Hi, Thanks for the question. Breathing problem after riding a bike is called dyspnoea on exertion. This could have many causes, but especially cardiac or respiratory problems. However, other common causes like having to do long distances after having stopped for a while could explain this. A chest X ray is a simple examination that shall give an idea about the size of the heart and the integrity of the lung tissue. This exam is of utmost importance in your case. Depending on the case, other tests like the electrocardiogramme to measure electrical activity of the heart and the cardiac ultrasound could also be very useful. I would suggest you visit a dentist for the evaluation of your dental state and appropriate medication, advice and refilling. Not feeling the tooth and in case of any infection could have consequences on the heart. Some streptococcal species that infect the teeth could easily spread to the heart to cause an infection called infectious endocarditis. I suggest you visit your cardiologist and book a visit with your dentist for a proper and more comprehensive management plan. Thanks for understanding and best regards, Luchuo, MD.