Learning from the past studies on postural tachycardia syndrome

Abstract

Postural tachycardia syndrome (PoTS) is assumed as a heterogeneous clinical syndrome, but it is absurd to discuss its nature under the single term of PoTS unless all variants of PoTS share the common pathophysiology. Review of the past studies on PoTS indicates that the nature of PoTS had already been theoretically elucidated. The present concept of PoTS corresponds to Da Costa syndrome (1871) in the English-speaking world, vagal neurosis (1892) or vegetative dystonia (1934) in the German-speaking world, and arterial orthostatic anemia (1925) in Sweden. In the English- and the German-speaking worlds, PoTS was considered as a condition coexisting with both the autonomic and the affective disturbances (psychosomatic disease). The interpretation of psychosomatic disease was different between the English- and the German-speaking world, however; while it was simply considered that the autonomic nervous activity was influenced by the affection in the former, it was speculated that interoception (centripetal impulse from the inner organs) produced both the autonomic nervous activity and the affection within the central autonomic network. In Sweden, PoTS had been recognized as a venous pooling syndrome due to deficient autonomic venous regulation, shelving the problem of the affective disturbance; the present concept of PoTS is rediscovery of the Swedish doctrine. Today, evidence has been accumulating that the affective disturbance in PoTS is caused by disturbance (increase?) in the interoception. When the interoception theory is adopted, the deficient autonomic venous regulation in PoTS can be necessariry explained by the excessive unloading of the cardio-pulmonary baroreflex while standing.