The purpose of this study is to determine whether the occurrence of idiopathic right ventricular outflow tract(RVOT) arrhythmia is relative to sex hormone levels in different stages of female menstrual cycle

• The predilection site of idiopathic ventricular arrhythmia is right ventricular outflow tract ,which is called idiopathic RVOT arrhythmia , a retrospective study reported the females are susceptibility to this kind of arrhythmia and another questionaire survey of triggers for RVOT-VT initiation indicated that women have RVOT-A initiation with recognized states of sex hormonal flux , but few researches were made to study the exact relation between this kind of arrhythmia and sex hormone levels, this is the aim of our study .40 females with regular menses(20 females with RVOT arrhythmia ,20 healthy volunteers) will be screened, the Participants will undergo ECG monitoring and their blood samples will be collected at various times throughout the study.

• subjects with right ventricular outflow tract arrhythmia
• subjects ,age match,healthy

Inclusion Criteria:

• Must be female
• Aged 20 to 45 years, with regular menstrual cycles.
• With normal BMI
• Without organic heart disease
• Healthy volunteers and women with RVOT arrhythmia are both being recruited.

Exclusion Criteria:

• Pregnancy
• Use of hormonal therapy including birth control pills or other drugs