There is no gold standard for the measurement of pulmonary regurgitation (PR) severity. Two-dimensional (2D) transthoracic echocardiography is most commonly used to quantify PR severity using color Doppler criteria for aortic regurgitation. However, this method is limited by visualization of only one or two dimensions of the proximal PR jet or vena contracta (VC) precluding accurate assessment of its shape or size. This limitation would be expected to be obviated by three-dimensional (3D) transthoracic echocardiography, which could provide a more accurate quantitative assessment of PR severity. This study evaluated 82 adult patients with PR using 2D and 3D. PR VC area by 3D was obtained by planimetry by positioning the cropping plane exactly parallel to the VC, which was viewed en face by cropping of the 3D data set. Regurgitant volumes were calculated by 2D (assuming a circular VC) and by 3D as a product of the VC and velocity time integral obtained by color Doppler-guided conventional Doppler interrogation of the PR jet.The 3D VC area correlated with 2D jet width (JW)/right ventricular outflow tract (RVOT) width (r = 0.71) and 2D VC area (r = 0.79). 3D JW/RVOT width correlated with 2D JW/RVOT (r = 0.87). 3D regurgitant volumes also correlated with 2D regurgitant volumes (r = 0.76). The 3D VC values of <0.20, 0.20-0.45, 0.46-1.15, and >1.15 cm(2) and regurgitant volumes of <15 ml, 15-50 ml, 51-115 ml, and >115 ml were effective as cutoffs for grades 1, 2, 3, and 4 PR, respectively. In conclusion, quantification of 3D VC area and regurgitant volumes correlate reasonably well with the current 2D methods for measurement of PR. Since 3D visualizes PR VC in three dimensions, it would be expected to provide a more accurate and more quantitative assessment of PR severity as compared to 2D.

Our preliminary study suggests that combined 2DTTE and 3DTTE has comparable accuracy to TEE in evaluating the LA and LAA for thrombus. In some patients TEE, but not 3DTTE, may misdiagnose pectinate musculature as thrombus.

We studied 31 patients with prosthetic valves (PVs) using two-dimensional and three-dimensional transthorathic echocardiography (2DTTE and 3DTTE, respectively) in order to determine whether 3DTTE provides an incremental value on top of 2DTTE in the evaluation of these patients. With 3DTTE both leaflets of the St. Jude mechanical PV can be visualized simultaneously, thereby increasing the diagnostic confidence in excluding valvular abnormalities and overcoming the well-known limitations of 2DTTE in the examination of PVs, which heavily relies on Doppler. Three-dimensional transthorathic echocardiography provides a more comprehensive evaluation of PV regurgitation than 2DTTE with its ability to more precisely quantify PV regurgitation, in determining the mechanism causing regurgitation, and in localizing the regurgitant defect. Furthermore, 3DTTE is superior in identifying, quantifying, and localizing PV thrombi and vegetations, in addition to the unique feature of providing a look inside mass lesions by serial sectioning. These preliminary results suggest the superiority of 3DTTE over 2DTTE in the evaluation of PVs and that it provides incremental knowledge to the echocardiographer.

We describe an adult patient with a primary left atrial leiomyosarcoma in whom live/real time three-dimensional transthoracic echocardiography showed echolucent areas within the mass consistent with necrosis or hemorrhage surrounded by dense band-like echo densities indicative of fibrosis or collagen giving a "doughnut" like appearance. These findings were consistent with histopathology, which showed areas of necrosis and dilated vascular channels within the fibrotic tumor. Our case further illustrates the usefulness of three-dimensional transthoracic echocardiography in characterizing the morphologic features of an intracardiac mass.

Alcohol-induced septal ablation (AISA) is an accepted treatment for hypertrophic cardiomyopathy (HCM) patients with left ventricular (LV) outflow obstruction who are unresponsive to medical therapy. As left atrial (LA) enlargement has been correlated with increased morbidity and mortality in HCM, we assessed LA volumes and ejection fraction (EF) prior to and after AISA using real time three-dimensional (3D) transthoracic echocardiography (TTE) in 12 patients (9 women; mean age 52 +/- 15 years; 11 Caucasian). All patients underwent successful AISA with no complications and their resting left ventricular outflow gradients decreased from 40.5 +/- 22.2 to 9.1 +/- 17.6 mmHg (P < 0.001) while their gradients with provocation decreased from 126.2 +/- 31.7 to 21.8 +/- 28.0 mmHg (P < 0.001). All patients showed improvements in their New York Heart Association (NYHA) functional class. Both the LA end-systolic (45.2 +/- 12.9 to 37.2 +/- 13.7 ml, P < 0.0001) and end-diastolic (79.6 +/- 18.9 to 77.1 +/- 18.6 ml, P = 0.001) volumes decreased after AISA. The LA EF increased from 43.1 +/- 9.0 to 52.5 +/- 8.8% (P = 0.001). The increase in LA EF correlated with the decrease in the resting left ventricular outflow gradient (R =-0.647, P = 0.03). In conclusion, 3D echocardiography can be utilized to follow LA function after AISA for HCM. AISA results in clinical improvement in patients with HCM and in improvement of LA EF that is correlated with the decrease in the left ventricular outflow gradient.