Novel technique for ST-T interval characterization in patients with acute myocardial ischemia.
BACKGROUND
The novel signal processing techniques have allowed and improved the use of vectorcardiography (VCG) to diagnose and characterize myocardial ischemia. Herein, we studied vectorcardiographic dynamic changes of ventricular repolarization in 80 patients before (control) and during Percutaneous Transluminal Coronary Angioplasty (PTCA).


METHODS
We propose four vectorcardiographic ST-T parameters, i.e., (a) ST Vector Magnitude Area (aSTVM); (b) T-wave Vector Magnitude Area (aTVM); (c) ST-T Vector Magnitude Difference (ST-TVD), and (d) T-wave Vector Magnitude Difference (TVD). For comparison, the conventional ST-Change Vector Magnitude (STCVM) and Spatial Ventricular Gradient (SVG) were also calculated.


RESULTS
Our results indicate that several vectorcardiographic parameters show significant differences (p-value<0.05) before starting and during PTCA. Statistical minute-by-minute PTCA comparison against the control situation showed that ischemic monitoring reached a sensitivity=90.5% and a specificity=92.6% at the 5th minute of the PTCA, when aSTVM and ST-TVD were used as classifiers.


CONCLUSIONS
We conclude that the sensitivity and specificity for acute ischemia monitoring could be increased with the use of only two vectorcardiographic parameters. Hence, the proposed technique based on vectorcardiography could be used in addition to the conventional ST-T analysis for better monitoring of ischemic patients.
Gabinete de Tecnología Médica, Facultad de Ingeniería, Universidad Nacional de San Juan (UNSJ), Avenue Libertador General-San Martín 1109 (O)J5400ARL San Juan, Argentina. Electronic address: rcorrea@gateme.unsj.edu.ar.
Raúl
R
Correa
Instituto Argentino de Matemática (IAM) "Alberto P. Calderón", Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina; Instituto de Ingeniería Biomédica (IIBM), Facultad de Ingeniería (FI), Universidad de Buenos Aires (UBA), Buenos Aires, Argentina. Electronic address: pedro.arini@conicet.gov.ar.
Pedro David
PD
Arini
Gabinete de Tecnología Médica, Facultad de Ingeniería, Universidad Nacional de San Juan (UNSJ), Avenue Libertador General-San Martín 1109 (O)J5400ARL San Juan, Argentina. Electronic address: lcorrea@gateme.unsj.edu.ar.
Lorena Sabrina
LS
Correa
Instituto de Ingeniería Biomédica (IIBM), Facultad de Ingeniería (FI), Universidad de Buenos Aires (UBA), Buenos Aires, Argentina. Electronic address: maxvalentinuzzi@arnet.com.ar.
Max
M
Valentinuzzi
Gabinete de Tecnología Médica, Facultad de Ingeniería, Universidad Nacional de San Juan (UNSJ), Avenue Libertador General-San Martín 1109 (O)J5400ARL San Juan, Argentina. Electronic address: laciar@gateme.unsj.edu.ar.
Eric
E
Laciar
D000328:Adult; D000368:Aged; D000465:Algorithms; D015906:Angioplasty, Balloon, Coronary / Q000379:methods; D019540:Area Under Curve; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000473:pathology; D005260:Female; D006801:Humans; D000860:Hypoxia; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000473:pathology*; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D012984:Software; D014672:Vectorcardiography / Q000379:methods*
Ischemic classifiers; Myocardial ischemia; PTCA; ST-T; VCG