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Biomedical subjects

H Kesteloot

Publications and source records attributed to H Kesteloot.

At least 163 records · Page 9Linked to original sources
PubMed1983

Transfer characteristics of an ink-jet writer for cardiovascular studies.

The transfer characteristic of a 16 channel ink-jet writer used in a cardiovascular laboratory is described. The test method for measuring linearity, gain and phase response is described and results given. The transfer function was calculated from the normalized experimental results and allows prediction of the behaviour of the writer for different input signals. It is shown that the ink-jet galvanometers are linear for signal input amplitudes between 0 and 2.5 V, and have a flat frequency response between DC and 640 Hz (+/- 1%).

Biomedical Engineering↗
PubMed1983

Apparent pulse wave velocity in the canine superior vena cava.

In order to evaluate clinically recorded jugular vein pulses it is necessary to understand the transmission process of the right atrial pressure pulse through the caval veins up to the jugular veins. The transmission speed at distinct points of the venous pressure curve was studied in the superior vena cava of 20 anaesthetised dogs. Under control conditions the propagation velocities varied from 1.2 +/- 0.49 to 2.5 +/- 1.36 m . s-1. During increased preload of the heart propagation velocities rose significantly from 2.2 to 4.2 m . s-1 per kPa as a function of mean venous pressure and from 2.3 to 5.8 m . s-1 per kPa as a function of phasic pressures. Right atrial pacing (between 60 and 120 beats . min-1) did not influence the propagation velocity of the studied distinct points. It was found that the summits of the pressure pulse propagate at only a slightly higher speed than the nadirs.

Animals↗
PubMed1983

Noninvasive determination of stiffness of the left ventricle by combined M-mode echo- and apexcardiography. An experimental method.

In order to compare an invasive with a noninvasive index of left ventricular stiffness during late diastole, M-mode echocardiogram, left ventricular pressure (LVP) and apexcardiogram (QLAC) were recorded simultaneously during acute dog experiments. The slope of the log pressure (P)-log volume (V) relationship is expressed by the ratio VdP/PdV. This index has been proven to be valid for the evaluation of left ventricular stiffness during late diastole. Diameter (D) changes were assumed to be proportional to volume changes. Continuous data from the ascending part of the A wave (due to atrial contraction) and the corresponding diameter change were used to calculate the slope (k1) of the log LVP--log D relation. During the same period the slope (k2) of the log QLAC--log D relation was also calculated. A significant linear correlation was found between values obtained semi-invasively from LVP-D (k1) and noninvasively from QLAC-D (k2) data: n = 21, r = 0.93, p less than 0.001. This shows the usefulness of VdP/PdV derived noninvasively from QLAC and M-mode echo for the assessment of stiffness of the left ventricle during late diastole.

Animals↗
PubMed1983

Efficacy of intravenous sotalol on ventricular arrhythmias occurring during maximal exercise stress testing.

The efficacy and safety of an intravenous dose of 40 to 100 mg sotalol was evaluated in fourteen symptomatic patients with ventricular arrhythmias occurring during maximal exercise stress testing. A statistically significant reduction in premature ventricular complexes (PVC's) occurring as singles, doublets and triplets was observed during both exercise (p less than 0.05) and recovery (p less than 0.01). Sotalol plasma levels after administration of 100 mg i.v. ranged from 3.7 to 4.75 micrograms/ml (average 4.2 micrograms/ml). The injected dose was well tolerated in all patients. Neither arrhythmogenic nor adverse effects were observed.

Adolescent↗
PubMed1982

Comparative effects of alinidine and propranolol in ischaemic heart disease.

The effects of single oral doses of alinidine 40 mg, propranolol 40 mg or placebo during a maximal exercise test on a bicycle ergometer in patients with angina pectoris were studied in a randomised, double blind study. 2 and 5 h after drug intake a small fall in resting heart rate and systolic blood pressure was observed both after alinidine and propranolol. At a fixed work load both drugs decreased heart rate, systolic blood pressure, double product and the extent of ST segment depression. Total work performed and time to appearance of angina pectoris were increased 2 h alinidine and propranolol. The same effects were still apparent 5 h after propranolol but not after alinidine. At peak exercise neither drug had any effect on the extent of ischaemic ST segment depression.

Blood Pressure↗
PubMed1982

Relationship between apexcardiogram, left ventricular pressure and wall stress.

Simultaneous measurement of left ventricular dimension and wall thickness by M-mode echocardiography, of left ventricular pressure by a tip-transducer manometer, and of the calibrated apexcardiogram with a pixie beam transducer, were made during acute experiments on anaesthetized dogs. Instantaneous values for chamber dimensions and wall thickness were obtained throughout the heart cycle by digitizing the echo-mechanocardiograms. From these data myocardial stresses, derived from a thick shell theory (meridional and circumferential components) and from Laplace's law, were computed. Laplace stress if shown to be an adequate expression for average wall stress. Its value was correlated with the calibrated apexcardiogram. The present investigation suggests that to a certain extent, the apexcardiogram not only reflects pressure changes but also dimensional changes of the left ventricle.

Animals↗
PubMed1982

A comparative study of serum lipids between Belgium and Korea.

Serum cholesterol values are markedly lower in Korea than in Belgium in both males and females. This is attributed to the much lower consumption of saturated fat in Korea. A mean population serum cholesterol value of about 160 mg/dl appears to be compatible with excellent general health and with the absence of ischemic heart disease or other atheromatous diseases. The influence of age, height and weight on cholesterol between Belgium and Korea is qualitatively similar but quantitatively different. High-density lipoprotein cholesterol values are lower in Korea than in Belgium, particularly in females. Differences in the HDL cholesterol level thus cannot explain the low prevalence of ischemic heart disease in Korea.

Adult↗
PubMed1982

Effect of betaxolol on heart rate at rest and during exercise.

Betaxolol, a new beta-receptor blocking drug administered as a single dosage of 40 mg given orally, causes a maximal reduction of heart rate at rest of 30%, during a submaximal exercise of 28% and at rest after exercise of 33%. The reduction in heart rate is still highly significant 48 hours after administration at rest, during exercise as well after administration. A smaller but still significant reduction in heart rate was found after the oral administration of 20 mg of betaxolol. Betaxolol appears to be more effective than a single oral dose of 160 mg of long-acting propranolol. No significant differences were found between 9 submaximal exercise tests performed within a period of 50 hours in normal subjects.

Adrenergic beta-Antagonists↗
PubMed1982

Clinical efficacy of torasemide, a new diuretic agent, in patients with acute heart failure: a double blind comparison with furosemide.

Torasemide 60 mg and furosemide 120 mg were administered intravenously in a randomized double blind study in twelve patients with acute heart failure. The action of both drugs on urinary electrolyte and water excretion was very similar. The administration of torasemide but not of furosemide resulted in a significant reduction of systolic and diastolic blood pressure. No side effects occurred with either of the drugs in this elderly patient group.

Adult↗
PubMed1982

Reproducibility of exercise-induced ventricular premature beats.

Repeated maximum exercise testing with an intertest interval of one hour is a valid model for testing drug efficacy and safety on ventricular arrhythmias occurring during exercise. In the two consecutive exercise tests the mean total number of VES was 182 and 184 respectively and the slope of the regression equation relating both tests was close to unity.

Adult↗
PubMed1981

Moxaprindine in the acute treatment of ventricular arrhythmias in patients with cardiovascular disease.

The antiarrhythmic activity of intravenous moxaprindine was evaluated in 26 patients with cardiovascular disease; the mean maximum dose was 2.5 +/- 0.12 mg/kg. Ventricular extopics were completely abolished in 19 patients and significantly reduced in four patients, but were not favourably affected in three patients. In one patient with numerous runs of ventricular tachycardia, normal sinus rhythm was restored. Coupled ventricular ectopic activity always completely disappeared. At the maximum dose, the PR-interval (+27.7 +/- 3.3%), the QRS-duration (+24.6 +/- 2.2%), the QT-interval (+17.0 +/- 1.5%) and the QTc-interval (+10.8 +/- 1.2%) were significantly prolonged. The QRS morphology essentially remained unchanged. Moxaprindine caused first degree atrioventricular block in eight patients. The sinus rate was slowed at every dosage level. Nevertheless, moxaprindine could safely be administered to patients with dysfunction of the specialized conduction system, or with a damaged myocardium. Serious side effects did not occur. Moxaprindine is a promising new antiarrhythmic drug for the treatment of ventricular arrhythmias, but its value and safely in the chronic oral treatment of these arrhythmias remain to be established.

Adult↗
PubMed1981

Intravenous metoprolol for the treatment of acute supraventricular tachyarrhythmias.

The antiarrhythmic effect of the cardioselective beta-adrenoreceptor blocking agent metoprolol, given intravenously, was studied in 20 patients with acute supraventricular tachyarrhythmias, including patients with congestive heart failure, acute myocardial infarction and complete bundle branch block. Six patients out of 9 with atrial fibrillation reverted to sinus rhythm. In all patients with atrial tachycardia and 3 out of 4 patients with atrial flutter restoration of sinus rhythm occurred. The drug was well tolerated and is of clinical value for the treatment of supraventricular tachyarrhythmias even in an elderly patient group.

Aged↗