A 37-year-old school teacher comes to the physician for a preventive care appointment. She denies any current symptoms, and she has not seen a doctor for many years. She takes over-the-counter vitamin and calcium supplements. She does not smoke and she drinks alcohol only on social occasions.
Her temperature is 37.2 C (99 F), blood pressure is 122/80 mm Hg, pulse is 84/min, and respirations are 14/min. Jugular venous pressure is normal. Cardiac auscultation reveals wide and fixed splitting of the second heart sound. There is a 2/6 mid-systolic ejection murmur heard best over the left second intercostal space. The remainder of her physical examination is unremarkable.
Which of the following would most likely be present on her electrocardiogram?

Question

A 37-year-old school teacher comes to the physician for a preventive care appointment.  She denies any current symptoms, and she has not seen a doctor for many years.  She takes over-the-counter vitamin and calcium supplements.  She does not smoke and she drinks alcohol only on social occasions.
Her temperature is 37.2 C (99 F), blood pressure is 122/80 mm Hg, pulse is 84/min, and respirations are 14/min.  Jugular venous pressure is normal.  Cardiac auscultation reveals wide and fixed splitting of the second heart sound.  There is a 2/6 mid-systolic ejection murmur heard best over the left second intercostal space.  The remainder of her physical examination is unremarkable.
Which of the following would most likely be present on her electrocardiogram?

Quizplus · Accepted Answer

This patient has the classic physical examination findings of a large atrial septal defect (ASD) with a left-to-right shunt. Depending on the duration and the size of the shunt, ASD patients can develop a number of ECG abnormalities. The QRS complex can become slightly prolonged with a characteristic rSr' or rsR' configuration, causing an incomplete or complete right bundle branch block pattern on ECG. Other ECG changes include first degree AV block, right axis deviation, and P wave changes suggestive of right atrial enlargement. (Choice A) Inferior Q waves can be seen in prior myocardial infarction, idiopathic dilated or restrictive cardiomyopathy, hypertrophic cardiomyopathy, left ventricular hypertrophy, left bundle branch block, Wolf-Parkinson-White pattern, and as a normal variant in some patients. However, they are not associated with ASD. In addition, this patient has no symptoms (e.g., chest pain, dyspnea) to suggest any of the above etiologies. (Choice B) Electrical alternans refers to a cyclic beat-to-beat variation in the QRS axis and amplitude. It is most frequently seen in patients with significant pericardial effusion. However, this patient's lack of jugular venous distention, hypotension, and peripheral edema makes this option less likely. (Choice C) Pulmonary hypertension and right ventricular hypertrophy can develop in patients with an unrecognized, large ASD associated with significant left-to-right shunting. Left ventricular hypertrophy is not typically seen in such patients. (Choice E) A short PR interval and delta waves are classically seen in patients with Wolf-Parkinson-White pattern (due to the presence of an accessory pathway) and in approximately 20% of patients with Ebstein's anomaly. Wolff-Parkinson-White typically presents with episodes of palpitations, chest pain, dyspnea, and tachycardia. Educational objective: ECG abnormalities commonly seen in patients with an atrial septal defect include first degree AV block, right axis deviation, and incomplete or complete right bundle branch block. __________ References: Thirty-year electrocardiographic follow-up after repair of tetralogy of Fallot or atrial septal defect (http://www.ncbi.nlm.nih.gov/pubmed/16963067)

A 37-Year-Old School Teacher Comes to the Physician for a Preventive