A 76-year-old man is brought to the emergency department after having 6 hours of shortness of breath and chest pain. His initial blood pressure is 102/72 mm Hg and pulse is 102/min. His oxygen saturation is 82% on 15 liters of oxygen via face mask. Bilateral rales are heard over the lower to middle lung fields. His initial ECG shows sinus tachycardia and a left bundle branch block. He is intubated and rushed to the cardiac catheterization lab.
He is found to have an occluded proximal left anterior descending artery and mild atherosclerosis involving the other coronary arteries. He has successful percutaneous revascularization with restoration of coronary flow. A pulmonary artery catheter is placed at the end of the procedure for hemodynamic monitoring and he is transferred to the coronary care unit. His current medications include aspirin, clopidogrel, intravenous unfractionated heparin, eptifibatide, furosemide, and propofol. Six hours after the procedure, his blood pressure is 78/48 mm Hg, and his pulse is 120/min and regular. His ECG shows sinus tachycardia and left bundle branch block pattern.
Hemodynamic readings from the pulmonary artery catheter show the following:

Which of the following is the most likely cause of this patient's hypotension?

Question

A 76-year-old man is brought to the emergency department after having 6 hours of shortness of breath and chest pain.  His initial blood pressure is 102/72 mm Hg and pulse is 102/min.  His oxygen saturation is 82% on 15 liters of oxygen via face mask.  Bilateral rales are heard over the lower to middle lung fields.  His initial ECG shows sinus tachycardia and a left bundle branch block.  He is intubated and rushed to the cardiac catheterization lab.
He is found to have an occluded proximal left anterior descending artery and mild atherosclerosis involving the other coronary arteries.  He has successful percutaneous revascularization with restoration of coronary flow.  A pulmonary artery catheter is placed at the end of the procedure for hemodynamic monitoring and he is transferred to the coronary care unit.  His current medications include aspirin, clopidogrel, intravenous unfractionated heparin, eptifibatide, furosemide, and propofol.  Six hours after the procedure, his blood pressure is 78/48 mm Hg, and his pulse is 120/min and regular.  His ECG shows sinus tachycardia and left bundle branch block pattern.
Hemodynamic readings from the pulmonary artery catheter show the following:

Which of the following is the most likely cause of this patient's hypotension?

Quizplus · Accepted Answer

11ec193a_95d7_adcb_853d_0f43cb441e22_MD0002_00 This patient's pulmonary artery catheterization readings show a low cardiac index and an elevated pulmonary capillary wedge pressure in the setting of a recent myocardial infarction. These findings are suggestive of significant left ventricular dysfunction, and cardiogenic shock is the most likely cause of his hypotension. (Choice B) There is a compensatory increase in cardiac output/index in the early stages of septic shock. Pulmonary capillary wedge pressure and systemic vascular resistance are typically reduced, which is useful for differentiation from other causes of shock. (Choice C) Patients with hypovolemia usually have low right atrial and pulmonary capillary wedge pressures, decreased cardiac index, and increased systemic vascular resistance. (Choice D) Pericardial tamponade causes increased right atrial and ventricular pressures and characteristic equalization of right atrial, right ventricular end diastolic, and pulmonary capillary wedge pressures. (Choice E) Patients with pulmonary embolus have elevated right atrial, right ventricular, and pulmonary artery pressures. Pulmonary capillary wedge pressure and systemic vascular resistance are generally not affected. Educational objective: Patients with cardiogenic shock will have a low cardiac index, increased systemic vascular resistance, and elevated pulmonary capillary wedge pressure. __________

A 76-Year-Old Man Is Brought to the Emergency Department After