Surgical procedures over the lung influence the heart activity. Sometimes this means that your heart starts having an irregular heart rhythm or arrythmia. Maybe you have a previous Atrial Fibrillation, but it also can complicate after pulmonary surgery. Either case is a situation for seeking medical consultation.
In this situation you can feel clear palpitations but sometimes you feel simple unexplained nervousness. Normally, the irregular heart rhythm produces associated shortness of breath and fatigue.
Of course, this complication should be promptly controlled. It is easy to detect performing an EKG (electrocardiogram). Treatment includes medication and sometimes certain procedures to restore the normal heart rhythm.
If you detect your heart rhythm is irregular and this is not your normal situation, ask for an urgent consultation at your surgeon or GP. If it happens in the context of an AF, again you should ask for a medical appointment.