<s>[INST] I had mitral valve repair done 1.5 years ago. Initial symptoms were elevated heart rate with minimal exertion. Dx with severe mitral regurgitation. Surgery was successful. Recovery went well for several weeks, then the symptoms of elevated heart rate minimal activities has come back. Lately symptoms beside elevated HR include fatigue, chest tightness/flutter feeling, leg pain climbing stairs. Recent holter monitor showed highest HR 143 with minimal activity, echocardiogram normal, EF 50%. My resting heart rate is good 60-70, 40 when sleeping. Have been given betablockers which lowered my bp, dizziness. No further answers or treament. Also have rate induced LBBB. [/INST] these complains could be a presentation of Paroxysmal Atrial Fibrillation, Paroxysmal Atrial Tachycardia, or arrhythmias, which are often common with progressed mitral reg urge, and after surgery. Rhythm assessment is very important for us to discuss on such problem, which seems missing here. Your resting heart rate appears to be in good range, the reason for your palpitations on slight exertion could be arrhythmias (which engraves due to tacky induced LBBB). I recommend thorough holder review, or use of event recorder, to further guide your treatment. </s>