Wecome to HCM
After going thrugh history,you are having sudden episodes of tachy cardia 160 BPM certainly warrants a good clinical examination and search for the cause,
Resting/sleeping pulse is fast we should suspect thyroid disorder
sudden increase in heart rate
could be a Paroxysmal tachycardia
(Atrial) wchich can come suddenly and transiently.we should also look for any heart valve condition if any?
During Tachycardia shortness of breath
Get examined by a Physician/Cardiologist and investgation like Comlete Blood Count and Xray chest,
ECG ,a 2 D Echocardiography
and Holter monitering and Pulmonary Function Test .
Should give you cause of your symptoms and tachycardia.
We can treat accordingly.
Best of Luck to you