My latest echocardiogram showed a slightly lower ef. should i be concerned?

Yes but: A lower ef means something is up. It should be investigated. If you use alcohol, you should stop. You need a nuclear or echo stress test. If you have paroxysms of fast heart rhythm, they should be investigated. Medication may restore your ef. Follow up is important.

PossiblyNoEasyAnswer: Ef is only a ratio, usually estimated by teichholz technique based on only 2, commonly off-angle, diameter measurements. Lv diastolic size + ef is usually a better indicator. Because of common errors & sloppiness it is crucial that you see, examine & understand the images yourself (not that hard) to ↓ errors. Tx often poor; if treatment strategy effective, lv size should be going ↓ & ef going ↑.