Paula,
Thanks for your question. Your episodes of chest discomfort are very impressive and need further investigation. They certainly could be caused by heart disease. I'm glad your gallbladder ultrasound was negative, but in rare cases, there still could be a problem, such as a stone in the tube that drains the gallbladder (cystic and/or common bile duct). There are also other problems that could cause your symptoms such as gastrointestinal disorders (hiatal hernia, esophagitis, ulcer disease), and pulmonary disorders.
Chest pain can be a difficult problem to sort out, but the most important one to rule out is heart disease. I suggest you make an appointment with your physician as soon as possible for a complete evaluation and EKG (electrocardiogram). He will probably suggest further studies such as a stress test. In your situation, you have additional risk factors of elevated cholesterol and triglycerides (lipids), and pre-diabetes. Other risk factors to consider are tobacco, excessive weight, high blood pressure, and family history of heart disease. If your heart checks out, then your doctor can proceed with other testing to find the cause.
Doctors take chest pain very seriously, and all patients are encouraged to seek medical attention should this symptom occur. If you get another episode such as those described, you should go to an emergency room immediately.
I hope this information has been helpful. Best wishes.
Martin Cane, M.D.