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Biomedical subjects

C Daubert

Publications and source records attributed to C Daubert.

42 records · Page 3Linked to original sources
PubMed1988

Critical analysis of cineangiographic criteria for diagnosis of arrhythmogenic right ventricular dysplasia.

Biplane 30-degree RAO and 60-degree LAO RV selective cineangiography was performed in 21 patients with significant ventricular arrhythmias (ventricular tachycardia in 14, salvos in three, and complex PVCs in seven) and a high presumption of arrhythmogenic RV dysplasia (ARVD), and in a control group of 10 presumed normal individuals. Comparing the two series revealed the lack of specificity of some angiographic images usually reported as suggestive signs of ARVD, such as slow dye evacuation of RV during the levophase and deep fissuring in the anterior wall with a "pile of plates" image. Inversely, localized morphologic and contraction abnormalities in the RV free wall were more sensitive and specific signs for diagnosis of ARVD; these were localized akinetic or dyskinetic bulges sometimes giving a true image of aneurysm (90%), wide and deep fissuring of the apex or of the inferior wall (33%), and large areas of akinesia. By order of frequency, these abnormalities were found on the apex in 71%, on the inferior wall in 52%, on the anterior wall in 48%, in the subtricuspid area in 38%, and on the pulmonary infundibulum in 33%. These localized lesions can suffice for the diagnosis of RV dysplasia in the absence of associated pathologies, such as ischemic heart disease or congenital defects. Usually a global RV systolic dysfunction is associated in ARVD, as confirmed by greater RV volumes (134 +/- 26 vs 79 +/- 10 ml/m2 for RVEDV, p less than 0.001; 76 +/- 34 vs 32 +/- 6 ml/m2 for RVESV, p less than 0.001), and lower RV ejection fraction (58 +/- 18% vs 47 +/- 8%, p less than 0.001) in the ARVD group compared to controls. Nevertheless, normal RV volumes and ejection fraction can be observed in some localized forms with mono- or bisegmental lesions in which RV systolic dysfunction is absent or moderate, and extensive forms with multiple segmental lesions where RV systolic dysfunction is constant and often severe. Six out of 21 patients in the ARVD group exhibited obvious global or segmental LV dysfunction, indicating the possibility of biventricular forms, as previously reported in other publications.

Adult↗
PubMed1988

Failure of the exercise test to predict the anterograde refractory period of the accessory pathway in Wolff Parkinson White syndrome.

Modifications of the delta wave on the surface ECG during an exercise stress test were compared to electrophysiological variations in accessory pathway (AP) refractoriness and in AV node conduction, during intravenous isoproterenol infusion in ten patients with WPW syndrome. In one patient, the delta wave persisted unchanged at the end of exercise and, with isoproterenol, there was a greater reduction in the AP anterograde effective refractory period (AERP) than in AV node conduction time. In three patients, the delta wave became less and less apparent but without completely disappearing; in these patients, the slight reduction of the AERP in the accessory pathway with isoproterenol was comparable to the reduction in AV node conduction time, explaining the progressive fusion between the two activation fronts. In the six other patients, the delta wave completely disappeared during exercise: in two cases, suddenly from one cycle to the next with strong concordance between the measured (isoproterenol) and the estimated (exercise test) AERP in the AP; in four cases, the disappearance was progressive with a significantly greater reduction in the AV node conduction time than in the measured AERP of AP which was nonetheless very short, 190 to 225 ms, during isoproterenol infusion. These findings confirm the limitations of the exercise test to predict the AERP of the AP. In addition, they demonstrate that modifications in the delta wave during exercise result from a balance between the relative effects of sympathetic stimulation on refractoriness of AP and normal AV conduction.

Adult↗
PubMed1986

Physiological relationship between AV interval and heart rate in healthy subjects: applications to dual chamber pacing.

The purpose of this paper is to specify the mathematical relationship between spontaneous AV interval (AVI) and heart rate (HR), the amplitude and rate of variation of AVI, and the physiological factors likely to affect these characteristics. Ten patients with healthy hearts were studied. Two catheter electrodes were positioned in the right atrium and at the tip of the right ventricle respectively, allowing the detection of endocardial signals. The AV and AA intervals for each heart cycle were digitized to an accuracy of +/- 1 msec. Measurements were made at rest, then during a stress test on an exercise bicycle, and finally during the recovery phase. The results show that adaptation is very precise and takes place instantly. Any variation in heart rate causes an immediate, inversely proportional variation in AVI. Adaptation follows a linear pattern, generally with relatively low amplitude and an average AVI reduction of 27.5 +/- 11.2 msec for an average HR increase of 78.7 +/- 22.5 bpm, i.e., a decrease of 4 +/- 2.1 msec for an HR variation of 10 bpm. The amplitude and variation rate of AVI seem to be independent of the age and base value of the PR interval. These observations may be useful for designing new VDD or DDD pacemakers that automatically adapt the AV interval to the instantaneous heart rate. The hemodynamic benefits of this adaptation were also demonstrated.

Adolescent↗
PubMed1980

[Study on myoglobinemia and its development during myocardial infarction (author's transl)].

Thirty six patients suffering from myocardial infarction were investigated by assay of their serum myoglobin, total creatine kinase and creatine kinase isoenzyme MB activities. Determination of serum myoblobin presents, with regard to creatine kinase MG, two major advantages: a very early increase after the onset of the pain (about three hours later) and a very quick clearance, allowing the diagnosis of a second episode of necrosis after about one day.

Creatine Kinase↗
PubMed1975

[Myocardial infarct in 2 stages].

The two-step myocardial infarction is defined by a peculiar course: the initial stage is a temporary rudimentary infarction, the late stage a typical transmural necrosis, separated by a free interval of a variable duration. A coronary arteriography undertaken when the recurrence starts might eventually lead to recommend an emergency operation: two-step myocardial infarction might represent one of the best indications for emergency aorta-to-coronary artyery by-pass operation.

Anticoagulants↗