A patient with mitral stenosis is preparing for surgery. What preoperative intervention is most appropriate?

Mitral stenosis is a valvular heart disease characterized by narrowing of the mitral valve orifice, leading to impaired left atrial emptying, increased left atrial pressure, pulmonary congestion, and risk of atrial fibrillation and thromboembolic events. Patients undergoing valve surgery require infection prevention due to high risk of infective endocarditis. Rationale: A. Holding all cardiac medications is unsafe because abrupt discontinuation may worsen hemodynamic stability, increase heart rate, and exacerbate pulmonary congestion. Certain medications are essential for maintaining cardiovascular stability preoperatively. B. Aerobic exercise is contraindicated in significant mitral stenosis because it increases heart rate and reduces diastolic filling time, worsening pulmonary congestion. This may increase risk of hemodynamic decompensation prior to surgery. C. Administering prophylactic antibiotics is appropriate to reduce risk of infective endocarditis in patients undergoing invasive cardiac procedures. It helps prevent postoperative infectious complications involving damaged or prosthetic valves. This protects against valvular infection risk. D. Encouraging fluid intake may worsen pulmonary congestion in mitral stenosis by increasing left atrial pressure. These patients are prone to volume overload. This intervention does not support cardiac preload management and may exacerbate symptoms.