Misdiagnosis of chronic recurrent ventricular tachycardia

24 patients with recurrent ventricular tachycardia were repeatedly misdiagnosed as having supraventricular tachycardia. Supraventricular tachycardia was recorded as the diagnosis 163 times in these patients. 72 12-lead electrocardiograms (ECGs) were available and they were reviewed together with the notes made at the time of the ECGs to discover the reasons for misdiagnosis. 7 consultant cardiologists, 22 consultant physicians, 13 senior registrars, and 57 registrars were involved in the misdiagnosis. Retrospective application of the established criteria used to distinguish ventricular tachycardia from supraventricular tachycardia with aberrancy enabled the diagnosis of ventricular tachycardia to be made in 22/24 patients (92%). In all but 2/72 episodes the only differentiating criterion noted by the attending physicians was dissociated atrial activity, and there seemed to be considerable bias in favour of the diagnosis of supraventricular tachycardia. 20/24 patients were given inappropriate treatment, which had dangerous consequences in 5.