Subarachnoid hemorrhage caused by a paradoxical septic embolism from pacemaker lead infection: A case report

Subarachnoid hemorrhage resulting from a paradoxical septic embolism associated with right-sided cardiac infection has not been previously reported. An 85-year-old woman with a history of aortic valve replacement and right ventricular pacemaker implantation 7 years earlier presented with sudden-onset left upper limb weakness and a small subarachnoid hemorrhage over the right frontal convexity. Contrast-enhanced computed tomography revealed a small aneurysm in the distal right middle cerebral artery. Transthoracic echocardiography revealed vegetation on the right ventricular pacemaker lead, and blood cultures showed growth of Listeria monocytogenes . Transesophageal echocardiography revealed a patent foramen ovale without evidence of infection in the left cardiac chambers or bioprosthetic aortic valve. The patient was diagnosed with subarachnoid hemorrhage due to the rupture of an infectious intracranial aneurysm, presumably caused by a paradoxical septic embolism originating from the pacemaker lead vegetation. After antibiotic therapy, follow-up transthoracic echocardiography revealed complete resolution of the lead vegetation. To our knowledge, this is the first reported case of subarachnoid hemorrhage resulting from a presumed paradoxical septic embolism associated with a pacemaker lead infection.