[Cardiovascular monitoring of psychotropic drugs]

It has been reported that a variety of cardiovascular side effects are induced by drugs, including psychotropic drugs. Among them, myocarditis/cardiomyopathy and long QT syndrome are addressed in this article. Myocarditis is due to inflammation of the myocardium, and the pericardium is also often involved. In that case, it is called myopericarditis. Myocarditis is caused by a variety of etiologies, including viruses, bacteria, inflammatory diseases, and drugs. Psychotropic drugs such as clozapine have been reported to induce myocarditis. In critical cases, the hemodynamics deteriorate due to cardiac insufficiency, which can be fatal. The principal of treatment of drug-induced myocarditis is, of course, cessation of the causative drug. Cardio-circulatory support including inotropes and, in severe cases, mechanical support, are also necessary. Cardiomyopathy can also be induced by drugs. Drug-induced cardiomyopathy usually presents as dilated cardiomyopathy, characterized by left ventricular dilatation and reduced contraction. Anthracyclin is well-known as a cause of drug-induced cardiomyopathy. The treatment of drug-induced cardiomyopathy is in accordance with chronic heart failure. Long QT syndrome (LQTS) is also a relatively common manifestation of the cardiovascular side effects of drugs. Especially, many psychotropic drugs can induce LQTS. LQTS does not simply mean prolongation of the QT interval in electrocardiography, but it includes life-threatening ventricular arrhythmia derived from QT prolongation. Torsade de Pointes is a common ventricular arrhythmia accompanying LQTS. To avoid or detect the occurrence of these serious cardiovascular side effects in time, careful monitoring based on ECG, symptoms, and blood tests is recommended when a drug reported to induce such side effects must be used. ECG must be routinely taken before the drug is initiated. In 2 to 4 weeks after initiation, ECG may be taken regardless of the cardiovascular symptoms. If any ECG changes are noted, such as QT prolongation or ST change, consultation with a cardiologist and further evaluation are required. After the initial check-up for cardiovascular side effects, ECG should be taken regularly every 3 to 6 months. If new changes in ECG or any symptoms suggesting cardiovascular disease, such as palpitation, chest pain, and exertional dyspnea, cardiology consultation is again needed. To detect early myocardial damage due to myocarditis or cardiomyopathy, the measurement of serum troponin T or I is also useful.