Mitral Stenosis in Emergency Medicine Medication

Updated: May 12, 2020
  • Author: Ethan S Brandler, MD, MPH; Chief Editor: Barry E Brenner, MD, PhD, FACEP  more...
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Medication

Medication Summary

The goal of medical therapy is to control the rapid ventricular rate and to prevent thrombus formation and embolization. Conversion of atrial fibrillation to sinus rhythm may also decrease symptoms.

Medications cannot correct mitral stenosis, but therapy can reduce the incidence and severity of symptoms and complications.

Drugs that increase diastolic filling time and decrease the heart rate are typically used. Beta-blockers are frequently used in this situation. Calcium channel blockers, such as diltiazem, and digoxin may also be used. Beta-blockers are preferred over digoxin because they control exercise-induced increases in heart rate.

Rhythm control is of questionable clinical significance. Amiodarone may be used to maintain sinus rhythm, but its use may cause complications.

Anticoagulation is used in patients with atrial thrombi, in patients with atrial fibrillation, or in patients with a prior thromboembolic event.

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Antiarrhythmics

Class Summary

These agents alter the electrophysiologic mechanisms that are responsible for arrhythmia.

Amiodarone (Cordarone)

Class III antiarrhythmic. Has antiarrhythmic effects that overlap all 4 Vaughn-Williams antiarrhythmic classes. May inhibit AV conduction and sinus node function. Prolongs action potential and refractory period in myocardium and inhibits adrenergic stimulation. Only agent proven to reduce incidence and risk of cardiac sudden death, with or without obstruction to LV outflow. Very efficacious in converting atrial fibrillation and flutter to sinus rhythm and in suppressing recurrence of these arrhythmias.

Has low risk of proarrhythmia effects, and any proarrhythmic reactions generally are delayed. Used in patients with structural heart disease. Most clinicians are comfortable with inpatient or outpatient loading with 400 mg PO tid for 1 wk because of low proarrhythmic effect, followed by weekly reductions with goal of lowest dose with desired therapeutic benefit (usual maintenance dose for AF 200 mg/d). During loading, patients must be monitored for bradyarrhythmias. Prior to administration, control the ventricular rate and CHF (if present) with digoxin or calcium channel blockers.

Oral efficacy may take weeks. With exception of disorders of prolonged repolarization (eg, LQTS), may be DOC for life-threatening ventricular arrhythmias refractory to beta-blockade and initial therapy with other agents.

Esmolol (Brevibloc)

Ultra–short-acting that selectively blocks beta1-receptors with little or no effect on beta2-receptor types. Particularly useful in patients with elevated arterial pressure, especially if surgery is planned. Shown to reduce episodes of chest pain and clinical cardiac events compared with placebo. Can be discontinued abruptly if necessary.

May be used with class I antiarrhythmics if digoxin therapy does not abort atrial arrhythmia. Administer in patients needing prompt slowing of ventricular rate in response to atrial flutter or fibrillation and who are most likely to become hemodynamically unstable if left without treatment or in those waiting for the start of the therapeutic effects of digoxin (average, 10 h). Useful in patients at risk for experiencing complications from beta-blockade; particularly those with reactive airway disease, mild-moderate LV dysfunction, and/or peripheral vascular disease. Short half-life of 8 min allows for titration to desired effect and quick discontinuation if needed.

Digoxin (Lanoxin)

Cardiac glycoside that has direct inotropic effects in addition to indirect effects on the cardiovascular system. Effects on myocardium involve a direct action on the cardiac muscle that increases myocardial systolic contractions as well as indirect actions that result in increased carotid sinus nerve activity and enhanced sympathetic withdrawal for any given increase in mean arterial pressure.

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Beta-adrenergic Blockers

Class Summary

These drugs inhibit chronotropic, inotropic, and vasodilatory responses to beta-adrenergic stimulation.

Metoprolol (Lopressor)

Selective beta1-adrenergic receptor blocker that decreases the automaticity of contractions. During IV administration, carefully monitor blood pressure, heart rate, and ECG.

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Calcium Channel Blockers

Class Summary

In specialized conducting and automatic cells in the heart, calcium is involved in the generation of the action potential. The calcium channel blockers inhibit movement of calcium ions across the cell membrane, depressing both impulse formation (automaticity) and conduction velocity.

Diltiazem (Cardizem CD, Cardizem SR, Tiazac, Dilacor)

During the depolarization, 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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Anticoagulants

Class Summary

These agents inhibit thrombogenesis.

Heparin

Augments activity of antithrombin III and prevents conversion of fibrinogen to fibrin. Does not actively lyse but is able to inhibit further thrombogenesis. Prevents reaccumulation of clot after spontaneous fibrinolysis. Most data are related to use of unfractionated heparin. Low molecular weight heparin probably is as effective but awaits the results from clinical studies.

Warfarin (Coumadin)

Inhibits vitamin K–dependent clotting factors II, VII, IX, and X and anticoagulant proteins C and S. Anticoagulation effect occurs 24 h after drug administration, but peak effect may happen 72-96 h later. Antidotes are vitamin K and FFP.

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