Thanks for writing in. I am a qualified and certified cardiologist. I read your question with diligence.
Symptoms you described could be of paroxysmal supraventricular tachycardia
(PSVT) or intermittent atrial fibrillation
. Treatment is with atenolol
for later and atenolor or diltiazem
for the former. If it is PSVT, for that can change only after you have been seen and examined by a specialist. Which may take some days. You can try some methods like: a)cut down of alcohol, coffee and tea intake b). when an episode start you try to induce vomiting by putting your clean fingers into back of mouth, trying to produce retching d) with your own hands press your closed eyes firmly and gently. These measure will surely cut short an episode till you get to see a doctor and medicines are changes from atenolol to other drugs after proper investigations. Good Luck.
With Best Wishes
Dr Anil Grover