Partial cut-off of the left ventricle: determinants and effects on volume parameters assessed by real-time 3-D echocardiography.

A total of 44 patients with coronary artery disease underwent real-time three-dimensional (3-D) echocardiography for end systolic (ES) and end diastolic (ED) left ventricular (LV) volumetric analysis to assess the effect of partial cut-off of the left ventricular (LV) apex on volumetric analysis by apical transthoracic echocardiography. Patients with LV cut-off were assigned to either group 1 (ejection fraction, (EF) < 49%) or group 2 (EF > or = 49%). Patients were additionally classified as group A if they had anterior or apical wall motion abnormalities (WMA) or group B if they had only inferoposterior or lateral WMA. Partial LV cut-offs were found in 22 subjects (50%). The estimated end diastolic cut-off volumes were as follows: 8.6 +/- 3.2 mL (group 1), 4.3 +/- 2.4 mL (group 2), 9.1 +/- 3.3 mL (group A) and 1.4 +/- 0.8 mL (group B). In group 1, more patients with LV volume cut-off were found than in group 2: chi(2) = 4.52, p < 0.05; and in group A more than in group B: chi(2) = 8.08, p < 0.01. In all, partial LV cut-off led to underestimation of LV volumes: 5.9 +/- 4.7 ml (ED) vs. 2.1 +/- 1.3 ml (ES), p <0.02. In conclusion, LV cut-offs can potentially alter the accuracy of echocardiographic volumetric analysis, particularly in anterior or apical WMA. Copyright 2003 World Federation for Ultrasound in Medicine & Biology