Right ventricular pressure-volume loops using simultaneous radionuclide angiography with a multiwire gamma camera and right heart catheterization.
BACKGROUND
The purpose of this study was to generate right ventricular (RV) pressure-volume loops (PVLs) from time-activity curves obtained by first-pass radionuclide angiography (RNA) and RV pressures obtained by right heart catheterization.


RESULTS
Short-lived tantalum 178 was used to obtain first-pass RNA at baseline (n = 31), after nitroglycerin (n = 5), or after the conclusion of cardiac catheterization (n = 13). From the radionuclide-derived RV ejection fraction and thermodilution stroke volume, the RV end-diastolic volume and end-systolic volume were measured. Special proprietary software was developed and used to integrate the pressure and the RNA data. The mean heart rate was 80 +/- 17 beats/min; RV ejection fraction, 39% +/- 12%; RV end-diastolic volume, 217 +/- 79 mL; RV end-systolic volume, 142 +/- 74 mL; and RV end-diastolic pressure, 10 +/- 7 mm Hg. The RV PVLs were of high quality and reproducible.


CONCLUSIONS
This study provides proof of concept of the feasibility of generating RV PVL; the short half-life (10 minutes) and low energy (59 keV) of Ta-178 allow the generation of multiple loops at low radiation exposure. Such studies could be performed at the bedside and provide a wealth of information that may have clinical and research merits.
Htay
Thein
T
Division of Cardiovascular Diseases, Department of Medicine, University of Alabama at Birmingham, 1900 University Boulevard, Birmingham, AL 35294, USA.
Mehta
Deval
D
Sun
Liang
L
Lacy
Jeffrey
J
Aqel
Raed
R
Heo
Jaekyeong
J
Iskandrian
Ami E
AE
D001794:Blood Pressure; D006328:Cardiac Catheterization / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D015902:Gamma Cameras; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging*; D015646:Ventriculography, First-Pass / Q000295:instrumentation / Q000379:methods*