Resting heart rate of between 53-60 bpm which rapidly increases to 130+ bpm with little physical exertion. some mild left sided chest discomfort with physical exertion and heart rate of 160 + bpm?

Heart rate : There are many variables in the body that affect heart rate. More information is needed to address your concern.See a doctor in person

Reconditioning?: An increase in the heart rate of this degree with mild exertion could be the hallmark of deconditioning but best to confirm this in the MD’s office. If there is no chest pain of discomfort at the time, it further suggests that there no serious coronary disease. However, recommend cardiology exam, a full ECG and further testing if warranted. Additionally, medications, anxiety may also cause this.

Atrial Tachycardia: Rapid irregular heart beating suggests atrial fibrillation (AF). This carries a risk of blood clots. If sudden onset and regualr beating it suggests PAT (paroxysmal atrial tachycardia) - more benign. This plus the stress can respond to beta-blockers, like atenalol. Some gadgets like Kardia Mobile can give a read-out. For medication however, you need to see an M.D.