Ventricular fibrillation and torsades de pointes

Conclusions

We have tried to give ageneral description of ECG traces (obtained from, patients during cardiac resuscitation) that showprogressive variations in amplitude, and we have attempted to develop a new set of diagnostic criteria. Two distinct arrhythmias were defined:

• 1. Ventricular fibrillation. This starts very soon after the preceding ventricular complex, appears as continuous oscillations resembling a fine tremor (frequency in the cycles per second range) and an amplitude that varies progressively to form bulges. We have no example of ventricular fibrillation reversing spontaneously in normothermic conditions.

• 2. Torsades de pointes. This is always initiated by a “specific electrical ventricular complex” and continues with progressive, regular, and successive inversions of the trace (with a frequency in the cycles per minute range) and ends spontaneously after a ventricular pause.

There are also two intermediate patterns:

• 1. Double peaks. This arrhythmia, which occurs during long episodes of torsades de pointes, has a slower frequency than episodes of ventricular fibrillation that occur duringhypothermia (an experimental condition that was used to permit the study of spontaneous termination of ventricular fibrillation).

• 2. The anarchic interlude of long episodes of spontaneously reversible torsades de pointes.