Acute Inferior Myocardial Infarction

This patient is having an acute inferior wall myocardial infarction. Given the patients early presentation and current EKG he is a candidate for thrombolytic therapy with TPA. He should be assessed for risk factors and given TPA.

Remember to check a right sided EKG to look for posterior (RV) extension of this infarct. This is apparently described as occurring in as many as 50% of inferior myocardial infarctions and in a range of 14-84% (depending on study criteria) of all left ventricular infarctions (1). The clinical triad of RV infarcts consists of :

  1. hypotension
  2. elevated jugular venous pressure
  3. clear lung fields

Although quite specific, this triad has a sensitivity of about 25% (2). These signs may not be entirely present if the patient is volume depleted.

Patients with RV infarction are volume dependent and giving them nitroglycerin sublingual can cause them to become profoundly hypotensive. This can iatrogenically extend the area of infarction. It is ALWAYS a good rule to get an EKG before doing any interventions with the exception of administering an aspirin. And ALWAYS get a right sided EKG in inferior infarction patterns.

For a good review on RV infarction see:

 

References:

  1. Cohn JN, Guiha NH, Broder MI, Limas CJ. Right ventricular infarction: clinical and hemodynamic features. Am J Cardiol 1974; 33:209-14.
  2. Dell'Italia LJ, Starling MR, O'Rourke RA. Physical examination for exclusion of hemodynamically important right ventricular infarction. Ann Intern Med 1983;99:608-11.

 

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