Here is an edited email I received from an athletic colleague:

John,

A 50 year-old male healthy athlete has the new problem of occasional periods of premature beats. She (or he, doesn’t matter) has visited the doctor and an ECG shows PVCs, or premature ventricular contractions. Otherwise the history, exam, ECG, ECHO and electrolytes are normal.

What’s up with PVCs? Why? Could they be 1) consequence of (chronic) exercise or 2) related in some way to overtraining.

Any thoughts?

PVCs are probably the second most common rhythm problem I see. Atrial arrhythmia, including AF and atrial flutter are the most common.

This image shows PVCs (beats 2, 4, 6 etc) occurring in what we call a bigeminal pattern. Atrial or ventricular beats that appear in an every other beat pattern are referred to as bigeminy, sometimes referred to as “boom-boom-pause.”

Here are six bullet points on PVCs:

1. There is an old rule–it’s called the rule of bigeminy. Basically, the long-short intervals of PVCs tend to promote themselves. The point is that PVCs often occur in a bigeminal pattern. It’s not unusual.

2. Understanding PVCs is harder than understanding cyclists. If I had only one adjective for PVCs, I would use capricious. We can’t often find a reason why PVCs come, why they leave, or why they come back.

3. It is worth quantifying facts about the PVCs:

• Response to exercise. PVCs that mostly occur at times of rest and suppress with exercise are usually benign. PVCs that worsen with exercise may be indicative of a heart under stress, say from a partial blockage of an artery or something else. A heart doctor should evaluate arrhythmia that gets worse with exercise.
• Quantity of PVCs. A 24-hour-holter monitor tells us how many PVCs occur on a given day. The normal person has about 100,000 heartbeats per day (athletes a few fewer). Patients with more than 20,000 PVCs per day are at risk for developing cardiomyopathy (weak heart). These patients should be referred to an electrophysiologist.

4. In an overwhelming majority of patients, especially those with a structurally normal heart, PVCs are benign. The word benign means the extra beats do not indicate heart disease or predict sudden demise.

5. Mandrola observations. PVCs might indicate training excess. I see this often in athletes. 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. But not always.

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.)

6. Ten treatment steps. The first step is to ask what company does the PVC keep? PVCs occurring in patients with a normal heart (by history, exam, ECG and ECHO) are almost always benign.

• Treatment steps 1-4 are reassurance. It is important to understand the problem, and its benign nature. Removing fear is always a good first step.
• Steps 5-8 include adjustment of lifestyle, both on a micro and macro style. This gets me back to the 4 legs of the table of health: good food, good exercise, good sleep and good attitude. Cutting back on caffeine and alcohol, looking critically at the dose of exercise, going to bed on time, and smiling are all great strategies for PVCs.
• Step 9 involves Buddhism. One must know that PVCs are impermanent. Right understanding of PVCs means knowing they will pass.
• Step 10 involves medicine. I hate when it gets to this step. Beta-blockers are my first choice. These drugs block adrenaline. They sometimes lessen the thudding associated with the irregular beats. Beta-blockers are also good for as-needed use, say for bad days when the PVCs are acting up. And the best part of using beta-blockers: lack of harm. Rarely do I use an anti-arrhythmic drug, like flecainide or propafenone or sotalol.
• Step 10 (a): Please don’t beat me up on this one. Some patients report benefit from magnesium supplementation. I have found it helpful in my case of atrial premature beats. Let me repeat, I am not promoting supplements. Healthy patients with benign arrhythmia might try taking magnesium, especially at night. Don’t take magnesium if you have kidney disease. And if you take too much, watch out for diarrhea.

Conclusions

Don’t try too hard to understand PVCs. A basic medical evaluation can exclude significant structural heart disease. Talk to your doctor. Come to a shared decision about what to do.

John Mandrola is a cardiologist who blogs at Dr John M.