NT Pro BNP- 160 & racing heart. Done?

Hi, my brother got infected with covid 19 a few months back and still have symptoms like constant racing heart rate, tremors, tinnitus, fatigue, etc. He is 30 years old and followed extremely healthy & fit lifestyle before corona. His echo was normal a couple of months back. Cardiologist had mentioned arrhythmia back then. However, lately he has started experiencing chest pain while walking or climbing stairs with elevated heart rate. His resting heart rate is 80-100 and it goes upto 150-180 when he starts walking. He is unable to perform day to day activity after covid. He has got NT Pro BNP done and its value is 160. Does it indicate initial stage of heart failure?? Should we get some other tests done??