MECHANISM OF PACEMAKER INDUCED COUGH - ABSTRACTS

Single chamber ventricular pacing (VVI) may be associated with a group of adverse symptoms known as the pacemaker syndrome. Cough is an unus ual but recognised feature of the pacemaker syndrome. A patient with a VVI permanent pacemaker experienced a disturbing cough during VVI pac ing. There were no other symptoms associated with the pacemaker syndro me. The effects of short-term ventricular pacing on the cough were exa mined while the subject was standing and lying. After control recordin gs, the pulse generator was programmed to either VVI 50 beats/min or 9 0 beats/min and recordings made over 60 seconds. There was an interval of 60s between recordings. Overall, five recording periods at VVI of 50 beats/min and VVI of 90 beats/min were made in random order. The pa tient was blinded to the order of programming. The recordings were rep eated with the subject lying. Cough was not found during normal sinus rhythm. During VVI pacing the patient experienced a tickling sensation in the throat associated with intermittent coughing. The number of co ughs decreased during each successive recording period. The pacing cou gh reflex was enhanced when the patient was lying down. The mechanism of cough during VVI pacing is uncertain. The findings suggest a possib le role for afferent vagal receptors from the airways.