Hi Ousaima,
1. During the development in the womb, the heart with its innervation makes a 180° turn. This means that the dominant and non-dominant body side and their association with partner or child are also turned. Righthanded person - left heart - partner side.

2. The right chamber pumps blood into the lungs, the left chamber pumps it from the lungs and into the body circuit. When the left chamber muscle is weak, blood is left in the lung circuit and the body isn't supplied properly.

3. Check out the book on page 151/152. 

4. Yes, also a healing peak in the cardiac muscle can go unidentified. That depends on the weight of the conflict and on the circumstances. 

5. What it means is that muscle tissue grows when there is both training and supply with nutrients. Translate "training" with "use" of the muscle. While we do use muscles in the stress phase, they aren't supplied optimally because of the lack of "rest and digest", of natural rhythm.