Qp:Qs Ratio
Pronunciation: kyoo-pee to kyoo-ess ratio
A hemodynamic measurement comparing pulmonary to systemic blood flow, expressed as the ratio of pulmonary flow (Qp) to systemic flow (Qs).
Full Definition
The Qp:Qs ratio is a critical hemodynamic parameter used to quantify the degree of left-to-right shunting in congenital heart disease. Qp represents pulmonary blood flow while Qs represents systemic blood flow. A ratio greater than 1.0 indicates increased pulmonary circulation due to left-to-right shunting, while ratios significantly above 1.5 often warrant surgical intervention. This measurement is fundamental in cardiac catheterization reports and surgical decision-making. Editorial teams must maintain consistent formatting with the colon separator and proper capitalization of the Q variables.
Usage
Usage note: Always use colon separator, not forward slash; maintain capital Q for both variables.
In Context
- "Cardiac catheterization revealed a Qp:Qs ratio of 2.1, indicating significant left-to-right shunting." — Catheterization report
- "The elevated Qp:Qs ratio supported the decision for surgical VSD closure." — Pre-operative assessment