[Measurement of pulse wave "augmentation index (AI) "and its clinical application].

Hypertension, hyperlipidemia, diabetes mellitus and obesity, all of these life-style related diseases advance arteriosclerosis and cause a cardiovascular event. It is said that the event can be greatly reduced by improvement of lifestyle or medication. The device is recently developed that enables us easily to measure AI i.e. augmentation index, and the studies applying the device have been clarifying the clinical usefulness of the index. The reflected wave from the peripheral artery is superimposed on the ejection wave generated by cardiac contraction, although the blood pressure waveform is observed as the synthesized one of those two. AI is defined as the proportion of the amplitude of the reflected wave to that of the ejection wave, and it does not only express a cardiac load, but also arterial stiffness. The vessel with arteriosclerosis generates a large reflected wave, and it reaches the left ventricle at high speed. Thereby the heart receives large mechanical stress which may cause cardiac hypertrophy, and as a result, the sustained stress may cause a serious accident. Thus, it is the management for both situations of the heart and the artery that matters, and AI can be regarded as a new marker of cardiovascular disease for suitable clinical management on both heart and artery.