title: Cyclical variation in paroxysmal supraventricular tachycardia in women.
abstract: BACKGROUND
  Paroxysmal supraventricular tachycardia (SVT) in premenopausal women is often judged to be related to anxiety, and may be associated with the menstrual cycle. The aim of this study was to determine whether a cyclical variation of episodes of SVT exists and to correlate such variation with cyclical variation in plasma ovarian hormones.
  
  
  METHODS
  26 women (mean age 36 [SD 8] years; with paroxysmal SVT were screened; those with regular menses who experienced at least three episodes of paroxysmal SVT in two consecutive 48-hour ambulatory ECG recordings were included. 13 patients (aged 32 [6] years) met these criteria. Patients underwent 48-hour ambulatory ECG monitoring and determination of plasma concentrations of oestradiol-17 beta and progesterone on day 7, 14, 21, and 28 of their menstrual cycle.
  
  
  RESULTS
  An increase in the number and duration of episodes of paroxysmal SVT was observed on day 28 as compared to day 7 of the menstrual cycle. A significant positive correlation was found between plasma progesterone and number of episodes and duration of SVT (5.6 [2.2] ng/mL; r=0.83, p=0.0004; and r=0.82, p=0.0005), while a significant inverse correlation was found between plasma oestradiol-17 beta and number of episodes and duration of SVT (155 [22] pg/mL; r=0.89, p<0.0001; and r=0.81, p=0.0007).
  
  
  CONCLUSIONS
  Women with paroxysmal SVT and normal menses exhibit a cyclical variation in the occurrence of the arrhythmia with their menstrual cycle. There is a close correlation between the episodes of paroxysmal SVT and the plasma concentrations of ovarian hormones. These data suggest that changes in plasma levels of ovarian hormones (and their interaction) may be of importance in determining episodes of arrhythmia in such patients. The mechanisms of these effects are unknown.
authors.affiliation: Istituto H San Raffaele, Rome, Italy.
authors.forename: G M
authors.initials: GM
authors.lastname: Rosano
authors.forename: F
authors.initials: F
authors.lastname: Leonardo
authors.forename: P M
authors.initials: PM
authors.lastname: Sarrel
authors.forename: C M
authors.initials: CM
authors.lastname: Beale
authors.forename: F
authors.initials: F
authors.lastname: De Luca
authors.forename: P
authors.initials: P
authors.lastname: Collins
mesh_terms: D000328:Adult; D015716:Electrocardiography, Ambulatory; D004958:Estradiol / Q000097:blood*; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology*; D011374:Progesterone / Q000097:blood*; D013614:Tachycardia, Paroxysmal / Q000097:blood / Q000209:etiology / Q000503:physiopathology*; D013617:Tachycardia, Supraventricular / Q000097:blood / Q000209:etiology / Q000503:physiopathology*
chemical_list: D011374:Progesterone; D004958:Estradiol