A patient is admitted with severe uncompensated pulmonary edema secondary to chronic heart failure. After diagnostic testing, it is found that the left coronary artery is blocked, which has led to his pulmonary edema. Which of the following signs and symptoms is consistent with this diagnosis?

Correct Answer: C

Rationale: The correct answer is C: Elevated pulmonary artery wedge pressure (PAWP) or PAOP. In this scenario, the left coronary artery blockage has led to decreased cardiac function, causing increased pressure in the pulmonary circulation leading to pulmonary edema. PAWP reflects left ventricular end-diastolic pressure, which is elevated in conditions like heart failure. Elevated central venous pressure (A) may be seen in heart failure but is not specific to this diagnosis. Elevated blood pressure (B) is not typically associated with uncompensated heart failure. Increased oxygen saturation (D) is not consistent with the diagnosis, as pulmonary edema often leads to decreased oxygen saturation due to impaired gas exchange.

Correct Answer: B

Rationale: The correct answer is B: Positive inotropic, negative chronotropic effect. Digoxin is a positive inotrope, meaning it increases the force of heart contractions, improving cardiac output in heart failure. It also has a negative chronotropic effect by slowing the heart rate, which can be beneficial in certain heart conditions. Option A is incorrect because digoxin has a positive inotropic effect. Option C is incorrect as it contradicts itself by stating both negative and positive inotropic effects. Option D is incorrect because digoxin does not have a positive chronotropic effect; it actually slows the heart rate.

Correct Answer: D

Rationale: The correct answer is D: Supraventricular tachycardia. Beta agonists, like adenosine or beta-blockers, are commonly used to treat supraventricular tachycardia by slowing down the heart rate. This condition involves rapid heartbeats originating above the ventricles. Choices A, B, and C are incorrect because beta agonists are not typically indicated for shock, hypertension, or cardiac arrhythmias, respectively. In hypertensive emergencies, other antihypertensive medications are preferred. In shock, fluid resuscitation and vasopressors are usually used. For cardiac arrhythmias, antiarrhythmic drugs or cardioversion are more appropriate treatments.

Correct Answer: D

Rationale: Step-by-step rationale for answer D: 1. Class I anti-arrhythmic drugs work by blocking sodium channels in the heart. 2. Blocking sodium channels slows the phase 0 depolarization of cardiac cells. 3. This decreases the conduction velocity and excitability of cardiac tissue. 4. Ultimately, it helps to stabilize the heart's electrical activity and prevent arrhythmias. Summary: A: Blocking calcium channels is typical for Class IV antiarrhythmics, not Class I. B: Increasing conduction through AV node is not the mechanism of Class I antiarrhythmics. C: Decreasing excitability of SA node is not how Class I antiarrhythmics work.

Correct Answer: B

Rationale: The correct answer is B because ACE inhibitors block the conversion of angiotensin I to angiotensin II, leading to vasodilation and decreased blood pressure. Option A is incorrect as calcium channel blockers are a different class of drugs. Option C is incorrect as ACE inhibitors do not have a direct inotropic effect on the heart. Option D is incorrect as ACE inhibitors do not have a direct effect on heart rate.