Emergence and resolution of the electrocardiographic spiked helmet sign in acute noncardiac conditions

Letter by Littmann Regarding Article, “Giant J Waves and ST-Segment Elevation Associated With Acute Gastric Distension”

“…In the original article and in subsequent publications, acute abdominal events such as ileus, bowel perforation, and gastric obstruction usually were associated with the spiked helmet pattern showing up in the inferior leads, whereas acute thoracic events such as aortic dissection, pneumothorax, and mechanical hyperventilation caused the spiked helmet sign in the chest leads. [2][3][4][5] Similar to the case of Hibbs et al, 1 normalization of the underlying noncardiac condition resulted in prompt resolution of the pseudo-ST-segment elevation. 5 We and others have hypothesized that the most likely cause of the spiked helmet sign was pulsatile epidermal stretch that occurred in concert with the cardiac cycle in the setting of an acute rise in intracavitary pressures.…”

“…[2][3][4][5] Similar to the case of Hibbs et al, 1 normalization of the underlying noncardiac condition resulted in prompt resolution of the pseudo-ST-segment elevation. 5 We and others have hypothesized that the most likely cause of the spiked helmet sign was pulsatile epidermal stretch that occurred in concert with the cardiac cycle in the setting of an acute rise in intracavitary pressures. [2][3][4][5] In the case report by Hibbs et al also, the apparent ST-segment elevation seen in the lateral chest leads resembled the spiked helmet sign.…”

“…5 We and others have hypothesized that the most likely cause of the spiked helmet sign was pulsatile epidermal stretch that occurred in concert with the cardiac cycle in the setting of an acute rise in intracavitary pressures. [2][3][4][5] In the case report by Hibbs et al also, the apparent ST-segment elevation seen in the lateral chest leads resembled the spiked helmet sign. An enlargement of leads V 3 through V 6 of their Figure 2 showed that the upright swing of the baseline started before the onset of the QRS complexes and therefore could not have reflected a true repolarization abnormality.…”

Response by Sharkey et al to Letter Regarding Article, “Giant J Waves and ST-Segment Elevation Associated With Acute Gastric Distension”

“…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."…”

“…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.…”