抄録
Clinical evaluation of atherosclerotic changes of the aorta is difficult except using angiography. The present study was intended to estimate extent of atherosclerosis or compliance of the aorta with non-invasive procedures.
To determine compliance of the aorta, the pressure-volume relationship was employed for the study. Up to this time, measurements of aortic pressure and volume have been done using invasive methodes.
In the present study, pressure-volume Lissajow's figure was plotted with computerized X-Y recorder from simultaneously recorded pulswave by miniature semiconductor pressure transducer fixed upon the brachial artery and plethysmogram by trans-thoracic impedance plethysmography.
Experimentally, pressure-volume Lissajow's figures were recorded invasively with the same computer processing from pressure wave by catheter tip pressure transducer introduced into the thoracic aorta and volume curve with mercury straingage binded on the thoracic aorta of dog.
High correlations were observed between pressure waves recorded by the invasive and noninvasive method and also plethysmogram between mercury straingage and trans-thoracic impedance plethysmography.
Changes of two pressure-volume Lissajow's fingures obtained by invasive or non-invasive techniques were closely correlated by hemodynamic alterations induced by propranolol and methoxamine administration.
These findings may support that the non-invasive pressure-volume Lissajow's figure is an indirect manifestation of the pressurevolume relationship of the thoracic aorta.
Non-invasive pressure-volume Lissajow's figures were recorded on 170 subjects of various aged.
Inclination from the origin to top of the pressurevolume Lissajow's figure was supposed to indicate compliance of the aorta.
The inclination of the third decade was 0.30+0.14mlmmHg and of more than 60 years old was 0.14+0.09mlmmHg.
Thus, non-invasive pressure-volume Lissajow's figure is an complehensive indicator of compliance of the aorta.
