Details of the patients in the study.

All patients were selected in the basis that they had healthy ventricles. AF = atrial fibrillation. Asterisks indicate patients recovering from a previous interrupted stimulation protocol. †Patient 9 required a shorter cycle length of 450 ms in order to maintain capture, avoiding escape beats. ‡Patient 13 reported slight discomfort at the paced rate of 500 ms and was therefore paced at a longer cycle length of 600 ms.