title: Circadian distribution of ischemic attacks and ischemia-related ventricular arrhythmias in patients with variant angina.
abstract: BACKGROUND
  There are limited data about the circadian distribution of ischemic episodes in patients with variant angina. Furthermore, no previous study investigated whether ischemia-related ventricular arrhythmias follow a circadian variation in these patients.
  
  
  METHODS
  The circadian variation of transient ischemia and ischemia-induced ventricular arrhythmias was assessed by cosinor methodology on 24-hour Holter recordings of 26 patients with variant angina.
  
  
  RESULTS
  On the whole, 301 ischemic episodes were detected in the population, with premature ventricular complexes occurring in 49 of them (16%). Ischemic episodes followed a typical circadian variation (acrophase hr 02:36, p < 0.01) in the total sample. However, a significant circadian variation of ischemic episodes was detectable in the 14 patients without (n = 167, acrophase hr 04:00, p < 0.0001), but not in the 12 patients with (n = 134, p = 0.14) hemodynamically significant coronary stenoses, independently of the location (anterior/inferior) of ischemia. There was no significant circadian variation of ischemia-related ventricular arrhythmias.
  
  
  CONCLUSIONS
  Among patients with variant angina, a clearcut circadian variation of ischemia is present in those without, but not in those with, hemodynamically significant coronary artery stenoses, thus suggesting that different pathophysiologic mechanisms may operate, at least in part, in triggering coronary spasm in these two subgroups of patients. There was no significant circadian variation of ischemia-related ventricular arrhythmias in these patients.
authors.affiliation: Istituto di Cardiologia Università Cattolica del Sacro Cuore Policlinico Agostino Gemelli, Roma.
authors.forename: G A
authors.initials: GA
authors.lastname: Lanza
authors.forename: G
authors.initials: G
authors.lastname: Patti
authors.forename: V
authors.initials: V
authors.lastname: Pasceri
authors.forename: M
authors.initials: M
authors.lastname: Manolfi
authors.forename: A
authors.initials: A
authors.lastname: Sestito
authors.forename: M
authors.initials: M
authors.lastname: Lucente
authors.forename: F
authors.initials: F
authors.lastname: Crea
authors.forename: A
authors.initials: A
authors.lastname: Maseri
mesh_terms: D000788:Angina Pectoris, Variant / Q000150:complications* / Q000503:physiopathology; D001145:Arrhythmias, Cardiac / Q000209:etiology; D002940:Circadian Rhythm; D006801:Humans; D017202:Myocardial Ischemia / Q000150:complications* / Q000503:physiopathology; D018754:Ventricular Dysfunction / Q000150:complications / Q000503:physiopathology