Spiked Helmet Sign: An Atypical Case of Transient ST-Segment Elevation on ECG

Spiked Helmet Sign: An Uncommon Electrocardiographic Marker

The spiked helmet sign (SHS) is a rare electrocardiographic marker associated with an increased risk of lethal ventricular tachyarrhythmias and sudden cardiac death. To our knowledge, this is the first study aimed at reviewing recent research progress on this electrocardiogram (ECG) pattern to summarize its electrophysiological mechanisms, epidemiological features, clinical characteristics, and clinical significance. SHS formation is attributed to sympathetic hyperactivity, which mediates increased dispersion of ventricular repolarization, leading to marked QT prolongation and macroscopic T-wave alternans. This pattern can be observed in critically ill patients with cardiac or noncardiac conditions. In particular, immediate identification of this ECG abnormality is crucial in recognizing and treating noncardiac conditions in older male patients.

Spiked Helmet Electrocardiographic Sign-A Systematic Review of Case Reports

First reported in 2011, the spiked helmet sign (SHS) is an electrocardiographic pattern of ST-segment elevation anecdotally associated with poor prognosis. This study aims to systematically evaluate the electrocardiographic characteristics, clinical presentations, and outcomes of all cases of SHS reported in the literature. PubMed, Scopus, Web of Science, and EMBASE were searched electronically from their inception until November 2022. The Joanna Briggs Institute Critical Appraisal Checklist for Case Reports was used to critically appraise included studies. Studies written in English describing at least one patient with SHS were included. Altogether, 26 case reports or series describing 39 patients with SHS were included. All included studies were rated of acceptable quality. Associated conditions were heterogeneous, with intracranial hemorrhagic complications being the most common (9 patients), followed by pneumothorax (6 patients) or severe pneumonia (4 patients), bowel ischemia or obstruction (6 patients), and autonomic dysfunction (3 patients with Takotsubo cardiomyopathy and 3 patients with spinal injury, cocaine overuse, and stellate gangliectomy). Two patients had multiple complications and 12 other patients suffered from sepsis, myocardial infarction, etc. Clinical outcomes were reported for 32 patients, of whom 19 (59%) died during hospitalization (6 patients with pneumothorax or pneumonia, 4 patients with intracranial hemorrhagic complications, 2 patients with bowel ischemia or obstruction, and 7 patients due to other reasons). SHS may be associated with poor prognosis, necessitating its prompt recognition by clinicians and swift evaluation for underlying causes. Larger studies are needed to elucidate its prevalence, clinical implications, and precipitating mechanisms.