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Biomedical subjects

M L Simoons

Publications and source records attributed to M L Simoons.

At least 235 records · Page 13Linked to original sources
PubMed1987

Incidence and prognostic implications of repetitive ventricular complexes during pre-discharge bicycle ergometry after myocardial infarction.

The clinical significance of repetitive ventricular complexes (RVCs) during pre-discharge bicycle ergometry after acute myocardial infarction has been assessed in 408 consecutive patients. RVCs occurred in 32 patients (8%). When compared to patients without RVCs, those with RVCs had a larger infarction, a higher prevalence of heart failure and late sustained ventricular tachycardia or fibrillation, a lower radionuclide ejection fraction and more frequent RVCs during pre-discharge 24-hour electrocardiographic monitoring. During a follow-up 30 patients died, 17 suddenly. Mortality was 15% (N = 5) in patients with RVCs during exercise test and 7% (N = 25) in those without RVCs. Sudden death occurred in only one patient with RVCs. When multivariate analysis was applied to clinical and exercise test data, RVCs during exercise did not predict cardiac mortality independent of variables related to left ventricular function, such as a history of previous myocardial infarction, persistence of heart failure in the late hospital phase and the extent of blood pressure rise during exercise test.

Arrhythmias, Cardiac↗
PubMed1987

Effect of beta-blockers on the relation between QT-interval and heart rate in exercise ECG.

QT-interval prolongation is a recognized risk indicator for ventricular arrhythmias and sudden cardiac death. The effect of beta-blockers on the change of the QT-interval relative to the change in heart rate was studied in 269 male patients who underwent computer-interpreted exercise tests. None of the patients studied used anti-arrhythmic drugs, diuretics or digoxin. In 141 men on beta-blockers the relation between Q-peakT interval and heart rate could be described as follows: Q-peakT = -1.48 X heart rate + 415. In 128 patients not on beta-blockers this relation was: Q-peakT = -1.14 X heart rate + 379. The difference of the slopes is 0.34 (0.22 - 0.46, 95% confidence interval). This difference was even more pronounced in a subgroup of coronary patients: 0.44 (0.30 - 0.57, 95% confidence interval). These results indicate that in men using beta-blockers the QT-interval shortens faster with increasing heart rate than in men not using them. At high heart rates patients on beta-blockers have a shorter QT-interval than those not using them. These observations could explain the beneficial effect of beta-blockers on exercise-induced ventricular arrhythmias and sudden death in coronary patients.

Adrenergic beta-Antagonists↗
PubMed1987

Value of predischarge data for the prediction of exercise capacity after cardiac rehabilitation in patients with recent myocardial infarction.

The aim of this study was to assess whether data related to predischarge clinical examinations, resting radionuclide ventriculography and symptom-limited bicycle ergometry can predict the achievement of a normal exercise capacity after a rehabilitation program in patients with a recent myocardial infarction. The study population consists of 141 consecutive patients who completed a 3-month training program. Patients with heart failure and/or severe angina were excluded. The rehabilitation program included two training sessions weekly during the 3 months. Working capacity (WC) increased from 79 +/- 17% at hospital discharge to 105 +/- 21% of normal values after rehabilitation (P less than 0.001), by 33% on average. Ninety-five patients achieved a normal WC. Conventional predischarge clinical evaluation, resting left ventricular ejection fraction, exercise induced angina, or ST segment depression were not predictive of normal WC after rehabilitation. Predischarge WC was the single best predictor of a normal WC after rehabilitation compared to those with a persistently low WC (84 +/- 15% in patients with normal WC vs 69 +/- 14% in those with persistently low WC, P less than 0.001). Nevertheless, 49% of patients with a baseline WC of less than 80% achieved a normal WC after rehabilitation. No correlation was found between the change of WC after rehabilitation and predischarge WC or ejection fraction. Therefore, the selection of patients for cardiac rehabilitation after a myocardial infarction should be based primarily on clinical grounds. Exclusion based on exercise induced angina, ST segment depression or low resting ejection fraction at hospital discharge or at entry in the rehabilitation program is not justified.

Adult↗
PubMed1987

Effect of ST-567 (a specific bradycardiac agent) in patients with unstable angina and myocardial infarction.

At the time of hospital admission the distinction between reversible ischaemia (angina) and myocardial damage (infarction) is often difficult. Thus it would be advantageous when a similar therapeutic approach could be used in both conditions. Alinidine was given intravenously (10-40 mg) to 24 patients with unstable angina. Heart rate decreased as well as systolic and mean arterial pressure, while stroke volume remained constant. One patient developed heart failure due to an overdose of alinidine (80 mg) in combination with a beta blocker. Furthermore, alinidine was administered in 32 patients with acute myocardial infarction, 23 of these suffered from heart failure. Similar haemodynamic effects were observed while a rise of pulmonary capillary wedge pressure occurred in two patients only. Alinidine appears to be a safe drug for reduction of heart rate in patients with unstable angina and acute myocardial infarction. Further studies to verify the clinical benefit of such a treatment are required.

Adrenergic beta-Antagonists↗
PubMed1986

Effects of nifedipine on left ventricular performance in unstable angina pectoris during a follow-up of 48 hours.

In 1981, a large, double-blind, randomized, multicenter trial was started in The Netherlands to evaluate the therapeutic effects of nifedipine or metoprolol in patients with unstable angina. This study, called the Holland Interuniversity Nifedipine Trial (HINT), included several hundred patients to establish potential therapeutic effects. From December 1982 until January 1984 the effects of nifedipine on left ventricular (LV) performance in a subgroup of 37 HINT patients were studied using radionuclide techniques. All patients (18 treated with nifedipine, 19 with placebo) underwent radionuclide angiography and 33 underwent thallium-201 scintigraphy just before and 48 hours after the start of treatment with the experimental medication. Radionuclide angiographic studies were also performed 1 hour (29 patients) and 4 hours (31 patients) after the start of treatment. The thallium-201 images showed defects in 24 (73%) of the baseline images and in 21 (64%) of the 48-hour images. No significant differences were seen between patients receiving nifedipine or placebo in the incidence of new defects or in the disappearance of defects at 48 hours. Changes in thallium-201 images were not related to recurrence of myocardial ischemia or the development of acute myocardial infarction. Nineteen of the 37 patients (51%) with baseline blood pool images had a reduced LV ejection fraction (EF) (38 +/- 10%) and 18 patients (49%) had a normal LVEF of 56 +/- 5%. LVEF improved after 48 hours in 8 patients receiving nifedipine and in only 1 patient receiving placebo (p less than 0.02). This effect was not present at 1 and 4 hours after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1986

Influence of nifedipine on left ventricular perfusion and function in patients with unstable angina: evaluation with radionuclide techniques.

In 1981, a large, double-blind, randomized trial was started in The Netherlands to evaluate the therapeutic effects of nifedipine and/or metoprolol in patients with unstable angina. This study has been called the Holland Interuniversity Nifedipine/metoprolol Trial (HINT) and required several hundred patients to establish potential therapeutic effects. From December 1982 to January 1984 the effects of nifedipine on left ventricular (LV) performance in a subgroup of 52 HINT patients were studied using radionuclide techniques. All patients (23 on nifedipine, 29 controls) underwent thallium-201 scintigraphy or radionuclide angiography just before and 48 h after the start of experimental medication. The radionuclide angiographic studies were also performed at 1 and 4 h after treatment. Nifedipine did not influence the incidence or disappearance of perfusion defects on the 48-h thallium images. No significant differences in overall LV ejection fraction (EF) were seen at any time between nifedipine-treated patients and controls. However, paired observations in 37 patients showed improvement of LVEF after 48 h in 8 patients on nifedipine and in only 1 control patient. Scintigraphic measurements on admission were not related to clinical outcome after 48 h. Concomitant administration of metoprolol did not influence LVEF in either group. It is concluded that nifedipine improves LVEF after 48 h in a subset of patients with unstable angina without affecting myocardial perfusion. This finding indicates that nifedipine has a predominant effect on afterload reduction in patients with unstable angina. However, early scintigraphic measurements had no significant predictive value for subsequent cardiac events.

Angina Pectoris↗