From the Guidelines
Right-sided myocardial infarction is primarily identified on ECG by ST-segment elevation in the right precordial leads, particularly lead V4R, which is the most sensitive and specific indicator, as recommended by the 2017 ESC guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation 1.
Key ECG Changes
- ST-segment elevation in lead V4R
- ST elevation in leads II, III, and aVF with the elevation in lead III greater than lead II, indicating inferior wall MI
- ST depression in leads V1 and V2 may paradoxically appear in right ventricular infarction
- Presence of atrioventricular blocks, particularly first-degree AV block, and atrial arrhythmias
Importance of Right-Sided ECG
A right-sided ECG should be performed by placing leads on the right side of the chest when right ventricular involvement is suspected, as stated in the 2012 ACCF/AHA focused update incorporated into the ACCF/AHA 2007 guidelines for the management of patients with unstable angina/non-ST-elevation myocardial infarction 1.
Pathophysiology and Management
These ECG changes reflect the pathophysiology of right ventricular damage, which typically occurs due to occlusion of the right coronary artery proximal to the right ventricular branches. Prompt recognition of these patterns is crucial as right ventricular infarction requires specific management considerations, including adequate volume loading and avoidance of preload-reducing medications, as noted in the third universal definition of myocardial infarction 1.
From the Research
ECG Changes Indicating Right-Sided MI Involvement
To identify right-sided myocardial infarction (MI) involvement on a 12-lead electrocardiogram (ECG), several changes can be observed:
- ST segment elevation in lead V3R, as seen in a case study 2
- ST segment elevation in leads V1 to V3 may be present, but its accuracy is low for diagnosing right ventricular infarction (RVI) 3
- Right chest leads can reveal unequivocal evidence of ischemic injury emanating from the right ventricle, while standard leads II and III show changes compatible with inferior myocardial infarction 4
- Double leads, such as ST-segment elevation (STE) in III > II, can be used to identify the culprit artery in inferior wall STEMI, which may indicate right-sided MI involvement 5
Specific Lead Changes
Some specific lead changes that may indicate right-sided MI involvement include:
- ST-segment elevation in lead III > II, with a pooled sensitivity of 0.89 and specificity of 0.68 5
- ST-segment depression in aVL > I, with a pooled sensitivity of 0.82 and specificity of 0.69 5
- ST-segment depression in V3/STE III ≤1.2, with a pooled sensitivity of 0.88 and specificity of 0.59 5
Optimization of Precordial Leads
Optimization of the precordial leads of the 12-lead ECG may improve detection of ST-segment elevation myocardial infarction, including right-sided MI involvement: