The sensation of losing consciousness has a number of causes. The discovery made by your physician raises questions that require more information for a definite answer. Most medical societies recommend that the discovery of a weakened heart muscle be followed by pursuit of the cause of that weakness. With the symptoms that you have felt, some investigation of your heart rhythm may also be warranted.
Briefly,
1. There is not yet enough information to properly "name" the problem affecting your heart.
2. Further testing with your Cardiologist is needed to gain that information and screen for heart rhythm disturbance.
3. The medicines recommended are in lines with current society recommendations. Follow up with your doctor is necessary to ensure that they are working (effects usually measurable beyond about three months).