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Biomedical subjects

J Lubsen

Publications and source records attributed to J Lubsen.

107 records · Page 6Linked to original sources
PubMed1984

Flecainide: one-year efficacy in patients with chronic ventricular arrhythmias.

During a one-week short-term in-hospital period, 60 patients with chronic ventricular arrhythmias were treated with 200 mg flecainide twice a day. Flecainide reduced premature ventricular complexes (PVCs) by more than 85% without causing important side-effects in 47 patients, who entered a one-year follow-up period and were followed with bimonthly 24-h ECGs. Median PVC-frequency remained reduced by more than 99% during the follow-up period. Repetitive ventricular beats and ventricular tachycardia were present in 83% and 42% of patients, respectively, before flecainide. During follow-up, these arrhythmias were seen in less than 32% and less than 10% of patients, respectively, at each 24-h ECG. Furthermore, the mean number of hours with repetitive ventricular beats and ventricular tachycardia remained reduced by more than 76% and more than 79%, respectively, throughout the follow-up period. Ventricular arrhythmias remained suppressed despite a gradual reduction in flecainide dosages (to a median of 300 mg day-1) and flecainide plasma levels. In nine out of 47 patients, an increase in ventricular arrhythmias above baseline values on one or more occasions was observed. During a flecainide withdrawal period, a 65-fold increase in median PVC-frequency was observed and ventricular tachycardia reappeared in 18 patients. Subjective side-effects were acceptable except for two patients. During the follow-up period, one patient developed reversible heart failure and sinus node dysfunction. During the total study period, four patients, with either severe coronary artery disease (2) or cardiomyopathy (2) developed lethal arrhythmias (3) or ischaemic events (1). We conclude that prolonged flecainide treatment is effective in a high proportion of patients with chronic ventricular arrhythmias. In some patients an arrhythmogenic effect may occur.

Adult↗
PubMed1984

Reference ranges of echocardiographic measurements in the Dutch population.

Reference ranges for echocardiographic measurements were determined in 609 healthy Dutch subjects, using height, weight, age, sex, RR-interval and blood pressure (in adults only) as determinants. End-systolic as well as end-diastolic measurements of the aortic root as well as left ventricular inner diameter, posterior and septal thickness were taken, as was the left atrial end-systolic diameter. Multiple linear regression was performed of the form: M = A.(age)B.(height)C.(weight)D.(RR-interval)E.(sex)F. The residuals were calculated in order to determine the percentile limits by means of linear interpolation. Sex and weight were significant determinants in all the echocardiographic parameters studied. The results were presented twofold, with a simple version for males and females separately, using only weight as a determinant and allowing graphical presentation, and secondly a complex version taking into account all determinants, which can only be solved with help of a calculator.

Adolescent↗
PubMed1984

Prediction of mortality in hospital survivors of myocardial infarction. Comparison of predischarge exercise testing and radionuclide ventriculography at rest.

The relative merits of resting ejection fraction measured by radionuclide angiography and predischarge exercise stress testing were compared for predicting prognosis in hospital survivors of myocardial infarction. Two hundred and fourteen survivors of myocardial infarction out of 338 consecutive patients with acute myocardial infarction were studied over a 14 month period. Hospital mortality was 13% (45 of 338) whereas 19 additional patients out of 214 died in the subsequent year (9%). High, intermediate, and low risk groups could be identified by left ventricular ejection fraction measurement. Mortality was 33% for nine patients with an ejection fraction less than 20%, 19% for 58 patients with an ejection fraction between 20% and 39%, and 3% for 147 patients with an ejection fraction greater than 40%. Mortality was high (23%) in 47 patients who were unable to perform the stress test because of heart failure (19) or other limitations (28). The patients could be stratified further into intermediate and low risk groups according to the increase in systolic blood pressure during exercise: six deaths occurred in 46 patients with a blood pressure increase of less than 30 mm Hg and two deaths occurred in 121 patients with an increase greater than or equal to 30 mm Hg. Maximum workload, angina, ST changes, and ventricular arrhythmias were less predictive than blood pressure changes. It is concluded that the prognostic value of radionuclide angiography at rest and of symptom limited exercise testing is similar. The latter investigation should be the method of choice since it provides more specific information for patient management.

Aged↗
PubMed1984

Oral flecainide for suppression of ventricular arrhythmias.

The efficacy and safety of oral flecainide for treatment of ventricular arrhythmias were assessed during a 3-day period in patients with various cardiac diseases. Of 11 patients who received a low dose of flecainide (median daily dose 240 mg), only 4 responded with 90% or greater reduction in premature ventricular complex frequency. Ventricular tachycardia could not be suppressed. During treatment no electrocardiographic changes occurred. 14 of the 19 patients who received a high dose of flecainide (median daily dose 480 mg), demonstrated a 90% or greater reduction in premature ventricular complexes, and ventricular tachycardia did not recur during treatment in 7 out of 9 patients. However, PQ, QRS, and QTc intervals were significantly increased. In general, flecainide was well tolerated and drug administration did not have to be discontinued because of side effects. Flecainide acetate treatment, with a median dose of 480 mg daily, appears to be highly effective for suppressing complex ventricular arrhythmias.

Administration, Oral↗
PubMed1983

Usefulness of quantitative echocardiography in congestive heart failure.

Echocardiography provides a harmless method which is of value in the assessment of the left ventricle in patients with congestive heart failure particularly when the patient is used as his own control. There are some obvious limitations. Considerable experience is needed in the proper application while adequate echocardiograms may not be obtained in all patients. Agreement in individual patients with other methods such as cine-angiocardiography or radionuclide ventriculography is limited. Whether this is inherent in the echocardiographic method or in the other commonly used methods is unclear since no in vivo 'golden standard' is available for comparison.

Angiocardiography↗
PubMed1983

Acute myocardial ischaemia: what information can be expected in the near future from ongoing clinical trials with nifedipine?

Nifedipine is a calcium antagonist with established anti-vasospastic action in man and, possibly cardioprotective effects during ischaemia. Although it is regularly used in the treatment of acute myocardial ischaemia, few double-blind randomized trials have been performed in this area. Recently, one trial was published which showed that nifedipine, when added to conventional treatment (beta-blockers, nitrates) of patients hospitalized for unstable angina pectoris (UAP) prevents recurrent ischaemia. Several further trials are known to be under way. The American nifedipine angina-myocardial infarction study (NAMIS) comprises sub-protocols both for patients diagnosed as UAP and patients diagnosed as acute myocardial infarction (AMI). In the former, a comparison is made between a nifedipine and a propranolol based regimen. Recurrence of ischaemia is the end point. In the NAMIS-protocol for AMI; nifedipine is compared with placebo. Infarct-size and complications are the end points. The Holland Interuniversity Nifedipine/metoprolol Trial (HINT) is similar in design to the NAMIS UAP-study. However, it has a placebo group for comparison and also deals with the combination of nifedipine and beta-blockade. NAMIS and HINT may resolve several important questions in reference to the treatment of acute myocardial ischaemia but they are of insufficient size to study effects on total mortality. Finally, in the area of secondary prevention after MI, a major trial (secondary prevention reinfarction nifedipine trial: SPRINT) is known to be under way in Israel.

Angina Pectoris↗
PubMed1983

Multicenter beta-blocker trials: certainties.

In general, therapeutic evaluation is based on a comparison between the 'treated' and the 'untreated'. The validity of the inference is based on the methods used in the formation of such groups. Randomized treatment allocation avoids selection bias and leads to interpretable statistical tests of significance. In addition, it defines the point in time at which follow-up starts. The use of placebo in a double-blind manner achieves comparability of information and also makes differences in the use of concomitant medication during follow-up interpretable as effects of the drug under study. Multicenter cooperation may enhance the representativeness of the data for the kind of patient to which the results may apply and makes it possible to check results for consistency between the clinics. These features of the design of recent beta-blocker trials in post-myocardial infarction patients enhance confidence in the results.

Adrenergic beta-Antagonists↗
PubMed1983

The haemodynamic effect of intravenous flecainide acetate in patients with coronary artery disease.

Flecainide acetate has been shown to be a potent antiarrhythmic agent which is active for more than 8 h, whether given intravenously or orally. However, the negative inotropic effect demonstrated in animal studies could hamper the potential clinical utility of the drug. Ten patients with coronary artery disease but without cardiac failure were given intravenous flecainide (2 mg/kg). Stroke index (SI), left ventricular systolic pressure (LVP), end diastolic pressure (EDP) and LV contractility indices (max dP/dt, VCE 40 mm Hg, peak VCE, Vmax from total pressure (TP] were measured immediately before and 10 min after flecainide, under resting conditions and during atrial pacing with heart rates up to 133 +/- 4.2 beats/min (mean +/- s.e. mean). It is demonstrated that flecainide has a negative inotropic effect, not only under resting conditions, but also less apparently during pacing-induced tachycardia. The effect appears to be dose-related and may result in a reduction of cardiac performance.

Adult↗
PubMed1980

Acute myocardial infarction: an easy diagnosis in general practice?

In the imminent myocardial infarction Rotterdam (IMIR) study, contacts by patients with their general practitioners for symptoms of potential coronary artery disease were registered. Those who had acute myocardial infarction were diagnosed on the basis of the modified World Health Organization criteria, and those with this definite diagnosis were then compared with the initial diagnosis made by the general practitioner at the moment of contact without laboratory assistance.Of the 1,343 patients included in the study, 93 (seven per cent) had ;definite' acute myocardial infarction and another 37 (three per cent) had ;possible' acute myocardial infarction according to the diagnostic criteria used.At the time of contact with the general practitioner 41 (44 per cent) of the 93 patients with definite myocardial infarction were recognized as such by the general practitioner, while in another 31 (33 per cent) the general practitioner diagnosed ;imminent' myocardial infarction.Of the 1,213 patients free of acute myocardial infarction at the time, 40 (three per cent) were incorrectly diagnosed by the general practitioner as having ;acute' myocardial infarction.In the 22 patients who in fact had acute myocardial infarction but in whom the general practitioner did not make this diagnosis at the time, it was found that there was an absence of physical signs and, similarly, in patients who subsequently did not have infarction the presence of physical signs was related to a falsepositive general practitioner diagnosis of myocardial infarction.In view of the inaccuracy of the general practitioner's provisional diagnosis of acute myocardial infarction, we believe that electrocardiogram and enzyme tests should be carried out systematically in all patients who present to general practitioners with symptoms of potential coronary artery disease. Laboratory support should be readily available and we support the idea of having a special diagnostic service.

Adult↗
PubMedDate not supplied

Improved prognosis during and after myocardial infarction: a plea for an integrated and stratified approach.

Immediately after the first signs and symptoms of acute myocardial infarction are detected, its prognosis is determined by the size of the area at risk, the availability of collaterals and the time at which interventions are carried out. Preservation of as much myocardial tissue as possible is the key issue. Relief of obstruction of the thrombosed nutrient artery and reperfusion of the myocardium in jeopardy within 4 hours after onset of symptoms can lead to limitation of the ultimate infarct size, maintained ventricular function and a marked reduction of the first year mortality. Early supportive therapy with beta-blockade and calcium antagonists may enhance this effect. Recent data published on 533 patients randomized to either a reperfusion strategy or to conventional therapy, combined with those from the recent literature on thrombolysis and early beta blockade, provide the basis for this point of view. Once infarction is unavoidable and in the process of consolidation, supportive therapy is recommended. This still can change the outcome by timely correction of electrical instability, normalization of afterload and heart-rate, and the avoidance of secondary complications such as peripheral thrombosis. To determine the best course after recovery from the infarction, a symptom limited bicycle stress test, radionuclide ventriculography and 24 hour ambulatory electrocardiogram at the time of discharge were compared in predicting one year survival in 351 hospital survivors. A history of previous myocardial infarction or of heart failure during the current episode proved to be the strongest clinical predictor of early death.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗