Left shoulder pain - blood flow ?

Hi, and thanks for visiting eHealth forum again!
Your concern is understandable. Pain in shoulder and occasionally to the arm after a rigorous activity (such as orgasm) is taken to be coming from heart unless proved otherwise. EKG should be done immediately after the onset of the pain. Usually heart pain is not continuous. It is more like it comes and goes with a pain free interval, however small in between. If this pain persists for a week, it is less likely to be due to heart, however angina can persist until heart rate and blood pressure comes back to normal. Also orgasm is taken to be the highest form of activity with heart rate and blood pressure doubling up. This has not been compared with similar physical activity as this releases a number of hormones including oxytocin, which is not released during physical activity. Hence more is the stimulation from orgasm, more is the chance of BP and heart rate going up and more is the chance of angina. Thus the pain comes some times only.

The other possibility is that the pain is due to a pinched nerve. This comes at certain positions and goes way once the pressure is lifted. Hence maybe you can visit a chiropractor while you have this pain and see if it is due to pinched nerve.

Other causes of pain in the shoulder and left arm region are gastric reflux or hiatal hernia. However endoscopy was normal, so this is ruled out.

There is nothing else that seems possible. See if you have an underlying thyroid disorder. This appears to be mediated by hormones and sympathetic activity and can probably be explained by that. It is really difficult to comment beyond this. Maybe you should get a complete cardiac evaluation including heart enzymes once this pain starts. Please consult a cardiologist and a chiropractor once the pain starts. Hope this helps. Take care!