A woman with coronary artery disease is starting to go for a walk. As she begins, her heart rate accelerates from a resting pulse of 60 bpm until it reaches a rate of 120 bpm, at which point she begins to feel a tightening in her chest. She stops walking to rest and the tightening resolves. This has been happening to her consistently for the last 6 months. Which of the following is a true statement?
AThis patient's chest pain is indicative of transmural ischemia
BPerfusion of the myocardium takes place equally throughout the cardiac cycle
CIncreasing the heart rate increases the amount of time spent during each cardiac cycle
DIncreasing the heart rate decreases the relative amount of time spent during diastole
EPerfusion of the myocardium takes place primarily during systole
A 17-year-old previously healthy, athletic male suddenly falls unconscious while playing soccer. His athletic trainer comes to his aid and notes that he is pulseless. He begins performing CPR on the patient until the ambulance arrives but the teenager is pronounced dead when the paramedics arrived. Upon investigation of his primary care physician's office notes, it was found that the child had a recognized murmur that was ruled to be "benign." Which of the following conditions would have increased the intensity of the murmur?
AInspiration
BPlacing the patient in a squatting position
CValsalva
DPassive leg raise
EHandgrip
An 83-year-old male presents with dyspnea, orthopnea, and a chest radiograph demonstrating pulmonary edema. A diagnosis of congestive heart failure is considered. The following clinical measurements are obtained: 100 bpm heart rate, 0.2 mL O2/mL systemic blood arterial oxygen content, 0.1 mL O2/mL pulmonary arterial oxygen content, and 400 mL O2/min oxygen consumption. Using the above information, which of the following values represents this patient's cardiac stroke volume?
A30 mL/beat
B70 mL/beat
C40 mL/beat
D60 mL/beat
E50 mL/beat
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