13th International Congress
THE "NEW FRONTIERS"
OF ARRHYTHMIAS 1998

January 24-31, 1998
Marilleva, Trento, Italy

RT-118

Echo-doppler determination of the interatrial electromechanical conduction time. Comparison with the interatrial conduction time

Lanfranco Antonini, Salvatore Greco, Salvatore Toscano, Dennis Konopacki, Massimo Santini.
Department of Heart Diseases, San Filippo Neri Hospital, Rome, Italy

Introduction

The atrial contraction timing is a basic element in the study of the filling of the ventricles¹.

Life expectations are improved by the DDD cardiac stimulation, compared to the VVI mode².

We have to keep into account the following fundamental data to program the best atrioventricular (AV) delay: 1) the interatrial conduction time (IACT), 2) the deceleration time that is the time from the peak protodiastolic velocity to the zero value³.

The interatrial conduction time may greatly change according to the different patients.

It is very important to measure the time necessary for an electrical stimulus from the right auricula to the left atrium, because we can program the AV delay that is an interval between the right chambers. If this time is longer than the programmed AV delay, the left atrial contraction will take place after the left ventricle begins to contract and the mitral valve may be partly or totally closed⁴. Consequently the left ventricle will be partly deprived of the end-diastolic portion and the pulmonary reverse flow will cause an increase in the capillary vein pressure.

The IACT is generally measured in an invasive way by introducing bipolar catheters into esophagus or in coronary sinus in order to measure the left atrial electric activity⁵.

The aim of our study is to develop a non invasive method to measure the IACT including the interatrial electromechanical conduction time (IAEMCT) in order to compare it with the results given by the bipolar catheter in the esophagus.