@entity591 with 1:1 atrioventricular conduction precipitated by XXXX .

@entity1 @entity1229 @entity341 @entity1109 @entity1163 @entity591 @entity2165 @entity955 @entity551 @entity2779 @entity2179 @entity2459
A 58-year-old @entity1 presented to the @entity341 with @entity2459 and significant @entity1163 while walking on the flat. The previous day he had undergone DC cardioversion for @entity955 ( @entity955 ) which had been initially successful. However, 6 h after cardioversion he was aware of intermittently raised but regular heart rates. On arrival at the @entity341 ( @entity341 ) he was well with no haemodynamic compromise. The ECG showed an @entity591 instead of @entity955 . Medications consisted of @entity2779 300 mg twice daily, @entity2179 5 mg at night and @entity1229 . @entity2179 was increased to 5 mg twice daily and he was discharged with a plan for outpatient ablation. He collapsed in the hospital car park with rapid palpitations, chest tightness and @entity1109 . On return to the @entity341 he was @entity551 with a heart rate of 200 bpm. The ECG showed 1:1 atrioventricular conduction (AV) of the @entity591 which promptly improved after administering intravenous @entity2165 . Class 1c antiarrhythmic agents such as @entity2779 can precipitate 1:1 AV conduction of @entity591 resulting in dangerous exacerbations of ventricular rate or even malignant @entity591 . It is therefore essential that concomitant AV blocking agents are used both prophylactically or acutely in suspected cases.
