Right Ventricular Infarction

Suspect and look for right ventricular (RV) infarction in all patients with inferior STEMI.

ECG diagnostic criteria

• V1 is the only standard ECG lead that looks directly at the right ventricle
• Lead III is more rightward facing than lead II and hence more sensitive to the injury current produced by the right ventricle

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Clinical Significance of RV Infarction

• RV infarction complicates up to 40% of inferior STEMIs (isolated RV infarction is extremely uncommon)
• These patients 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!

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

NB. ST elevation in the right-sided leads is a transient phenomenon, lasting less than 10 hours in 50% of patients with RV infarction.

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Example ECG

Example 1a

Inferior STEMI. Right ventricular infarction is suggested by:

• ST elevation in V1
• ST elevation in lead III > lead II

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Example 1b

Repeat ECG of the same patient with V4R electrode position:

• There is ST elevation in V4R consistent with RV infarction

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Example 2

Another example of right ventricular infarction in the context of inferior STEMI:

• ST elevation in lead III > lead II
• Isoelectric ST segment in V1 with marked ST depression in V2
• There is ST elevation in V4R.

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Example 3

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

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Example 4a

Try this one yourself…

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Example 4b

Same patient, 9 minutes later…

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References

• Morris F, Brady WJ. ABC of clinical electrocardiography: Acute myocardial infarction-Part I. BMJ. 2002; 324: 831-4. [full text]
• Edhouse J, Brady WJ, Morris F. ABC of clinical electrocardiography: Acute myocardial infarction-Part II. BMJ. 2002; 324: 963-6. [full text]

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Advanced Reading

Online

Textbooks

• Zimmerman FH. ECG Core Curriculum. 2023
• Mattu A, Berberian J, Brady WJ. Emergency ECGs: Case-Based Review and Interpretations, 2022
• Straus DG, Schocken DD. Marriott’s Practical Electrocardiography 13e, 2021
• Brady WJ, Lipinski MJ et al. Electrocardiogram in Clinical Medicine. 1e, 2020
• Mattu A, Tabas JA, Brady WJ. Electrocardiography in Emergency, Acute, and Critical Care. 2e, 2019
• Hampton J, Adlam D. The ECG Made Practical 7e, 2019
• Kühn P, Lang C, Wiesbauer F. ECG Mastery: The Simplest Way to Learn the ECG. 2015
• Grauer K. ECG Pocket Brain (Expanded) 6e, 2014
• Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice: Adult and Pediatric 6e, 2008
• Chan TC. ECG in Emergency Medicine and Acute Care 1e, 2004

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LITFL Further Reading

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