Heart Health

How does alcohol affect the heart?

Published 5.1.2017
Moderate, chronic alcohol consumption is said to be good for the heart. Moderate is almost always defined as one or two drinks a day. However, for many people, alcohol consumption often accompanies an event or celebration, where alcohol consumption might well exceed two drinks. Such alcohol consumption could be defined as acute, meaning intense but rare. How does the heart react under those conditions?

The New York Times (NYT) covered a recent journal article that looked to measure the heart response after acute alcohol consumption and compare it to that of chronic, moderate consumption. The event that provided an ample supple of subjects was the annual Munich Oktoberfest in Germany. Researches excluded anyone whose breath alcohol content (BAC) was above the German legal limit.

From the NYT coverage:

More than a quarter of the group had a condition called sinus tachycardia, marked by a resting heart rate of more than 100 beats per minute. About 1 to 2 percent of the general population have repeated episodes of tachycardia, which in some cases can pose risks.

They also found slightly increased, but not statistically significant, levels of other kinds of irregular heartbeats, including the heart palpitations of atrial fibrillation, a potentially serious condition. The arrhythmias increased with higher breath alcohol levels.

Heart response to short term excessive alcohol intake is known. All quotes from this point are taken from the actual study.

From a cardiovascular perspective, acute excessive alcohol consumption has been associated with the so called ‘Holiday Heart Syndrome’.8 This syndrome affects individuals without a specific cardiac history resulting in both ventricular and supraventricular arrhythmias, predominantly atrial fibrillation.8,9 Small case series confirmed a relation between alcohol use and atrial fibrillation.10,11 Regarding chronic alcohol consumption, population-based studies reported a dose-response effect on the development of atrial fibrillation.

The people tested were note legally drunk by German law. They did this in part because alcohol’s effect on the heart is usually reported as a secondary data point noted in a study designed to look at something else. Now that there are smart phones, getting electrocardiogram (ECG) data is much easier.

In the acute alcohol cohort, 30 s ECG recordings were obtained using the smart phone based AliveCor device (AliveCor, San Francisco, CA, USA). A two-electrode hardware extension wirelessly communicating with a software application was held with both hands by the participant, resembling a lead I ECG.

There are actually two studies being reported on in this paper, the one at the fest, where they used the smart phone and asked a few basic questions, and another where EKGs were taking lying down and a more complete survey of information was taken.

During all 16 days of the 2015 Munich Octoberfest we included 3028 participants for analysis. Their mean age was 34.7 ± 13.3 years, 905 (29.9%) were women (Table 1). Reflecting the international attendance, individuals originated from 60 different countries, whereas the majority of 69% was from Germany.

The acute alcohol results are from the fest, the other is known as chronic— people who admit that they drink alcohol regularly and moderately, which is supposed to be good for the heart. No surprise, men drank more than women at Oktoberfest.

The mean chronic consumption of alcohol in KORA S4 was 15.8 ± 21.4 g/d. On average, men consumed nearly three time as much alcohol as women. The highest chronic alcohol consumption was observed in the 3rd age quartile (37–48 years of age, Figure 1B).

Their smart phone ECGs provided them with good quality data in most cases, and recordings that couldn’t be read were excluded. Sinus tachycardia or a heart rate of greater than 100 beats per minute was the primary association researches found with BAC. Other types of arrhythmias were also noted, but none were statistically significant, as noted in the NYT coverage.

In contrast, the moderate chronic drinkers had no arrhythmias associated with BAC. The bottom line then is that binge drinking acute alcohol consumption is not great for the heart. A little bit of alcohol everyday is a good thing for the ticker, but save up your drinks and have them over the weekend.