Sudden unexplained death is common in patients with hemoglobinopathies including sickle cell disease and thalassemia. The prolongation of the QTc interval is a risk factor for fatal arrhythmia in adults.

To study the prevalence of QT prolongation in patients with sickle cell anemia or thalassemia followed at Ibn-Rochd CHU in Casablanca and to study the association between QT prolongation and the risk of sudden death.

We examined electrocardiograms (ECG) of 52 consecutive patients (>14 years) carrying hemoglobinopathies (sickle cell anemia or thalassemia) followed at the Ibn-Rochd university hospital in Casablanca between February 2017 and July 2018. The duration of the interval QTc was calculated using Bazett's formula and classified into three categories by sex (normal, long, short). The Chi-square test was used to study the association between prolonged QTc and sudden death. The statistical analysis was univariate and the significance level was set at (P<0.05).

Among the 52 ECGs examined, there were 3 cases of prolongation of the QT interval, including 2 patients with homozygous thalassemia and one patient with homozygous sickle cell disease, representing a percentage of 5.78% of all followed patients. The study of the association between prolonged QTc and the risk of mortality revealed a mortality rate of 66,7% with long QTc interval vs. 2% in normal QTc interval (P=0.007).

Prolonged QT in patients with sickle cell anemia or thalassemia is a risk factor for increased mortality.