Alcohol consumption increases the risk of irregular heartbeat
High alcohol consumption is known to have numerous adverse health effects. Scientists at the University of Munich Clinic and the German Center for Cardiovascular Research (DZHK) have now been able to demonstrate by means of a study at the Oktoberfest in Munich that an increased risk of cardiac arrhythmias is one of these effects.
The researchers were able to show visitors to the Munich Oktoberfest “that the higher the alcohol level, the greater the risk of cardiac arrhythmias,” according to the University of Munich clinic. The team around Dr. med. Stefan Brunner and Dr. In his study, Moritz Sinner has for the first time prospectively the relationship between acute alcohol consumption and cardiac arrhythmia - that is. during or immediately after alcohol consumption - examined in a large number of subjects. The researchers published their results in the "European Heart Journal".
Atrial fibrillation due to high alcohol consumption?
For a long time now, doctors have suspected that cardiac arrhythmias caused by alcohol can lead to atrial fibrillation. This suspected relationship between the consumption of large amounts of alcohol over a short period of time and the occurrence of cardiac arrhythmias in otherwise otherwise heart-healthy people has so far only been proven in small studies and not prospectively, the scientists report. The effect is called "Holiday Heart Syndrome".
More than 3,000 volunteers examined at the Oktoberfest
For the current study, the research team led by Dr. Brunner and Dr. In 2015 Sinner examined 3,028 volunteer participants on all 16 days at the Munich Oktoberfest. Of course, not all subjects had consumed the same amount of alcohol and, according to the scientists, the alcohol level ranged from 0 to 3.0 per thousand (0-3.0 g / kg). The fact that the subjects had no higher alcohol levels was due to the fact that, according to the study protocol, 3.0 per mille was the maximum amount of alcohol allowed to participate in the study. The study participants were on average around 35 years old and 30 percent were women.
Almost a third of the subjects with cardiac arrhythmia
With the help of a portable, smartphone-based system, the researchers were able to create electrocardiograms (EKGs) of the test subjects in order to analyze their heart rhythm. The scientists measured alcohol levels using a breath alcohol measuring device. “In their study, the researchers found cardiac arrhythmias in 30.5 percent of the participants. In 25.9 percent of cases there was a so-called sinus tachycardia, in which the heart beats faster than normal, ”reports the University of Munich clinic. According to the experts, the frequency of cardiac arrhythmias in the general population is usually around one to four percent.
The risk increases with the amount of alcohol
"The breath alcohol concentration was significantly associated with an increased risk of cardiac arrhythmia," the scientists report. Every additional gram of alcohol per kilogram increased the risk of cardiac arrhythmias by 75 percent. The excessive beer consumption at the Oktoberfest thus shows an extremely disadvantageous effect on the heart function. In addition to the data obtained at the Oktoberfest, the researchers also analyzed the influence of habitual, chronic alcohol consumption in 4,131 participants from the so-called KORA S4 study (cooperative health research in the Augsburg area), reports the clinic of the University of Munich. "For this study, we quantified the average amount of alcohol consumed in grams per day," explains Dr. Sinner.
Effect particularly strong with acute alcohol consumption
According to the researchers, only 2.7 percent of the participants in the KORA study had cardiac arrhythmia, with 0.4 percent having sinus tachycardia. However, the experts report that there was a slight, significant association between the daily amount of alcohol and sinus tachycardia. The likelihood of this increased by three percent per additional gram of alcohol per day, the Munich scientists continued. "We confirmed the connection between sinus tachycardia and chronic alcohol consumption in the KORA study," emphasizes Dr. Sinner. Although the effect was significantly weaker compared to the influence of acute alcohol consumption, the main results of the investigations at the Oktoberfest could be confirmed, said Sinner.
Connection with atrial fibrillation only indirectly confirmed
While the connection between acute alcohol consumption and the increased risk of cardiac arrhythmia was clearly demonstrated in the current study, the scientists were unable to prove that acute alcohol consumption directly leads to atrial fibrillation. The so-called "Holiday Heart Syndrome" could not be clearly confirmed in the investigation. According to the researchers, however, they found “a very strong and robust association between alcohol and cardiac arrhythmias, which can be viewed as a precursor to atrial fibrillation”
Particularly strong effects on respiratory sinus arrhythmia
The University of Munich clinic further reports that the study showed a connection between alcohol consumption and changes in the respiratory-dependent fluctuations in the heart rate, the so-called respiratory sinus arrhythmia. Respiratory sinus arrhythmia reflects an imbalance in the autonomic nerve supply to the heart. The unconscious control system, which controls body functions such as heartbeat or breathing, is apparently unbalanced by alcohol consumption. In addition, it is known that "atrial fibrillation can occur when patients develop a sinus tachycardia triggered by an autonomous imbalance," emphasizes Dr. Sinner.
Follow-up examinations required
Although the “Holiday Heart Syndrome” could not be demonstrated prospectively in the study, the Munich researchers report that the results will help clinicians and scientists to better classify the changes in the circulation during acute alcohol consumption. Follow-up examinations now need to clarify, for example, whether atrial fibrillation and other prolonged cardiac arrhythmias occur after acute alcohol consumption, Dr. Brunner.
Fear of permanent arrhythmia?
The researchers make the assumption that the cardiac arrhythmias recorded at the Oktoberfest were often only limited in time and disappear again when the alcohol level is reduced. However, this is not certain, since the ECG was only checked once, the experts emphasize. For example, in subjects with an existing heart disease, alcohol-induced cardiac arrhythmia could also continue, the researchers explain. "In order to be able to finally answer these questions, we will need further research results with a longer recording of the ECG after alcohol consumption", the study authors concluded. (fp)