Biomedical subjects

R Videbaek

Publications and source records attributed to R Videbaek.

25 records · Page 2Linked to original sources

PubMed1995

Prognostic value of echocardiography compared to other clinical findings. Multivariate analysis based on long-term survival in 456 patients.

The prognostic significance of conventional clinical and echocardiographic data in patients referred to echocardiography was retrospectively analyzed. 456 patients (206 females and 250 males) were studied in the department of cardiology in a district hospital. Survival after 3 years was 64%. By multivariate analysis five factors contained independent, significant, prognostic information (hazard ratios for death are given in parentheses): left ventricular wall motion score index (WMI) < or = 1.2 by echocardiography (2.5), status as inpatient (2.1), age > 65 years (1.7), clinical heart failure (1.9) and atrial fibrillation (1.5). A stepwise multivariate analysis was performed by entering variables into a model initially forced to contain information on age, hospitalization status, treatment of heart failure and heart rhythm. In this analysis, a poor WMI (< or = 1.2) and a dilated right ventricle contained further independent prognostic information. In conclusion, among conventional clinical and echocardiographic data, WMI was the most powerful predictor of long-term survival, and despite knowledge of major clinical features echocardiography provided further prognostic information.

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PubMed1994

An echocardiographic method for selecting high risk patients shortly after acute myocardial infarction, for inclusion in multi-centre studies (as used in the TRACE study). TRAndolapril Cardiac Evaluation.

The aim of our study was to examine if echocardiography can reproducibly be used in a multicentre study to select high risk patients with reduced left ventricular function early after an acute myocardial infarction (MI). In the TRAndolapril Cardiac Evaluation Study (TRACE) patients with reduced left ventricular systolic function were randomized 3-7 days post MI to receive either the ACE inhibitor trandolapril, or placebo. Twenty-seven Danish centres participated and 7001 consecutive MI patients were screened for entry. Local doctors and technicians who had received a brief but thorough training course recorded a two-dimensional echocardiographic examination on videotape 2-6 days after MI. Within 24 h, wall motion index (WMI) was visually assessed by one of two cardiologists (examiners) with considerable experience in echocardiography. A WMI of < or = 1.2 (corresponding to a left ventricular ejection fraction (LVEF) < or = 0.35) meant that the patient was eligible for randomization in the TRACE study. Two other experienced cardiologists with substantial experience in echocardiography (controllers) performed blind reassessment of 155 randomly chosen videotapes. We showed that 93% of the 7001 screened MIs had an assessable echocardiogram. WMI was < or = 1.2 in 37% of patients. The one-year mortality was inversely related to WMI, being 60%, 30%, 14% and 11% in patients with a WMI < 0.8, 0.8-1.2, 1.3-1.6 and > 1.6, respectively. In the random sample of 155 videorecordings that were reevaluated, 97% were found to be technically adequate for analysis both by the examiners and the controllers.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1993

Arterial pulse pressure and vasopressin release in humans during lower body negative pressure.

The hypothesis was tested that narrowing of arterial pulse pressure (PP) is a determinant of arginine vasopressin (AVP) release in humans. Six normal males completed a two-step lower body negative pressure (LBNP) protocol of -20 and -50 mmHg, respectively, for 10 min each. None of these subjects experienced presyncopal symptoms. Arterial plasma AVP and plasma renin activity (PRA) (at 2-min intervals) only increased subsequent to a decrease in PP (invasive brachial arterial measurements) and stroke volume (ultrasound Doppler technique, n = 4). Simultaneously, mean arterial pressure did not change. A selective decrease in central venous pressure and left atrial diameter (echocardiography, n = 4) at LBNP of -20 mmHg did not affect AVP or PRA, whereas arterial plasma norepinephrine increased (n = 4). During LBNP, significant (P < 0.05) intraindividual linear correlations were observed between log(AVP) and PP in four of the subjects with r values from -0.75 to -0.99 and between log(PRA) and PP in all six subjects with r values from -0.89 to -0.98. In conclusion, these results are in compliance with the hypothesis that narrowing of PP in humans during central hypovolemia is a determinant of AVP and renin release.

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PubMed1993

Plasma immunoreactive neuropeptide Y in congestive heart failure at rest and during exercise.

The purpose of the study described here was to study plasma immunoreactive Neuropeptide Y (NPY) at rest and during exercise in patients with congestive heart failure (CHF) and in healthy subjects. Thirty-five patients, mean age 64 years, with CHF in optimal treatment and with a mean ejection fraction of 32%, were studied at rest and during exercise. Twelve age and sex matched healthy subjects were compared for resting values. Another nine healthy subjects were studied at rest and during exercise at a constant low load of 75W and at a high load defined as 80% of their individual maximal capacity. In patients with congestive heart failure mean plasma immunoreactive NPY at rest was 10.3 pmol l-1 and was not significantly different from the control group. No differences between patients with slight and severe CHF were found and there was no correlation between plasma immunoreactive NPY and left ventricular ejection fraction. Mean maximal exercise time was on average 6.3 min. Only three patients exercised more than 10 min. At maximal exercise mean plasma immunoreactive NPY was 10.6 pmol l-1 the same as at rest. Plasma noradrenaline was increased in CHF patients compared to healthy subjects, and rose further during exercise. In healthy subjects plasma immunoreactive NPY rose significantly on both workloads, but more on the high load (p < 0.05), when the rise was first significant after 10 min. Plasma immunoreactive NPY at rest and during exercise was not increased in CHF patients in optimal medical treatment. Consequently plasma immunoreactive NPY is not a useful marker of the severity of CHF in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1989

Cerebral blood flow before and after cardioversion of atrial fibrillation.

In nine patients with atrial fibrillation (AF) of less than 3 months' duration, CBF was measured the day before and after and again 30 days after electrical cardioversion therapy to sinus rhythm. The day before cardioversion therapy, median CBF (expressed as initial slope index 1, ml/100 g.min-1) was 35.8 and the day after it was 37.1. After 30 days in sinus rhythm, CBF was 39.4 (NS), although the end-tidal PCO2 values were lower than the pretreatment values. After correction for changes in end-tidal PCO2, the median CBF had increased significantly from 35.8 to 40.3 on day 1 and to 46.7 on day 30. The reduced CBF during AF could be a contributing factor in the development of cerebrovascular complications in patients with AF.

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PubMed1988

Myocardial contractility and performance capacity after magnesium infusions in young healthy persons: a double-blind, placebo-controlled, cross-over study.

To evaluate the effect of intravenous magnesium (Mg) treatment on the inotropic state of the heart and maximal work capacity, 9 healthy volunteers were entered in a double-blind, placebo-controlled, cross-over study. Separated by an interval of three weeks, the volunteers were tested twice, each time randomly allocated to receive either an intravenous injection of 10 mmol magnesium chloride dissolved in 100 ml isotonic sodium chloride or placebo of isotonic sodium chloride only. Before and after each infusion myocardial inotropism was evaluated by echocardiography. Mitral-septal distance (MSA) was used as a measure for ejection fraction. On each test day an ergometer bicycle exercise test was performed, and maximal work capacity was calculated. Magnesium treatment reduced the MSA (from 4.2 to 2.9 mm, p = 0.07), while no difference was found after placebo treatment. Likewise, a tendency toward increasing fractional shortening after magnesium treatment was detected, although this difference was not statistically significant (p = 0.1). No difference in maximal work capacity between the magnesium and placebo periods was found. Serum magnesium concentrations and placebo periods was found. Serum magnesium concentrations rose significantly after the infusions (from 0.82 to 1.38 mmol/l, p less than 0.001). It is concluded that intravenous magnesium does not exert a negative inotropic effect on the myocardium as previously stated. On the contrary, we found a tendency toward a positive inotropic effect. However, the observed differences are of borderline statistical significance and a more extended study, employing invasive measurements of cardiac inotropism appears to be necessary.

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PubMedDate not supplied

Prognostic value of echocardiography in 190 patients with chronic congestive heart failure. A comparison with New York Heart Association functional classes and radionuclide ventriculography.

Survival in 190 consecutive patients with congestive heart failure, discharged from a general hospital, was studied. Sixteen patients were in New York Heart Association (NYHA) class I, 87 in II, 83 in III and 4 in IV. Median left ventricular ejection fraction (LVEF) from radionuclide ventriculography was 0.30 (range 0.06-0.74). Two-year survival was 68%. Wall motion index was the only echocardiographic variable with significant, independent, prognostic information on survival. The 2-year survival in NYHA classes I and II was 90.7% for wall motion index > or = 1.3, and 78.6% when < 1.3. In classes III and IV survival was 68.9% for wall motion index > or = 1.3 and 39.9% when < 1.3. Addition of LVEF gave further information about survival. This study demonstrates that echocardiography is of great value in determining prognosis in congestive heart failure patients, and that wall motion index contains the majority of the information. Wall motion index is closely correlated to LVEF, however prognostication is improved when information about LVEF is added.

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