Ventricular ejection physiology — MCQs

A 16-year-old boy comes to the physician for a routine health maintenance examination. He feels well. He has no history of serious illness. He is at the 60th percentile for height and weight. Vital signs are within normal limits. The lungs are clear to auscultation. A grade 3/6 ejection systolic murmur is heard along the lower left sternal border. The murmur decreases in intensity on rapid squatting and increases in intensity when he performs the Valsalva maneuver. This patient is at increased risk for which of the following complications?

A 19-year-old man presents to the clinic with a complaint of increasing shortness of breath for the past 2 years. His shortness of breath is associated with mild chest pain and occasional syncopal attacks during strenuous activity. There is no history of significant illness in the past, however, one of his uncles had similar symptoms when he was his age and died while playing basketball a few years later. He denies alcohol use, tobacco consumption, and the use of recreational drugs. On examination, pulse rate is 76/min and is regular and bounding; blood pressure is 130/70 mm Hg. A triple apical impulse is observed on the precordium and a systolic ejection crescendo-decrescendo murmur is audible between the apex and the left sternal border along with a prominent fourth heart sound. The physician then asks the patient to take a deep breath, close his mouth, and pinch his nose and try to breathe out without allowing his cheeks to bulge out. In doing so, the intensity of the murmur increases. Which of the following hemodynamic changes would be observed first during this maneuver?

A 60-year-old male engineer who complains of shortness of breath when walking a few blocks undergoes a cardiac stress test because of concern for coronary artery disease. During the test he asks his cardiologist about what variables are usually used to quantify the functioning of the heart. He learns that one of these variables is stroke volume. Which of the following scenarios would be most likely to lead to a decrease in stroke volume?

A 37-year-old male presents to your clinic with shortness of breath and lower extremity edema. He was born in Southeast Asia and emigrated to America ten years prior. Examination demonstrates 2+ pitting edema to the level of his knees, ascites, and bibasilar crackles, as well as an opening snap followed by a mid-to-late diastolic murmur. The patient undergoes a right heart catheterization that demonstrates a pulmonary capillary wedge pressure (PCWP) of 24 mmHg. The patient is most likely to have which of the following?

Which factor most strongly influences coronary blood flow during exercise?

A 59-year-old woman comes to the physician for a 3-month history of progressively worsening shortness of breath on exertion and swelling of her legs. She has a history of breast cancer, which was treated with surgery followed by therapy with doxorubicin and trastuzumab 4 years ago. Cardiac examination shows an S3 gallop; there are no murmurs or rubs. Examination of the lower extremities shows pitting edema below the knees. Echocardiography is most likely to show which of the following sets of changes in this patient? $$$ Ventricular wall thickness %%% Ventricular cavity size %%% Diastolic function %%% Aorto-ventricular pressure gradient $$$

You are interested in studying the etiology of heart failure reduced ejection fraction (HFrEF) and attempt to construct an appropriate design study. Specifically, you wish to look for potential causality between dietary glucose consumption and HFrEF. Which of the following study designs would allow you to assess for and determine this causality?

A 53-year-old man with a past medical history significant for hyperlipidemia, hypertension, and hyperhomocysteinemia presents to the emergency department complaining of 10/10 crushing, left-sided chest pain radiating down his left arm and up his neck into the left side of his jaw. His ECG shows ST-segment elevation in leads V2-V4. He is taken to the cardiac catheterization laboratory for successful balloon angioplasty and stenting of a complete blockage in his left anterior descending coronary artery. Echocardiogram the following day shows decreased left ventricular function and regional wall motion abnormalities. A follow-up echocardiogram 14 days later shows a normal ejection fraction and no regional wall motion abnormalities. This post-infarct course illustrates which of the following concepts?

A 36-year-old woman is admitted to the hospital for the evaluation of progressive breathlessness. She has no history of major medical illness. Her temperature is 37°C (98.6°F), pulse is 110/min, and respirations are 22/min. Pulse oximetry on room air shows an oxygen saturation of 99%. Cardiac examination shows a loud S1 and S2. There is a grade 2/6 early systolic murmur best heard in the 2nd right intercostal space. Cardiac catheterization shows a mixed venous oxygen saturation of 55% (N= 65–70%). Which of the following is the most likely cause of this patient's breathlessness?

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?