title: Abnormal heart rate recovery after exercise: a comparison with known indicators of increased mortality.
abstract: BACKGROUND
  Abnormal heart rate (HR) recovery at 1 min after exercise (< or =12 beats) was recently suggested to be a predictor of all cause and cardiac mortality.
  
  
  OBJECTIVE
  This study aimed to (1) correlate HR recovery at 1 min after exercise with known exercise and myocardial perfusion markers of increased cardiac mortality, and (2) compare the known exercise and myocardial perfusion markers of increased cardiac mortality between patients with a normal and abnormal HR recovery at 1 min after exercise.
  
  
  METHODS
  One hundred patients with known or suspected coronary artery disease referred for exercise stress testing (ETT) were prospectively enrolled. Percent, ETT time peak HR, HR reserve, summed stress score (SSS), extent of stress (SE%) and reversible perfusion abnormalities (RE%) were recorded in every patient.
  
  
  RESULTS
  There was poor correlation with markers of myocardial ischemia or infarction [SSS (r = 0.15), SE% (r = 0.05), RE% (r = 0.12), all p = n.s.] but highly significant correlation between HR recovery at 1 min after exercise and chronotropic variables [ETT time (r = 0.56), peak HR (r = 0.65), HR reserve % (r = 0.64), all p < 0.001]. Patients on beta-blockers had significantly more incidence of an abnormal HR recovery at 1 min after exercise, compared to patients not on beta-blockers (88 vs. 56%, p < 0.01).
  
  
  CONCLUSIONS
  Abnormal HR recovery at 1 min after exercise has no correlation with known myocardial perfusion markers of increased cardiac mortality. Patients with an abnormal HR recovery do not appear to have an increased incidence or more severe myocardial infarction or ischemia. However, there is a strong correlation between HR recovery at 1 min after exercise and the chronotropic variables during exercise.
authors.affiliation: Division of Nuclear Cardiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass 02115, USA.
authors.forename: M Y
authors.initials: MY
authors.lastname: Desai
authors.forename: E
authors.initials: E
authors.lastname: De La Peña-Almaguer
authors.forename: F
authors.initials: F
authors.lastname: Mannting
mesh_terms: D000367:Age Factors; D000368:Aged; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000401:mortality / Q000503:physiopathology; D010477:Perfusion; D011237:Predictive Value of Tests; D011446:Prospective Studies; D020127:Recovery of Function / Q000502:physiology*; D013318:Stroke Volume / Q000502:physiology; D016019:Survival Analysis