Ventricular arrhythmias and arrhythmia substrate in patients with chronic hemolytic disorders with hemosiderosis

ABSTRACT

Twenty patients with one of the thalassemia syndromes on regular blood transfusion and ten matched controls were subjected to clinical assessment, 12 lead ECG, serum ferritin level [FER], hemoglobin level [HB], serum electrolytes, echo Doppler examination, signal averaged ECG [SAECG] and 24 hours Holter monitoring. The results indicated that supraventricular and ventricular arrhythmias were much more common in patients group than control group; patients showed higher FER level, lower HB level but no significant difference in serum electrolytes. They also showed larger left ventricular and diastolic and end systolic diameters with no significant difference in ejection fraction. Corrected QT interval was longer in the patients group. SAECG was positive for late potentials in 20% of patients vs no one in the control group. Patients with late potentials [Gp A] were compared with patients with normal SAECG [Gp B]. Multiple regression analysis showed that older age, positive SAECG and lower ejection fraction, respectively, predict the occurrence of higher grades of arrhythmia. Patients with chronic hemolytic disorder on regular blood transfusion frequently had significant arrhythmias. High grade arrhythmias are more encountered with older age, presence of late potentials and lower left ventricular function