Biological factors and overestimation of left ventricular ejection fraction by gated SPECT.
BACKGROUND
Some patients present an overestimated left ventricular ejection fraction (LVEF) on electrocardiogram-gated myocardial scintigraphy (gated SPECT).


OBJECTIVE
To establish the relationship between biological factors and overestimated LVEF.


METHODS
We selected 3838 patients who underwent gated SPECT between May 20, 2000 and September 16, 2005 with normal perfusion images and LVEF > or =50%. The following variables were analyzed: gender (29.4% females and 70.6% males), age (from 20 to 94 years - mean: 56 years), weight (from 33.5 to 150 kg - mean: 79.6 kg), height (from 138 to 220 cm - mean: 171 cm) and BMI (from 13.9 to 54 - mean: 27.2). In a subgroup of 1002 patients who underwent echocardiogram, the diastolic diameter (from 36 to 68 mm - mean 47.5 mm) and systolic diameter (from 22 to 41 mm - mean 29.8 mm) variables were included. The patients were divided into two groups: normal LVEF (< or =80%) and overestimated LVEF (>80%). The odds ratio (OR) for presenting an overestimated LVEF was calculated for each variable using logistic regression.


RESULTS
The following odds ratios were found (p < 0.005): female gender OR = 3.585 (95%CI: 2.745 to 4.683), age in years OR = 1.020 (95%CI: 1.011 to 1.029) and height in cm OR = 0.893 (95%CI: 0.829 to 0.962). Weight and BMI were not significantly associated with LVEF (p>0.2). In the subgroup of 1002 patients, a statistically significant influence was found in overestimated LVEF values for the systolic diameter, gender and height variables.


CONCLUSIONS
Although systolic diameter influences the overestimation of LVEF, the gender and height variables have an independent influence on LVEF overestimation by gated SPECT.
Seção de Medicina Nuclear, Fleury - Medicina e Saúde, São Paulo, SP - Brasil. marco.oliveira@fleury.com.br
Marco Antônio Condé de
MA
Oliveira
Paulo Schiavom
PS
Duarte
Maria Margarita C
MM
Gonzalez
Valdir Ambrósio
VA
Moises
Gilberto
G
Alonso
Eduardo Vilaça
EV
Lima
Paola Emanuela
PE
Smanio
Luiz Roberto Fernandes
LR
Martins
Carlos A R
CA
Oliveira
Luiz Eduardo
LE
Mastrocolla
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001685:Biological Factors; D001827:Body Height; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography / Q000379:methods*; D003971:Diastole / Q000502:physiology; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012737:Sex Factors; D013318:Stroke Volume / Q000502:physiology*; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*; D055815:Young Adult
D001685:Biological Factors