A027: Left ventricular function parameters and arterial load in a healthy versus hypertensive population

The heart and the arterial system are functionally coupled. Hemodynamics are determined by preload, cardiac contractility and afterload. In hypertension, these factors may be changed. The aim is to assess non-invasively the hemodynamic profile by evaluating left ventricular filling and contractility and afterload parameters in normotensives and hypertensives. Seventy-seven healthy volunteers (mean blood pressure 79 mmHg) and 25 hypertensives (mean blood pressure 102 mm Hg) were enrolled. Blood pressure and heart rate were measured at baseline and every 10 minutes thereafter in supine position. All had an echocardiography (HP Sonos 2500) with assessment of left ventricular geometry, diastolic and systolic function. At the same time a radial tonometer (Colin) continuously registered the arterial pressure wave. Aortic pressure was estimated from the radial artery pressure using a validated radial-aorta pressure transfer function. Arterial compliance was calculated by the pulse pressure method. Total peripheral resistance was calculated as the ratio of mean blood pressure and cardiac output. Outcome measures were 1) cardiac filling: pulmonary venous and transmitral flow 2) cardiac contractility 3) afterload: aortic pressure, total peripheral resistance and total arterial compliance. Filling of the heart was impaired in hypertensives: diastolic (36 ± 13 vs 46 ± 13 cm/s), systolic (39 ± 11 vs 50 ± 14 cm/s) pulmonary venous flow parameters decreased, transmitral E-wave decreased (68 ± 23 vs 79 ± 18 cm/s) while transmitral A-wave increased (74 ± 16 vs 48 ± 14 cm/s) (p < 0.01). Systolic function did not differ between both groups. Total peripheral resistance and central mean aortic pressure were significantly increased (1.6 ± 0.50 vs 1.3 ± 0.30 mmHg.s/ml and 105 ± 17 vs 80 ± 10 mmHg), while arterial compliance was significantly lowered in the hypertensives (0.7 ± 0.3 vs 1.1 ± 0.4 ml/mmHg) (p < 0.01). We conclude that preload, contractile state and afterload can be well assessed in a non-invasive way by echocardiography and tonometry. In hypertension diastolic filling and arterial load are impaired while contractile function is preserved.