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Publications (3)5.93 Total impact

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    ABSTRACT: The prognosis for patients with complications and syncope following myocardial infarction depends on the left ventricular ejection fraction (LVEF) and the mechanism of the syncope. The aim of this study was to evaluate the results of an electrophysiological study (EPS) following isoproterenol infusion in patients with a negative EPS under basal conditions. The population included 60 patients, aged 60 +/- 12 years, 5 of whom had syncope on effort or with stress. The EPS included measurement of AV conduction, with programmed atrial and ventricular stimulation. It was repeated following infusion of 2 to 4 microg/kg of isoproterenol. Results: An arrhythmia was identified as preceding the syncope in 27 patients (45%): ventricular tachycardia (VT) n = 16, supraventricular tachycardia (n = 5), 2nd or 3rd degree AV block (n = 3), vaso-vagal reaction (n = 3): 3 subjects developed coronary ischaemia. The subjects with VT on Isuprel differed from those without VT, with a lower LVEF (34 +/- 8 vs 45 +/- 14%) (p < 0.05), a higher incidence of effort related syncope (4 vs 1) and a higher risk of cardiac death (6/16 vs 2/44) (p < 0.01). In conclusion, we recommend repeating the electrophysiogical test under Isuprel in patients with complications after MI and a negative EPS in the basal state whether or not they have exercise related syncope, which will reveal an arrhythmia in 45% of cases. Subjects with inducible VT are at high risk of cardiac death.
    Archives des maladies du coeur et des vaisseaux 02/2006; 99(2):129-33. · 0.40 Impact Factor
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    ABSTRACT: Isoprenaline (isoproterenol) is a beta-adrenergic drug, used to increase the heart rate and, during electrophysiological study, to facilitate the induction of supraventricular (SVT) and ventricular tachycardias (VT). Decrease in heart rate during isoprenaline infusion is a rare phenomenon. The purpose of the study was to evaluate the incidence, the possible mechanisms, and the significance of a paradoxical bradycardia induced by isoprenaline infusion. Electrophysiological study was performed for the evaluation of tachycardias (n = 551) or dizziness/syncope (n = 214) in 765 patients aged from 15 to 85 years. The study was negative in the basal state, and was repeated after isoprenaline infusion (2-4 microg/min). In 714 patients, this perfusion increased the heart rate to 100-140 bpm. A bradycardia was noted in 51 patients (7%). Two bradyarrhythmias were noted: (1) sinus or junctional bradycardia (cycle length - 10%) occurred in 43 patients, aged 15-70 years, generally studied for unexplained syncope (n = 37); a young age (40+/-16 years), syncope (n = 37) and absence of heart disease (n = 27) were more frequent than that in patients without isoprenaline-induced sinus or junctional bradycardia; another arrhythmia (SVT or VT) was induced in seven patients with syncope, five with heart disease and two without; six young patients (<50 years) had no syncope and were studied for SVT or VT; (2) eight patients, aged 65+/-11 years, developed second-degree atrioventricular (AV) block which was supraHisian (n = 4) or infraHisian (n = 4); they were studied for exercise-related syncope; they had no signs of myocardial ischaemia and AV block was reproduced by ajmaline testing: isoprenaline revealed organic conduction disturbance. The occurrence of paradoxical bradycardia was a rare finding during isoprenaline infusion (7%); sinus or junctional bradycardia was a sign of hypervagotonia, but was without clinical significance in 35% of these patients. The development of second-degree AV block was always pathological and associated with AV conduction disturbances, which occurred spontaneously during exercise. Isoprenaline infusion appeared to be a simple means to detect organic AV conduction disturbance in patients complaining of exercise or stress-related dizziness/syncope and unable to perform exercise test.
    Europace 12/2005; 7(6):621-7. · 2.77 Impact Factor
  • Europace 01/2003; 4. · 2.77 Impact Factor