Diagnostic validity of electrocardiography compared with echocardiography for diagnosing left ventricular hypertrophy in patients with β- thalassemia major

Background: Left ventricular hypertrophy (LVH) is an important risk factor in determining
cardiovascular disease prognosis. Echocardiography (ECHO) is a sensitive and specific tool for
detection of LVH but cost and operational consideration tend to limit its utility; in contrast, the
Electrocardiography (ECG) is widely available, expensive and less operator dependent. Since the
comparison of diagnostic validity between ECG and ECHO for evaluating of LVH has not been
well studied, this survey was carried out on a number of major β-thlassemia patients.
Materials and Methods: This descriptive–analytical study was performed on 135 patients
(including male and female) with major β- thalassemia over 8 years old. Patients with heart failure,
valvular or structural heart disease, renal and endocrine disease and Hb<10g/dl were excluded.
ECG and ECHO were performed 48 h after blood transfusion. ECG criteria of LVH and
myocardial performance index (MPI) in ECHO were measured. Sensitivity, specificity, positive
predictive value (PPV) and negative predictive value (NPV) of ECG indexes were calculated
separately for both sexes and compared with ECHO findings.
Results: The patients included 64 (47/4 %) males and 71 (52/6 %) females. ECG indexes were
found as follows: 70% sensitivity of the Sokolow–Lyon index, 14.3%; specificity, 90.3% PPV, 40%
NPV and. Sensitivity of the Sokolow–Lyon–Rappaport, specificity, PPV, and NPV were 61.9%,
25/8%, 27/4%, 60%, respectively. Sensitivity of the Cornell index was66.6%. specificity13.3% ,
PPV 86% and NPV 4.7%,Sensitivity of the White–Bock index was 0%, specificity 100%, PPV 0%
and NPV was 68.9%. There was significant relationship between ECG indexes and some ECHO
parameters. In this study there was a reverse and significant relationship between left acceleration
time (AT) and the Sokolow–Lyon–Rappaport index statistically (r = 0.181, p = 0.035). There was a
significant direct relationship between left deceleration time (DT) and the Sokolow–Lyon–
Rappaport index (r = 0.181, p = 0.036). A reverse significant relationship between right AT and the
Sokolow–Lyon index was seen (r = 0.173, p = 0.044). A direct and significant relationship between
diastolic inter ventricular septum diameter (IVSd) and the Sokolow–Lyon–Rappaport index was
also observed (r = 0.186, p = 0.031).
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ارزش تشخيصي الكتروكارديوگرافي دكتر نورمحمد نوري و دكتر شاهرخ رجائي
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Conclusion : The findings of this study showed that ECG, compared with ECHO, has very low
diagnostic validity for LVH but ECG indexes has statistically significant relationship with some
ECHO parameters (AT, DT, IVSd , LVIDd ) of left ventricular mass.