Multimodality imaging and clinical significance of isolated congenital absence of the pericardium

Abstract

Background. Congenital absence of the pericardium is a rare anomaly characterized by variable and non-specific clinical manifestations. The prevalence of this pathology in the population is approximately 0.0001 – 0.044% and it is almost three times more common in men. However, the real prevalence, including asymptomatic and undiagnosed cases, may be higher. Purpose – highlighting the echocardiographic and tomographic signs of isolated congenital absence of the pericardium. Materials and methods. A 42-year-old patient M. Echocardiography did not permit to obtain standard echo images via typical echocardiographic approaches due to poor acoustic window. Magnetic resonance imaging and computed tomography of the heart revealed marked left heart rotation and confirmed the most common variant of congenital absence of the pericardium, that is complete left-sided absence pericardial agenesis. Results. The presented case illustrates the non-specificity of clinical symptoms in patients with congenital absence of the pericardium. The electrocardiogram of the patient showed right axis deviation, right bundle branch block, poor R wave progression in the precordial leads. Chest X-ray in the anterior-posterior projection typically shows a pronounced displacement of cardiac silhouette to the left without deviation of the trachea, elongated left border of the heart and inability to delineate the right border, indicating left heart rotation. Echocardiography revealed an unusual orientation of the heart in the chest, i.e. the displacement of the heart (particularly, of the apical segments) to the left and backwards. In cases when the pericardium is absent on the right and on both sides, the right ventricle can indeed be enlarged, sometimes there is a paradoxical motion of the interventricular septum, severe tricuspid regurgitation as well as the swinging motion of the cardiac apex. Magnetic resonance imaging and computed tomography of the heart enable detection of the displacement of the heart to the left half of the chest with cardiac apex directed backwards, the interposition of lung tissue between the ascending aorta and the pulmonary artery trunk. Conclusions. Congenital absence of the pericardium is a rare pathology and thus it can be challenging in terms of diagnosis, while sometimes it remains undiagnosed. The combination of echocardiography with magnetic resonance imaging and/or computed tomography allows to accurately diagnose congenital absence of the pericardium and assess the risks associated with it. Most patients with complete unilateral or bilateral congenital absence of the pericardium have a favorable prognosis and do not require treatment.