Can benign arrhythmias be symptomatic?  Are thousands of PACs per day common?

32 year old healthy fit female (non-smoker, do not drink coffee, etc). Diagnosed with ectopic atrial arrhythmia after ECG showed PACs and 1st grade AV block and 24 hour halter monitor showed thousands of PACs over the day, with various doubles and a few triples. Have been suffering symptoms for 5 weeks (the arrhythmia was diagnosed at that time due to presentation with the symptoms). Symptoms include chest pain (moves around), dizziness, unable to take a full breath and mood drops (sudden lethargy, sadness feeling of doom, but NOT anxiety and not panicked), fluctuation in resting heart rate (154 down to 64 and so on at rest), fluctuation in blood pressure.

Family doctor has explained the arrhythmia is benign and not life threatening. He is unsure of the cause (magnesium and potassium normal, iron normal and ferritin only slightly low, thyroid within normal ranges) so has arranged for me to see a cardiologist soon for echo and stress test.

Can benign arrhythmias be symptomatic? Mine is, just wondering if that is to be expected. What can cause this? I know it is very common. Is thousands of PACs per day common? Is the AV block just another benign aspect of this arrhythmia? Thanks.

Submitted by Emma from Australia on 09/21/2016

by Mehdi Razavi, MD

It is of course impossible to reach any conclusion without a detailed history and physical exam.
PAC’s in general are very common and for the most part benign. They can, however, be a harbinger of more serious arrhythmias, specifically atrial fibrillation. That being said, if the PAC’s are causing significant symptoms therapy (typically using anti-arrhythmic drugs or ablation) may be warranted. Indeed, they can lead to “blocked” impulses and secondary transient drop in heart rate.