That can be a tricky question, especially if you don't know the facts about heart rate and rhythm. Here are five common myths -- and the truth about each one.
Myth #1: An erratic heartbeat means you’re having a heart attack.
Almost never. It's fairly common to feel your heart flutter, flip-flop, or skip a beat from time to time. If you monitor the heart rhythm of any person long enough, almost everyone will display the occasional skipped or extra beat. It is very unusual for these sensations (without accompanying chest pain or shortness of breath) to indicate the occurrence of a heart attack. If the feelings of skipping or flip-flopping are new or frequent, or if the sensation is more of a fluttering, the sensations may suggest the presence of an abnormal heart rhythm (arrhythmia).
"The vast majority of arrhythmias are benign," says Gordon F. Tomaselli, MD, professor of medicine at Johns Hopkins University School of Medicine in Baltimore. But that doesn't mean you should ignore arrhythmias. Some arrhythmias raise the risk of a stroke, heart failure, and sudden death. So it’s prudent to alert a doctor about any erratic beats (especially if new or frequent) -- even in the absence of bothersome symptoms.
Arrhythmias can affect the heart’s upper chambers (atria) or -- more ominously, but much less frequently -- the lower chambers (ventricles). The most common atrial arrhythmia, atrial fibrillation (often called "AFib," for short), causes the heart to beat irregularly and makes stroke more likely. More than 2 million Americans have AFib.
AFib often causes a rapid heart rate, but it can also cause a slow heart rate or have no effect on heart rate. An ECG can help diagnose AFib.
Myth #2: A fast pulse means you’re stressed out.
Stress can spike your resting heart rate, sometimes nudging it to beat more than 100 times per minute, a condition called tachycardia. But smoking or consuming lots of caffeine can also do the trick. So can dehydration, fever, anemia, and thyroid disease.
In the absence of an obvious cause, anyone who experiences tachycardia at rest should consult a doctor. Even heart rates in the upper range of normal may signal a health issue. "If you don’t have a good explanation for a [resting heart] rate above 85, that should dictate a search for something else," Tomaselli says. "Most of the time, tachycardia is caused by an abnormal heart rhythm," says Joseph E. Marine, MD, associate professor of cardiology at Johns Hopkins University School of Medicine in Baltimore.