The continuous hr fluctuations between 40 bpm and 190 bpm are incapacitating me (can't do efforts anymore) while on duotrav .will cause heart damage?

Need evaluation: If your heart is frequently fluctuating between 40 and 190, you need to see a cardiologist. There is an illness called "tachy-brady" syndrome. Depending on the specifics, various drugs and sometimes a pacemaker are used to regulate the rhythm. Intermittent bouts of fast and slow hr are not dangerous unless you have other symptoms like passing out.