My Name is Peter , I have Been taking Diltiazam for about 4 years following 2 abrupt episodes of runaway Heart beat I managed to get to hospital in time to see it run past 205 before control was gained . 2 episodes 6 months apart. I am an avid cyclist My BP PRE Episode 1 is a consistent 120 /70 it is still 110/70 CONSTANT I have my own Meter Checked by my physician as consistent. I was put on Diltiazam following the First I am On 600 mg Day of Theopholine for 35 years and Normally My heart rate resting would be 80 -86 BPM ON DIltiazam It is 68 BPM CONSTANT Thus it is Controlling the Natural effects of THeopholine. As an Avid Cyclist I find it hard to Climb hills I used to have a heart rate range of 140 to 175 for exercise without pains or Oxygen deprivation ( I am COPD) and able to cycle very spiritedly NOW ion Diltiazam I can Barely cycle over 20 KMH at a max 140 BPM. NO MATTER HOW HARD I TRY My HR is limited to 140 B PM and I cannot cycle Faster than that level allows me or climb the lowest grade of hill Walking is spinal injury limited to no more than 35 meters Then I have nerve impingement CYCLING IS SAFE and EVVECTIVE and the ONLY exercise I can do beyond the boundary of my WHeel chair. Diltiazam is limiting me from keeping healthy CAN I STOP TAKING DILTIAZAM It is more of a health deterrent than Health protector yes it works but negatively in my opinion. It did not Stop the second AF attack