UCN2 and heart failure: Patients with heart failure (n = 8) and age and gender‐matched healthy subjects (n = 8) underwent bilateral forearm arterial blood flow measurement using forearm venous occlusion plethysmography during intra‐arterial infusions of urocortin 2 (3.6–36 pmol min−1), urocortin 3 (360–3600 pmol min−1) and substance P (2–8 pmol min−1).