Significance of late ventricular potentials in myotonic dystrophy.

In 39 patients with myotonic dystrophy, we found a high percentage of infrahissian cardiac conduction abnormalities (51%) and late potentials (46%), whereas spontaneous and inducible ventricular arrhythmias were rare. These results suggest that the prolongation of QRSD and the duration of the low-amplitude signal on the signal-averaged electrocardiogram were related to delayed activation of the His and Purkinje tissue rather than true late potentials.

Is it possible to identify infrahissian cardiac conduction abnormalities in myotonic dystrophy by non-invasive methods?

OBJECTIVE: To identify intracardiac conduction abnormalities in patients with myotonic dystrophy from their clinical, ECG, and genetic features. METHODS: 39 consecutive patients (mean (SD) age 42. 9 (12.1) years; 16 female, 23 male) underwent clinical examination, genetic studies, resting and 24 hour ambulatory ECG, signal averaged ECG, and electrophysiological studies. RESULTS: 23 patients suffered from cardiac symptoms, 23 had one or more cardiac conduction abnormality on resting ECG, one had sinus deficiency, and 21 (53.8%) had prolonged HV intervals. No correlation was found between the severity of the neurological symptoms, onset of disease, cardiac conduction abnormalities on ECG, and the intracardiac conduction abnormalities on electrophysiological study. The size of the DNA mutation was longer in the abnormal HV interval group than in the normal HV interval group (3.5 (1.8) v 2.2 (1.0) kb, p < 0.02). Signal averaged ECG parameters (total QRS duration (QRSD) and duration of low amplitude signals /= 100 ms with LAS 40 >/= 36 ms identified patients with an abnormal HV interval with good sensitivity (80%) and specificity (83. 3%). CONCLUSIONS: Infrahissian conduction abnormalities are common in myotonic dystrophy and can be identified using signal averaged electrocardiography.

[Paralysis of the posterior branch of the radial nerve caused by a lipoma]. / Paralysie de la branche postérieure du nerf radial due à un lipome.

A case of compression of the posterior branch of the radial nerve by a lipoma is reported. This case is unusual because of the large size of the tumor (13 cm x 6 cm) and the interest of CT to exclude a liposarcoma. The risk of liposarcoma is greater with large size tumors. Reported 27 cases have been analyzed. The posterior branch of the radical nerve is particularly vulnerable because of the anatomic relationships. Thus benign extraneural sof-tissue tumors of the extremities may be responsible of nerves compressions.

[Retention of urine caused by fecaloma in the course of a Guillain-Barre syndrome (author's transl)]. / Rétention d'urines par fécalome au cours d'un syndrome de Guillain-Barre.

Sphincteral disorders are very rarely seen in a Guillain-Barre syndrome. The authors report a case of such a syndrome in a woman, in the course of which a retention of urine appeared making diagnosis more difficult. The cause actually was mechanical.