Hello, Welcome to Health Care Magic. Thanks for writing. I am Dr.Saddiq ul Abidin. I have read your question completely, I understand your concern and will try to help you in best way possible. The kind of arrhythmias you have mentioned here, can not and shouldn t be taken lightly. But it would have been more helpful if i had known about the exact history and cause of such arrhythmias ( irregular heart rhythms) and any cardiac workup you have had in the past. Also that whether you are taking some drugs, to control and alter the rate and rhythm of your heart for SVT and A fib? However here a little clarification needs to be done, as simply increased heart rate up to 90 isn t termed as tachycardia either, and without an EKG, it is difficult to comment that whether it was supra ventricular or A fib. Also that since your pulse was regular, so it cant be A-fib either, it might also be a sinus tachycardia in response to laxative effect, causing loss of body water,hypovolumic state or electrolyte imbalance, all contributed by inducing diarrhea with Suprep, before the preparation, for any sort of procedure on the Gut. I would recommend you to discus the whole incidence with your cardiologist in detail, and get a detailed cardiac evaluation done and pay regular visits to a cardiologis,t to be started on either of the beta blockers, Digoxin, Amiodarone, diltiazem or verapamil ( all antiarrythmic durgs) depending on your recent cardiac status. Also if A-fib continues and becomes chronic, it needs to be discussed with the cardiologist, regarding prophylactic therapies to avoid risk of ischemic strokes. I hope this answered your question.If you have more queries I am happy to answer.Otherwise rate before closing the discussion Regrads. Dr.Saddiq ul Abidin M.B.B.S(Licensed Family Physician) Resident Medicine.