Atrial fibrillation and continuous hypotension induced by sildenafil in an intermittent WPW syndrome patient

A 55-year-old Japanese man was hospitalized for palpitations and severe chest oppression one hour after he ingested about 1500 ml of beer and sildenafil (Viagra) 50 mg. At 43 years of age, he had been diagnosed with intermittent WPW syndrome following a paroxysmal supraventricular tachycardia (PSVT) attack. He took a 1 mg tablet of doxazosin daily for mild hypertension. On admission, his blood pressure was 90/54 mmHg and his heart beat was weak and irregular with a rate of about 220/min. Since atrial fibrillation (Af) was diagnosed on an electrocardiogram (minimum RR interval; 0.22 seconds), direct current shock was performed with 100 joules and 150 joules but conversion to sinus rhythm failed. Sinus rhythm returned spontaneously from Af four hours after taking sildenafil. Since blood pressure was 50/17 mmHg despite the return to sinus rhythm, blood pressure was maintained by dopamine for twelve hours after sinus rhythm returned. The patient underwent catheter ablation for curative therapy and thereafter has not had any further episodes of tachycardia.