Abstract Introduction Pulmonary arteriovenous malformations (PAVMs) are a well-recognized source of paradoxical emboli in Hereditary Hemorrhagic Telangiectasia (HHT). Agitated-saline contrast studies with “early” left-sided bubbles are often interpreted as intracardiac shunt, potentially delaying recognition of PAVMs. We present a young woman with acute cerebral infarction in whom targeted imaging localized the shunt to the pulmonary circulation. Case Presentation A 22-year-old woman with chronic thrombocytopenia presented to the emergency department with complaints of a brief episode (1 minute) of confusion and garbled speech. The National Institutes of Health Stroke Scale (NIHSS) was 0. Complete blood count and chemistries were unremarkable except platelets 110 × 10³/µL. Non-contrast computed tomography (CT) of the head was negative; brain magnetic resonance imaging (MRI) showed a punctate acute infarct in the left parietal lobe. She reported a maternal history of HHT with PVAMs and stroke in her 40s; genetic testing for HHT was pending. Transthoracic echocardiography (TTE) with agitated saline demonstrated a large right-to-left shunt with bubbles appearing in the left atrium within three cardiac cycles, initially suggesting an intracardiac shunt. Transesophageal echocardiography (TEE), however, showed no patent foramen ovale (PFO) by color Doppler or septal interrogation. With direct visualization of the pulmonary veins, microbubbles were seen entering from the pulmonary veins, consistent with an intrapulmonary shunt. CT angiography of the chest revealed multiple PAVMs. Pulmonary angiography confirmed three PAVMs (Figure 1), all successfully treated via transcatheter embolization with vascular plug devices. She was discharged in stable condition with referral to an HHT Center of Excellence for multidisciplinary follow-up and genetic counseling. Discussion This case highlights a diagnostic pitfall: “early” (≤3-beat) left-sided bubble appearance on agitated-saline study is not specific for intracardiac shunt and may occur with large PAVMs. Systematic TEE evaluation that includes targeted imaging of the pulmonary veins can accurately localize the shunt source when TTE suggests right-to-left flow, but septal defects are absent. Prompt recognition enabled definitive embolization and secondary stroke prevention in this young patient. Clinicians evaluating cryptogenic stroke or transient ischemic symptoms—particularly in patients with personal or family features suggestive of HHT—should maintain a high index of suspicion for PAVMs and ensure referral to specialized HHT centers. This abstract is funded by: None
Felix et al. (Fri,) studied this question.