Cardiac ballet: repetitions of complex electrocardiographic patterns.

During the past 12 years 7 examples have been encountered of brief arrhythmic episodes which we have called the "cardiac ballet". They consist of sequences of multiform ventricular (QRST) complexes, with or without ventricular complexes of the shape of sinus beats interspersed. The special feature of the arrhythmia is that the characteristic patterns of the sequences are from time to time replicated. All of our 7 examples of this condition have been associated with the R on T phenomenon (Smirk, 1949; Smirk and Palmer, 1960; Ng, 1968), and in one case an episode of ventricular fibrillation was recorded. Another recurrent ventricular arrhythmia is " repetitive paroxysmal ventricular tachycardia", which has been described by Parkinson and Papp (1947), Katz and Pick (1956a), and Stock (1962), but almost all their published traces differ from the episodes we are about to describe. Further, Parkinson and Papp (1947) drew attention to the generally good prognosis in repetitive paroxysmal ventricular tachycardia, whereas 5 out of our 7 patients died.