Title :
Effect of QT interval correction during autonomic blockade in combination with changes in posture
Author :
Soria, M. Llamedo ; Arini, Pd ; Risk, MR ; Laguna, P.
Author_Institution :
Nat. Technol. Univ., Buenos Aires
Abstract :
The measurement of QT interval on ECG is a marker for malignant ventricular arrhythmias. When QT is measured, it must be corrected to become independent of heart rate (HR) and become a comparable measure of repolarization between different conditions. The objective of this work was to evaluate different types of QT interval correction (Bazzett, Individual and Hodges) for different QT/RR relations. This was accomplished with selective blockade of sympathetic and vagal autonomic systems by using combinations of postural changes and drugs. When comparing vagal condition (supine) versus sympathetic condition (standing atropine) a significant shortening of 43 ms (P<0.006) was observed. Whereas when comparing sympathetic (standing) versus vagal condition (supine propranolol) a significant lengthening of 23 ms (P<0.005) was observed. The Individual correction method achieved the best uncorrelation between QT and RR interval, making QT more independent of HR and ANS status
Keywords :
biomechanics; diseases; electrocardiography; medical signal processing; muscle; neurophysiology; 23 ms; 43 ms; ECG; QT interval correction; autonomic blockade; heart rate; posture change; repolarization; standing atropine; supine propranolol; sympathetic autonomic system; vagal autonomic system; ventricular arrhythmia; Autonomic nervous system; Cancer; Databases; Drugs; Electrocardiography; Heart rate; Heart rate interval; Hemodynamics; Mathematics; Position measurement;
Conference_Titel :
Computers in Cardiology, 2005
Conference_Location :
Lyon
Print_ISBN :
0-7803-9337-6
DOI :
10.1109/CIC.2005.1588152
