Hyperventilation as a cause of panic attacks.

Studies on the platelet function of acute febrile mucocutaneous lymph node syndrome and trial of prevention of thrombosis by flurbiprofen. synthesis of thromboxane A2 by platelets from patients with Kawasaki disease. The syndrome characterised by repeated panic attacks has been known by several names, including muscular exhaustion of the heart, neurasthenia, irritable heart, anxiety neurosis, effort syndrome, and cardiac neurosis.1 More recently The Diagnostic and Statistical Manual of Mental Disorders has created a subcategory of panic disorder as a diagnostic entity of its own, distinguished from generalised anxiety disorder.2 The manual's definition of panic disorder states that attacks are manifested by the sudden onset of intense apprehension, fear, or terror, often associated with feelings of impending doom. The most common symptoms experienced during an attack are dyspnoea; palpitations; chest pain or discomfort; choking or smothering sensations; dizziness , vertigo, or unsteady feelings; feelings of unreality; paraesthesias; hot and cold flushes; sweating; faintness; trembling or shaking; and fear of dying, going crazy, or doing something uncontrolled during the attack. Attacks usually last minutes; more rarely hours. Several suggestions have been made recently for distinguishing between generalised anxiety and panic disorder. Double blind studies have shown that antidepressants are effective in the treatment of patients with panic disorders,3-6 leading to the hypothesis that panic attacks of sudden onset with appreciable autonomic symptoms and overwhelming fear may represent an "endogenous" or "biogenic" form of anxiety disorder. The mechanism by which antidepressants achieve this effect is in dispute, however, being seen by some as evidence of a central, noradrenergic basis to anxiety7 and by others as an effect on depressive features which may accompany the panic disorder.8 A second aetiological hypothesis proposes that panic attacks may be a consequence of peripheral beta adrenergic hyper-activity9 or of a hyperdynamic beta adrenergic circulatory state.10 Beta adrenergic agonists induce panic attacks in patients already susceptible to the disorder; conversely, beta adrenergic antagonists (for example, propranolol) can reverse or suppress panic attacks. These findings have been taken to suggest that subjects who experience panic attacks may have an underlying beta adrenergic supersensitivity. Another possible cause of panic attacks is hyperventilation, which is an important component of panic attacks but has received no mention in recent reviews.'1 12 In contrast to the other possible causes of these attacks hyperventilation may be diagnosed with simple tests and can be treated. Lewis suggested that many, if not all, people may sometimes …