In order to provide income over the lifetime of the retiree, the TDF is designed to increasingly invest in deferred annuities as the TDF reaches its target retirement date and investors in the TDF get older.
Freebase(0.00 / 0 votes)Rate this definition: Echocardiography. Echocardiogram, often referred to cardiac echo or simply an echo is a sonogram of the heart. Echocardiography uses standard two-dimensional, three-dimensional, and Doppler ultrasound to create images of the heart.
An echocardiogram, also known as an echo, is a test that uses sound waves to build up a moving picture of the heart.It is similar to the ultrasound scan used in pregnancy and is extremely safe.he additional use of Doppler (a special part of the ultrasound examination that looks at blood direction and velocity) may add an extra 10-20 minutes. However, it may take up to an hour when there are multiple heart problems and the echocardiogram is more complicated.