Human atrial repolarization: effects of sinus rate, pacing and drugs on the surface electrocardiogram.

Objectives: We studied the effects of rate and some cardioactive drugs on the atrial surface electrocardiogram (ECG).

Background: In atrioventricular block, atrial surface ECG is unmasked. The effect of rate alone permits detection of the effect of other exogenous stimulations such as drugs in the presence of rate alterations.

Successful radiofrequency ablation of a true paraHissian accessory pathway.

Radiofrequency catheter ablation seems to become a first-line therapy for patients with paroxysmal tachycardias using an accessory pathway. We report the case of a 31-year-old woman who suffered from drug-resistant recurrent reciprocating tachycardia, using an uncommon accessory pathway. The 12-lead electrocardiogram in sinus rhythm showed the following characteristics: a positive delta waves in leads I, II, aVL, aVF, QRS axis = 0 degrees, R/S in lead V1 < 1, and a special QRS pattern in the precordial leads (QS or Qr in V1-V3 and QRS transition > V3).

[Arrhythmogenic dysplasia of the right ventricle in a 16-month-old child].

The clinical history of a 16-month old child with an arrhythmogenic right ventricular dysplasia is reported. This is one of the youngest patients described in the literature. The pitfalls of the diagnosis and the particularities of the treatment of recurrent ventricular tachycardias are underlined.