ICD shocks have been associated with progression of heart failure, increased mortality and a detrimental effect on the quality of life. The recent MADIT-RIT and ADVANCE-III trials showed that simple programming changes of the devices could reduce the amount of inappropriate and unnecessary ICD therapy with up to 70%. However, many patients are still at high risk of ICD therapy and receive antiarrhythmic pharmacotherapy as a consequence. Previous studies have investigated how different cardiovascular drugs affect the risk of arrhythmias; however there is a relative paucity of studies investigating the effect of combination of drugs and different dosages of the specific drugs on the risk of ICD therapy and long-term mortality. The goal of this project is to investigate how conventional anti-arrhythmic as well as non-anti-arrhythmic cardiovascular pharmacotherapy, alone and in combination, influences the risk of ICD therapy and mortality, and how the delivery of ICD therapy translates into risk of mortality.