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Īlthough 'Doppler' has become synonymous with 'velocity measurement' in medical imaging, in many cases it is not the frequency shift (Doppler shift) of the received signal that is measured, but the phase shift (when the received signal arrives). The combination of flow and tissue velocities can be used for estimating left ventricular filling pressure, although only under certain conditions. In addition, with slightly different filter/gain settings, the method can measure tissue velocities by tissue Doppler echocardiography. Contrast-enhanced ultrasound-using gas-filled microbubble contrast media can be used to improve velocity or other flow-related medical measurements.Īn advantage of Doppler echocardiography is that it can be used to measure blood flow within the heart without invasive procedures such as cardiac catheterization. Velocity measurements allow assessment of cardiac valve areas and function, any abnormal communications between the left and right side of the heart, any leaking of blood through the valves ( valvular regurgitation), calculation of the cardiac output and calculation of E/A ratio (a measure of diastolic dysfunction). One of the limitations is that the ultrasound beam should be as parallel to the blood flow as possible.

An echocardiogram uses high frequency sound waves to create an image of the heart while the use of Doppler technology allows determination of the speed and direction of blood flow by utilizing the Doppler effect.Īn echocardiogram can, within certain limits, produce accurate assessment of the direction of blood flow and the velocity of blood and cardiac tissue at any arbitrary point using the Doppler effect. Thus, (1) Doppler MR is common in patients with previous MI (2) the murmur may be absent in patients with Doppler MR, particularly in those in whom EF is depressed and (3) in patients with anterior MI, the degree of Doppler MR is inversely related to LV function.Doppler echocardiography is a procedure that uses Doppler ultrasonography to examine the heart.

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The distal septum and anterobasal free wall were more frequently dyssynergic in patients with than in those without Doppler MR (difference significant for patients with anterior MI). Doppler MR was present in 24 of 28 patients (86%) with an EF of 40% or less and in 16 of 44 (36%) with EF more than 40% (p < 0.001). The degree of Doppler MR correlated with EF (r = −0.61), LV systolic volume (r = 0.47), and systolic and diastolic mitral anulus circumference (r = 0.52 and 0.51, respectively). Mitral prolapse or aversion and papillary muscle fibrosis were infrequent in MI patients, whether or not Doppler MR was present. Of the patients with Doppler MR, 12 of 27 (44%) with a left ventricular (LV) ejection fraction (EF) greater than 30% and 1 of 13 (8%) with an EF of 30% or less (p < 0.01) had an MR systolic murmur. Of 15 patients who underwent Doppler studies both times, 3 (all with anterior MI) had MR only on the second study. MR was more frequent in patients who underwent Doppler study 3 months after MI than in those who underwent Doppler at discharge (anterior MI = 83% vs 50%, p < 0.01 inferior MI = 47% vs 27%, p = not significant). MR was found by Doppler in 29 of 42 patients (62%) with anterior MI, 11 of 30 (37%) with inferior MI (p < 0.01) and in none of 20 normal control subjects.

In 72 patients with previous myocardial infarction (MI), mitral regurgitation (MR) was assessed by pulsed-wave Doppler echocardiography and compared with physical and 2-dimensional echocardiographic findings.

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