Right ventricular myocardial infarction initial care: Difference between revisions
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* However, frequent ventricular ectopy and [[ventricular tachycardia]] may limit the use of doses above 10 µg/kg per min. Additionally, since [[dobutamine]] decreases [[peripheral vascular resistance]], higher doses may cause [[hypotension]] as a result of an inadequate rise in [[cardiac output]] to match the decrease in [[systemic vascular resistance]]. | * However, frequent ventricular ectopy and [[ventricular tachycardia]] may limit the use of doses above 10 µg/kg per min. Additionally, since [[dobutamine]] decreases [[peripheral vascular resistance]], higher doses may cause [[hypotension]] as a result of an inadequate rise in [[cardiac output]] to match the decrease in [[systemic vascular resistance]]. | ||
====Transvenous pacing|Pacing==== | ====Transvenous pacing|Pacing==== | ||
==References== | ==References== | ||
{{reflist|2}} | {{reflist|2}} | ||
Revision as of 01:37, 12 September 2012
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Right ventricular myocardial infarction Microchapters |
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Differentiating Right ventricular myocardial infarction from other Diseases |
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Diagnosis |
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Treatment |
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Pharmacological Reperfusion |
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Mechanical Reperfusion |
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Antithrombin Therapy |
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Antiplatelet Agents |
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Other Initial Therapy |
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Right ventricular myocardial infarction initial care On the Web |
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Right ventricular myocardial infarction initial care in the news |
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Blogs on Right ventricular myocardial infarction initial care |
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Directions to Hospitals Treating Right ventricular myocardial infarction |
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Risk calculators and risk factors for Right ventricular myocardial infarction initial care |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
In addition to the reperfusion therapy for STEMI, the acute treatment of right ventricular myocardial infarction is supportive. Volume expansion with normal saline is the primary supportive treatment for the hemodynamic abnormalities of a right ventricular myocardial infarction. Inotropic agents such as intravenous dobutamine, is appropriate in patients whose hypotension is not corrected after 1 L of saline infusion. B-blocker therapy with metoprolol is contraindicated due to bradycardia. Additionally, nitroglycerin is contraindicated in these patients due to risk of hypotension.
Treatment
Initial supportive therapy
- Initial therapy in symptomatic patients is aimed at reversing the decreased filling and right-sided stroke volume and at improving right ventricular function.
Aggressive fluid resuscitation
- Intravenous fluid, usually isotonic saline, should be given to raise the central filling pressure in an attempt to maximize forward flow out of the right ventricle, thereby preventing inappropriate low left-sided filling pressures [1] [2]
- In most cases, several liters of saline are infused rapidly until there is an increase in the pulmonary capillary wedge pressure to approximately 15 mmHg.
- If central hemodynamic monitoring in not available, one to two liters of saline can be infused while closely following the blood pressure and urine output and examining the patient for signs of pulmonary congestion.
Avoid drugs which decrease preload
- Systemic cardiac output is dependent upon filling of the left ventricle. In the setting of right ventricular dysfunction and decreased contractility, reduced preload results sequentially in diminished right sided stroke volume, reduced flow to the left heart, and a fall in cardiac output. As a result, any medication (such as diuretics or nitrates) or maneuver which decreases preload should be avoided.
- Even an increase in vagal tone caused by insertion of a bladder catheter can acutely decrease preload and lead to cardiogenic shock.
Inotropic stimulation
- When fluid resuscitation is insufficient, inotropic and chronotropic stimulation with dobutamine may increase forward flow and augment cardiac output.
- Dobutamine may also act by reducing pulmonary vascular resistance and therefore right ventricular afterload.
- The usual starting dose is 5 µg/kg per min. The dose is titrated up to 20 µg/kg per min depending upon the clinical response.
- However, frequent ventricular ectopy and ventricular tachycardia may limit the use of doses above 10 µg/kg per min. Additionally, since dobutamine decreases peripheral vascular resistance, higher doses may cause hypotension as a result of an inadequate rise in cardiac output to match the decrease in systemic vascular resistance.
Transvenous pacing|Pacing
References
- ↑ Kinch, JW, Ryan, TJ. Right ventricular infarction. N Engl J Med 1994; 330:1211. PMID 8139631
- ↑ Dell'Italia, LJ, Starling, MR, Crawford, MH, et al. Right ventricular infarction: Identification by hemodynamic measurements before and after volume loading and correlation with noninvasive techniques. J Am Coll Cardiol 1984; 4:931. PMID 6092446