Isolated respiratory failure caused by myasthenia gravis

Isolated respiratory failure due to myasthenia gravis that selectively invo lved the respiratory muscles alone is extremely rare and difficult to diagn ose. We reported herein, a 46 year old patient who presented with acute res piratory failure, 4 weeks after thymoma resection. The respiratory failure was due to myasthenia gravis that selectively affected the respiratory musc les only without having any peripheral signs. The initial response to thera py with pyridostigmine was unexpectedly complicated with severe bradycardia that made insertion of permanent pacemaker essential, before further thera py.