Bilateral Intracardiac Microbubbles in a Patient With Giant Hiatus Hernia: A Case Report

Intracardiac microbubbles may occur inadvertently during a cardiac procedure, which are typically reported in patients with central venous catheters or cardiac prosthetic valves. Here, we report a case wherein a microbubble filling in the bilateral atriums and ventricles was revealed during echocardiography despite the patient not having the aforementioned risks. An 87-year-old man with hypertension was admitted with a diagnosis of heart failure caused by a giant hiatal hernia. While awaiting hernia surgery, he started vomiting and suddenly went into a coma. A contrast-enhanced computed tomography (CT) scan of the abdomen showed a thickening of the gastric wall, intramural gas, and portal vein gas. Considering these findings, a giant esophageal hiatus hernia was suspected as the cause of the intracardiac microbubbles. In addition, an echocardiogram showed a patent foramen ovale, and the magnetic resonance imaging (MRI) of the head showed multiple cerebral infarctions bilaterally in the cerebral hemispheres. Therefore, a paradoxical air embolism was suspected to cause the coma in this patient. A giant esophageal hiatus hernia can cause portal vein gas triggered by an increased intragastric pressure (which causes vomiting). Then, the portal vein gas flows into the right heart via the sinusoids. Cerebral air embolism can also develop via a shunt, such as a patent foramen ovale, and trigger a foreign body reaction via inflammation and cause coma. When microbubbles are observed in the heart on an echocardiogram, it is necessary to seek the place of entry because it can be a lethal sign due to complications that could follow, such as a cerebral air embolism or pulmonary air embolism.