Long-term stimulation of a diaphragm muscle pouch

Denervated hydraulic pouches were fashioned from a retrosternal portion of the right hemidiaphragm and electrically stimulated for several hours at voltages selected to achieve pressures commensurate with those encountered in the right ventricle. The data revealed a progressive decline in pressures generated by the pouch with time, the deterioration perhaps enhanced by inpaired perfusion of the pouch but statistically independent of systemic blood pressures. Therefore it was concluded that contraction of the diaphragm muscle could not be used clinically to assist the heart.