Yeah...Most bronchodilators can cause cardiac side effects. You may consider asking your doctor to try atrovent. Your combivent contains both atrovent and albuterol. The albuterol and most other bronchodilators are beta agonists. This means that your heart may race. The atrovent is an anticholinergic. It may not make your heart race and still provide some relief. It's a drug USUALLY prescribed for COPD patients, but I find I get some good results with it. The propellent bothers me so I have to make sure and use a spacer.