Usefulness of isometric exercise during dobutamine administration for stress echocardiography.

An isometric exercise was performed by 170 consecutive patients at peak dose dobutamine, before atropine administration. The test was well tolerated, heart rate increased significantly during exercise, and atropine administration was avoided in 29% of patients.

Repair of tricuspid atresia in 100 patients.

One hundred consecutive patients with situs solitus of the atria and tricuspid atresia have undergone surgical repair since 1968. In patients with ventriculoarterial concordance, a nonvalved Dacron conduit or an aortic valve homograft was interposed between the right atrium and right ventricular outlet chamber. In patients with ventriculoarterial discordance, an aortic valve homograft established continuity between the right atrium and pulmonary artery. Among 73 patients with ventriculoarterial concordance, the hospital mortality rate was 11% (eight deaths), and in 27 patients with ventriculoarterial discordance, it was 15% (four deaths). Before 1974, the year of operation was a significant determinant of hospital mortality (p less than 0.001). Thereafter, the hospital mortality declined and is currently 3.7%. In 82 patients with ages ranging from 4 to 16 years, there were six deaths (7.3%) whereas there were six deaths (33.3%) in 18 patients less than 4 or more than 16 years (p less than 0.001). Mode of ventriculoarterial connection and type of repair did not influence significantly the hospital mortality. There were six late deaths due to infection (two), reoperation (two), heart failure (one), and sudden death (one). Regardless of the mode of ventriculoarterial connection, use of a homograft valve produced better results, i.e., more asymptomatic patients (NYHA Class I) (p = 0.0168) and higher postoperative exercise capacity. Postoperative catheterization data and angiocardiographic measurements in patients with ventriculoarterial concordance demonstrated significant advantages with the interposition of a homograft valve between the right atrium and outlet chamber. Of 82 surviving patients, 94% are in NYHA Class I or II.

[Auriculo-Hisian conduction of patients with bundle branch block. Clinical significance]. / La conduction auriculo-hissienne des malades porteurs d'un bloc de branche. Signification clinique.

The clinical and electrophysiological data in 52 consecutive patients with bundle branch block and followed-up for an average period of 20.8 +/- 10.4 months was reviewed. The patients were divided into two groups: Group A with normal AH intervals (36 patients) and Group B with prolonged AH intervals (16 patients). These two groups differed in age, the average being higher in Group B (p < 0.05), in history of syncope (more common in Group A: p < 0.01) and in the duration of PR interval (p < 0.05). On electrophysiological investigation the Wenckebach point was lower in Group B (118 +/- 29 ms) than in Group A (160 +/- 33) (p < 0.001). The effective right atrial refractory period was significantly longer in Group B (321 +/- 111 ms) than in Group A (246 +/- 59 ms) (p < 0.05). The effective refractory period of the atrioventricular node was also significantly longer in Group B (492 +/- 190 ms) than in Group A (333 +/- 125 ms (p < 0.05). On the other hand, there was no significant difference in the HV interval or in the number of patients managed by permanent pacing.