Hello jaymc2011, greetings from healthcaremagic.com I am Dr Sourav Chakraborty and will be helping you out with your query. First of all please do not panic or be scared as these will not help you further. You have not mentioned your age , gender and other co-morbid conditions that you might be suffering from. Also type of life style you have , these are important we do look in to to come into significant conclusion. Do you exercise regularly ? or just started recently , if so then your heart is still getting used to such a unaccustomed hard work , may be. You mentioned that you take clonidine for panic attack , well rarely it is associated with cardiac arrythmia and hypotension . Other side effects to look out for are dry mouth, drowsiness, dizziness, headache, constipation, impotence, urinary retention; dry, itching, burning sensation in the eye, GI upset, weakness, sedation, pruritus, body aches , urticaria, nausea, insomnia. Please keep in mind about these side effects or talk to your doctor about the same. If you are seriously in to bodybuilding and do lots of weight related work out, then better get a baseline ECG and an Echocardiogram done to rule out structural heart disease. Hyper trophic obstructive cardiomyopathy is quite prevalent in body-builders and in sport person, and it is fatal if ignored . So such causes need to be ruled out soon. I assume that you don t have breathlessness with your current complaint but if you do , please visit your cardiologist at the earliest , you need thorough clinical evaluation which i lack and my interpretation is based completely upon your very limited case scenario. If you are above 35 years of age with till now a very sedentary lifestyle and with regular smoking and drinking habits then i might consider ischemic heart disease or coronary aretry insuffiency too, for which you need to under coronary angiogram . Do not neglect your symptoms and visit your doctor at the earliest . Hope i have been able to help you. Take care