A Teenage boy with Murmur
A 14-year-old boy presents with decreased exercise tolerance. He is noted to have a grade III/VI systolic ejection murmur best heard at the left upper sternal border and a grade II/VI mid-diastolic murmur at the lower left sternal border. The first heart sound is normal. The second heart sound is widely split and fixed. A right ventricular impulse is palpated. On a chest roentgenogram, the pulmonary artery segment is enlarged, and pulmonary vascular markings are increased. An ECG shows right axis deviation. Which of the following disorders is likely to be found?
| A) | Crescendo-decrescendo systolic ejection murmur begins shortly after the first heart sound |
|---|---|
| B) | rSR' pattern in leads V3R and V1 with normal T waves |
| C) | An inverted "3" sign of the barium-filled esophagus |
| D) | A large left-to-right shunt, precordial activity is increased , with bounding peripheral pulses |
| E) | Evidence of biphasic P waves in leads I, aVR, and V6, with prominent negative deflection in V1 |
Answer:(B)rSR' pattern in leads V3R and V1 with normal T waves
One of the most common types of structural congenital heart disease to present in adolescence is atrial septal defect (ASD), and the most common presentation is a heart murmur. However, some patients present with arrhythmias, decreased exercise tolerance, or a paradoxic embolus.
The physical examination can show classic findings of an ASD; in some cases, however, the findings may be extremely subtle. The murmur associated with the ASD is not caused by blood flow traversing the actual defect but rather by the increased volume of blood flow across the pulmonary valve and, to a lesser extent, across the tricuspid valve. Thus, the murmurs of an ASD are a systolic ejection murmur at the upper left sternal border and a mid-diastolic murmur at the lower left sternal border. The second heart sound is widely split and fixed with regard to respiration. On palpation, a right ventricular impulse is present.
The chest radiogram shows evidence of an enlarged pulmonary artery segment in the posteroanterior projection. The superior vena cava shadow may not be visible because of the rotation of the heart secondary to right ventricular volume overload. Pulmonary vascularity is increased, and the heart may be somewhat enlarged. The lateral projection shows the right ventricular enlargement with filling of the retrosternal airspace. The QRS axis is directed slightly to the right (+100 degrees), and the precordial leads demonstrate right ventricular enlargement of the so-called volume overload type that is characterized by an rSR' pattern in leads V3R and V1 with normal T waves.
Echocardiogram with color Doppler examination can demonstrate the ASD. However, because the atrial septum is a posterior structure, it may not be visualized adequately with a transthoracic echocardiogram; therefore, a transesophageal echocardiogram is frequently necessary for diagnosis. Closure of the defect is recommended for patients with ASD to decrease the risk of pulmonary vascular obstructive disease, stroke, and arrhythmias.
Aortic stenosis (choice A) is often associated with bicuspid aortic valve and presents with dyspnea on exertion, chest pain, and syncope. The systolic ejection murmur intensity increases toward midsystole, then decreases, and the murmur ends just before the second heart sound. It is generally a rough, low-pitched sound that is loudest at the base of the heart and most commonly is appreciated in the second right intercostal space.
Coarctation of the aorta (CoA) (choice C) results in obstruction between the proximal and the distal aorta. On examination, the femoral pulses are weak and delayed relative to the brachial pulses. Radiography in patients with late onset of CoA may reveal cardiomegaly. An inverted "3" sign of the barium-filled esophagus or a "3" sign on a highly penetrated chest radiograph (frontal view) may be visualized. Rib notching secondary to collateral vessels may also be seen. Turner syndrome must be considered in a girl with coarctation of the aorta.
Patent ductus arteriosus (PDA) (choice D) usually presents with a "machinery murmur" that is continuous beginning after S1, peaking at S2, and trailing off during diastole. S2 often is obscured by the murmur. Phonocardiographic data from the past suggested the occurrence of paradoxical splitting of S2 related to premature closure of the pulmonary valve and a prolonged ejection period across the aortic valve. Indomethacin is often effective in closing the PDA in premature infants.
Ventricular septal defect (choice E) is the most common congenital defect of the heart and usually presents with a wide spectrum of symptoms including growth failure, congestive heart failure, and chronic lower respiratory infections. Inlet defects may be associated with left-axis deviation of the frontal plane QRS with Q waves in leads I and aVL. In patients with large pulmonary blood flow, LA hypertrophy is evidenced by biphasic P waves in leads I, aVR, and V6, with prominent negative deflection in V1.