diastolic pressure-time index
A hemodynamic parameter representing coronary perfusion pressure during diastole, calculated from aortic pressure measurements.
Full Definition
The diastolic pressure-time index (DPTI) is a hemodynamic measurement that quantifies the area under the aortic pressure curve during diastole, representing the driving pressure for coronary perfusion. Since coronary flow occurs predominantly during diastole when the ventricle is relaxed, DPTI serves as an indicator of coronary perfusion pressure and myocardial oxygen supply. It is often paired with the tension-time index (TTI) to calculate the endocardial viability ratio (DPTI/TTI), which predicts subendocardial ischemia risk. DPTI is particularly relevant in assessing patients with aortic stenosis, heart failure, or those requiring mechanical circulatory support.
Usage
Usage note: Used in calculating endocardial viability ratio; particularly relevant in mechanical circulatory support.
In Context
- "The diastolic pressure-time index was significantly reduced, suggesting impaired coronary perfusion." — Hemodynamic assessment report
- "Calculation of the endocardial viability ratio requires both diastolic pressure-time index and tension-time index." — Cardiac catheterization laboratory protocol