An EKG is not a very good source to dx pericarditis.
With a stethoscope there is what is called the pericardial friction rub: The most important physical sign of acute pericarditis may have up to 3 components per cardiac cycle and is high-pitched, scratching, and grating. It can sometimes be elicited only when firm pressure with the diaphragm of the stethoscope is applied to the chest wall at the left lower sternal border. The pericardial friction rub is heard most frequently during expiration with the patient upright and leaning forward.
Also a blood test should detect troponin I. Hypothyroidism should be ruled out. If the pain is related to pericardial effusion the pain my be relieved by sitting up and leaning forward and it is intensified by lying supine.
Infectious pericarditis should produce abnormal body temperature and if over 100 the individual should be hospitalized. There is viral pericarditis caused by a bacteria.
Noninfectious can be ideopathic (cause unknown). Other causes can be tumors, acute MI (heart attack), aortic dissection, etc. etc. Almost all non-infectious causes can easily be determined. The cause of abnormal fluid production depends on the underlying etiology, but usually it is secondary to injury or insult to the pericardium (ie, pericarditis). Transudative fluids result from obstruction of fluid drainage, which occurs through lymphatic channels. Exudative fluids occur secondary to inflammatory, infectious, malignant, or autoimmune processes within the pericardium.
Idiopathic effusions are well tolerated in most patients.
As many as 50% of patients with large, chronic effusions were asymptomatic during long-term follow-up. The information above should give you some insight on the subject of pericarditisand talking points with your doctor on any follow up visits.
Pericarditis (non-infectious) is painful and, if not treated aggressively, may become chronic and cause recurrent pain, off and on, for years.
Presumably they didn't find anything infectious in his blood? If they had, it would be critical to get an expert on it once. Non-infectious pericarditis is the kind of thing that's often difficult to diagnose, and might come up if other avenues of diagnosis don't find anything.
If he were my son, I would waste no time taking him to a cardiologist. Besides the pain, there is the shadow on the EKG that will give much more information to a specialist, and the possibility of greater-than-usual variations in bp. Dizziness when he stands up may very well reflect low bp, which is generally benign in the absence of other symptoms, but if it shoots 'way up occasionally you may be looking at a different animal.
Anyone on the heart forum will tell you not to fool with heart issues. We hope it isn't his heart, or anyway it isn't serious, but it's important not to delay seeing a specialist.
Good luck.
I believe pericarditis is an inflamation in the lining surrounding the heart.