Response by Sharkey et al to Letter Regarding Article, “Giant J Waves and ST-Segment Elevation Associated With Acute Gastric Distension”
In his letter, Dr Littmann notes similarities in ECG findings between our case report1 and those previously reported in critically ill patients without acute myocardial infarction and labeled as the “spiked helmet” sign.2,3 The spike represents the QRS complex, and the helmet represents an upward deflection of the ECG baseline beginning before and ending after the QRS complex. Dr Littmann has postulated the upward ECG shift represents a mechanical mechanism resulting from cardio-synchronous diaphragmatic contraction or “pulsatile epidermal stretch.”2,3
We have examined the ECG tracings from Dr Littmann’s publications and respectfully disagree with his suggestion that our case represents an example of the spiked helmet sign. The spiked helmet tracings demonstrate ST-segment elevation but without a well-defined J wave as was present in our case. In our case, the availability of serial 12-lead ECG tracings is useful in revealing the temporal increase in both the J-wave amplitude and the associated ST-segment elevation. As Dr Littmann noted, the ECG baseline in our case shifts upward in leads V4 through V6 before the QRS onset. However, the slope of this shift is gradual, in contrast to the slope of the upward shift immediately following the QRS complex, likely representing different physiologic processes. We think that the ST-segment elevation, especially prominent in leads V4 through V6, represents the J wave, whereas the gradual upward slope before the QRS onset represents continuation of ventricular repolarization with a superimposed P wave and atrial repolarization. In our case and the cases of Dr Littmann, sinus tachycardia was present with consequent shortening of the time available for ventricular and atrial repolarization, another possible influence on the ECG changes.
Regardless of mechanism, our case and the spiked helmet examples reported by Dr Littmann illustrate the importance of careful examination of the ECG in critically ill patients. In both conditions, the unusual ECG appearance differs from that of patients with acute myocardial infarction caused by coronary artery obstruction.
Scott W. Sharkey, MD
Quirino Orlandi, MD
Maria Teresa Olivari, MD
Circulation is available at http://circ.ahajournals.org.
- © 2016 American Heart Association, Inc.