Altered cardiovascular coupling in patients with sudden sensorineural hearing loss in comparison to healthy subjects

The causes of idiopathic sudden sensorineural hearing loss (SSNHL) are still unclear while SSNHL seems to be a multicausal disease. To date limited information about autonomic regulation and, especially, cardiovascular coupling (CVC) are available for those patients. The objective of this study was to characterize short-term (30 min) CVC in 23 SSNHL patients in comparison to 23 healthy age and gender matched normal hearing control subjects (CON). Further on, the results from CVC should be compared with those from standard heart rate variability (HRV) and blood pressure variability (BPV) analyses. The results showed that HRV is not affected by the disease whereas BPV analysis revealed significant differences between both groups (p<0.01) whereby SSNHL exhibit a decreased short-term BPV. Results from CVC analysis demonstrated that especially the applied nonlinear methods exhibit an increased short-term CVC in SSNHL patients (p<0.01) indicating more complex interactions of short-term HR and BP regulatory processes. In conclusion, this study was the first to show a changed and decreased short-term BPV and increased nonlinear CVC in SSNHL patients. Our findings might help to improve diagnostic strategies for hearing loss caused by vascular factors.