title: [Correlation of heart rate variability with SYNTAX II on chronic angina].
abstract: BACKGROUND
  The heart rate variability (HRV) is a prognostic value of cardiovascular risk. It is unknown the correlation between HRV and coronary severity on patients with chronic angina. The objective was to determine the correlation between HRV and the SYNTAX II score in chronic angina.
  
  
  METHODS
  Cross-sectional study in patients of 18 years or older with stable angina and indication of coronary angiography who went to a third level center. The SYNTAX II score was established by using coronary angiography, while HRV was obtained by a 24-hour Holter ECG. The correlation between SYNTAX II and HRV was performed with Pearson's test. Values of SDNN < 100 ms and RMSSD < 15 ms were considered risk factors.
  
  
  RESULTS
  61 patients were included. 45 had a decreased value of SDNN (73.77%) and eight had a decreased value of RMSSD (13.11%). There was no correlation between HRV and SYNTAX II score. There were more events of ventricular tachycardia in the group of patients with low SDNN than in those with normal SDNN (15.5% vs. 0.0%; p = 0.04).
  
  
  CONCLUSIONS
  There was no correlation between HRV and the severity of coronary artery disease in stable chronic ischemic heart disease. However, those patients with low HRV showed more events of ventricular tachycardia.
authors.affiliation: Servicio de Cardiología, Hospital General de Zona 2, Instituto Mexicano del Seguro Social, Irapuato, Guanajuato, México. enriquebernalmd@yahoo.com.mx.
authors.forename: Tatiana Chantal
authors.initials: TC
authors.lastname: Castro-de la Torre
authors.forename: Norma
authors.initials: N
authors.lastname: Amador-Licona
authors.forename: Enrique
authors.initials: E
authors.lastname: Bernal-Ruíz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D060050:Angina, Stable / Q000175:diagnosis* / Q000503:physiopathology; D003430:Cross-Sectional Studies; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012720:Severity of Illness Index
keywords: Chronic stable angina; Heart rate