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A 54-year-old male is seen in clinic with complaints of palpitations and light-headedness. Physical examination is
remarkable for a heart rate of greater than 200 beats per minute and a blood pressure of 75/40 mm Hg. What
adjustments have probably occurred in the cardiac cycle?


A. Diastolic time has decreased and systolic time has increased

B. Diastolic time has decreased but systolic time has decreased more

C. Systolic time has decreased and diastolic time has increased

D. Systolic time has decreased but diastolic time has decreased more

E. Systolic time has decreased but diastolic time has not changed

d?

BB?

The correct answer is D. Under normal conditions, one-third of the cardiac cycle is spent in systole and
two-thirds spent in diastole. As heart rate increases dramatically, the time spent in diastole falls precipitously
but the time spent in systole falls only slightly.

thanks antigen1...

dd

dd---here too