Forearm reactive hyperemic blood flow and arm-cranking exercise capacity in healthy and heart failure subjects

Background: The relationship between lower limbs maximal vasodilatory capacity and exercise capacity in congestive heart failure (CHF) and healthy subjects has been well-documented. However, the relationship between upper limbs maximal vasodilatory capacity and exercise is less well-established. Methods and Results: Twelve patients with CHF, 16 age- matched normal subjects, and 11 very fit individuals underwent an arm-cranking exercise test using maximal oxygen uptake (arm VO2max) and measurements of peak forearm reactive hyperemic blood flow. Despite similar forearm strength, arm VO2max was significantly reduced in patients with CHF when compared to normal and very fit individuals (13.9 +/- 2.9, 23.5 +/- 4.8, and 36.4 +/- 8.5 mL/kg/min, respectively, P <.05). Similarly, peak reactive hyperemia was lower in CHF patients as compared to normal and very fit individuals (18.6 +/- 5.9, 24.3 +/- 5.8, and 41.1 +/- 8.1 mL/100 mL/min, respectively, P <.05). There was a strong relationship between peak reactive hyperemic blood flow and arm VO2max (r =.75; P <.001) in all subjects. Conclusions: These results suggest a significant relationship between forearm vasodilatory capacity and arm-cranking VO2max to CHF patients, sedentary, and very fit individuals.