Peak Filling and Ejection Rates

Peak filling rate (PFR) is measured during diastole in a MuGA (Multiple Gated Acquisition) study. The raw PFR is determined from the curve of left ventricular volume as a function of time. The peak slope of this curve during diastole gives the raw PFR in ml/sec. The normalized peak filling rate is the raw PFR divided by end-diastolic volume. The time to PFR is the time between end-diastole to the point at which PFR is achieved. The peak ejection rate (PER) is also derived from the volume curve of the left ventricle. It is the peak slope during systole.

The PFR is related to the compliance of the ventricles and the pressure gradient between the atrium and ventricle. Peak filling rates normally decline with age. A normal PFR is greater than or equal to 2.5 end-diastolic volumes per second. The time to PFR should be less than 180 msec. I can't find normal values for PER and time to PER.

The PFR is decreased in

• Coronary artery disease
• Congestive heart failure: About 40% of patients with CHF have preserved systolic function, but impaired diastolic function.
• Cardiomyopathies
• Aortic valve disease
• Rejection following cardiac transplant
• Hypertension: Isolated decreased PFR may be an early indicator of hypertensive heart failure.
• Medications: Nitroglycerin, beta blockers, doxorubicin

The PFR may be elevated in the following conditions:

• Constrictive pericarditis (not always)
• Mitral regurgitation
• Medications: Calcium channel blockers

Having said all that, apparently no one uses these parameters for diagnostic purposes.

References

• Mettler FA and Guiberteau MJ. Chapter 6: Cardiovascular System. In Essentials of Nuclear Medicine Imaging. Fifth Edition. Saunders, Philadelphia. 2006.
• Williams S. Equilibrium MUGA. Aunt Minnie. 2002.