Lamin A/C Mutations are important to recognized for therapeutic and prognostic reasons. We present the clinical cases of two sisters with Lamin A mutation presenting with complex atrial arrhythmias, atrioventricular block and ventricular arrhythmias, associated with ventricular noncompaction and abnormal pulmonary vein anatomy. The successful treatment of complex irregular atrial arrhythmias by the use of noncontact dipole density mapping and radiofrequency ablation (RFA) is described in both sisters with long-term follow up results.