What is the main use of Class 1C antiarrhythmic drugs?

Class 1C antiarrhythmic drugs primarily work by blocking sodium channels in cardiac tissues, which plays a crucial role in stabilizing heart rhythms. By inhibiting these channels, they slow down conduction through the heart and help to restore a normal rhythm in cases of arrhythmias. This stabilization is particularly beneficial in treating conditions like atrial fibrillation and ventricular tachycardia.

The other options presented do not accurately describe the primary use of Class 1C antiarrhythmic drugs. They do not primarily function to increase blood pressure or lower heart rates directly; instead, their main action is rhythm stabilization. Moreover, these drugs are not indicated for anxiety disorders, making their primary role in cardiology distinctly separate from psychiatric applications.