I have had episodes of sudden chest tightness while sitting (no warning). No pain really. Sometimes it leads to near syncope (black vision, sweating, dizziness..). I have had heart tests that have not seen anything (echo, stress test). It may be vaso-vagal syncope but I am concerned that it is always preceded by chest tightness first (center, near neck) it happens sitting and it is very sudden onset. Are there other possibilities? I also sometimes get heart 'fluttering' which feels similar. Not tachycardia. That happens sitting or walking. I had one of those that lasted 7 seconds and I couldn't talk. Felt fine when it stopped. I do drink coffee. Lowish resting heart rate. Lowish blood pressure. I had PE and pulmonary hypertension years ago which got better. I had PE recently with no pulmonary hypertension.