Chrinic smoker with retrosternal chest pain

A 50 years old male, chronic smoker, with the known history of prolong hypertension come to visit you after experiencing Retrosternal chest pain which is dull in nature. The chest pain is lasted for about 25 minutes and radiated to the left jaw, neck and arm. Chest x-ray and ECG was performed

1) What abnormality shows in the X-Ray
2) What abnormality seen in the ECG
3) What other investigation you would like to perform
4) What other clinical sign you would look for
5) What is your provisional diagnosis
6) Which coronary artery is usually causes the diagnosis in (5)