Background The prevalence of myocardial perfusion alterations in autoimmune diseases has been estimated by previous studies at 40%. There is no consensus on the scrutiny of cardiovascular alterations in patients with Antiphospholipid Syndrome. Objectives To evaluate the existence and seriousness of ischemic cardiomyopathy or asymptomatic ventricular dysfunction in a group of patients with primary or secondary Antiphospholipid Syndrome using 99Tc MIBI Gated-SPECT and equilibrium radioisotope ventriculography. Methods This is a transversal study performed in collaboration with the Rheumatology Departments of the following hospitals: General Naval de Alta Especialidad (SEMAR), Centro Médico Nacional 20 de Noviembre (ISSSTE), and the Department of Nuclear Medicine of the Instituto Nacional de Cardiología “Ignacio Chávez”. The study started on January 1, 2010 and ended on November 15, 2010. Twelve patients participated in the study and all of them underwent a myocardial perfusion study with 99Tc MIBI Gated-SPECT and a planar equilibrium radioisotope ventriculography and SPECT. Results A total of 12 patients participated. There was no evidence of ischemic cardiomyopathy in any of the patients. The systolic and diastolic functions of the left ventricle were normal on all cases. Right ventricle alterations were observed: a third had dilation; one had systolic dysfunction (8%); and 4 had diastolic dysfunction (33%). The association of right ventricle dysfunction and the presence of seropositivity of anticardiolipin andtibodies isotype IgG and lupus anticoagulant (p=0.041) stands out. Conclusions Even though the Antiphospholipid Syndrome is associated with accelerated atherosclerosis, this group of patients didn’t present any evidence of coronary disease or left ventricle dysfunction. However, right ventricle anomalies were found. These anomalies might be related to alterations of pulmonary circulation. Further studies are needed to establish the origin of these alterations. References Ian N. Bruce, Dafna D. Gladman. Single Photon Emission Computed Tomography Dual Isotope Myocardial Perfusion Imaging in women with Systemic Lupus Erythematosus. II. Predictive Factors For Perfusion Abnormalities. J Rheumatol 2003; 30: 288-91. Alexanderson E, Cruz P. Endothelial dysfunction in patients with antiphospholipid syndrome assessed with positron emission tomography. J Nucl Cardiol (2007);14:566-72. Nilda Espinola Zavaleta, Erick Alexánderson. Análisis de la utilidad de ecocardiografia de contratte y medicina nuclear en afecciόn cardiovascular de origen autoinmune. Archivos de Cardiología de México Vol. 75 2005:42-48. E. Alexánderson, A. Gόmez-Leόn. Myocardial ischemia in patients with primary antiphospholipid syndrome: a 13N-ammonia PET assessment. Rheumatology 2008;47:894-896. Disclosure of Interest None Declared