P180	Comparative evaluation of ventriculo-arterial coupling in type 2 diabetes and controls using non-invasive carotid arterial wave intensity approach.
H.von Bibra, A.Illmann, U.Pischa, T.Siegmund, P-M.Schumm-Draeger
Academic Hospital Bogenhausen, München, DE.

Cardiovascular (CV) involvement in type 2 diabetes (DM) with preclinical myocardial disease still awaits clarification and remains a clinically relevant issue. In order to evaluate ventriculo-arterial coupling in preclinical CV disease, we used a wave intensity approach. Methods. 65 DM patients (HbA1c 6.9±1.4%, 73% on insulin, 38% on oral therapy) and 57 control individuals were selected. All individuals had normal systolic left ventricular (LV) function by 2-d echocardiography and no evidence of overt coronary artery disease. Groups were comparable with regards to age (58±10 years), incidence of hypertension (44 vs 32%) and other CV risk factors, cardiac medication, left atrial and LV size. Myocardial velocities were assessed by tissue Doppler and the characteristics of pulse wave intensity non-invasively, using a combined Doppler and echo-tracking system (Aloka SSD-5500, Tokyo). From instantaneous changes of diameter and flow in the right carotid artery, local arterial stiffness (epsilon, pulse wave velocity) and wave intensity (product of pressure and velocity changes with respect to time) were calculated. From the two characteristic wave intensity peaks, the early systolic compression wave (W1) is related to LV inotropism and the late systolic expansion wave (W2) influenced by peripheral resistance. Results. DM patients had significantly higher heart rate (69±6 vs 64±10 bpm, p<0.03), systolic blood pressure (138±19 vs 128±15 mmHg, p<0.001), rate pressure product (p<0.001), pulse pressure (p<0.003) and LV filling pressure (p<0.002). Diastolic Myocardial velocity was decreased at diastole (VE 8.0±1.7 vs 9.5±1.7 cm/s, p<0.0001) but not at systole. Mitral A velocity was increased (p<0.003). Epsilon (162±75 vs 120±35 kPa, p<0.003) and pulse wave velocity (7.6 ±1.8 vs 6.7±1.1m/s, p<0.005) were higher and so was W1 (10979±4738 vs 9057±4209, p<0.05) but not W2. In both groups, there were significant inverse correlations for Ve with epsilon (p<0.02). W1 correlated significantly with systolic blood pressure and the rate pressure product. Conclusion: In patients with type 2 diabetes, a preserved pump function is maintained against increased arterial stiffness and impedance at expense of increased myocardial oxygen requirements. Tissue Doppler and wave intensity approach may have the potential for therapeutic monitoring.

Copyright © 2005 S. Karger AG, Basel. Any further use of this abstract requires written permission from the publisher.