14th International Congress
THE "NEW FRONTIERS"
OF ARRHYTHMIAS 2000

Jan. 29 - Feb. 5, 2000
Marilleva, Trento, Italy

RT-83

Effect of coronary angioplasty and stent implantation on QT dispersion

Maria Stella Fera, Andrea Mazza, Roberto Violini, Giovanni Pulignano, Edoardo Pucci, Ernesto Lioy, Francesca Bettiol, Ezio Giovannini.
Cardiology Department, S. Camillo Hospital, Rome, Italy

Introduction

QT interval dispersion has been proposed in literature as a measure of ventricular repolarization inhomogeneity^1,2, and may represent the electrophysiologic substrate for the development of malignant ventricular arrhythmias and sudden cardiac death^3,4. Measurements of QT interval duration variability have been studied in several cardiovascular diseases, included ischemic heart disease, and a clear correlation between QT interval dispersion and prognosis has been clearly defined. QT dispersion values have been extensively correlated with: dynamic variations of the electrical recovery induced by acute myocardial ischemia⁵, successful thrombolytic therapy in acute myocardial infarction⁶, viable myocardium extension and left ventricular function improvement in Q-wave myocardial infarction⁷, increased susceptibility to ventricular arrhythmias^8,9, cardiac mortality¹⁰ and sudden cardiac death^11,12 after previous myocardial infarction. However, no data are reported about to which degree the myocardial ischemia extension influences QT dispersion changes¹³. A significant impact of revascularization procedures, such as percutaneous transluminal coronary angioplasty (PTCA), on the dispersion of ventricular refractoriness have been recently showed¹⁴.

Aim of our study was to assess whether or not PTCA could reduce the QT interval dispersion measured on a surface 12-lead ECG in a population of patients affected by acute ischemic syndromes and if different results could be obtained in patients with unstable angina vs patients after a previous myocardial infarction.