Right ventricular myocardial infarction: Difference between revisions

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==[[Right ventricular myocardial infarction secondary prevention|Secondary Prevention]]==
==[[Right ventricular myocardial infarction secondary prevention|Secondary Prevention]]==
===Echocardiography===
* Echocardiography may be limited in [[Right ventricular myocardial infarction|right ventricular infarction]] by suboptimal views of the right ventricle. In addition, interpretation of right ventricular function may be affected by coexistent pulmonary disease (such as [[Chronic obstructive pulmonary disease|obstructive lung disease]] or [[pulmonary embolism]]).
* Despite these limitations, [[echocardiography]] is often a useful test that can be performed at the bedside when the diagnosis of [[Right ventricular myocardial infarction|right ventricular infarction]] is suspected. Right ventricular size and function and the degree (if any) of [[tricuspid insufficiency]] can all be evaluated <ref>Zehender, M, Kasper, W, Kauder, E, et al. Right ventricular infarction as an independent predictor of prognosis after acute inferior myocardial infarction. N Engl J Med 1993; 328:981. PMID 8450875</ref> Useful information concerning left-sided structures and function can also be obtained <ref>Zehender, M, Kasper, W, Kauder, E, et al. Right ventricular infarction as an independent predictor of prognosis after acute inferior myocardial infarction. N Engl J Med 1993; 328:981. PMID 8450875</ref><ref>Kahn, JK, Bernstein, M, Bengston, JR. Isolated right ventricular myocardial infarction. Ann Intern Med 1993; 118:708. PMID 8460858</ref>
* Right ventricular peak systolic pressure may be estimated from the Doppler signal of [[tricuspid insufficiency]] using the modified Bernoulli equation:
*:* Right ventricular peak systolic pressure  =  RAP  +  4V(2)
*:*:* Where RAP equals the estimated right atrial pressure based upon examination of the jugular neck veins, V is the velocity of the [[tricuspid insufficiency]] jet by Doppler ultrasonography, and V(2) refers to V squared. A right ventricular peak systolic pressure above  30 mmHg is considered elevated. Mild elevation is 30 to 45 mmHg, moderate 45 to 60 mmHg, and severe is greater than 60 mmHg.
* In the absence of [[pulmonary stenosis]] (which is rare), right ventricular systolic pressure is equal to the pulmonary artery systolic pressure. As a result, this equation is useful for estimating the presence and severity of [[pulmonary hypertension]]. When significant [[pulmonary artery hypertension]] (>45 to 50 mmHg) complicates [[Right ventricular myocardial infarction|right ventricular infarction]], the failing right ventricle may be unable to pump blood from the right heart into the left heart. In this setting, a positive inotropic agent such as [[dobutamine]] may be effective in augmenting forward flow while also decreasing [[pulmonary vascular resistance]] and right ventricular overload (see below)
=== Other Imaging Findings ===
=== Other Imaging Findings ===
* '''Radionuclide ventriculography and technetium-99m-pyrophosphate scanning'''
* '''Radionuclide ventriculography and technetium-99m-pyrophosphate scanning'''

Revision as of 11:53, 6 September 2012

Myocardial infarction
ICD-10 I21-I22
ICD-9 410
DiseasesDB 8664

Right ventricular myocardial infarction Microchapters

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Overview

Pathophysiology

Pathophysiology of Reperfusion
Gross Pathology
Histopathology

Causes

Differentiating Right ventricular myocardial infarction from other Diseases

Epidemiology and Demographics

Risk Factors

Natural History, Complications and Prognosis

Diagnosis

Diagnostic Criteria

History and Symptoms

Physical Examination

Electrocardiogram

Chest X Ray

Echocardiography or Ultrasound

Coronary Angiography

Other Imaging Findings

Treatment

Initial Care

Pharmacological Reperfusion

Reperfusion Therapy (Overview of Fibrinolysis and Primary PCI)
Fibrinolysis

Mechanical Reperfusion

The Importance of Reducing Door-to-Balloon Times
Primary PCI
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Assessing Success of Reperfusion

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2] Patient Info

Overview

Pathophysiology

Gross Pathology

Causes of Right ventricular myocardial infarction

Differentiating Right ventricular myocardial infarction from other Diseases

Epidemiology & Demographics

Risk Factors

Triggers

Natural History, Complications & Prognosis

Diagnosis

Diagnostic Criteria

History & Symptoms | Physical Examination | Electrocardiogram | Chest X Ray | MRICT | Echocardiography or Ultrasound | Coronary Angiography

Treatment

Pre-Hospital Care | Initial Care

Secondary Prevention

Other Imaging Findings

  • Radionuclide ventriculography and technetium-99m-pyrophosphate scanning
    • These techniques have acceptable sensitivities and specificities for making a diagnosis of right ventricular infarction [1] [2] [3] [4] Radionuclide angiography can detect wall motion abnormalities and hypoperfusion in the affected right ventricle. It can also be used to quantitate both left and right ventricular ejection fractions. Technetium scanning, on the other hand, is particularly useful for late diagnosis, as it shows areas of necrotic or dying myocardium.
    • However, both methods are cumbersome and time consuming. They are also frequently difficult to perform at the bedside, particularly when the patient is unstable in the intensive care unit and nuclear cardiology equipment is not readily portable. Thus, these tests are best performed later in the course to further quantify the degree of right ventricular infarction and dysfunction.

Risk Stratification

  • The presence of right ventricular infarction adversely affects the early prognosis. One study, for example, evaluated 200 consecutive patients with acute inferior myocardial infarction [5] Those with ST elevation in V4R had an almost eight-fold increase in in-hospital mortality (31 versus 6 percent) and morbidity when compared to those without changes in V4R.
  • Elderly patients who have right ventricular involvement with an inferior wall myocardial infarction are at particularly high risk. In a study of 198 patients ≥75 years of age, right ventricular involvement was associated with an in-hospital mortality of 47 percent compared to a 10 percent mortality in the absence of right ventricular involvement [6]
  • For patients who survive an acute right ventricular infarction, however, the prognosis is generally good. As an example, among 522 patients with an inferior wall infarction who were treated with a thrombolytic agent and hirudin or heparin in the HIT-4 study, 32 percent had right ventricular involvement and these patients had a higher 30 day mortality when compared to those without right ventricular involvement (5.9 versus 2.5 percent) [7] However, this was related to a larger infarct size rather than right ventricular involvement; right ventricular involvement was not an independent predictor of survival.
  • The right ventricle frequently recovers the majority of its function, probably due at least in part to decreased oxygen demand of the thin-walled right ventricle [8] [9]. These patients may, however, have a more frequent requirement for a permanent pacemaker. [10]

Treatment

  • 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 [11] [12] 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
  • Pacing
  • Reperfusion

The indications for these modalities are similar to those in left ventricular infarction. Patients in whom reperfusion is achieved typically show a dramatic improvement in the hemodynamic profile within 24 hours [17] [18]

  • As an example, one study of 53 patients reported that primary angioplasty resulted in normal flow in the right coronary artery and its major right ventricular branches in 77 percent of patients; reperfusion was associated with prompt and striking recovery of right ventricular function at three days [19] Failure to reperfuse resulted in lack of functional recovery, persistent hypotension, low cardiac output, and a higher mortality rate (58 versus 2 percent for those with successful reperfusion, p=0.001).

References

  1. Kinch, JW, Ryan, TJ. Right ventricular infarction. N Engl J Med 1994; 330:1211. PMID 8139631
  2. Cohn, JN. Right ventricular infarction revisited. Am J Cardiol 1979; 43:666. PMID 420117
  3. Zehender, M, Kasper, W, Kauder, E, et al. Right ventricular infarction as an independent predictor of prognosis after acute inferior myocardial infarction. N Engl J Med 1993; 328:981. PMID 8450875
  4. Kahn, JK, Bernstein, M, Bengston, JR. Isolated right ventricular myocardial infarction. Ann Intern Med 1993; 118:708. PMID 8460858
  5. Zehender, M, Kasper, W, Kauder, E, et al. Right ventricular infarction as an independent predictor of prognosis after acute inferior myocardial infarction. N Engl J Med 1993; 328:981. PMID 8450875
  6. Bueno, H, Lopez-Palop, R, Bermejo, J, et al. In-hospital outcome of elderly patients with acute inferior myocardial infarction and right ventricular involvement. Circulation 1997; 96:436. PMID 9788824
  7. Zeymer, U, Neuhaus, K-L, Wegscheider, K, et al. Effects of thrombolytic therapy in acute inferior myocardial infarction with and without right ventricular involvement. J Am Coll Cardiol 1998; 32:876. PMID 9768705
  8. Williams, JF. Right ventricular infarction. Clin Cardiol 1990; 13:309. PMID 2189611
  9. Cohn, JN. Right ventricular infarction revisited. Am J Cardiol 1979; 43:666. PMID 420117
  10. Zehender, M, Kasper, W, Kauder, E, et al. Right ventricular infarction as an independent predictor of prognosis after acute inferior myocardial infarction. N Engl J Med 1993; 328:981. PMID 8450875
  11. Kinch, JW, Ryan, TJ. Right ventricular infarction. N Engl J Med 1994; 330:1211. PMID 8139631
  12. 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
  13. Goldberger, JJ, Himelman, RB, Wolfe, CL, Schiller, NB. Right ventricular infarction: Recognition and assessment of its hemodynamic significance by two-dimensional echocardiography. J Am Soc Echocardiogr 1991; 4:140. PMID 2036226
  14. Berger, PB, Ruocco, NA, Ryan, TJ, et al. Frequency and significance of right ventricular dysfunction during inferior wall left ventricular myocardial infarction treated with thrombolytic therapy. Am J Cardiol 1993; 71:1148. PMID 8097614
  15. Kinn, JW, Aljuni, SC, Samyn, JG, et al. Rapid hemodynamic improvement after reperfusion during right ventricular infarction. J Am Coll Cardiol 1995; 26:1230. PMID 7594036
  16. Bowers, TR, O'Neill, WW, Grines, C, et al. Effect of reperfusion on biventricular function and survival after right ventricular infarction. N Engl J Med 1998; 338:933. PMID 9521980
  17. Kinn, JW, Aljuni, SC, Samyn, JG, et al. Rapid hemodynamic improvement after reperfusion during right ventricular infarction. J Am Coll Cardiol 1995; 26:1230. PMID 7594036
  18. Bowers, TR, O'Neill, WW, Grines, C, et al. Effect of reperfusion on biventricular function and survival after right ventricular infarction. N Engl J Med 1998; 338:933. PMID 9521980
  19. Bowers, TR, O'Neill, WW, Grines, C, et al. Effect of reperfusion on biventricular function and survival after right ventricular infarction. N Engl J Med 1998; 338:933. PMID 9521980

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