Heart rate dynamics and their relationship to psychotic symptom severity in clozapine-treated schizophrenic subjects.
The analysis of heart rate variability (HRV) has proven to be useful in evaluating the neuroautonomic dysfunctions associated with various clinical conditions. The purpose of this study was to investigate the linear and non-linear dynamic measures of HRV, and to evaluate their relationship with the psychotic symptom severity, in clozapine-treated schizophrenic subjects. Fifty schizophrenic patients treated with clozapine as monotherapy and 50 normal control subjects were evaluated for HRV analysis. The HRV measurements were obtained from a 30-min resting electrocardiogram (ECG). The severity of psychotic symptoms was assessed using the Positive and Negative Syndrome Scale (PANSS). In the patient group, the complexity and symbolic dynamics measures as well as the time and frequency domain measures of HRV were significantly lower than in the control group (P<0.01). The intermediate-term fractal scaling component value was significantly higher in the patient group (P<0.01). The PANSS total score and the positive symptom subscale score had significant negative correlations with the sample entropy (SampEn) value (P<0.01). In conclusion, schizophrenic patients treated with clozapine had markedly different heart rate dynamics compared to normal control subjects. The severity of psychotic symptoms was associated with the SampEn value, suggesting that the non-linear complexity measure might be useful in assessing the neuroautonomic dysfunction in schizophrenia.
Kim
Jong-Hoon
JH
Department of Psychiatry, Gil Medical Center, Gachon Medical School, Guwol-dong, Namdong-gu, Incheon, South Korea.
Yi
Sang Hoon
SH
Yoo
Cheol Sung
CS
Yang
Seung Ae
SA
Yoon
Se Chang
SC
Lee
Kyu Young
KY
Ahn
Yong Min
YM
Kang
Ung Gu
UG
Kim
Yong Sik
YS
D000328:Adult; D014150:Antipsychotic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D016022:Case-Control Studies; D003024:Clozapine / Q000008:administration & dosage* / Q000009:adverse effects; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D017711:Nonlinear Dynamics; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000209:etiology*; D012559:Schizophrenia / Q000188:drug therapy / Q000503:physiopathology*; D013997:Time Factors
D014150:Antipsychotic Agents; D003024:Clozapine