That is a very interesting question but without knowing more about your grandmother's chronic bronchitis and congestive heart failure, including her symptoms, test results and treatment, it is very difficult to make even general recommendations. It may be helpful to call Lung Line at 1-800-222-LUNG (5864) and speak with one of the nurses about your grandmother's condition. In addition, we can mail our booklet on chronic bronchitis to you and that reviews our general recommendations.