Hi Tom, I suspect it has to do with the Vagus Nerve and the parasympathetic nervous system and its control on the heart.
Both the Sympathetic Nervous System (causes the Fight or Flight response we all know so well) and the Parasympathetic Nervous System (counteracts the Sympathetic Nervous System's effects) have inputs at the heart. What one system does, the other undoes. emedicine.medscape.com/article/1923077-overview#a1
For fight or flight, for example, the Sympathetic system increases your heart rate but decreases digestive activity. After the adversarial situation is over, the Parasympathetic system slows your heart rate and increases digestion.
Not quite answering your question, but an excellent article on the Valsalva Maneuver, follows.www.ems1.com/ems-products/education/articles/397955-The-Valsalva-Maneuver/
There is a group of manipulations of various reflexes that may more generally be referred to as Vagal Maneuvers.
Some of them are discussed following. For the large part, anyone needing to use these procedures should have been instructed by a physician as to the advisability of any particular procedure, in any particular case, and dependent on other health conditions. Carotid artery massage (something only to be performed by Doctors and not as commonly used now) can loosen clots causing serious problems, pressing on the eyes may be a problem for people with retinal conditions, etc. In addition, some arrhythmias require medical attention. If someone were to use the Vagal or Valsalva maneuver to constantly break a run of ectopics, and not having been seen by a doctor, they might be masking a disorder that requires additional attention.
"Vagal maneuvers are another type of treatment for arrhythmia. These simple exercises sometimes can stop or slow down certain types of supraventricular arrhythmias. They do this by affecting the vagus nerve, which helps control the heart rate.
Some vagal maneuvers include:
Holding your breath and bearing down (Valsalva maneuver)
Immersing your face in ice-cold water
Putting your fingers on your eyelids and pressing down gently
Vagal maneuvers aren't an appropriate treatment for everyone. Discuss with your doctor whether vagal maneuvers are an option for you."
Yet coughing seems to be a natural response, I do it very often in response to patterns or long episodes of PVCs and have done so largely for the entire time (40 years) that I've experienced them. Although it's not as directly applicable to PVCs, it seems to work. I suspect it is related to altering the heart rate in such a manner that the normal discharge of the heart's natural pacemaker manages to occur at a time that prevents the ectopic focus from being able to discharge, i.e., it shifted the timing relationship. Rather like the situation in benign arrhythmias that go away on exertion since the heart's natural pacemaker is firing faster than the ectopic focus.
And a site I stumbled upon that may be of interest to you or others. As always, anyone reading any online articles must use discretion and be sure to consult with their doctor. www.lifeoffbeat.com/stop-heart-palpitations-instantly/www.lifeoffbeat.com/
Best health wishes and reduction in PVCs your way.