001 COMPARISON OF MECHANICAL ASYNCHRONY IN HEART FAILURE PATIENTS WITH WIDE AND NARROW QRS COMPLEXES USING REAL-TIME 3D ECHOCARDIOGRAPHY

E. Liodakis, O. Al Shareef, D. Dawson, P. Pearson, P. Nihoyannopoulos.Hammersmith Hospital, London, UK

Introduction: Electrical asynchrony is often observed in patients suffering from left ventricular dysfunction. Previous studies have shown that when electrical asynchrony is used as a selection criterion for cardiac resynchronization therapy (CRT), 30% of the patients do not respond to this treatment. Mechanical asynchrony expressed with the Dysynchrony Index (DI), which derives by calculating the standard deviation of the time for each of the 16 segments of the Left Ventricle, as defined by the American Society of Echocardiography (ASE), to reach its minimum volume, is also a major finding in patients suffering from heart failure. In this study we assessed the ability of real time 3D echocardiography (RT3DE) to quantify mechanical asynchrony, as well as the correlation between the DI and the QRS length.

Methods: We investigated 40 patients with any degree of left ventricular dysfunction. RT3D scanning was performed using the SONOS-7500 system and the X4 transducer from apical projections. The 4D full volume was then analysed offline using the TomTec software (4D LV Analysis 1.2) to derive the DI and the ejection fraction. A Marquette ECG machine was used to acquire an ECG from each patient. For the statistical analysis we used the SPSS 11 package.

Results: From the 40 patients investigated 40% had mild, 35% moderate and 25% severe heart failure. 50% of the subjects had a narrow and 50% had a wide (>140) QRS complex. A positive correlation was found between the QRS length and the DI (r = 0.44, p<0.001). We also observed that there was a group of outliers that presented with low mechanical and high electrical asynchrony. This group may represent the patients that are selected for CRT treatment, according to the electrical criteria but fail to benefit. Another group …