Our data suggest that the initial reduction in HRV in patients at the time of onset of WS is transient and related to the presence of hypsarrhythmia.

The influence of posture on the effect of carotid sinus massage (CSM) in patients with heart disease has not been systematically evaluated. In the present study CSM was performed in 80 patients (mean age 55 +/- 10 (SD) years) suffering from various cardiovascular diseases. Each subject had unilateral right- and left-sided CSM performed in the supine and in the sitting position, while heart rate and systolic blood pressure were monitored. No statistically significant differences in the CSM-induced response in systolic blood pressure or heart rate were found between the two postures. In the supine position the drop in heart rate was significantly greater after right-sided than after left-sided CSM (P less than 0.05). In only one patient (1%) was a significant carotid sinus reflex evoked. The response was cardioinhibitory with asystole for 3700 ms during right-sided, supine CSM. These results imply that posture does not influence the effect of CSM in patients suffering from heart disease.

No abstract