I also have had another " bout " with Thumper ,as I call my Heart. PVC's & PAC's .. Just went thru all the tests , Other than the 20 plus times a minute, Healthy Heart .. I also had a PDA Closure in 1959, ( Ductus valve ) I was 4 , am 50 now , Diagnosed w/ WPWS in 1984 ( Wolfe Parkinson White Syndrome ) Had MVP about 15 years ago , now is gone , same cardio that Diagnosed it , now cant see the MVP .. Amazing that our Hearts can " heal " themselves ..
A couple of things here .. First
There are medicines that may help slow the rhythms down when they occur, but don't keep them from occurring, while others - "antiarrhythmics" - may help suppress them. If the episodes are happening frequently enough, or they are quite distressing, there is a procedure called an electrophysiology study which is a specialize type of heart catherization; it measures the electrical system of the heart and then tries to induce (in effect, reproduce) the abnormal rhythm. If the rhythm is induced, the extra connection is mapped out and then a special catheter is inserted into the heart (from the groin) and the tip placed next to the connection. Ultrasound is then emitted at the tip, which disrupts the connection, thereby curing the rhythm permanently (there's a 90-95% success rate for this procedure).
Thyroid disease can possibly make extra heartbeats worse, or more common, or produce a type of abnormal rhythm called atrial fibrillation if the thyroid is overactive (hyperthyroidism). Too much thyroid stimulates the system, and thus can cause extra heartbeats. It is diagnosed by a blood test. If you are concerned, then you should ask your Doctor.
My Cardio said if mine continued and became unbearable he would recommend the electrophysiology study . You may check into it .
Another is... Have your Thyroid checked .. it's a simple blood test , if found deficiant or over active , Medication , will help .
Next is Anxiety . I have read that Anxiety can " cause " or Enhance PVC & PAC activity . And Believe me it's also Visa Versa , Having them can cause Anxiety .. I think Hopes gave a good Idea , turn on music or something to take your mind "off " the flips & Flops & Ka-thumps .. Myself , if Thumper is acting up in day time , I put on Comedy Central, or the Golden Girls , I get to laughing , and hours later , I realize I had " forgotten " about the PVC's & PAC's .. You might give it a try .. Works for me ..
Hope you feel better & get some relief. Take Care .