P-310: Comparison of brachial artery diameter measured by oscillometry and ultrasound

Introduction: Volume oscillometry is a non-invasive method to measure isobaric arterial compliance. An ordinary blood pressure cuff applied on the upper arm performs the measurement. Oscillations in the cuff around the upper arm are transformed into changes of volume during concomitant pressures registration allowing for calculation of arterial compliance as a function of transmural pressure. The volume of the large arteries under the cuff is determined by summation of the compliance over the transmural pressure range from approximate −50 mmHg to subjects actual mean arterial pressure. Methods: Twelve healthy postmenopausal women of age 69 (55–73) years were examined by 4 occasions with 2 weeks between. Measurements were made at baseline, and after sublingual glyceryl trinitrate (GTN). Each ultrasonic diameter was measured 4 times followed by 4 oscillometric measurements on the other arm. Brachial arterial compliance was measured using a volume-oscillometric method (Artcomp®, Critikon®). Results: There was no significant change in BT before and after GTN. The oscillometry seems to systematic overestimate the artery volume under the cuff by 21% (before )and 15% (after GTN), but without any significant difference. We would expect a higher volume because there is more than one large artery under the cuff. A second problem is that the ultrasonic arterial volume was measured on the right arm, where the oscillometry was measured on the left. Conclusions: It is possible to determine brachial artery volume using oscillometric compliance measurement with a satisfying result. Indirectly verifying that the oscillometric isobaric measurement of arterial compliance is iving realistic values. (See Figure) (See Table) Baseline After GNT P-Value Systolic/diastolic BP (mmHg) 129 ± 20/65 ± 12 126 ± 17/68 ± 11 ns/ns Ultrasonic diameter (mm) 3.16 ± 0.29*** 3.74 ± 0.39*** *** Oscillometric diameter (mm) 3.82 ± 0.60 4.29 ± 0.69 * *P