ICD-9 codes are important in this expanded coverage and determining which patients should and should not be included in the registry. For example, a claim with a diagnosis of 427.1 ventricular tachycardia as secondary prevention does not need to be included in the registry. However, a claim with this same diagnosis, 427.1 ventricular tachycardia, as primary prevention, as in MADIT I or MUST patients (post-EP study), should be included in the registry. The important difference in these two claims is the determination that the patient is considered primary or secondary prevention.

Other diagnosis codes that may identify patients with previous arrhythmias (secondary prevention) are:

427.1      Ventricular tachycardia
427.41    Ventricular fibrillation
427.42    Ventricular flutter
427.5      Cardiac arrest
427.9      Cardiac dysrhythmia, unspecified