Anaesthetic management of a patient with Atrial Septal Defect with Pulmonary Hypertension posted for Total Abdominal Hysterectomy: a Case Report

Abstract

An asymptomatic 52 year old lady with Atrial Septal Defect of Ostium Secundum type with mild Pulmonary Hypertension was admitted in our hospital with complains of menorrhagia. After a thorough pre- operative evaluation, adequate preparation she underwent total abdominal hysterectomy under combined epidural and general anaesthesia. By providing proper intraoperative and postoperative care, patient was managed without any complication and was discharged home within a week. 1 . Based on the portion of atrial septum that has failed to develop normally, ASDs are anatomically classified into four types: ostium secundum (85%), ostium primum (10%), sinus venosus(5%), and coronary sinus defects(rare). Spontaneous closure occurs by 18 months in almost all patients born with ASDs 8mm rarely close spontaneously and may require surgery later in life 2 . The majority of ASDs are detected in childhood although a significant minority is only diagnosed in adult life. Initially right ventricular compliance is substantially greater than the left ventricle and this is associated with the development of a left-to-right shunt. Pulmonary blood flow is increased and pulmonary hypertension develops with increasing age. A consequence of these physiological changes is dilatation of both left and right atria, the right ventricle and the pulmonary arteries in order to accommodate the increased blood volume. Ultimately either the right ventricle fails, or right ventricular compliance falls, resulting in a reduction in the magnitude of shunting, or even flow reversal 3 . Presentation depends upon the magnitude of the left to right shunt. Effort dyspnea is seen in 30% of patients by the third decade and more than 75% of patients by the fifth decade. Atrial arrhythmias (atrial fibrillation and flutter) are common and are secondary to atrial dilatation. Clinical examination reveal fixed splitting of the second heart sound coupled with a pulmonary flow murmur. The classically described electrocardiogram of an ASD is right bundle branch block (RBBB) and axis deviation (right for secundum and left for primum) 4 . Complications of ASD in adults include: paradoxic emboli, effort dyspnea, atrial tachyarrhythmia, right sided heart failure with pregnancy, pulmonary hypertension and mitral insufficiency 5 .