High-degree atrioventricular block in acute ethanol poisoning: a case report

INTRODUCTION: Acute ethanol ingestion can prolong the PR interval, but searching Medline, we have found only one report of Wenckebach-type atrioventricular block in ethanol poisoning. We present a high-degree atrioventricular block in an ethanol-poisoned patient. CASE PRESENTATION: A 17-year-old woman with a non-contributory medical history ingested 3dcl of vodka and was found comatose. On arrival she was somnolent with nausea, tympanic temperature 36.0°C, pulse 70 counts/min, blood pressure 90/60 mmHg, respiratory rate 12 counts/min and SpO(2) 96% on room air. Her blood ethanol level was 130 mg/dL; other blood laboratory test results were normal. ECG revealed sinus rhythm, first-degree atrioventricular block with a PR interval of 0.32 seconds and intermittent second- and third-degree atrioventricular blocks with up to 4-second-long pauses that appeared 15-30 seconds after each vomiting. She was given thiethylperazine and vomiting resolved within an hour. ECG 12 hours after admission revealed a first-degree atrioventricular block with a PR interval of 0.24 seconds. One month later Holter monitor showed a sinus rhythm and first-degree atrioventricular block with a PR interval of 0.21 seconds. Vagal maneuvers did not provoke high-degree atrioventricular block. The echocardiogram was normal. CONCLUSION: Acute ethanol poisoning has the potential to prolong the PR interval in adults with first-degree atrioventricular block and provoke intermittent second- and third-degree atrioventricular blocks, possibly by its direct inhibitory action on the conduction system and increasing parasympathetic tone due to nausea and vomiting.