The drugs used to treat arrhythmias can lead to arrhythmias and even malignant arrhythmias when used in excess. 1, digitalis drugs, quinidine, amiodarone, propafenone and other drugs that can lead to arrhythmias and lower the heart rate in excess; 2, beta-blockers, which often lead to sinus bradycardia when taken in excess. In addition, improper application of cardiac drugs can lead to arrhythmias, such as epinephrine, isoprenal, dobutamine, etc.; 3, non-potassium-protective diuretics such as furosemide, if long-term application and not monitoring electrolytes will lead to severe hypokalemia, hypocalcemia, the probability of inducing malignant arrhythmias will be greatly increased; 4, psychiatric system drugs such as anti-anxiety, depressants, long-term overdose will also lead to arrhythmias, in taking drugs The side effects of drugs must be minimized by following medical advice.