Digital arterial tone in hypertensive subjects

Summary. The digital arterial tone has been measured in 12 consecutively referred hypertensive subjects before and after 8 weeks treatment with propranolol. Similar measurements were performed in 12 normotensive, age‐matched controls. The study showed uniformly, that the digital arterial tone increased with falling local temperature applied at the digits (measured at 30, 20, 15, 10 and 5o C). Among the untreated hypertensive subjects the digital arterial tone was significantly higher compared to normotensive controls. After treatment with propranolol a significant increase in digital arterial tone was demonstrated, and most pronounced among the patients complaining of tendency to cold fingers. Additional body‐cooling increased arm and finger systolic blood pressure significantly, but not the digital arterial tone. The frequent Raynaud‐like symptoms in patients treated with non‐selective beta‐adrenoreceptor blocking drugs seem to be due to blockade of peripheral beta‐II adrenergic receptors giving rise to more pronounced alpha‐mediated vasoconstriction.