[Torsades de pointe. Apropos of 60 cases]

The authors report a personal series of 60 cases of "torsade de pointe" (the largest series published to date) seen in the Cardiology department of Amiens Hospital over a period of 11 years. They review the essential features of this arrhythmia, which was well described by F. Dessertenne in 1966, but which is still sometimes confused with certain forms of ventricular tachycardia. "Torsade de pointe" is still a topical issue, as 25% of the cases in this series were seen over the last two years. These cases were classified into three groups according to their aetiology: severe bradycardia (21 cases), potassium depletion (16 cases), drug causes (23 cases). This arrhythmia was essentially associated with iatrogenic factors, in particular potassium depletion (41.6% of cases). The classical notion of predisposed patients was confirmed: elderly patients (mean age of 68 years), with cardiovascular disease in 70% of cases (i.e. heart failure or coronary insufficiency, hypertension) and with a marked female predominance (70% women). The ECG between episodes of "torsade de pointe" always revealed a prolonged QT interval which, in relation to the heart rate, was more marked in the patients with potassium depletion. During an attack, the average ventricular rate was 210/min (range: 170 to 290/min). 20% of cases subsequently developed ventricular fibrillation. The overall mortality was 16.6% (10 out of 60 cases), but there have been no deaths since 1977 due to the better understanding of this arrhythmia.(ABSTRACT TRUNCATED AT 250 WORDS)