While assessing a 68-yr-old with ascites, the nurse also notes jugular venous distention (JVD) with the head of the patient's bed elevated 45 degrees. The nurse knows this finding indicates

Correct Answer: C

Rationale: The jugular veins empty into the superior vena cava and then into the right atrium, so JVD with the patient sitting at a 45-degree angle reflects increased right atrial pressure. JVD is an indicator of excessive fluid volume (increased preload), not decreased fluid volume. JVD is not caused by incompetent jugular vein valves or atherosclerosis.

Correct Answer: D

Rationale: The left bundle branch is supplied by the left coronary artery, not the right, so it remains unaffected by a right coronary artery blockage.

Correct Answer: A

Rationale: Acetylcholine hyperpolarizes the SA node, slowing heart rate via increased potassium permeability.

Correct Answer: D

Rationale: Vasopressin causes vasoconstriction, not dilation, unlike the others which dilate skin arterioles.

Correct Answer: A

Rationale: The action potential reaches the epicardial base of the left ventricle in about 0.22 seconds via Purkinje fibers.