I am a 42 year old male in good physical health. I haven't had any previous heart related issues. My BP is 110/70 and my total cholesterol is 216 with HDL, LDL, and triglycerides all within acceptable range. I was having some chest discomfort and shortness of breath so my primary physician suggested I do a cardio stress test. The treadmill test and EKG were both normal. However, the cardiologist said that my ejection fraction was at 45% and wanted to do a retest in 6 months. I am a little concerned and wondered how serious this low EF is? Everything else was completely normal. The cardiologist didn't seem too concerned, but I am very worried. Could this EF number be the cause of my symptoms? Should I do another cardio stress test and echocardiogram sooner? Thank you for your time.