Dear doctor.
Just wanted to ask a question about this mysterious phenomenon, as it's mentally bothersome for myself and several others suffering from cardiac neurosis. In the heart rhythm community here the question occur from time to time.
First, may the R on T phenomenon occur in a healthy heart (with no de/repolarization abnormalities on EKG and normal echo/stress test)? If it does, will it just be pure luck that determines if a PVC falls on the T wave?
Second, may this phenomenon, if it occur in healthy hearts, be dangerous and induce fibrillation or Torsades? I understand that this phenomenon is responsible for TdP in the setting of prolonged QT, but does this also apply to healthy hearts? Or can I (and other people with normal hearts) forget this entirely?
Last: I understand that a similar phenomenon is responsible for paroxysmal atrial fibrillation (PAC on atrial repolarization). Does this also apply only to people with structural heart disease like enlarged atria? The reason I ask is because I'm diagnosed with PACs and some of them are conducted with RBBB abberancy, so I think they are somewhat early in the cycle.
It is OK to use a somewhat technical terminology in your answer.
Thank you in advance.