Increased pulse-wave velocity in patients with anxiety: implications for autonomic dysfunction.

Decreased vagal function is associated with vascular dysfunction. In this study, we compared vascular indices and correlated heart rate and QT variability measures with vascular indices in patients with anxiety disorders and normal controls. We compared age- and sex-matched controls (n=23) and patients with anxiety (n=25) using the Vascular Profiler (VP-1000; Colin Medical Instruments, Japan), approved by the US Food and Drug Administration. Using this machine, we obtained ankle and brachial blood pressure (BP) in both arms (brachial), both legs (ankle), and carotid artery, and lead I electrocardiogram (ECG) and phonocardiogram. Using these signals, pulse-wave velocity (PWV), and arterial stiffness index % and preejection period can be calculated. We also obtained ECG sampled at 1000 Hz in lead II configuration in supine posture to obtain beat-to-beat interbeat interval (R-R) and QT interval variability for 256 s. Patients with anxiety had significantly higher carotid mean arterial pressure (MAP) %, brachial-ankle PWV (BAPWV), arterial stiffness index %, MAP, and diastolic BP of the extremities compared to controls. We found significant negative correlations (r values from .4 to .65; P<.05 to .007) between R-R interval high-frequency (0.15-0.5 Hz) power (which is an indicator of cardiac vagal function), and increased BAPWV and systolic BP of the extremities only in patients. We were unable to find such correlations in controls. We also found significant positive correlations between QT variability index (a probable indicator of cardiac sympathetic function) and MAP of the extremities and BAPWV only in the patient group. These findings suggest an important association between decreased vagal and increased sympathetic function, and decreased arterial compliance and possible atherosclerotic changes and increased BP in patients with anxiety.