Circadian rhythms of blood pressure and heart rate in patients with human T-lymphotropic virus type-I-associated myelopathy.

Noninvasive ambulatory blood pressure and heart rate monitoring were used to investigate cardiovascular dysfunction in patients with human T-lymphotropic virus type-I (HTLV-I)-associated myelopathy (HAM). The subjects were 23 patients with HAM, and 23 sex- and age-matched normotensive healthy volunteers (controls). Circadian rhythms of blood pressure and heart rate were present in both the HAM patients and controls. Amplitudes and the 24-hr mean systolic and diastolic blood pressures were significantly lower in the patients than in the controls. The 24 hr mean heart rate was significantly higher in the patients, the difference being particularly marked during the night. Differences in the acrophases of the systolic and diastolic blood pressures and heart rate between patients and controls were small but still significant. These results suggest that subclinical cardiovascular autonomic dysfunction is present in HAM patients.