Heart Rate Turbulence

Home

Heart Rate Turbulence
What is HRT?
Calculation
Publications
HRT Program

Contact
About this site


Last updated Tue Mar 27 23:03:47 2007

HRT Demo

Sections of a Holter ECG of a patient two weeks after acute myocardial infarction. The patient survived without complications. "Local tachogram": Subsequent to the PVC the RR intervals shorten, and after a few beats a counterreaction is initiated. The RR intervals gradually increase between the 6th and the 12th beat followed by an eventual return of the system to its initial frequency. Sections of a Holter ECG and local tachogram of a patient two weeks after acute myocardial infarction. The patient died suddenly three months later. HRT is almost entirely absent. Calculation of Turbulence Onset Calculation of Turbulence Slope Quantification of HRT

(1) Turbulence Onset: percentage difference between the average value of the first two normal intervals following the PVC and of the last two normal intervals preceding the PVC. Initially, TO is determined for each individual PVC, followed by the determination of the average value of all individual measurements.

(2) Turbulence Slope: steepest slope of a linear regression line through five consecutive measurement points in the averaged tachogram. The Turbulence Slope calculations are based on the averaged tachogram and expressed in ms per RR interval.