Evaluation of left ventricular asynchrony by radionuclide angiography: comparison of phase and sector analysis.
The aim of this study was to assess the optimal method to evaluate asynchrony in equilibrium radionuclide angiography (RNA).


METHODS
We studied 20 patients (14 males and 6 females, age range 25-60 yr) with RNA during atrial and sequential atrioventricular (AV) pacing, which increased left ventricular (LV) asynchrony. Both studies were performed at the same heart rate. Asynchrony was assessed either on phase images, by computing the standard deviation of the phase distribution (SD-P) and by sector analysis. Systolic and diastolic asynchrony were evaluated as the coefficient of variation of time to end systole (CV-TES) and time to peak filling rate (CV-TPFR) in four sectors. In addition, phase values were computed on time-activity curves from the same sectors, and their standard deviation (SD-Psec) was computed.


RESULTS
During atrial pacing SD-P was 32.3 degrees +/- 6.7 degrees and did not change during AV pacing (32.1 degrees +/- 5.6 degrees, p = n.s.). Both CV-TES and CV-TPFR had a significant increase during AV pacing (from 7.7% +/- 3.9% to 11.5% +/- 6.4%, p < 0.01, and from 8.4 degrees +/- 5.8 degrees to 12.9 degrees +/- 6.7 degrees, p < 0.001). AV pacing led to a significant increase in SD-Psec (from 6.3 degrees +/- 4.0 degrees to 12.6 degrees +/- 9.7 degrees, p < 0.05). Moreover, reproducibility was assessed in 15 additional age-matched patients. The results of the reproducibility study indicate a better repeatability for CV-TES and CV-TPFR.


CONCLUSIONS
The findings of this study suggest that sector analysis with calculation of indices of LV systolic and diastolic asynchrony is better suited for quantitation of LV temporal nonuniformity.
Cattedra di Medicina Nucleare-Istituto di Scienze Radiologiche, Facoltà di Medicina, Università Federico II., Napoli, Italy.
L
L
Pace
S
S
Betocchi
F
F
Franculli
F
F
Piscione
A
A
Ciarmiello
P
P
Sullo
M
M
Chiariello
M
M
Salvatore
D006328:Cardiac Catheterization; D002304:Cardiac Pacing, Artificial; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging*; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D004912:Erythrocytes; D005260:Female; D005583:Fourier Analysis; D015637:Gated Blood-Pool Imaging / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D015203:Reproducibility of Results; D013670:Sodium Pertechnetate Tc 99m; D016277:Ventricular Function, Left / Q000502:physiology*
D013670:Sodium Pertechnetate Tc 99m