Assessment of right atrial (RA) and right ventricular (RV) function by gated blood pool scan with krypton-81m:  RA and RV pressure-volume loops with simultaneous pressure data.
We developed a new method of analyzing right atrial (RA) and right ventricular (RV) function by Krypton-81m gated blood pool scan (Kr-81m-GBPS). Pressure data were recorded simultaneously with a modified Swan-Ganz catheter.  Krypton-81m (Kr-81m) is ideally suited to hemodynamic study of the right heart because of the following characteristics:  physical half-life of 13 seconds; high photon yield and gamma ray energy of 190 KeV; low radiation exposure; and deployment during exhalation when the left heart is not active.  A computerized method for list mode data acquisition was developed to collect data from the gamma camera, ECG wave, and RA and RV pressure simultaneously.  RA and RV volume curves were obtained by calibrating the time-activity curves with end-diastolic volumes and cardiac output. Ejection fraction (EF) was used in the calculation of volume and cardiac output (CO) was measured by the thermodilution method.  From RA and RV pressure and volume curves, RA and RV pressure-volume (P-V) loops were created simultaneously and displayed on the same plane.  One spanning cardiac cycle of RV beats was separated into four phases:  the ventricular emptying phase, the early ventricular filling phase, equilibrium, and the late ventricular filling phase.  One spanning cardiac cycle of RA beats also was separated into four phases as follows:  the atrial filling phase, the early atrial emptying phase, equilibrium, and the late atrial emptying phase. P-V loops of RA and RV were shifted after sublingual nitroglycerin administration.  This new method is potentially useful in the study of right heart hemodynamics.
Division of Cardiology, Hirano General Hospital, Gifu, Japan.
M
M
Ishiguro
T
T
Hirano
S
S
Watanabe
H
H
Matsuo
A
A
Goto
M
M
Arakawa
D016280:Atrial Function, Right / Q000502:physiology*; D002302:Cardiac Output; D002306:Cardiac Volume; D006801:Humans; D007727:Krypton Radioisotopes; D011669:Pulmonary Wedge Pressure; D016278:Ventricular Function, Right / Q000502:physiology*; D015646:Ventriculography, First-Pass / Q000295:instrumentation / Q000379:methods*