An electrocardiogram that demonstrates grouped beating: what is the rhythm?

@article{Morady1996AnET,
  title={An electrocardiogram that demonstrates grouped beating: what is the rhythm?},
  author={Fred Morady And Frank Pelosid Morady},
  journal={Journal of cardiovascular electrophysiology},
  year={1996},
  volume={7 6},
  pages={581-2}
}