Background-thalassemia major is a unique disease characterized by early
severe diastolic dysfunction, due to iron myocardial deposition alone,
while left ventricular systolic dysfunction and failure seem to be
multifactorial in aitiology.
ObjectivesThe purpose of this study was to investigate left ventricular
diastolic dysfunction using a new echo index as speckle tracking in
comparison with the conventional methods.
Material and methodsEighty-eight consecutive patients (38 male, 50
female) aged 368.2yr with -thalassemia major and preserved LV ejection
fraction (LVEF>55%) were studied. Patients were divided into two groups
according to the E mitral/E mitral annulus ratio (E/E): group A patients
with E/E ratio 8 and group B patients with E/E >8. Cutoff value of eight
was used to separate patients with normal and abnormal diastolic
function. All subjects were studied thoroughly by tissue Doppler
echocardiography as also by 2D left ventricular and atrial strain
imaging 2-4d following blood transfusion. Blood samples were also taken
for plasma BNP measurements at the same time.
ResultsLeft atrial volumes(LAV max, LAV min) as also left atrial index
were significantly higher in patients with diastolic dysfunction
compared with patients without diastolic dysfunction(LAV max: 57.6 +/-
19.4 vs. 71.3 +/- 22.9, P<0.01,LAV min: 20.2 +/- 11.4 vs. 33.9 +/- 18,
P<0.01, LAVI: 37.66 +/- 12.18 vs. 47.13 +/- 14.77, P<0.01). Radial 2D
strain (RS) and peak atrial 2D strain (AS) were significantly reduced in
patients with suspected diastolic dysfunction compared with patients
without diastolic dysfunction (RS: 43.48 +/- 13.92 vs. 35.58 +/- 11.32,
P<0.05; AS: 36.36 +/- 8.45 vs. 29.85 +/- 9.25, P<0.01). Using ROC
analysis, peak atrial 2D strain at a cutoff of 41.1cm/s was highly
accurate (AUC: 0.66, P<0.05 in ruling out diastolic dysfunction (E/E<8)
with a sensitivity of 90% and a specificity of 81%.
ConclusionsB-thalassemic major patients with preserved left ventricular
systolic function had impaired left atrial function at the longitudinal
axis and left ventricular function at the radial axis. The new echo
markers have better prognostic value than the traditional echo indexes
in detecting latent diastolic dysfunction in -thalassemia major, earlier
than E/E ratio
