title: A Prediction Formula for Double Product in Pregnancy.
abstract: BACKGROUND
  Maternal cardiovascular changes in pregnancy are numerous and increase in double product throughout pregnancy is the part of the same process. Double product is a cardinal surrogate of the myocardial oxygen demand and cardiac workload. It is the product of heart rate and systolic blood pressure and an important determinant of cardiovascular risk in hypertensive patients.
  
  
  OBJECTIVE
  This study was intended to determine the double product by comparing normal individuals with different trimesters of pregnancy.
  
  
  METHODS
  A cross sectional study was conducted in 220 healthy women in the age range of 18-35 years with 60 subjects each in 1(st), 2(nd) and 3(rd) trimesters and 40 non pregnant subjects as control group. Cardiovascular parameters were recorded in both the groups. Statistical analysis was done by comparison of parameters using one-way ANOVA and post-hoc by Tukey-Krammer test. Correlation of double product and weeks of pregnancy was done using Pearson's correlation. Regression analysis was done to know the predictor of double product.
  
  
  RESULTS
  It was observed that there was statistically very highly significant increase (p=0.000) in the double product throughout the pregnancy and duration of pregnancy was found to be the predictor of the product.
  
  
  CONCLUSIONS
  The increase in the double product is due to increase in heart rate and stroke volume. Double product is the useful predictor for early identification of preeclampsia and acute myocardial infarction in pregnant women when compared to normal non- pregnant women and hence helps in the early management of complications.
authors.affiliation: Assistant Professor, Department of Physiology, KLE's J N Medical College , Belagavi, Karnataka, India .
authors.forename: Anita
authors.initials: A
authors.lastname: Teli
authors.affiliation: Assistant Professor, Department of Physiology, BLDEU's Shri B.M. Patil Medical College , Bijapur, Karnataka, India .
authors.forename: Shrilaxmi
authors.initials: S
authors.lastname: Bagali
authors.affiliation: Consultant Cardiac Surgeon, Department of Cardiothoracic and Vascular Surgery, KLE's Dr Prabhakar Kore Hospital and MRC Belagavi, Karnataka, India .
authors.forename: Ravi
authors.initials: R
authors.lastname: Ghatanatti
keywords: Acute myocardial infarction; Diastolic blood pressure; Heart rate; Myocardial oxygen demand; Systolic blood pressure