Medication Summary
Medications are useful to help stabilize patients who are waiting for emergency surgery. Agents used in patients who have sustained a myocardial rupture include inotropes, vasodilators, and diuretics.
Inotropic Agents
Class Summary
Inotropes are used in patients with a ventricular septal defect (VSD) or free-wall rupture to increase myocardial contractility and cardiac output in the state of hypotension.
Dopamine
Dopamine stimulates alpha1-adrenergic, beta-adrenergic, and dopaminergic receptors, which are stimulated at lower dosages (< 2 µg/kg/min) and result in renal and mesenteric arterial vasodilation. Beta-adrenergic stimulation occurs at dosages of 2-10 µg/kg/min with positive inotropic effects. Alpha-adrenergic stimulation at dosages exceeding 10 µg/kg/min results in vasoconstriction and increase in blood pressure and afterload.
Dobutamine
Dobutamine is primarily a beta-receptor agonist with both inotropic and chronotropic effects.
Vasodilators
Class Summary
Vasodilators may be used in patients with VSD or mitral regurgitation (MR) to decrease afterload and, subsequently, shunt severity.
Sodium nitroprusside (Nitropress)
Sodium nitroprusside reduces peripheral resistance by acting directly on arteriolar and venous smooth muscle.
Nitroglycerin IV (Nitro-Bid, Nitrostat, Nitro-Dur, Nitrolingual, NitroMist)
Nitroglycerin is primarily a venodilator that decreases both preload and afterload. It is preferred to sodium nitroprusside in patients with acute myocardial infarction (AMI).
Diuretics, Loop
Class Summary
Diuretics can be used in pulmonary edema caused by VSD or MR.
Furosemide (Lasix)
Furosemide is a loop diuretic that decreases preload through reduction of plasma volume and direct vasodilation.
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Photograph of heart of 43-year-old man demonstrating site of stab wound over left ventricular lateral free wall (shown as vertical tear).
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Photograph of heart sectioned transversely at level of middle left ventricle showing posterior ventricular septal defect at site of recent acute myocardial infarction.
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Photograph of mitral valve and subvalvular apparatus showing site of ischemic papillary muscle (PM) rupture (R).
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Magnified photograph of transverse section of middle left ventricle (LV) showing transmural lateral free-wall rupture (R).
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Chest radiograph in posteroanterior projection showing large pseudoaneurysm manifesting as bulge in left cardiac border.
