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Biomedical subjects

R Krémer

Publications and source records attributed to R Krémer.

17 recordsLinked to original sources
PubMed1996

Prevention of thromboembolic events in valvular heart disease.

Thromboembolic events are major causes of morbidity and mortality in patients with native heart valve disease and artificial heart valves. Oral anticoagulation can reduce these complications. The indication for and intensity of oral anticoagulation depends on both, the risk for thromboembolic events and the risk of hemorrhage. The indications for oral anticoagulation in the various pathological conditions are defined. Risk factor adjusted intensity of oral anticoagulation and risk factor modification are new and very important aspects in the management of these patients which may lead to a reduction in anticoagulation associated complications and an improvement in antithrombotic effectivity. Further studies to identify the optimal therapeutic ranges of anticoagulation for the individual patient are needed. Multi-centre prospective randomized studies in this field should help us to answer the still open questions including new hemostatic molecular markers to further identify patients with different risk profiles.

Anticoagulants↗
PubMed1992

Arrhythmias in the natural history of aortic stenosis.

In aortic stenosis, severe ventricular arrhythmias may be linked to left ventricular dysfunction and are a factor to be considered when a surgical decision is to be made. Conduction disturbances are frequent, sometimes not related to the severity of the stenosis and may endanger patient's life.

Aortic Valve Stenosis↗
PubMed1991

Atrial natriuretic factor during percutaneous transluminal coronary angioplasty.

To study the release of plasma atrial natriuretic factor (ANF) and to explain the mechanism underlying its increase during myocardial ischemia, we measured plasma ANF and mean pulmonary capillary wedge pressure (PCW) before, during and after percutaneous transluminal coronary angioplasty (PTCA) in eight patients. All patients were free of calcium channel antagonists and beta-blocking drugs. Evidence of myocardial ischemia was observed in all patients with an increase of PCW from 3.2 +/- 1.2 to 10.6 +/- 2.9 mm Hg (mean +/- SD; p less than 0.001). Heart rate and mean blood pressure did not change significantly. We observed an increase of plasma ANF during PTCA, from 53 +/- 24 to 100 +/- 37 pmol/L (mean +/- SD; p less than 0.005). There was a correlation between absolute values of ANF and PCW before and during PTCA (r = 0.64, p less than 0.01). After PTCA, ANF levels remained increased for at least twenty minutes (p less than 0.005 vs basal state) despite a decrease in PCW. Thus, increase of PCW during this very short-term left ventricular ischemic dysfunction induces an increase of plasma ANF, which persists during a certain time when PCW returns to normal.

Aged↗
PubMed1989

Detection of restenosis after coronary angioplasty for single-vessel disease: how reliable are exercise electrocardiography and scintigraphy in asymptomatic patients?

The diagnostic value of exercise electrocardiography and thallium myocardial scintigraphy for the detection of restenosis was assessed in 111 patients undergoing control angiography 6 months after successful coronary angioplasty. All patients were free of symptoms at the time of the study. A diameter reduction of 70% or more at the site of angioplasty was considered restenosis. The sensitivity of exercise electrocardiography is low (64%). Exercise ECG and scintigraphy are highly specific (respectively 90% and 93%). The predictive value of a positive ECG or thallium scintigraphy is poor (respectively 53% and 63%). The value of a negative scintigraphic result is slightly better than the predictive value of a negative ECG (98% vs 95%; NS). A negative exercise scintigraphy almost excludes severe restenosis. These non-invasive tests seem suitable for the detection of asymptomatic restenosis.

Angioplasty, Balloon, Coronary↗
PubMed1987

Value, sensitivity and specificity of stroke volume ratio in routine equilibrium gated scintigraphy.

The stroke volume ratio (SVR) is a new, non invasive method to quantify ventricular volume overload (VVO). We have analyzed its value, sensitivity and specificity in routine clinical practice. The results of 238 consecutive patients (pts) were analysed prospectively within a 3 months period. The SVR was expressed as the ratio of left ventricular (LV) stroke counts over the right ventricular (RV) stroke counts measured on the time-activity curves. One region of interest was drawn per ventricle on the phase and amplitude images. Values above 1.6 were considered as LVVO and below 0.9 as RVVO. Fifty-one patients had VVO due to valvular regurgitation or left-to-right shunt; 187 patients had no evidence of VVO. Mean value obtained for 23 normal subjects with adequate positioning was 1.27 +/- 0.14 (MV +/- SD), ranging from 0.9 to 1.47. Among patients with adequate positioning, no difference was observed in subgroups with dilated cardiopathy (DC) or anteroseptal aneurysm (AA) despite a low EF. MV for patients with LV or RV hypertrophy (H) were statistically different. Sensitivity was 82% for the 51 patients with VVO. False negatives were due to biventricular overload or mild VVO. Specificity evaluated in the 187 patients without VVO was 76%. The 45 false positives were due to poor separation of the right cardiac chambers and/or of the 2 ventricles. They were observed in 4 patients with AA, 3 patients with DC, 7 patients with LVH, 4 patients with RVH and 24 patients with inadequate positioning. No explanation was found in 3 patients. We conclude that cardiac equilibrium blood pool scintigraphy has an adequate sensitivity and specificity to evaluate patients with VVO.

Cardiomegaly↗
PubMed1979

[Unstable angina].

Explore the source record for details and available documents.

Angina Pectoris↗
PubMed1977

[Aortic valve replacement at the cardiac insufficiency stage].

80 adult patients with isolated aortic valvulopathy and cardiac insufficiency have been investigated. Among 10 non operated patients, there has been 9 deaths during a three years follow-up. Among 70 operated patients early mortality is not higher than among patients without cardiac failure, but late mortality is significantly higher (27, 1 p. 100), bacterial endocarditis and sudden deaths being particularly frequent. Subjective improvement is constant among survivors but cardiomegaly and left ventricular hypertrophy do not change much. The authors think aortic valve replacement is beneficial even in patients with cardiac failure.

Adult↗