Approval for the medtronic entrust models d153atg, d153drg, d153vrc, d154atg, d154drg, d154vrc, medtronic model 9987 application software and the medtronic model 2696 incheck patient assistant are indicated for use in icd patients with atrial tachyarrhythmias, or who are at significant risk of developing atrial tachyarrhythmias.  The entrust models d153drg, d153vrc and d154 drg are intended to provide ventricular antitachycardia pacing and ventricular defibrillation for automated treatment of life-threatening ventricular arrhythmias.  The entrust models d153atg and d1534atg are intended to provide ventricular antitachycardia pacing and ventricular defibrillation for automated treatment of life threatening ventricular arrhythmias.  In addition, the device is intended to provide pacing, cardioversion, and defibrillation for treatment of patients with: 1) symptomatic, drug-refractory atrial fibrillation and/or 2) life-threatening ventricular tachyarrhythmias.  Atrial rhythm management features such as atrial rate stabilization (ars), atrial preference pacing (app) and post mode switch overdrive (pmop) are indicated for the suppression of atrial tachyarrhythmias in icd-indicated patients with atrial septal lead placement and  one or more of the above icd indications.  Notes:  a) use of the device has not been demonstrated to decrease the morbidity related to atrial tachyarrhythmias.  B) the effectiveness of high frequency burst pacing (atrial-50hz burst therapy) in terminating device classified atrial tachycardia (at) was found to be 17% , and in terminating device classified atrial fibrillation (af) was found to be 16.85% in the vt/at population studied.  C) the effectiveness of high frequency burst pacing (atrial-50hz burst therapy) in terminating device classified atrial tachycardia (at) was found to be 11.7% , and in terminating device classified atrial fibrillation (af) was found to be 18.2% in the af only population studied.