ECHOCARDIOGRAPHIC ASSESSMENT OF SYSTOLIC AND DIASTOLIC LEFT-VENTRICULAR FUNCTION USING AN AUTOMATIC BOUNDARY DETECTION SYSTEM - CORRELATIONWITH ESTABLISHED INVASIVE AND NON INVASIVE PARAMETERS

Systolic and diastolic left ventricular function was assessed using an echocardiographic automatic boundary detection system (ABD) in 50 uns elected patients undergoing left cardiac catheterisation. Automatic bo undary detection system derived parameters (fractional area change [FA C], peak positive rate of area change [- dA/dt] and peak negative rate of area change [-dA/dt]) were compared with invasively (left ventricu lar angiography and pressures) and non invasively (Doppler mitral fill ing velocities and isovolumic relaxation time) acquired conventional i ndices of ventricular function. Adequate detection of endocardial boun daries and subsequent measurements using the ABD system were achieved in 40/50 (80%) patients in the short axis parasternal view, in 41/50 ( 82%) in the apical four chamber view and in 34/50 (68%) in both views. For the whole group of patients the FAC (maximal left ventricular dia stolic area- minimal left ventricular systolic area - maximal left ven tricular diastolic area) estimated in the short axis view correlated w ith the angiographic ejection fraction (EF) measured in the right obli que projection (r = 0.51, p < 0.001);There was only a weak correlation of the FAC estimated in the apical four chamber view with the EF (r = 0.36, p < 0.01). The mean FAC (mean value of the FAC in the short axi s and apical four chamber views) correlated reasonably with the EF (r = 0.62, p < 0.0001). There was no correlation between ABD derived para meters and left ventricular end diastolic pressure (LVEDP) in these pa tients. In a subgroup of patients with normal coronary arteries and le ft ventricular function (n = 17), although there was no correlation be tween EF and FAC, there was a strong positive correlation between FAC (apical four chamber and mean) and LVEDP (r = 0.77, p < 0.01 and r = 0 .87, p < 0.01 respectively). No correlation was found in these patient s between EF and LVEDP. In a further subgroup of patients with angiogr aphically abnormal left ventricular function (EF < 45%), there was a p ositive correlation between FAC (short axis, apical four chamber and m ean) and EF (r = 0.52, p < 0.05, r = 0.83, p < 0.0001 and r = 0.80, p < 0.001 respectively) and a negative correlation between FAC (short ax is and mean) and LVEDP (r = -0.52, p < 0.05 and r = -0.60, p < 0.01 re spectively). There was also a negative correlation between LVEDP and E F in the same subgroup of patients (r = -0.65, p < 0.01). None of the ABD derived parameters correlated with non invasively acquired indices of diastolic ventricular function (peak early left ventricular diasto lic filling blood velocity [Emax], peak late diastolic velocity [Amax] , E/A ratio and isovolumic relaxation time [IVRT], but there was a con sistent positive correlation between - dP/dt and + dA/dt estimated in the four chamber view (r = 0.5, p < 0.01, all patients). Therefore, al though ABD derived parameters cannot be used in an interchangeable way with ejection fraction, they do provide a rapid, bedside method for t he assessment of left ventricular function. FAC and dA/dt do appear to reflect left ventricular performance both in patients with normal ven tricles and in patients with impaired left ventricular function.