physio day-1

A 29-year-old man is brought to the emergency room 6 hours after the onset of severe epigastric pain and vomiting. His heart rate is 110/min and blood pressure is 98/72 mm Hg. He is diagnosed with acute pancreatitis, and fluid resuscitation with normal saline is initiated. Which of the following is the most likely immediate effect of fluid resuscitation in this patient?

• Increase in cardiac afterload

• Increase in volume of distribution

• Increase in myocardial oxygen demand

• Increase in plasma oncotic pressure

• Increase in glomerular filtration fraction

A 67-year-old woman comes to the physician because of intermittent chest pain and dizziness on exertion for 6 months. Her pulse is 76/min and blood pressure is 125/82 mm Hg. Cardiac examination shows a grade 3/6, late-peaking, crescendo-decrescendo murmur heard best at the right upper sternal border. An echocardiogram confirms the diagnosis. Three months later, the patient returns to the physician with worsening shortness of breath for 2 weeks. An ECG is shown. Which of the following changes is most likely responsible for this patient's acute exacerbation of symptoms?

• Impaired contractility of the left ventricle

• Impaired pulmonary artery outflow

• Increased myocardial perfusion pressure gradient

• Decreased left ventricular preload

• Decreased impulse conduction across the AV node

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 is most likely to occur when the patient stands up?

• A

• B

• C

• D

• E

A 2-week-old newborn is brought to the physician because of worsening feeding difficulty since birth. Examination shows a grade 2/6 harsh holosystolic murmur, heard most clearly at the left lower sternal border, and a soft mid-diastolic rumble over the cardiac apex. Echocardiography shows shunting of blood through the ventricular septum during systole. The patient undergoes surgery for closure of the defect. Which of the following sets of changes are expected after successful repair of this cardiac defect?

• A

• B

• C

• D

• E

An investigator is studying cardiovascular changes during exercise. He is following a 25-year-old female volunteer who is training for a marathon. Her training consists of running on a treadmill for increasing amounts of time. During her training sessions, laboratory studies show increased concentrations of adenosine and lactate in the active muscles. Which of the following is most likely a direct effect of these metabolites?

• Decreased stroke volume

• Decreased capillary pressure

• Decreased systemic vascular resistance

• Increased venous return

• Increased mixed venous oxygen saturation

An investigator is studying the reaction of mutated voltage-gated potassium channel subunits. The mutation alters gating properties by reducing the potassium conductance through these channels, which manifests on ECG with a prolongation of the QT interval. Which of the following labeled phases of the action potential will be most affected by this mutation?

• A

• B

• C

• D

• E

A 63-year-old woman comes to the physician because of a 6-month history of fatigue and shortness of breath on exertion in addition to a 1-month history of ankle swelling. She has a history of sleep apnea. Examination of the lower extremities shows bilateral pitting pedal and ankle edema. Cardiac examination shows a widely split S2 that varies with respiration. An ECG shows right bundle branch block. Which of the following is the most likely etiology of the patient's lower extremity edema?

• Localized lymphatic obstruction

• Dermal accumulation of glycosaminoglycans

• Thrombus formation in a deep vein

• Increased capillary hydrostatic pressure

• Decreased plasma oncotic pressure

A 38-year-old woman comes to the physician because of an 8-week history of shortness of breath and dull chest pain. She has a history of antiphospholipid syndrome. Physical examination shows jugular venous distention. Right heart catheterization shows a mean pulmonary arterial pressure of 30 mm Hg and a pulmonary capillary wedge pressure of 10 mm Hg. Further evaluation is most likely to show which of the following?

• Constriction of the renal afferent arteriole

• Dilation of the coronary sinus

• Decreased left ventricular contractility

• Mitral valve leaflet thickening

• Hemosiderin-laden macrophages

Prior to undergoing a total knee arthroplasty, a 62-year-old man with coronary artery disease undergoes diagnostic cardiac catheterization. The catheter is inserted via the femoral artery and then advanced to the ascending aorta. Pressure tracing of one cardiac cycle is shown. The notch indicated by the arrow is most likely caused by which of the following?

• Opening of the pulmonic valve

• Opening of the mitral valve

• Right atrial relaxation

• Closure of the aortic valve

• Right ventricular contraction

A 70-year-old man comes to the physician for a follow-up examination of diffuse exertional chest pain which he has successfully been treating with sublingual nitroglycerin for the past year. The patient has been taking lisinopril daily for essential hypertension. His pulse is 75/min and regular, and blood pressure is 155/90 mm Hg. Cardiac and pulmonary examination show no abnormalities; there is no peripheral edema. A decrease of which of the following is the most likely explanation for the improvement of this patient's chest pain?

• Peripheral arterial resistance

• Electrical conduction speed

• Venous pooling

• Coronary arterial resistance

• End-diastolic pressure