TITLE:
QT Dispersion and QTc Interval in Patients with Adult Sickle Cell Disease: Electrocardiographic (EKG) and Echocardiographic Evaluation
AUTHORS:
Taysir S. Garadah, Adla B. Hassan, Mohamed Al Alwai, Ahmed A. Jaradat, Fathia Qurishi, Abdulla Alajmi
KEYWORDS:
Sickle Cell Anemia, Tissue Doppler, QT Dispersion, Bahrain
JOURNAL NAME:
International Journal of Clinical Medicine,
Vol.5 No.10,
May
13,
2014
ABSTRACT: Background: QT
dispersion (QTd) varies according to heterogeneity of recovery time in the myocardium,
and the impact of iron overload on the QTd in adult patients with Sickle Cell
Disease (SCD) is not clear. Aim: This cross-sectional study was designed to
evaluate corrected QTc interval and QTd on 12 leads ECG in patients with SCD, and
assess the LV systolic and diastolic function using Pulsed Doppler
Echocardiogram. Method: All patients were evaluated clinically with pulse Doppler
echocardiography. Twelve leads ECG were taken to measure QTd and QTc. Blood
samples withdrawn to assess the blood level of ferritin and hemoglobin. Pearson
correlation coefficient was used to measure the linear relationship between
serum ferritin and QTd. Results: The study included patients with SCD (n = 70,
age 15.7 ± 8.9 years), compared with age-matched healthy control group (n = 70,
age 15.9 ± 8.9 years). In patients with SCD compared with healthy control group
the QTc (msec) 416 ± 23.21 ms vs. 401 ± 24.12 (p = 0.75), and the QTd were
slightly longer in SCD compared with the control of 43 ± 22.1 vs. 38 ± 20.16 msec,
(p = 0.071) with no significant difference. M mode echo showed that SCD
patients compared with control had higher LVMI gm/M2 of 105 ± 10.3
vs. 83 ± 7.1, P = 0.001, larger LV end diastolic dimension (cm) of 5.5 ± 0.32 vs.
4.72 ± 0.35, p = 0.03, RV diameter (cm) of 2.8 ± 0.42 vs. 2.4 ± 0.31, (p = 0.041)
and RV wall thickness (mm) of 0.31 ± 0.06 vs. 0.28 ± 0.03, (p = 0.024). Pulsed
Doppler showed high LV transmitral E wave velocity of 85.23 ± 1.92 vs. 62.43 ± 1.67
m/s (p = 0.001), A wave (msec) 46.26 ± 4.7 vs. 56.24 ± 3.2 m/s, p = 0.032, with
E/A ratio of 1.86 ± 0.01 vs. 1.10 ± 0.03, (p = 0.024) and DT of E wave (msec)
of 156.43 ± 23.5 vs. 189.87 ± 19.5, (p = 0.031). Left ventricle ejection
fraction percentage was similar between both groups, but SCD had significantly
higher right ventricle tricuspid annular plane systolic excursion TAPSE (cm) of
1.23 ± 0.21 vs. 1.11 ± 0.23
cm (p = 0.02), and the tricuspid valve velocity showed
significant higher velocity (m/s) in the SCD patients of 2.9 ± 0.14 vs. 1.7 ± 0.09,
p = 0.004 indicating higher pulmonary artery pressure with calculated right
ventricle systolic pressure of 38.64 vs. 16.56 mmHg. Conclusion: SCD patients
compared with control have higher but not significant QT dispersion and
corrected QT interval with a significantly larger LV mass and LV diastolic
filling indices suggestive of restrictive diastolic pattern. These data
indicate that LV diastolic abnormalities compromised initially in patients with
SCD.