A case of life-threatening supraventricular tachycardia storm associated with theophylline toxicity.

A 76-year-old man taking theophylline was admitted to our hospital with congestive heart failure and supraventricular tachycardia (SVT). After admission, he developed cardiogenic shock as a result of SVT storm, which was refractory to medical treatment including adenosine and electrical cardioversion. The serum theophylline concentration at admission was identified as toxic. Therefore, theophylline toxicity was considered as a major cause of the SVT storm. Hemodynamic stability was achieved by using mechanical circulatory support. Additionally, continuous hemodiafiltration was performed to remove theophylline, and it was effective for suppression of SVT. The patient was successfully weaned off mechanical circulatory support. After the patient's general status had improved, an electrophysiological study was performed, and it showed orthodromic atrioventricular reentrant tachycardia with a right free wall accessory pathway. Radiofrequency catheter ablation was successfully performed. <Learning objective: SVT is often hemodynamically stable and medically well-controllable with adenosine. However, SVT is occasionally refractory or life-threatening under specific conditions such as theophylline toxicity, since theophylline has an inhibitor effect on adenosine. Mechanical circulatory support should be used in case of life-threatening SVT storm associated with theophylline toxicity.>.