Massive fire ant envenomation triggered fatal Takotsubo cardiomyopathy mimicking STEMI in a 71-year-old woman, leading to refractory cardiogenic shock and death within 24 hours.
Case Report (n=1)
Massive fire ant envenomation can act as a severe physiological stressor triggering fatal Takotsubo cardiomyopathy that mimics ST-elevation myocardial infarction.
Abstract Background Takotsubo cardiomyopathy (TCM), or stress-induced cardiomyopathy, is characterized by transient left ventricular systolic dysfunction precipitated by emotional, physical, or medical stress. While emotional triggers are well documented, TCM secondary to physiological stressors such as insect envenomation is exceedingly rare. Fire ant (Solenopsis invicta) stings can provoke severe pain, hypersensitivity reactions, and a catecholamine surge that may induce myocardial stunning and cardiogenic shock. Case A 71-year-old wheelchair-dependent woman with a history of congestive heart failure with mid-range ejection fraction, diabetes mellitus, and stroke presented after being found poorly responsive by family. On arrival to an outside hospital (OSH), numerous fire ant bites were noted. An electrocardiogram (EKG) showed ST-segment elevation in several leads consistent with inferior ST elevation myocardial infarction (STEMI); lateral reciprocal changes; ST elevation in V3 and V4; and a high-sensitivity troponin of 47 nanograms per liter (normal /= 12 nanograms per liter). She was given thrombolytics at the OSH before transfer to our facility. While in the ambulance, and again in our emergency department, she suffered ventricular tachycardia arrest requiring defibrillation. After return of spontaneous circulation, EKG again showed acute STEMI and high sensitivity troponin peaked at 1,711 nanograms per liter. Emergent coronary angiography demonstrated small chronic occlusions, with the only acute lesion in a distal obtuse marginal artery not amenable to percutaneous intervention. Left ventriculography revealed apical ballooning and akinesis with basal hyperkinesis, suggesting TCM. Despite aggressive management with vasopressors, inotropes, and mechanical ventilation, the patient developed refractory cardiogenic shock and expired within 24 hours. Discussion This case illustrates a rare fatal presentation of stress-induced cardiomyopathy triggered by systemic inflammatory and catecholaminergic responses to fire ant envenomation. The clinical picture closely mimicked STEMI; however, the absence of a sizable acute culprit lesion and the presence of characteristic wall motion abnormalities were more consistent with TCM. Awareness of this rare etiology is essential. Early identification of TCM in the setting of emotional, physical, or medical stress may allow prompt hemodynamic intervention and improve outcomes. Clinicians should maintain a high index of suspicion for TCM in patients with STEMI-like findings following severe stressors or underlying illness. Figure 1. (Left) Fire ant bites located on the right shoulder and chest. Figure 2. (Right) Left Ventriculogram view indicating apical ballooning and akinesis with basal hyperkinesis of left ventricle. This abstract is funded by: None
Bunke et al. (Fri,) conducted a case report in Takotsubo cardiomyopathy (n=1). Massive fire ant envenomation triggered fatal Takotsubo cardiomyopathy mimicking STEMI in a 71-year-old woman, leading to refractory cardiogenic shock and death within 24 hours.