An ECG (EKG) is not a very good source to make a diagnosis without further evidence from another source to confirm. Usually, the ST interval on the ECG may be elevated, and the underlying cause can an electrolyte imbalance, medication, artifact, etc.
If you have symptoms such as dry cough, shortness of breath, fatigue, chest pain, etc., that would lend some credence to a congested heart failure diagnosis.
Thanks for sharing, and if you have more precise information regarding your health, feel free to post a followup.