<s>[INST] My husband, age 32, is having a fluttering sensation as often as every several min. high on the right side of his chest. He has been fatiqued with headaches for the last couple wks. Other than that, lightheadedness and saw black spots today when he felt faint. Any ideas on what might be causing this? He weighs 190 and is very physically active and a smoker. Thyroid issues over a decade ago. [/INST] Thanks for your question on Healthcare Magic. I can understand your concern. Since he is active smoker, possibility of arrhythmia (rhythm disturbances in heart) is more. Arrhythmia can cause similar kind of symptoms like Fluttering sensations in chest, dizziness, black outs etc. So consult cardiologist and get done 1. Ecg 2. 2d echo 3. Holter monitoring (24 hours continuous recording of ecg). You may need anti arrhythmia drugs on the basis of these reports. If all these reports are normal then no need to worry for arrhythmia or other heart diseases. Smoking cessation should be done as soon as possible in any case. Don't worry, you will be alright. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks. </s>