Diaphragmatic action potentials recorded on standard electrocardiogram. A clinical and experimental study.

A transient pseudoatrial dissociation (Deitz-Marques phenomenon) occurring immediately after right atrial pacing in a 44-year-old woman, and spontaneously together with periods of hiccups in a 50-year-old man are presented. The same phenomenon was produced experimentally in three dogs, after rapid diaphragmatic stimulation. The diaphragmatic origin of fibrillary-like waves on standard ECG is argued because of dependence on respiratory phases and because it does not influence the basic sinus rhythm.