Focal atrial tachycardia (AT) is a relatively uncommon form of arrhythmia. 10% of supraventricular tachycardia are due to AT. It can be diagnosed in a patient without any structural heart disease, however in the elderly, cardiovascular disease is often present. We report a rare occurence of focal atrial tachycardia, proven on three dimensional (3D) electrophysiology mapping of the heart in a 44-years-old woman with underlying mixed connective tissue disease and chronic rheumatic heart disease who was successfully treated with radiofrequency ablation. Primary question remained unanswered whether the arrythmia could be linked to her underlying disease, or purely a coincidental finding.