Is Change In The PRT Axis In An EKG Report A Matter Of Concern?

I am 49 years old and healthy. Good chlestoral, weight etc. For about a year, I have been having shortness of breath when exercising (cardio). Had an EKG in August that read: PR: 100/130 ms QRS 86 ms QT/QTc: 364/395 ms P/QRS/T axis: 68/64/40 deg bp 71 bpm sinus rhythm; RSR in V1 and V2 Normal variant of ECG Unconfirmed report A couple weeks ago, I took a very hard exercise class and thought I could be having a heart issue - extreme shortness of breath (lasting for a couple hours after), dizzy, nauseous. The next day, I saw a cardiologist (who did not have the prior EKG). The March EKG reads: Borderline ECG Right atrial enlargement Rightward axis Normal sinus rhythm with sinus arrhythmia PRT axis: 78-90-82 QT/QTc 392/416 ms QRS duration 82 ms PR interval 132 ms Vent rate 68 bpm Doctor was not concerned; scheduled stress test for late April. Question: Is the change in the PRT axis from 68/64/40 to 78/90/82 significant? If so, should I do something different now or just wait for stress test in late April?