Morillo Carlos A, Guzmán Juan C
Syncope and Autonomic Disorder Unit, Arrhythmia Service, Cardiology Division, Department of Medicine, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada.
Rev Esp Cardiol. 2007 Oct;60 Suppl 3:10-4.
Inappropriate sinus tachycardia (IST) is an uncommon form of arrhythmia which is characterized by an exaggerated increase in heart rate that is out of proportion to normal physiologic demands. Usually, IST is triggered by orthostasis, minimal exertion, and psychological stress. The etiology of IST remains ill-defined. However, proposed mechanisms include: enhanced sinus node automaticity, alterations in autonomic function associated with increased sympathetic activity or reduced parasympathetic activity, and impaired baroreflex control. Recently, increased levels of autoantibodies to beta-adrenergic receptors have been observed in patients with IST. The clinical presentation of IST is highly varied and ranges from short episodes of palpitations associated with dyspnea, atypical precordial pain, cephalalgia, fatigue, and occasional syncope and presyncope to incapacitating incessant tachycardia. In general, IST is a diagnosis of exclusion. It is important that other causes of sinus tachycardia are excluded before making a diagnosis. Evaluation of autonomic function is essential for a diagnosis of IST. Treatment of IST is based on autonomic function findings and involves multidisciplinary management, including cardiac rehabilitation. Control and restitution of normal autonomic function is essential. The prognosis is benign though regular follow-up is required to optimize therapy.
不适当窦性心动过速（IST）是一种罕见的心律失常形式，其特征是心率过度增加，与正常生理需求不成比例。通常，IST由体位性低血压、轻微运动和心理压力引发。IST的病因仍不明确。然而，提出的机制包括：窦房结自律性增强、与交感神经活动增加或副交感神经活动减少相关的自主神经功能改变以及压力反射控制受损。最近，在IST患者中观察到β-肾上腺素能受体自身抗体水平升高。IST的临床表现高度多样，从与呼吸困难、非典型心前区疼痛、头痛、疲劳以及偶尔的晕厥和先兆晕厥相关的短暂心悸发作到使人衰弱的持续性心动过速不等。一般来说，IST是一种排除性诊断。在做出诊断之前排除窦性心动过速的其他原因很重要。自主神经功能评估对于IST的诊断至关重要。IST的治疗基于自主神经功能检查结果，涉及多学科管理，包括心脏康复。控制和恢复正常自主神经功能至关重要。尽管需要定期随访以优化治疗，但预后良好。
