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Biomedical subjects

Y Myreng

Publications and source records attributed to Y Myreng.

30 records · Page 2Linked to original sources
PubMed1989

Effects of verapamil on left ventricular relaxation and filling dynamics in coronary artery disease: a study by pulsed Doppler echocardiography.

The effect of verapamil on left ventricular diastolic function in coronary artery disease was assessed by Doppler echocardiography of transmitral flow velocities in 20 patients. At baseline, isovolumic relaxation time was prolonged compared with that in 18 age-matched normal subjects (95 +/- 13 msec versus 74 +/- 12 msec, p less than 0.001), but decreased to 80 +/- 14 msec (p less than 0.001) after treatment. The ratio between early and atrial-induced transmitral velocities (E/A-ratio) at baseline was lower in patients than in normal subjects (1.1 +/- 0.2 versus 1.4 +/- 0.3, p = 0.01), as was the filling fraction of the first third of diastole (43% +/- 5% versus 50% +/- 4%, p less than 0.001). Verapamil treatment increased the E/A-ratio to 1.3 +/- 0.4 (p less than 0.001) and filling fraction to 45% +/- 4% (p = 0.055) because of increased early filling. No change in systolic performance or heart rate was observed. Thus, coronary artery disease was associated with retarded relaxation and impairment of early filling. However, verapamil treatment enhanced relaxation and induced a filling shift toward early diastole, which indicated improved diastolic performance. The changes probably reflected reduced myocardial ischemia.

Adult↗
PubMed1989

Age-dependency of left ventricular filling dynamics and relaxation as assessed by pulsed Doppler echocardiography.

Left ventricular diastolic function was assessed from transmitral flow velocity curves as measured by Doppler echocardiography in healthy individuals aged 21-69 years, each decade comprising 12 subjects. By ageing, progressive changes in the various filling parameters were observed. When comparing the youngest and oldest age groups, the ratio between peak velocities in early and late diastole decreased from 2.0 +/- 0.3 to 1.2 +/- 0.3 (P less than 0.001). The filling fraction of first third of diastole decreased from 54 +/- 5% to 45 +/- 4% (P less than 0.001). Isovolumic relaxation time increased from 61 +/- 11 ms to 77 +/- 12 ms (P less than 0.01). Correlation coefficients of velocity ratio, filling fraction and isovolumic relaxation time vs. age were r = -0.71 (P less than 0.001), r = -0.56 (P less than 0.001) and r = 0.44 (P less than 0.001), respectively. When isovolumic relaxation time and age were used together in multivariate regression analysis, only age was an independent predictor of velocity ratio and filling fraction. Stroke volume, peak velocity in left ventricular outflow tract, heart rate and systolic blood pressure were similar in all age groups. Thus, velocity ratio and filling fraction indicated a relative filling shift towards late diastole by ageing and were more sensitive than systolic parameters in reflecting age-related changes in cardiac function. The changes could be explained neither by delayed relaxation nor by change in systolic parameters. When using Doppler echocardiography for evaluation of left ventricular filling, age-matching of reference groups is necessary.

Adult↗
PubMed1988

Effects of beta-adrenergic blockade on left ventricular relaxation and filling dynamics in coronary artery disease: a pulsed Doppler echocardiographic study.

Left ventricular (LV) filling as assessed by Doppler transmitral flow velocity measurements was studied in 20 male patients with coronary artery disease (CAD) and in 18 normal individuals. Stroke volume, blood pressure and heart rate in the two groups were not significantly different. Compared to normals, the ratio between early and atrial-induced peak velocities was significantly lower in the patients (1.2 +/- 0.3 vs. 1.40 +/- 0.3, P = 0.01), as was the fraction of transmitral filling during the first 1/3 of diastole (45 +/- 7% vs. 50 +/- 4%, P less than 0.001). Isovolumic relaxation time (IV R) was 96 +/- 13 ms in patients vs. 74 +/- 12 ms in normals (P less than 0.001). The CAD patients were treated with atenolol for 13-24 days. The velocity ratio increased by 30% (P less than 0.001) due to a 12% increase in early (P = 0.004) and an 11% decrease in atrial-induced peak velocities (P = 0.01). Filling fraction and deceleration rate of early inflow both increased by 22% (P less than 0.001). IV R decreased by 8% (P = 0.01). After atenolol treatment, heart rate and blood pressure decreased by 23% and 10% (P less than 0.001), respectively, whereas stroke volume increased by 14% (P less than 0.001). Thus, CAD was associated with Doppler indices of retarded LV filling and myocardial relaxation. After atenolol treatment, significant increases in velocity ratio and filling fraction indicated a shift of filling from late towards early diastole, suggesting improved diastolic function. However, different factors related to beta-adrenergic blockade may have contributed to the observed changes.

Adrenergic beta-Antagonists↗
PubMed1988

Acute phase reactants and complement activation in patients with acute myocardial infarction.

The acute phase proteins, C-reactive protein (CRP), orosomucoid, alpha 1-antitrypsin and haptoglobin, the native complement components C3 and C4, activation products of C3, and the terminal SC5b-9 complement complex were quantified in samples obtained on admittance and on days 1, 2, 3 and 6 in 21 patients with non-complicated acute myocardial infarction (AMI) and in 22 controls. For all proteins peak and median concentrations were higher in the AMI group than in the controls, but the difference was significant only for CRP and orosomucoid. Median CRP concentration was 46 mg/l in the AMI group and 2.5 in the control group. The corresponding orosomucoid concentrations were 1.6 and 1.2 g/l. There was no correlation between the concentration of CRP in peripheral blood and the degree of complement activation. Furthermore, no correlation was observed between complement activation and the size of infarction. The present study cannot demonstrate that the increased concentrations of CRP and other acute phase reactants observed in patients with AMI, are associated with systemic fluid-phase complement activation. Furthermore, the complement activation previously shown locally in infarcted myocardium cannot be demonstrated systemically in non-complicated AMI.

Acute-Phase Proteins↗
PubMed1987

Reproducibility of cardiac stroke volume estimated by Doppler echocardiography.

Doppler echocardiography was used to measure cardiac stroke volume in 10 patients with coronary artery disease who were treated with cardioactive drugs. Stroke volume estimates were determined at the aortic orifice by multiplying area by systolic velocity integral measured both from the suprasternal and the apical approach. Recordings were done independently by 2 experienced observers on the same day and repeated once after 1 to 21 days. Analysis of variance showed that no systematic differences were introduced by the 2 observers and Doppler approaches or by measuring on different days. The coefficient of variation between any pair of measurements in each patient was 9%. This variability is probably a result of the method or spontaneous fluctuations of the stroke volume and not of the varying recording conditions. The ultrasonic method detects day-to-day changes of cardiac stroke volume larger than 20% with a probability greater than 0.95.

Adult↗