Dynamic ECG Changes in Myasthenia Gravis

Sudden onset chest pain with shortness of breath and dynamic ECG changes point towards acute coronary syndrome but a case report on 69 years old gentleman presented to ED with one day history of chest pain associated with grade III shortness of breath, ECGs were recorded which showed the initial normal sinus rhythm with LBBB (left bundle branch block0 changed to type 2 AV BLOCK [atrio ventricular block]. A new onset LBBB in background of chest pain and SOB (shortness of breath) strongly pointed towards ACS (acute coronary syndrome). But the serum levels of cardiac biomarkers were normal. Past Medical history was suggestive of Myasthenia gravis on pyridostigmine. Pyridostigmine inhibits acetylcholinesterase this results in an increase in the amount of acetylcholine available for the already depleted acetylcholine receptors. Bradycardia and Heart Blocks secondary to muscarinic side effects of pyridostigmine are seen in emergency department