What could be the reason for my intermittent palpitations?

Hello doctor,

I have palpitations intermittently while doing my job and during rest for the past two weeks. Also, I have neck pain and phlegm while coughing. But there is no cough always. I have severe acidity too. Sometimes I take Rantac tablets before food. But it is not reducing. I took the ECG when I had palpitation, and the doctor told it is normal. I have tested my blood also. All results lipid profile, electrolytes, thyroid, liver results are normal. Only uric acid is 8.07 mg/dL. I am a BP patient and taking medicine for the past 14 years. Telma 40 mg in the morning and Asomex 2.5 mg in the night. Eight years before I was diagnosed with LBBB. But the doctor told me that it is normal after testing the stress echo method. I am monitoring my BP and pulse at my home, and it is always 140/90 mmHg or 150/85 mmHg. While getting up or resting time, the pulse is very low below 60 bpm. But after my morning walk, the pulse will be above 72 bpm. I have consulted a cardiologist, and they have asked to conduct echo and holter and recommended me not to do TMT. Yesterday I did the echo and Holter test. I got the echo result only and attaching that. My exercise is brisk walking. I am walking four days a week, around 30 to 40 minutes. That is the only exercise. I am a non-alcoholic and a non-smoker. Could you please give a solution to the issues I am facing now.