A 16-year-old girl was admitted to the cardiac intensive care unit following cardiac arrest secondary to massive bilateral pulmonary embolism. Venoarterial extracorporeal membrane oxygenation was initiated to restore systemic circulation. She developed severe biventricular dysfunction and respiratory failure with markedly reduced pulmonary compliance, requiring high levels of positive end-expiratory pressure with lung-protective ventilation.
On day 7, she experienced sudden hemodynamic deterioration. Electrocardiography revealed a spiked helmet sign (SHS), characterized by a sine wave-like pattern with spike-like QRS complexes superimposed on an undulating baseline (figure 1A).
Myocardial ischemia was considered unlikely given her clinical profile and high-sensitivity troponin I kinetics (220-350 ng/L). Chest computed tomography demonstrated pneumomediastinum (figure 2, arrows), which was also visible on chest radiography (figure 3; arrow indicates a radiolucent line surrounding the cardiac silhouette). Tracheal and esophageal perforations were excluded. Barotrauma was identified as the cause of both pneumomediastinum and SHS. After optimization of lung-protective ventilation, follow-up imaging confirmed complete resolution of the pneumomediastinum, paralleled by normalization of the electrocardiogram (figure 1B). SHS has been described in association with intracranial hemorrhage, sepsis, acute abdominal processes, and tension pneumothorax, but not with pneumomediastinum. These conditions share the common feature of increased pressure within a closed cavity. In this case, elevated intrathoracic pressure may have increased myocardial wall stress, activated stretch-sensitive ion channels, disrupted repolarization, and impaired contractility.
The patient was successfully weaned from venoarterial extracorporeal membrane oxygenation and mechanical ventilation. She was ultimately discharged after a 4-month hospital stay, with complete recovery of neurological function and biventricular performance.
FUNDINGNot funded.
ETHICAL CONSIDERATIONSEthics committee approval was waived. Informed consent was obtained from the patient and her legal representative. The SAGER guidelines regarding potential sex and gender bias were followed.
STATEMENT ON THE USE OF ARTIFICIAL INTELLIGENCEArtificial intelligence was used exclusively for linguistic proofreading.
AUTHORS’ CONTRIBUTIONSG. Balagué-Dobon: writing—original draft preparation; data collection. J.M. Moreno-Coca: writing—review and editing of the original draft; acquisition and preparation of the 3 figures. R. Andrea: conceptualization and project administration; validation and supervision of the entire work; writing—review and editing; corresponding author.
CONFLICTS OF INTERESTThe authors declare no conflicts of interest directly related to the subject matter of this manuscript.