A Heart too Drunk to Drive; AV Block following Acute Alcohol Intoxication

Abstract

Acute excessive alcohol consumption is associated with heart rhythm disorders like atrial fibrillation but also premature ventricular contractions, collectively known as the "holiday heart syndrome". More rarely but clinically significant are reports of atrioventricular (AV) conduction disturbances in binge drinkers with no underlying heart disease or chronic alcohol consumption. To obtain better insights into common denominators and the potential underlying mechanisms we collected and compared individual case reports of AV block following acute alcohol intoxication in otherwise healthy people. By screening PubMed, Google Scholar, Scopus and JSTOR, fifteen cases were found of which eight were sufficiently documented for full analysis. Blood alcohol levels ranged from 90 to 958 mg/dl (19 to 205 mM). Second and third degree AV block was observed most (6/8) albeit that in two of these patients a vagal stimulus led to deterioration from first into higher order AV block. In all cases, patients reverted to normal sinus rhythm upon becoming sober again. Mildly lowered body temperature (35.9 ± 0.5°C) was observed but can be excluded as a major cause of conduction blockade. We hypothesize that ethanol induced partial inhibition of calcium and potentially also sodium currents in conductive tissue structures may be one of the mechanisms of conduction slowing and block that may become exaggerated upon increased vagal tone. An impairment of gap junction function cannot be excluded as a contributing factor. In conclusion, cases of documented alcohol induced AV block are very rare but events can occur at relatively low serum alcohol levels which should prompt to awareness of this phenomenon in alcohol intoxicated patients.

Presumed Alcohol-Induced Ventricular Tachycardia Storm: A Case Report

“…The mechanisms that contribute to the development of arrhythmias likely involve intramyocardial and adrenal release of catecholamines, increased acetaldehyde levels, deranged plasma electrolytes (most commonly magnesium and potassium), and abnormal autonomic nervous system discharges [6][7][8][9]. Moreover, it has been proposed that high serum ethanol levels can cause the prolongation of PR, QRS, and QT intervals, possibly due to interference with sodium, potassium, and calcium ion channels in the heart, and these changes can sensitize the myocardium to atrial and ventricular arrhythmias [10,11].…”

Electrocardiogram Changes with Acute Alcohol Intoxication: A Systematic Review

“…Ethanol consumption might be associated with intra myocardial [ 11 ] as well as adrenal release of catecholamines [ 12 ], abnormal autonomic nervous system discharges or electrophysiological consequences of acetaldehyde (the metabolite of ethanol) [ 12 ]. Other likely causes of arrhythmias in the setting of acute alcohol intoxication are deranged plasma electrolytes, particularly low potassium and magnesium [ 13 ]. High serum alcohol levels may interfere with sodium, potassium and calcium ion channels in the heart [ 14 ].…”

“…Bradycardia and atrioventricular (AV) block have been occasionally reported with acute alcohol intoxication. It is possible that decreased calcium as well as sodium currents are related with AV block after alcohol consumption [ 13 ]. Van Stigt et al .…”

“…Van Stigt et al . [ 13 ] studied 8 cases of AV block following acute alcohol consumption. Five patients had first-degree AV block and 3 patients presented with second-degree AV block.…”

“…The authors did not identify an apparent dose-response relationship between serum alcohol concentration and degree of AV block. In 7 patients, complete recovery occurred, while in 1 patient first-degree AV block persisted during follow-up and may have been present previously [ 13 ].…”