Treatment of refractory congestive heart failure by cardiac resynchronization.

The contributions of long-term cardiac resynchronization as a supplemental treatment of refractory congestive heart failure have recently been reported. Several completed studies support the validity of this new therapy, capable of improving quality of life as well as increasing exercise capacity. These gains hinge on a careful patient selection, on the proper placement of the leads, particularly that responsible for left ventricular stimulation, and on an individualized patient follow-up. The results obtained thus fat fully justify considering cardiac resynchronization as an additional option in the treatment management of patients refractory to conventional measures. Ongoing studies should help to further defining its impact on morbidity and overall mortality, as well as the potential role for back up defribillator.

[Wolff-Parkinson-White syndrome. Value of transesophageal atrial stimulation coupled with exercise test for the study of anterograde conduction in the accessory pathway]. / Syndrome de Wolff-Parkinson-White. Intérêt de la stimulation auriculaire transoesophagienne couplée à l'épreuve d'effort pour l'étude de la conduction antérograde dans la voie accessoire.

In patients with Wolff-Parkinson-White syndrome the anterograde conduction properties of the accessory pathway determine the ventricular rate in case of atrial fibrillation (AF). Anterograde conduction in the accessory pathway was evaluated in 20 patients (mean age 31 years) by means of transoesophageal atrial pacing with increasing frequency (up to 460 per minute), first at rest, then during exercise on an ergometric bicycle and upon immediate recovery. The exploration was completed by a search for the disappearance of pre-excitation during exercise and after an intravenous injection of ajmaline 1 mg/kg. The shortest cycle (SC) of atrial pacing with 1:1 conduction by the accessory pathway regularly decreased by 80 +/- 26 ms (n = 18), i.e. 27 p. 100 of its value at rest. At immediate recovery SC increased by 40 +/- 53 ms (n = 9). Atrial fibrillation was induced at rest and/or during exercise in 12 patients. The shortest interval (SI) between two pre-excited ventricular complexes was 290 +/- 80 ms (n = 8) at rest and 244 +/- 53 ms (n = 8) during exercise. With a substantial group of values (n = 12) there was good correlation between SC and SI both at rest and during exercise. With a smaller group of values (n = 3) SI was clearly greater than SC, suggesting a concealed conduction in the accessory pathway during atrial fibrillation. Disappearance of pre-excitation during exercise was observed in 4 patients, 3 of whom had a short (less than 250 ms) SC and/or SI.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparative study of auricular stimulation by transesophageal and endocavitary approach for evaluating sinus and atrioventricular node function]. / Etude comparée de la stimulation auriculaire par voie transoesophagienne et endocavitaire pour l'évaluation de la fonction sinusale et du noeud atrio-ventriculaire.

The purpose of this study was to find out whether non-invasive transoesophageal pacing could effectively replace right intra-atrial pacing for the indirect evaluation of sinus node and atrioventricular (AV) node function. In a population of 17 patients the corrected sinus node recovery time (CSRT), the atrio-sinu-atrial conduction time (ASACT) and Wenckebach's point (W) were calculated by intracavitary pacing, then by transoesophageal pacing. There was no significant difference between the two methods in pre-pacing sinus cycle. With right intra-atrial pacing, mean CSRT value was 365 +/- 54 ms (with 5 values greater than 520 ms), mean ASACT value was 229 +/- 29 ms (with 8 values greater than 220 ms), and W occurred at a mean cycle length of 425 +/- 29 ms. With transoesophageal pacing, mean CSRT value was 406 +/- 87 ms (with 5 values greater than 520 ms), mean ASACT value was 222 +/- 17 ms (with 8 values greater than 220 ms), and W occurred at a mean cycle length of 408 +/- 26 ms. The two methods correlated very closely for CSRT and W (r = 0.97) and relatively well for ASACT (r = 0.84). The number of CSRT and ASACT values regarded as prolonged was the same with the two methods; 84% of recorded (i.e. maximal) CSRT values occurred with the same length of pacing cycle. There was no statistically significant difference between the two methods in the calculation of CSRT and ASACT, but W occurred at a slightly shorter cycle (p less than 0.05) with transoesophageal pacing. Thus, transoesophageal pacins is a non-invasive, easy to perform method for indirect exploration of sinus node and AV node function in patients who do not require subnodal conduction studies.