Dysthymia and tertiary rhythms are relatively common arrhythmias that are specific manifestations of premature beats. Usually, patients in dysthymia or tertiary rhythm do not have a significant life-threatening condition. However, if the patient has severe organic heart disease, such as acute myocardial infarction, myocarditis, or heart failure, the presence of frequent premature ventricular beats in duple or triple rhythm may further affect cardiac function, or even induce malignant arrhythmias such as ventricular tachycardia and ventricular fibrillation, leading to serious complications such as cardiogenic shock and sudden cardiac death. Therefore, patients with severe underlying cardiac disease, such as patients with severe cardiac insufficiency or acute myocardial ischemia who develop typical dysthymia or ternary rhythms, must be treated aggressively, or else sudden cardiac death may result.