Jain et al used ejection times to identify a patient with constrictive pericarditis. The authors are from the Mayo Clinic.
Evaluation: cardiac catheterization
Measurements in the arterial pressure tracings:
(1) ejection time in the aorta during inspiration in milliseconds
(2) ejection time in the aorta during expiration in milliseconds
(3) ejection time in the pulmonary artery during inspiration in milliseconds
(4) ejection time in the pulmonary artery during expiration in milliseconds
The readings in the aorta and pulmonary artery are taken simultaneously.
difference for ejection times in the aorta =
= (ejection time during expiration) - (ejection time during inspiration)
difference for ejection times in the pulmonary artery =
= (ejection time during expiration) - (ejection time during inspiration)
differences of these 2 differences =
= (differences for ejection times in the aorta) - (differences for ejection times in the pulmonary artery)
Interpretation:
• Constrictive pericarditis is associated with elevated differences of the differences (mean 50.8)
• Absence of constrictive pericarditis has a difference of the differences with mean 5.4.
• A value >= 25 is consistent with constrictive pericarditis, with the probability increasing as the value increases.
