This young patient is exhibiting signs and symptoms of right heart failure in the setting of a longstanding cardiac murmur. This combination raises immediate concern for Eisenmenger syndrome, a feared sequela of congenital heart disease comprised of the triad of a right-to-left intracardiac shunt, cyanosis, and pulmonary arterial disease. A bubble study, in which agitated saline injected intravenously appears in the left atrium during echocardiography, is commonly used to diagnose a right-to-left shunt.
Eisenmenger syndrome typically develops as a result of failure to diagnose and treat a left-to-right intracardiac shunt during childhood. Congenital cardiac conditions that can lead to Eisenmenger include ventricular septal defect (VSD), atrial septal defect (ASD), and patent ductus arteriosus (PDA). When left untreated, the increased pulmonary blood flow (due to the left-to-right shunt) can lead to pulmonary vascular disease and pulmonary arterial hypertension (PAH). As PAH progresses, pressures in the right heart increase, leading to reversal of the shunt so that net blood flow is right-to-left. In addition to the development of cyanosis and heart failure, this occurrence can be accompanied by disappearance of the longstanding left-to-right shunt murmur.
Frank and Jacobe describe the evaluation and management of the pediatric patient with a heart murmur. They note that red flags increasing the likelihood of a pathologic murmur include a holosystolic or diastolic murmur, grade of 3/6 or higher, abnormal S2, murmur intensity greatest at the upper left border of the sternum, a systolic click, and a murmur that gets louder when the patient stands. Such patients require further evaluation by a pediatric cardiologist.
Saha et al. conducted a longitudinal observational study of 201 patients with diagnosed Eisenmenger syndrome. They note a mean age of diagnosis of 19 years, but with wide variability (standard deviation 12 years). Twelve different congenital lesions were detected, but the three most common were VSD (33%), ASD (30%), and PDA (14%). 20 of the 201 patients died during the mean follow-up period of 55 months.
Illustration A shows a patient with nail clubbing. Video V shows an echocardiogram with a positive bubble study due the presence of a large ASD.
Answer 1: End stage aortic stenosis may cause heart failure and sudden syncope, but would generally be associated with the presence of a systolic murmur in an older patient. It is not associated with a positive bubble study.
Answer 2: Mitral insufficiency would be expected to present with a systolic murmur, and is not associated with a positive bubble study.
Answer 4: Ventricular aneurysm is most commonly seen as a complication following acute myocardial infarction. It may result in heart failure due to decreased cardiac output, but would not associate with a positive bubble study.
Answer 5: Dynamic left ventricular outflow tract obstruction is consistent with hypertrophic cardiomyopathy. This condition is not typically associated with a positive bubble study.
Frank JE, Jacobe KM. Evaluation and management of heart murmurs in children. Am Fam Physician. 2011 Oct 1;84(7):793-800. Review.
PMID:PMID: 22010618 (Link to Abstract)
Saha A, Balakrishnan KG, Jaiswal PK, Venkitachalam CG, Tharakan J, Titus T, Kutty R. Prognosis for patients with Eisenmenger syndrome of various aetiology. Int J Cardiol. 1994 Jul;45(3):199-207.
PMID:PMID: 7960265 (Link to Abstract)
USMLE World Step 1 QBank Question #202. Copyright © USMLEWorld, LLC 2012