Systemic septic emboli in tricuspid endocarditis due to an atrial communication with a right-to-left shunt

We present the case of a patient admitted to hospital in septic shock. He had a history of tricuspid valve infective endocarditis (IE) 6 months prior and regularly injected intravenous drugs. A bedside echo on arrival confirmed vegetations on his tricuspid valve, torrential tricuspid regurgitation and signs of significantly raised right-sided pressures. The admission chest radiograph showed consolidative changes in the lungs, suggestive of septic pulmonary emboli. He was commenced on antibiotics and treated in the high-dependency unit. He subsequently developed an acutely ischaemic right foot and nasal tip. Suspicions were raised of a paradoxical septic embolus through a right-to-left shunt, subsequently confirmed on bubble echo which showed passage of agitated saline between the atria. This was not apparent clinically or on echocardiogram during his previous episode of tricuspid valve IE, raising the possibility of the development of an acquired inter-atrial communication since his previous episode.