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 is a test that uses high-frequency. sound waves (ultrasound) to check your heart. The sound. waves bounce (or âechoâ) off structures in your heart, and. the echoes are shown as images on a monitor. A stress echocardiogram compares your heart when it is at. rest and when it is working hard.