Atrial Septal Defect A 75-year-old female who presented with dyspnea, orthopnea, lower extremities swelling and palpitations is reported here. She had a 3 years history of atrial fibrillation and...

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Extracted text: Atrial Septal Defect A 75-year-old female who presented with dyspnea, orthopnea, lower extremities swelling and palpitations is reported here. She had a 3 years history of atrial fibrillation and one-year history of cardiac failure NYHA (New York Heart Association) class II. Transthoracic echocardiography revealed a dilated right atrium and dilated left atrium as well as Atrial septal defect type, with left-to-right shunt. 1. How common is Atrial Septal Defect? Where is located? Ratio Female/Male? 2. Why her condition is not diagnosed previously? 3. People with such a defect typically have more than a normal amount of blood in the right atrium. Why does blood flow from left to right across the septum rather than in the opposite direction? 4. The excess of blood can cause hypertension in one circuit. Which one?