Important advances in technology: echocardiography

Abstract

Echocardiography has evolved over the past 45 years from a simple M-mode tracing to an array of technologies that include two-dimensional imaging, pulsed and continuous wave spectral Doppler, color flow and tissue Doppler, and transesophageal echocardiography. Together, these modalities provide a comprehensive anatomic and functional evaluation of cardiac chambers and valves, pericardium, and ascending and descending aorta. The switch from analog to digital signal processing revolutionized the field of ultrasound, resulting in improved image resolution, smaller instrumentation that allows bedside evaluation and diagnosis of patients, and digital image storage for more accurate quantification and comparison with previous studies. It also opened the door for new advances such as harmonic imaging, automated border detection and quantification, 3-dimensional imaging, and speckle tracking. This article offers an overview of some newer developments in echocardiography and their promising applications.

Keywords: 3-dimensional echocardiography; cardiac ultrasound; echocardiography; strain imaging.

S.F. Nagueh, M.D.

M.A. Quiñones, M.D.

Figure 1.

Images of the common echocardiography and Doppler modalities used in cardiac ultrasound.

Figure 2.

Contrast echocardiography using pulse sequencing technology performed in a patient with a dilated cardiomyopathy in whom there was suspicion of a thrombus at the apex (Panel A; arrows). Note in Panel B the excellent contrast effect that fills the entire LV cavity excluding the presence of a mass. Also note the contrast effect within the myocardium resulting from micro bubbles within the capillary circulation.

Figure 3.

Panels A and B show end-diastolic and end-systolic frames, respectively, of a 2-dimensional echo parasternal view of the left ventricle, illustrating automatic measurements of left ventricular dimensions using a new pattern recognition technology. Panel C shows the same technology applied to pulsed-wave spectral Doppler.

Figure 4.

Three-dimensional echocardiography images obtained by TEE during an intervention to close a large paravalvular defect in a mechanical mitral prosthesis (yellow arrow). A reconstruction of the defect using 3D color Doppler is shown on panel B (arrows). Panel C illustrates placement of the guide wire (white arrow) across the defect (yellow arrow), which required making a loop in the left atrium and was guided by 3D. Panel D shows an image taken at the conclusion of the procedure demonstrating the two occluders in place. TEE: transthoracic echocardiogram; 3D: 3-dimensional.

Figure 5.

Left ventricular volume curve derived from a single-beat 3-dimensional acquisition and with automated border detection software.

Figure 6.

Effective regurgitant orifice area (EROA) in a patient with mitral regurgitation derived with 3D color Doppler (Panel C). EROA is reconstructed from multiple orthogonal tomographic planes derived from the 3D acquisition (Panels A, B and D). 3D: 3-dimensional.

Figure 7.

Biplane real-time images acquired simultaneously during a 3-dimensional transthoracic echocardiographic examination of the left atrial appendage. The image in Panel B is orthogonal to the plane outlined by the line in Panel A. A thrombus is seen in the left atrial appendage (Panel B).

Figure 8.

Longitudinal strain imaging derived with speckle tracking in an apical long-axis view. Strain is derived along six segments from base to apex. The individual regional strain curves are depicted in the right upper panel with the dotted white line indicating global strain in that view. The regional values for peak systolic strain are shown on the left lower panel. The right lower quadrant represents a color histogram that plots the time course of one cardiac cycle on the x axis and the circumference of the left ventricle on the y axis. The colors represent strain values, with the higher values highlighted with darker colors. The homogeneity of colors indicates synchronous contraction and relaxation along the six segments.

Figure 9.

Longitudinal strain imaging obtained in a 45-year-old man with severe hypertension, concentric left ventricular hypertrophy, and normal ejection fraction (EF) (> 65%). Panel A shows strain imaging in the apical 2-chamber view. Regional strain curves from the apical 4-chamber, 2-chamber, and long-axis views are illustrated in panel B together with a “bulls-eye” depiction of peak systolic strain in all segments. Note that despite a normal EF, peak systolic strain is diminished in basal and mid septal, anteroseptal and inferior segments as well as in the apical inferior segment.

Figure 10.

A bedside, focus examination of the heart is performed by a physician using a hand-held device. The patient presented to the emergency department with chest pain suggestive of pericarditis.