Learned heart-rate control by a patient with a ventricular parasystolic rhythm

A 31-year-old woman with a ventricular parasystolic rhythm is described. The arrhythmia was always absent below a rate of 72 per minute, and always present over a rate of 106 per minute. Voluntary heart-rate control was learned using a biofeedback techinque, as a result of which she could increase her rate by 25 per minute and decrease it by 1-2 per minute. Both voluntary speeding and exercise brought on the arrhythmia, but later in the training she could reach a higher heart-rate before the arrhythmia appeared. Propranolol inhibited the arrhythmia only to the extent that is slowed the heart.