neuropsychologic effects of diazepam related to single dose kinetics and liver function.

The neurophysiologic and neuropsychologic effects and their relation to the kinetics of diazepam (DZ) were studied in 10 patients with impaired liver function of various degrees and in three normal subjects after 10 mg DZ i.v. The plasma concentration data were treated according to a two-compartment open model. Neurophysiologic effect measurements were obtained from galvanic skin response, continuous reaction times (CRT), heart rate, and averaged evoked potentials; neuropsychologic measurements were obtained from trail making A + B, hidden pattern, word fluency, and subtraction tests; in addition, clinical effects were rated by Beechers Mood Scale and Spielbergers Anxiety Scale. Except for trail making A and word fluency all tests discriminated well between the experimental conditions with or without diazepam. No difference from normal in the response to acute diazepam administration could be detected in patients with reduced liver function. A linear correlation between prolongation in CRT and DZ log plasma concentration was demonstrated in the entire, heterogenous patient material. In the clinical ratings only items of a predominantly sedative and autonomic significance responded to the diazepam injection, while predominantly anxiolytic items did not.

Diazepam↗

PubMedDate not supplied

Mitral and aortic valvular flow: quantification with MR phase mapping.

When magnetic resonance phase mapping is used to quantitate valvular blood flow, the presence of higher-order-motion terms may cause a loss of phase information. To overcome this problem, a sequence with reduced encoding for higher-order motion was used, achieved by decreasing the duration of the flow-encoding gradient to 2.2 msec. Tested on a flow phantom simulating a severe valvular stenosis, the sequence was found to be robust for higher-order motion within the clinical velocity range. In eight healthy volunteers, mitral and aortic volume flow rates and peak velocities were quantified by means of phase mapping and compared with results of the indicator-dilution technique and Doppler echocardiography, respectively. Statistically significant correlations were found between phase mapping and the other two techniques. Similar studies in patients with valvular disease indicate that phase mapping is also valid for pathologic conditions. Phase mapping may be used as a noninvasive clinical tool for flow quantification in heart valve disease.

Aortic Valve↗