Radial and ulnar artery dominance in normal digits.

Pulse volume plethysmography was done on 1249 digits in 125 volunteers to determine relative blood flow to each digit. Twenty-five volunteers had diminished pulse contours (24:1 female to male); 20% of these had cold intolerance compared with 1% of the remaining volunteers. The 200 hands without vasospasm were used to calculate vessel dominance by comparing pulse volume plethysmography amplitudes during radial or ulnar artery compression. Only 5% were found to have ulnar artery dominance (ie, pulse volume plethysmography amplitude larger during radial artery compression) in all digits, and 28% were found to have complete radial artery dominance. Ulnar dominance in three or more digits was seen in 21.5% compared with 57% with radial artery dominance; 21.5% had equal dominance. Overall, 87% of thumbs and 70.5% of index, 60% of long, 52% of ring, and 52% of small fingers were radial dominant.