Isovolumetric contraction and relaxation — MCQs

A 70-year-old man presented to a medical clinic for a routine follow-up. He has had hypertension for 20 years and is currently on multiple anti-hypertensive medications. The blood pressure is 150/100 mm Hg. The remainder of the examinations were within normal limits. Echocardiography showed some changes in the left ventricle. What is the most likely reason for the change?

An 80-year-old African American male presents complaining of worsening shortness of breath that occurs during his weekly round of golf. He also notes he has been waking up at night "choking and gasping for air", though he has been able to gain some relief by propping his head on a stack of pillows before he goes to bed. Upon auscultation, a low frequency, early diastolic gallop is heard over the apex while the patient rests in the left lateral decubitus position. This finding is most consistent with which of the following?

A 76-year-old male with a history of chronic uncontrolled hypertension presents to the emergency room following an episode of syncope. He reports that he felt lightheaded and experienced chest pain while walking his dog earlier in the morning. He notes that he has experienced multiple similar episodes over the past year. A trans-esophageal echocardiogram demonstrates a thickened, calcified aortic valve with left ventricular hypertrophy. Which of the following heart sounds would likely be heard on auscultation of this patient?

On cardiology service rounds, your team sees a patient admitted with an acute congestive heart failure exacerbation. In congestive heart failure, decreased cardiac function leads to decreased renal perfusion, which eventually leads to excess volume retention. To test your knowledge of physiology, your attending asks you which segment of the nephron is responsible for the majority of water absorption. Which of the following is a correct pairing of the segment of the nephron that reabsorbs the majority of all filtered water with the means by which that segment absorbs water?

A 54-year-old man is brought to the emergency department after having been hit by a car while riding his bicycle. He was not wearing a helmet. Despite appropriate life-saving measures, he dies 2 hours later because of a severe intracranial hemorrhage. Autopsy of the heart shows general thickening of the left ventricular wall with narrowing of the ventricular chamber. Which of the following conditions is the most likely underlying cause of the described cardiac changes?

A 21-year-old man presents to his physician for a routine checkup. His doctor asks him if he has had any particular concerns since his last visit and if he has taken any new medications. He says that he has not been ill over the past year, except for one episode of the flu. He has been training excessively for his intercollege football tournament, which is supposed to be a huge event. His blood pressure is 110/70 mm Hg, pulse is 69/min, and respirations are 17/min. He has a heart sound coinciding with the rapid filling of the ventricles and no murmurs. He does not have any other significant physical findings. Which of the following best describes the heart sound heard in this patient?

A 74-year-old man comes to the physician for a 6-month history of progressively worsening fatigue and shortness of breath on exertion. He immigrated to the United States 35 years ago from India. His pulse is 89/min and blood pressure is 145/60 mm Hg. Crackles are heard at the lung bases. Cardiac examination shows a grade 3/6 early diastolic murmur loudest at the third left intercostal space. Further evaluation of this patient is most likely to show which of the following?

A 73-year-old woman presents to clinic with a week of fatigue, headache, and swelling of her ankles bilaterally. She reports that she can no longer go on her daily walk around her neighborhood without stopping frequently to catch her breath. At night she gets short of breath and has found that she can only sleep well in her recliner. Her past medical history is significant for hypertension and a myocardial infarction three years ago for which she had a stent placed. She is currently on hydrochlorothiazide, aspirin, and clopidogrel. She smoked 1 pack per day for 30 years before quitting 10 years ago and socially drinks around 1 drink per month. She denies any illicit drug use. Her temperature is 99.0°F (37.2°C), pulse is 115/min, respirations are 18/min, and blood pressure is 108/78 mmHg. On physical exam there is marked elevations of her neck veins, bilateral pitting edema in the lower extremities, and a 3/6 holosystolic ejection murmur over the right sternal border. Echocardiography shows the following findings: End systolic volume (ESV): 100 mL End diastolic volume (EDV): 160 mL How would cardiac output be determined in this patient?

A 72-year-old man with severe aortic regurgitation and compensated heart failure is being evaluated for surgical intervention. His echocardiogram shows LV end-diastolic dimension of 7.5 cm, ejection fraction of 45%, and severe aortic regurgitation with a regurgitant fraction of 60%. Pressure-volume loop analysis shows a markedly widened loop with increased stroke work. Evaluate the compensatory mechanisms maintaining his cardiac output and predict the timing for surgical intervention based on cardiac cycle mechanics.

A 35-year-old woman with constrictive pericarditis undergoes right heart catheterization showing equalization of diastolic pressures across all cardiac chambers (RA, RV, PA, PCWP all approximately 20 mmHg). Ventricular pressure tracings show a distinctive 'square root sign' during diastole. Evaluate the mechanism by which pericardial constriction alters the normal pressure dynamics during the cardiac cycle and predict the effect on cardiac output during exercise.