Q: While performing bubble echocardiography to diagnose hepatopulmonary syndrome - bubbles usually appear in left atrium within how many heart beats?



Answer: 7 heart beats

Intravenous microbubbles (from agitated normal saline) are normally obstructed by pulmonary capillaries. In hepatopulmonary syndrome they rapidly transit the dilated pulmonary vessels and appear in the left atrium usually within 7 heart beats.

The hepatopulmonary syndrome results from the formation of microscopic intrapulmonary arteriovenous dilatations in patients liver failure. The vascular dilatations cause overperfusion relative to ventilation, leading to ventilation-perfusion mismatch and hypoxemia.



Value of contrast echocardiography for the diagnosis of hepatopulmonary syndrome - European Journal of Echocardiography, Volume 8, Issue 5, Pp. 408-410.