| 심지영¹, 박성하¹, 김성애¹, 양우인¹, 문선하¹, 김진미¹, 이현진¹, 최의영¹, 강석민¹, 하종원¹, 임세중¹, 정남식¹ |
Background Arterial stiffening is a common characteristic of hypertension. Ambulatory arterial stiffness index (AASI) has been shown to correlate strongly with classic measures of arterial stiffness and to provide prognostic information on cardiovascular mortality. Theoretically, increase in arterial stiffness should be associated with detrimental effect on ventriculovascular interaction. Therefore, increase in arterial stiffness may result in decrease in myocardial functional reserve during exercise. However, the association of AASI with left ventricular (LV) filling pressure during exercise and exercise capacity have not been addressed.
Methods In 124 (60 males, age: 53.5 ± 9.9) treated hypertensive patients, 24 hour ambulatory blood pressure (BP) measurement and multistage supine bicycle exercise testing were performed. AASI was calculated as 1 minus the regression slope of diastolic BP plotted against systolic BP from individual 24 hour BP mornitoring. Doppler echocardiographic parameters were measured at rest and during supine bicycle exercise (25 W, 3 minutes increments).
Results The mean 24 hr ambulatory systolic BP, diastolic BP and AASI were 131.4 ± 14.5 mmHg, 83.9 ± 10.4 mmHg, and 0.44 ± 0.16, respectively. The AASI was not correlated with baseline echocardiographic parameters including LV mass index (r = 0.126, p= 0.163) and E over E' at rest (r = 0.103, p = 0.254). However, it was well correlated with the change of E over E’from rest to 50 W exercise (r = 0.214, p = 0.039) and exercise duration (r = -0.189, p = 0.035). Multiple linear regression analysis, controlled for variables such as age, gender, LV mass index, left atrial volume index, heart rate at 50 W, systolic BP at 50W, and exercise duration, revealed that AASI was independently associated with the change of E over E' from rest to 50 W exercise (β = 0.282, p = 0.01).
Conclusion The results from this study demonstrate that increased AASI is associated with increased LV filling pressure during exercise and decreased myocardial functional reserve in hypertensive patients.
|
