Orthostatic changes in hemodynamics — MCQs

A 66-year-old woman presents to the emergency department after a fall 4 hours ago. She was on her way to the bathroom when she fell to the ground and lost consciousness. Although she regained consciousness within one minute, she experienced lightheadedness for almost half an hour. She has experienced on-and-off dizziness for the past 2 weeks whenever she tries to stand. She has a history of type 2 diabetes mellitus, hypertension, hypercholesterolemia, and chronic kidney disease secondary to polycystic kidneys. Her medications include aspirin, bisoprolol, doxazosin, erythropoietin, insulin, rosuvastatin, and calcium and vitamin D supplements. She has a blood pressure of 111/74 mm Hg while supine and 84/60 mm Hg on standing, the heart rate of 48/min, the respiratory rate of 14/min, and the temperature of 37.0°C (98.6°F). CT scan of the head is unremarkable. Electrocardiogram reveals a PR interval of 250 ms. What is the next best step in the management of this patient?

An experiment to determine the effects of gravity on blood pressure is conducted on 3 individuals of equal height and blood pressure oriented in different positions in space. Participant A is strapped in a supine position on a bed turned upside down in a vertical orientation with his head towards the floor and his feet towards the ceiling. Participant B is strapped in a supine position on a bed turned downwards in a vertical orientation with his head towards the ceiling and his feet just about touching the floor. Participant C is strapped in a supine position on a bed in a horizontal orientation. Blood pressure readings are then taken at the level of the head, heart, and feet from all 3 participants. Which of these positions will have the lowest recorded blood pressure reading?

A 33-year-old pilot is transported to the emergency department after she was involved in a cargo plane crash during a military training exercise in South Korea. She is conscious but confused. She has no history of serious illness and takes no medications. Physical examination shows numerous lacerations and ecchymoses over the face, trunk, and upper extremities. The lower extremities are cool to the touch. There is continued bleeding despite the application of firm pressure to the sites of injury. The first physiologic response to develop in this patient was most likely which of the following?

A 27-year-old woman G2P1 at 34 weeks estimated gestational age presents with bouts of sweating, weakness, and dizziness lasting a few minutes after lying down on the bed. She says symptoms resolve if she rolls on her side. She reports that these episodes have occurred several times over the last 3 weeks. On lying down, her blood pressure is 90/50 mm Hg and her pulse is 50/min. When she rolls on her side, her blood pressure slowly increases to 120/65 mm Hg, and her pulse increases to 72/min. Which of the following best describes the mechanism which underlies this patient’s most likely condition?

A 58-year-old man presents to the emergency department following a fall while walking in a grocery store. He has a history of at least 6 previous collapses to the ground with no warning. When these episodes occur, he becomes pale, diaphoretic, and recovers quickly within a few seconds. These episodes always occur when he is standing. His past medical history is significant for type 2 diabetes mellitus, hypercholesterolemia, and one myocardial infarction. His medication list includes aspirin, clopidogrel, bisoprolol, metformin, rosuvastatin, and valsartan. Further history reveals that he has constipation, early satiety, and recently lost 2.2 kg (5 lb) of weight. While lying down, his blood pressure is 145/64 mm Hg and the heart rate is 112/min. After 2 minutes of standing, the blood pressure is 120/65 mm Hg and the heart rate is 112/min. A 12-lead ECG showed Q waves in leads II, III, and aVF. Laboratory results are given below: Hemoglobin 13.8 g/dL White blood cell count 8500/mm3 Platelets 250,000/mm3 Sodium 142 mEq/L Potassium 4.4 mEq/L Calcium 9.1 mg/dL Creatinine 1.0 mg/dL TSH 1.4 U/mL HbA1c 10.2% What additional clinical feature would most likely be present in this patient?

A 73-year-old woman comes to the physician because of recurrent episodes of losing consciousness for several seconds upon standing. She has a history of hypertension, which has been treated with hydrochlorothiazide. Her blood pressure is 130/87 mm Hg in the supine position and 100/76 mm Hg 30 seconds after standing up. Cardiac examination shows no abnormalities. Which of the following sets of changes in venous return, cardiac output, and blood pressure (respectively) is most likely to occur when the patient stands up?

A 68-year-old woman is brought to the emergency department by ambulance after she was found down by her daughter. She lives alone in her apartment so it is unclear when she began to develop symptoms. Her medical history is significant for cardiac arrhythmias, diabetes, pericarditis, and a stroke 2 years ago. On presentation her temperature is 98.1°F (36.7°C), blood pressure is 88/51 mmHg, pulse is 137/min, and respirations are 18/min. On physical exam her skin is cold and clammy. If special tests were obtained, they would reveal dramatically decreased pulmonary capillary wedge pressure, increased systemic vascular resistance, and mildly decreased cardiac output. Which of the following treatments would most directly target the cause of this patient's low blood pressure?

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?

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?

A 69-year-old woman is admitted to the hospital with substernal, crushing chest pain. She is emergently moved to the cardiac catheterization lab where she undergoes cardiac angiography. Angiography reveals that the diameter of her left anterior descending artery (LAD) is 50% of normal. If her blood pressure, LAD length, and blood viscosity have not changed, which of the following represents the most likely change in LAD flow from baseline?