31.   Gentle handling is essential because jolts can cause fatally irregular heart rhythms.

32.   He said he was not certain that in all cases the new machines could distinguish heart rhythms that should be shocked from those that should not.

33.   He has paroxysmal atrial fibrillation, which produces brief bursts of irregular heart rhythm.

34.   Heart rates, heart rhythms and blood pressure will be monitored before, during and after the mission.

35.   His irregular heart rhythms triggered the pager, which began recording the patterns of electrical impulses traveling through his heart.

36.   His most recent erratic heart rhythm occurred last Sunday in Waterloo, Iowa, on the eve of his final debate with Gore in Iowa.

37.   His doctor also prescribed two other drugs to help regulate his heart rhythm by treating previously undetected underlying heart failure.

38.   I discussed this with several doctors who felt there was not enough electricity in electrolysis to change my heart rhythm, but I stand by my story.

39.   However, Thibault said, a high dose of potassium can cause abnormal heart rhythms and cardiac arrest.

40.   If the electrophysiologic tests show he has such a risk, then the doctors will immediately implant a device designed to slow dangerously fast heart rhythms.