Clinical findings associated with cardiovascular autonomic dysfunction in adult sickle cell anaemia patients.

Background: Involvement of the cardiovascular autonomic nervous system in various diseases is often associated with increased morbidity and mortality.

Objective: The objective of this study was to examine the clinical features associated with cardiovascular autonomic neuropathy (CAN) in adult Nigerians with sickle cell anaemia.

Methods: A cross-sectional study was carried out on 62 steady state sickle cell anaemia patients recruited from the adult out-patient clinic. Cardiovascular autonomic dysfunction was determined based on abnormal values in at least two of five non-invasive tests: Valsalva manoeuvre, heart rate variation during deep breathing, heart rate response to standing, blood pressure response to sustained handgrip, and blood pressure response to standing. All the subjects were initially evaluated in the clinic for symptoms of cardiovascular disease and peripheral vascular disease, and then clinically examined to assess their cardiovascular and neurological status at rest.

Results: Out of the 44 patients with cardiovascular autonomic neuropathy 23 were males, while 21 were females. The mean ages were 28.3 +/- 5.8 y for patients with CAN and 28.0 +/- 5.0 y for patients without CAN (P = 0.817). Sickle cell anaemia patients with CAN had significantly lower ankle systolic blood pressure, reduced ankle brachial blood pressure index, mean arterial blood pressure and haematocrit than patients without CAN. Of all the variables evaluated leg ulcers, postural dizziness, erectile dysfunction in men, and history of recurrent acute chest syndromes were found significantly more in patients with CAN than without. Clinical abnormalities tend to worsen with increasing degree of cardiovascular autonomic dysfunction.

Conclusion: Significant cardiac morbidity is associated with abnormal cardiovascular autonomic function in sickle cell anaemia.