The Effects of Smoking Cessation on Cardiac Neural Regulation in Patients with Schizophrenia

• Main Authors: Fan-chin Kung, 孔繁錦
• Other Authors: 郭博昭
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/02292864073833192333

碩士 === 慈濟大學 === 神經科學研究所 === 94 === Schizophrenia has been described as a “life shortening illness”, which reduces patients’ life expectancy by ten to fifteen years. Besides having the higher suicide rate and accident rate, patients with schizophrenia are with attenuated function of cardiac neural regulation and higher sudden cardiogenic death rate. The reason could be the pathological mechanism of the illness itself, the side effects of the medications, or the other comorbid conditions such as anxiety disorder, depressive disorder, metabolic syndrome, or nicotine dependence. Most of the schizophrenic patients are habitual cigarette smokers, and the smoking rate of schizophrenic patients is as high as seventy to eighty percents, comparing the rate twenty-five percents in general population. Sudden death rate of schizophrenic patients is three times higher and cardiovascular death rate is two-times higher than general population. Since the smokers are at even higher risk for sudden cardiogenic death, it is reasonable to firstly investigate the effects of the factor of cigarette smoking on cardiac neural regulation in patients with schizophrenia. The mainly common pathway of sudden cardiogenic death is cardiac neural dysregulation, which could be conveniently screened and monitored by heart rate variability spectral analysis. The objective of this study was to examine the effects of cigarette smoking and smoking cessation on cardiac neural regulation in a group of male adult schizophrenic patients. We recruited 35 adult schizophrenic patients (all are male, 17 habitual cigarette smokers and 18 non-smokers) who were clinically diagnosed without history of diabetic neuropathy, cardiac arrhythmia, or other cardiovascular diseases, without anxiety disorder, depressive disorder, or metabolic syndrome, without prescription of antipsychotics such as clozapine, olanzapine, or ziprasidone or other cardiovascular drugs, and showed equivalent symptom severity. The experiments were performed on Day 0 (before smoking cessation, as the baseline), Day 1 (the first day of smoking cessation), Day 3, Day 7, Day 14, Day 21, and Day 28. In the daytime of the experimental day, after lying for at least five minutes, each patient received a 5-minute lead I ECG recording in the quiet supine position, with his eyes open and breathes normal. The heart rate variability (HRV) power spectrum analyses were performed using an automatic HRV analyzer (SSIC, Enjoy Research Inc., Taiwan). The results suggested that the habitually-smoking schizophrenic patients, as compared to the nonsmoking patients, manifested further cardiac neural dysregulation, including decreased total autonomic function activity, slightly increased sympathetic outflow and impaired parasympathetic function activity which could be somewhat reversed by smoking cessation. The results supported the hypothesis that cardiac neural patients, and smoking cessation could reverse part of the noxious effects. Derived from this hypothesis is that an even stronger advise for schizophrenic patients to quit smoking may be clinically appropriate.