Medication Summary
The mainstay of treatment is preload and afterload reduction, particularly in the setting of mitral regurgitation with pulmonary edema. Nitrates and diuretics reduce filling pressures, and inotropics and an intraaortic balloon pump are useful in the setting of hypotension and hemodynamic instability. [7]
In the setting of chronic mitral regurgitation with good ventricular function, no evidence supports the prophylactic use of vasodilators, including angiotensin-converting enzyme inhibitors (ACEIs). [7] However, consider ACEIs in patients who develop heart failure but who are not surgical candidates or whose symptoms persist postoperatively. Beta-blockers and spironolactone are also appropriate agents. [7]
Diuretics
Class Summary
These agents are used to reduce preload and the left ventricular volume.
Furosemide (Lasix)
An excellent preload reducer. Increases excretion of water by interfering with chloride-binding cotransport system, which, in turn, inhibits sodium and chloride reabsorption in ascending loop of Henle and distal renal tubule.
Dose must be individualized. Depending on response, administer at increments of 20-40 mg, no sooner than 6-8 h after the previous dose, until desired diuresis occurs. When treating infants, titrate with 1-mg/kg/dose increments until a satisfactory effect is achieved.
Nitrates
Class Summary
These agents are useful in preload reduction and as antianginal agents.
Nitroglycerin topical (Nitro-Bid)
Causes relaxation of the vascular smooth muscle via stimulation of intracellular, cyclic guanosine monophosphate production, which causes a decrease in blood pressure.
Nitroprusside (Nipride, Nitropress)
DOC for afterload reduction. Has an effect on afterload reduction but also some effect on preload; produces vasodilation and increases inotropic activity of the heart. In addition, reduces peripheral resistance by directly acting on arteriolar and venous smooth muscle.
Anti-arrhythmics
Class Summary
These agents are used for the control of atrial fibrillation in the setting of chronic mitral regurgitation.
Digoxin (Lanoxin)
DOC in rate control of atrial fibrillation. Cardiac glycoside with direct inotropic effects in addition to indirect effects on the cardiovascular system.
Diltiazem (Cardizem)
Useful as second line of therapy in rate control of atrial fibrillation and chronic mitral regurgitation. During the depolarization, it inhibits the calcium ion from entering the slow channels or the voltage-sensitive areas of the vascular smooth muscle and myocardium.
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Acute mitral regurgitation. Transesophageal echocardiogram demonstrating prolapse of both mitral valve leaflets during systole.
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Acute mitral regurgitation. Transthoracic echocardiogram demonstrating bioprosthetic mitral valve dehiscence with paravalvular regurgitation.
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Acute mitral regurgitation. Severe mitral regurgitation as depicted with color Doppler echocardiography.
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Acute mitral regurgitation. Four-chamber apical view of a two-dimensional transthoracic echocardiogram demonstrates mitral valve prolapse (MVP), a common cause of mitral regurgitation.
