Backgrounds: Orthostatic hypotension (OH) is associated with cardiovascular diseases, heart failure, and increased mortality. We evaluated whether OH was affected by cardiac structure and function or autonomic function in elderly hypertensive outpatients.
Patients and methods: In 64 hypertension patients (mean age 74.2±1.7 years old), we evaluated changes in blood pressure (BP) and heart rate variability before and after standing up using the MemCalc system. In addition, we retrospectively reviewed their medical records and echocardiographic data.
Results: Of the total patients, 28% had OH [decrease of systolic blood pressure (SBP) ≥20 mmHg and/or diastolic BP ≥10 mmHg]. Multivariate linear regression analysis showed that stroke volume (SV)/pulse pressure (PP) was associated independently with orthostatic change in SBP (P=0.007). The patients with OH tended to have a lower SV (57.3±13.1 vs. 68.1±16.3 ml, P=0.009) and lower SV/PP (1.02±0.26 vs. 1.33±0.45, P=0.001) than those without OH. The significance in difference in SV/PP remained even after adjustment for age, sex, BMI, estimated glomerular filtration rate, number of antihypertesive drugs, history of diabetes, and SBP at rest (P=0.036). However, there were no significant differences in change in the low frequency/high frequency ratio after standing up (P=0.899) between patients with and without OH.
Conclusion: Elderly hypertensive patients with OH may have a reduced arterial compliance, measured as SV/PP, and may not have differences in sympathetic nerve activities, measured as the low frequency/high frequency ratio.