Electrocardiographic findings in sickle cell cardiovascular autonomic neuropathy.

BACKGROUND

There is a lack of data on the relationship between cardiovascular autonomic neuropathy (CAN) and electrocardiographic parameters in sickle cell anaemia.

AIMS AND OBJECTIVES

The purpose of the study was to compare the electrocardiographic findings in adult sickle cell anaemia patients with CAN with those of patients without this complication.

METHODS

A cross sectional study was done using 62 consecutively recruited sickle cell anaemia patients who met the inclusion criteria for the study. Cardiovascular autonomic dysfunction was determined based on abnormal values in at least two of five non-invasive tests: Valsalva manoeuver, heart rate variation during deep breathing, heart rate response to standing, blood pressure response to sustained hand grip, and blood pressure response to standing. The subjects were subsequently evaluated with electrocardiography.

RESULTS

Sickle cell anaemia patients with CAN had statistically significantly increased P-wave duration (p < 0.001), PR-interval (p < 0.05) and QTc dispersion (p < 0.05) compared with patients without CAN. Significantly increased frequencies of Q waves and first degree atrio-ventricular block were found in patients with CAN than in those without CAN (p = 0.026, p = 0.014, respectively). Significant correlations were noted between the severity of CAN [number of abnormal autonomic function tests (AFT)] and (1) P-wave duration (p = 0.008), (2) PR- interval (p = 0.013). Significant association was found between the number of abnormal AFT and (1) presence of Q-waves, and (2) degree of anaemia (haematocrit class).

CONCLUSION

Electrocardiographic features consistent with atrio-ventricular and ventricular repolarization abnormalities are associated with CAN in sickle cell anaemia. Further studies are required to evaluate the prognostic implications of these findings in sickle cell patients with cardiovascular autonomic dysfunction.