Response to Letter Regarding Article, “ECG Response: May 20, 2014”
I thank Kordalis et al for their letter in regard to the ECG showing a right ventricular infarction.1 Because V1 through V2 are directly over the right ventricle, ST-segment elevation in these leads is most useful for suggesting a right ventricular infarction when it is associated with an acute inferior wall ST-segment elevation infarction. As Kordalis et al indicated, a progressive decrease in the degree of ST-segment elevation in V2 through V5 is a useful finding, as well, although this may also be seen with an acute anterior wall myocardial infarction. Therefore, the ECG criteria for a right ventricular infarction are not absolute, but are relative to the other ECG changes present. Importantly, infarction of the right ventricle may occur in up to 40% to 50% of inferior wall myocardial infarctions and rarely occurs as an isolated finding. Therefore, in the presence of an acute inferior wall myocardial infarction, right ventricular involvement should be considered if there is ST-segment elevation in V1 through V2. It would be unusual to have both an inferior and anterior wall myocardial infarction occur simultaneously. Hence, the criterion Kordalis et al indicated is also a useful finding. However, most importantly, right-sided leads should be obtained to confirm the presence of a right ventricular infarction and to distinguish the anterior ST-segment changes from an anterior wall myocardial infarction. Right-sided leads will show ST-segment elevation in rV3 through rV5 through rV6 when a right ventricular infarction is present. Given the frequency of right ventricular involvement with an inferior wall myocardial infarction, and the clinical implications associated with right ventricular involvement, as well, I feel that right-sided leads should be routinely obtained whenever there is an acute inferior wall myocardial infarction. When right-sided leads are recorded, they should be labeled so as to avoid making an incorrect diagnosis, such as an old anterolateral myocardial infarction (attributable to the Q waves seen in V4 through V6) or an acute anterolateral infarction if there is ST elevation in rV4 through rV6.
Philip J. Podrid, MD
Boston University School of Medicine
Harvard Medical School
VA Boston Healthcare System
- © 2014 American Heart Association, Inc.