title: A study of heart rate variability and QT dispersion in patients of acute ST elevation myocardial infarction.
abstract: OBJECTIVE
  To study the effect of Heart Rate Variability (HRV) and QT dispersion (QTd) in patients presenting with acute ST elevation myocardial infarction (STEMI).
  
  
  METHODS
  100 patients of Acute myocardial infarction (AMI) were evaluated by history and examination. Electrocardiogram (ECG) and Holter monitoring was done in all patients. HRV, QTd, Standard Deviation of the mean RR interval (SDNN) and Standard Deviation of the average of RR interval measured every five minutes during 24 hr (SDANN) were calculated. Results were statistically analyzed using Student 't' test, Paired 't' test and Pearson's formula.
  
  
  RESULTS
  The most common presenting symptoms were chest pain (88%) and dyspnoea (50%). Tachycardia was seen in 565 while congestive heart failure was present in 29% patients. Mean SDNN was 61.4 +/- 24.4 ms and SDANN was 50 +/- 18.2 ms. HRV values were significantly decreased while QTd was higher in patients who died in comparison to patients who survived. A strong negative correlation was seen between HRV and QTd.
  
  
  CONCLUSIONS
  Markers of autonomic regulation of heart like HRV and QTd provide valuable information about the future course of events in a patient following acute STEMI which can be utilized to plan the future course of management in patients especially predisposed to adverse and catastrophic outcomes.
authors.affiliation: Centre of Cardiology & Cardiovascular Research, J. N. Medical College, Aligarh Muslim University, India.
authors.forename: A
authors.initials: A
authors.lastname: Wahab
authors.forename: M S
authors.initials: MS
authors.lastname: Zaheer
authors.forename: M U
authors.initials: MU
authors.lastname: Rabbani
authors.forename: S
authors.initials: S
authors.lastname: Wahab
mesh_terms: D000368:Aged; D001341:Autonomic Nervous System; D015415:Biomarkers; D002637:Chest Pain; D004417:Dyspnea; D005260:Female; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000503:physiopathology*; D011379:Prognosis; D013223:Statistics as Topic
chemical_list: D015415:Biomarkers