Is it safe to use class 1C antiarrhythmic drugs in patients with coronary artery disease and/or cardiomyopathy?

Class 1C antiarrhythmic drugs (AADs) are a key treatment option for effective rhythm control in several common arrhythmias. Here, we review the relevant background on Class 1C AADs, these drugs' indications and contraindications, and potential safe ways to use them. The safety profile of 1C AADs, and related restrictions on their use, has been largely based on the decades-old CAST trial, but more recent evidence may favor re-evaluating previously excluded populations. This review examines opportunities to reconsider certain patient populations that have previously been excluded from the use of 1C AADs. This reconsideration is made feasible due to advances in cardiac reperfusion, medical therapies for heart failure, and cardiac imaging.