Last week, you learned about whether exercise can actually make you live longer, and how much exercise is enough for optimal longevity benefits.
In today’s episode, we’re going to look at another critical component of exercise – your heart – specifically, whether you need to be concerned about heart palpitations during exercise.
A new study found that many athletes have electrical heart “issues,” but these issues may not actually be meaningful from a cardiac risk standpoint. The study looked at the criteria for interpretation of electrocardiograms (ECGs) of people’s hearts and noted that an increasing number of sporting bodies report unacceptably high levels of false-positive ECGs in pre-participation cardiac screening. This means that athletes and fitness enthusiasts who have electrical abnormalities in the heart during exercise may be experiencing something that’s completely normal for an athlete, and that doesn’t necessarily reflect a serious cardiac pathology, including a PVC.
And while a PVC may sound like something out of a science fiction novel or a do-it-yourself household plumbing guide, it actually stands for premature ventricular contraction. Here’s how it works:
Every time your heart squeezes blood out to the rest of your body, it requires an electrical impulse. In a normal electrical conduction, impulses originate from an area in the top right corner of the heart known as the sinus node. The electricity then spreads across the upper two chambers of the heart (the atria) and is then transmitted to the lower two chambers (the ventricles) through the atrioventricular node.
During a normal heartbeat, your heart’s ventricles contract blood out to your entire body after your heart’s atria have helped to fill them. In this way, the ventricles can pump the maximum amount of blood both to the lungs and to the rest of the body.
So how can this electrical misfiring happen? Every piece of tissue in your heart is electrically active. This means that all heart tissue can conduct electricity. However, all heart tissue can not only conduct electricity, but can also generate electricity. Normally, your heart tissue is conducting electricity generated by the sinus node. However, occasionally it will generate electricity on its own as well – and when this happens a premature contraction results.
When a PVC happens, your heartbeat is not initiated by your sinoatrial node (your body’s normal heartbeat initiator), but rather by special fibers in your ventricles that are triggered by the atrioventricular node, bypassing the normal method of electrical stimulation. This means your ventricles contract first – before your atria have optimally filled the ventricles with blood.
And this not only means that blood circulation of oxygen and nutrients is way less efficient, it also means that you can feel things like palpitations, skipped beats, extra heart contraction, irregular heart rhythm, slight chest pain, a feeling of faintness and fatigue, or shortness of breath.
But here’s what’s important to know, and what the latest research highlights: the occasional PVC is actually common, especially for athletes exercising at high intensities, and it doesn’t necessarily mean you’re going to drop dead of a heart attack.
See also: 6 Heart Attack Risk Factors
That’s right – nearly everybody has a skipped or extra heartbeat every now and then. As a matter of fact, cardiac electrophysiologist and cyclist Dr. John Mandrola wrote a blog post on PVCs saying that PVCs are the second most common rhythm problem he sees (he points out that a related electrical abnormality called an atrial arrhythmia, also known as a “heart flutter,” is the most common).
In that same post, Dr. Mandrola also points out a few other interesting facts, including:
- In an overwhelming majority of people, especially those with normal heart structure, PVCs are benign – which means that the extra beats do not actually indicate heart disease or any other serious and immediately threatening issue.
- The normal person has about 100,000 heartbeats per day (elite athletes with slower heartbeats would have fewer) and only people with more than 20,000 PVCs per day are actually at risk for developing cardiomyopathy (weak heart). That means about 20% of the time you feel a flutter or palpitations, you’re likely experiencing PVCs.
- The presence of PVCs might indicate training excess. According to Dr. Mandrola:
“It might happen during a big training block or immediately afterwards. Of course, my theory is that PVCs associate with excess inflammation. The reason I see inflammation as the link is because PVCs often occur in patients who are exposed to stress. The middle-aged person going through a divorce, the doctor embroiled in a lawsuit, the minister who takes care of everyone but himself, the grad student during exams. The theme here is that PVCs tend to cluster at times of high inflammation–be it physical, mental or emotional…
Recently, a cycling friend told me his PVCs had resolved almost as soon as he stopped training for races. He still rides, fast at times, but doesn’t ‘train.’ (I’m not advocating not racing; it’s just an anecdote.)”
- PVCs could potentially be aggravated by dietary deficiencies. For example, Dr. Mandrola says that he has had some patients report improvement from magnesium supplementation and Dr. Mark Sircus said the same thing when I interviewed him on the podcast episode “The Shocking Information on q Compound That Pharmaceutical Companies Really Don’t Want You to Know About.“
While electrolytes may matter less than Gatorade would have you believe, they’re certainly important for heart health and electrical conductivity in hard charging athletes. In an era of mineral-depleted diets, excessive stress, and over-exercise, I suspect deficiencies are a much bigger contributor to the problem than many people might think (yet another reason why I slather my body with magnesium oil after every hard workout).
In a nutshell, you can think of PVCs as a canary in the mine. As a matter of fact, in this helpful forum discussion on MedHelp, it’s pointed out that two conditions are known to cause PVCs during exercise – one is coronary artery disease and the other is myocarditis (heart inflammation) and both are often aggravated by poor exercise conditions and excess adrenaline (from stress and/or overtraining). But in the absence of these two factors, PVCs may actually be no big deal at all.
Have you experienced PVCs during exercise? What did you do? Share your thoughts over at the Click to check for reference page!
Please note that all content here is strictly for informational purposes only. This content does not substitute any medical advice, and does not replace any medical judgment or reasoning by your own personal health provider. Please always seek a licensed physician in your area regarding all health related questions and issues.
Heart exercising cartoon courtesy of Shutterstock.
Disclaimer
All content here is for informational purposes only. This content does not replace the professional judgment of your own health provider. Please consult a licensed health professional for all individual questions and issues.