Abstract 11682: Spiked Helmet Sign - Poor Prognostic Sign or Artifact?

• Published in: Circulation (New York, N.Y.) N.Y.), 2022-11, Vol.146 (Suppl_1), p.A11682-A11682
• Main Authors: Al-Saiegh, Yousif, Spears, Jenna, Liskov, Steven, Yan, Gan-Xin
• Format: Article
• Language: English
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/circ.146.suppl_1.11682

81 year old female with lung cancer suffered a PEA cardiac arrest while receiving chemotherapy. She received 20 minutes of CPR. Upon arrival to the ICU, she was afebrile, BP 85/55 mmHg on mechanical ventilation. Labs were unrevealing. ECG showed sinus tachycardia with normal intervals and ST segments. Pulmonary embolism and aortic pathology were ruled out. A TTE showed normal biventricular size and function without significant valvular abnormalities. An anaphylactic reaction to the chemotherapy was hypothesized as etiology of her arrest. After initiation of norepinephrine, dynamic oscillatory changes were noted on telemetry and confirmed on 12 lead ECG with a sharp R wave, convex ST changes and QT prolongation, resembling the spiked helmet sign (Fig. 1). Prompt work up showed no abnormal labs and a hyperdynamic left ventricle on TTE. The patient recovered well and was discharged to a nursing facility. The spiked helmet sign was first described in 2011 and defined as an upward shift of the isoelectric baseline followed by a sharp R wave and a convex ST segment elevation; commonly seen in inferior leads. It was exclusively observed in critically ill patients and associated with a high mortality. The mechanism has not been established yet. Proposed mechanisms include possible activation of the diaphragm by the inferior wall of the left ventricle or increased intrathoracic pressure during ventilation. We propose referred aortic pulsation as the mechanism. Specifically, when the left leg (LL) lead - as seen in this patient and frequently done in clinical practice- is placed on the abdomen. This explains the synchronicity of the upsloping with the QRS complex, and why it affects the inferior leads (Fig. 1c). We were able to reproduce the pattern by manually tapping on the LL lead in the same patient (Fig. 1b). The spiked helmet sign is associated with a poor prognosis despite poorly understood mechanism. Further studies are required to prove a cardiac mechanism as opposed to an artifact.