If i had a normal stress echo 9 months ago would i need to be evaluated for worsening palpitations or does the stress echo last for a certain length of time?

Stress echo is not the test of choice for palpitation for a 39 year old lady. You need to have heart rhythm monitoring by 3 day holter or loop monitoring. Negative stress echo within 12 months should not be repeated. If you are extremely high risk for CAD, a different stress test should be done such as nuclear stress test.

Different tests for different reasons. While a normal stress test is reassuring for possible ischemia or coronaries (vessels that supply blood to the heart) integrity, palpitations are different and tests involve monitoring for arrhythmias or irregular heart beats that has to do with the electrical circuits in the heart.