Bradycardia, Or Having An Abnormally Low Heart Rate, Has No Effect On Cardiovascular Disease Risk
While a heart rate lower than 60 beats per minute may be fine if you’re always physically active or even taking certain drugs, it can mean something more worrying if you’re neither. Specifically, it can be a sign of bradycardia, which the Mayo Clinic defines as “a slower-than-normal heart rate.” Yet, even though it relates to heart health, a new study finds having bradycardia doesn’t put one at risk of cardiovascular disease.
Published in JAMA Internal Medicine, the study aimed to determine if having bradycardia without symptoms (such as dizziness, shortness of breath, or fatigue) could be linked to cardiovascular disease. "For a large majority of people with a heart rate in the 40s or 50s who have no symptoms, the prognosis is very good," said corresponding author Dr. Ajay Dharod, an instructor of internal medicine at Wake Forest Baptist Medical Center, in a press release. "Our results should be reassuring for those diagnosed with asymptomatic bradycardia."
The researchers arrived at these results after looking at data from 6,733 participants in the Multi-Ethnic Study of Atherosclerosis. This study followed 5,831 men and women aged 45 to 84 over the course of 10 years to monitor mortality and cardiovascular disease events. They found the average resting heart rate among those who weren’t on heart rate-modifying drugs was 63 beats per minute (bpm). Only 5.3 percent of participants had a heart rate lower than 50 bpm — regardless of whether they were taking medication or not.
Results showed there was no correlation between a heart rate lower than 50 and risk of developing cardiovascular disease. And while there was no effect on mortality rates when it came to slow heartbeats, the researchers found mortality increased once bpm rose above 80. Meanwhile, for those who were taking heart rate medications, there was an elevated risk of mortality once heart rate dropped to 50 bpms or less.
"Bradycardia may be problematic in people who are taking medications that also slow their heart rate," Dharod concluded. "Further research is needed to determine whether this association is causally linked to heart rate or to the use of these drugs."
In healthy adults, the heart beats between 60 and 100 times per minute, depending on the person’s age. To find your heart rate, you’ll need to take your pulse. With your fingers, press the blood vessels on your wrist until you feel a slight beat. Count these for 10 seconds and multiple by six.
Source: Dharod A, et al. Association of Asymptomatic Bradycardia With Incident Cardiovascular Disease and Mortality: The Multi-Ethnic Study of Atherosclerosis (MESA). JAMA Internal Medicine. 2016.