Is a resting cardio echo accurate?

See below: It depends on the reason it's being done. Usually, it's as good as the reader.

Typically: Loaded question and depends on what finding you are referring to. There are other tests that may be more accurate but not always indicated. Such as a cardiac MR. Depending on what you are looking for an echocardiogram is usually a good first test and depending on the results you may not need to perform further testing