Pacing for unilateral diaphragm paralysis

Abstract

Symptoms of unilateral diaphragmatic paralysis can range from sleep-related symptoms to exert ional dyspnea or orthopnea. At times unilateral diaphragm paralysis is found on routine chest radiograph alone when an elevated hemidiaphragm is seen. Ventilatory failure will usually only result if there is bilateral diaphragmatic involvement. When diaphragmatic paralysis is suspected, confirmatory testing is done by inspiratory fluoroscopy (sniff test) and electromyography of the phrenic nerve. To determine if the conduction path of the phrenic nerve is intact from the cervical region to the diaphragm, the key test is fluoroscopic visualization of the diaphragm with transcutaneous stimulation of the phrenic nerve in the neck. If the diaphragm moves during stimulation then the phrenic nerve is intact, but there is a disruption of the signal pathway from the respiratory center in the brain to the phrenic nerve causing the diaphragm not to function. © 2007 Springer-Verlag London Limited.