Clinical Notes : Cardiology

150. ECG STEMI - Right Ventricular Infarction

STEMI RVI V4R.jpg

ECG - Right Ventricular Infarction STEMI

Clinical significance of Right Ventricular Infarction

Right ventricular infarction complicates up to 40% of inferior STEMIs.

Isolated RV infarction is extremely uncommon.

  • Patients with RV infarction are very preload sensitive (due to poor RV contractility) and can develop severe hypotension in response to nitrates or other preload-reducing agents.

  • Hypotension in right ventricular infarction is treated with fluid loading, and nitrates are contraindicated.

 

The ECG changes of RV infarction are subtle and easily missed !

 

How to spot right ventricular infarction

The first step to spotting RV infarction is to suspect it… in all patients with inferior STEMI !

In patients presenting with inferior STEMI, right ventricular infarction is suggested by the presence of:

  • ST elevation in V1 – the only standard ECG lead that looks directly at the right ventricle.

  • ST elevation in lead III > lead II – because lead III is more “rightward facing” than lead II and hence more sensitive to the injury current produced by the right ventricle.

 

Other useful tips for spotting right ventricular MI:

  • ST elevation in V1 > V2.

  • ST elevation in V1 + ST depression in V2 (= highly specific for RV MI).

  • Isoelectric ST segment in V1 with marked ST depression in V2.

 

Right ventricular infarction is confirmed by the presence of ST elevation in the right-sided leads (V3R-V6R).

 

Right-sided leads

There are several approaches to recording a right-sided ECG:

  • A complete set of right-sided leads is obtained by placing leads V1-6 in a mirror-image position on the right side of the chest (see diagram, below).

  • It may be simpler to leave V1 and V2 in their usual positions and just transfer leads V3-6 to the right side of the chest (i.e. V3R to V6R).

  • The most useful lead is V4R, which is obtained by placing the V4 electrode in the 5th right intercostal space in the midclavicular line.

  • ST elevation in V4R has a sensitivity of 88%, specificity of 78% and diagnostic accuracy of 83% in the diagnosis of RV MI.

 
 
 
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Full right sided 12-lead ECG

STEMI RVI V4R.jpg

V4R in 12-lead ECG

 

Example 1a : Inferior STEMI. Right Ventricular Infarction (anterior leads)

IInferior STEMI. Right ventricular infarction is suggested by:

  • ST elevation in V1

  • ST elevation in lead III > lead II

STEMI RVI ex 1a.jpg

Inferior STEMI. Right Ventricular Infarction (anterior leads)

 

Example 1b : Inferior STEMI. Right Ventricular Infarction (V4R leads)

Repeat ECG of the same patient with V4R electrode position:

 

There is ST elevation in V4R consistent with RV infarction

STEMI RVI ex 1b.jpg

Right Ventricular Infarction (V4R leads)

Example 2 : Right Ventricular MI

Another example of right ventricular MI:

  • There is an inferior STEMI with ST elevation in lead III > lead II.

  • There is subtle ST elevation in V1 with ST depression in V2.

  • There is ST elevation in V4R.

 
STEMI RVI ex 2.jpg

Right Ventricular MI

Example 3 : Right Ventricular Infarction (V3R - V6R leads)

This ECG shows a full set of right-sided leads (V3R-V6R), with V1 and V2 in their original positions.

RV infarction is diagnosed based on the following findings:

  • There is an inferior STEMI with ST elevation in lead III > lead II.

  • V1 is isoelectric while V2 is significantly depressed.

  • There is ST elevation throughout the right-sided leads V3R-V6R.

 

Right Ventricular Infarction (V3R - V6R leads)

 

Management

Refer A+E

In OOH settings where delay in transfer to A+E is inevitable : 

  • aspirin

    • 300 mg orally immediately, followed by 75 mg once daily

  • oxygen

    • Supplemental oxygen is indicated only if oxygen saturation is less than 90%

  • morphine

    • 2-4 mg intravenously every 5-15 minutes until adequate pain control is achieved

  • glyceryl trinitrate

    • if not hypotensive :

      • 0.3 to 1 mg sublingually every 5 minutes,

      • maximum 3 doses

    • if hypertensive or heart failure

      • 5 micrograms/minute intravenously initially,

      • increase by 5-20 microgram/minute increments every 3-5 minutes according to response,

      • maximum 200 micrograms/minute

 
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Life in the Fast Lane

Austalian Emergency Medicine website. 

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ST-elevation myocardial infarction

BMJ Best Practice

Last reviewed : March 2019

Last updated : September 2018

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