Left Atrial Enlargement



Left Atrial Enlargement


Alexander J. Towbin, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Ventricular Septal Defect (VSD)


  • Patent Ductus Arteriosus (PDA)


Less Common



  • Heart Failure



    • Dilated Cardiomyopathy


  • Hypertrophic Obstructive Cardiomyopathy


  • Hypertension


Rare but Important



  • Mitral Valve Stenosis


  • Mitral Valve Regurgitation


  • Left Atrial Myxoma


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Left atrial enlargement can be caused by left-to-right shunts, mitral valve disease, or left ventricular dysfunction


  • Chest radiograph findings



    • Double density of heart, splaying of carina, and posterior displacement of esophagus


Helpful Clues for Common Diagnoses



  • Ventricular Septal Defect (VSD)



    • Most common congenital heart defect in children



      • Occurs in 50% of children with congenital heart defect


      • Isolated defect in 20% of children with congenital heart defect


    • 2 main locations: Membranous or muscular septum



      • Membranous defects account for 70% of VSDs


      • Multiple defects can be present


    • Associated with Down syndrome, DiGeorge syndrome, Turner syndrome


    • Holosystolic murmur on auscultation


    • Small VSDs often close spontaneously



      • Large VSDs can be closed surgically or with catheter intervention


  • Patent Ductus Arteriosus (PDA)



    • Ductus arteriosus connects proximal descending aorta to main pulmonary artery



      • Essential for fetal circulation


    • Normally closes spontaneously after birth



      • Prostaglandins can help keep ductus arteriosus open


      • Indomethacin helps to close duct


    • Risks for PDA: Prematurity, prenatal infection



      • 65% of infants born < 28 weeks of fetal gestation have PDA


    • Accounts for 5-10% of all congenital heart defects


    • 2x more common in females


    • Most cases are sporadic



      • Increased risk with Down syndrome, Holt-Oram syndrome, and Carpenter syndrome


    • Continuous machinery murmur at upper left sternal border


    • For some types of congenital heart defect, survival is dependent on PDA



      • Ductal dependent lesions for systemic flow: Hypoplastic left heart, critical aortic stenosis, interrupted aortic arch


      • Ductal dependent cyanotic lesions: Pulmonary atresia, transposition of great arteries


Helpful Clues for Less Common Diagnoses



  • Heart Failure



    • Inability of heart to pump sufficient blood to meet metabolic needs of body



      • Heart failure leads to decreased cardiac output


    • Common causes: Congenital heart defect, viral myocarditis, dilated cardiomyopathy, and occult arrhythmias


    • Congenital heart defect is most common cause of heart failure in children < age 1


    • Other causes are also known as heart muscle disease



      • Muscular disease is most common cause of heart failure and transplant in children older than 1 year old


      • 1/3 of patients with muscular disease die or require transplant within 1 year of presentation


    • Dilated Cardiomyopathy



      • Characterized by ventricular dilation and decreased contractility


      • Often presents with heart failure


      • Multiple etiologies: Viral myocarditis, congenital heart defect, Takayasu arteritis, metabolic disorders, and nutritional deficiencies



      • Most often thought to be idiopathic


      • Chest radiograph shows cardiomegaly and pulmonary congestion


  • Hypertrophic Obstructive Cardiomyopathy



    • Most common hereditary cardiac disorder



      • Autosomal dominant disorder


    • Usually presents in adolescence or later


    • Asymmetric septal hypertrophy leads to left ventricular outflow tract obstruction


    • Can present with sudden death


  • Hypertension



    • Increasing prevalence in children and adolescents



      • Association of hypertension and obesity


    • Left ventricular hypertrophy is finding of end-organ damage



      • Can be seen in up to 41% of children with hypertension


    • Hypertension is often due to underlying disorder



      • Renal parenchymal disease is most common cause


      • Other causes: Endocrine disorders, aortic coarctation, renal vascular disease, and pheochromocytoma


    • Secondary hypertension is more common in children than adults


    • Echocardiogram to evaluate for left ventricular hypertrophy


Helpful Clues for Rare Diagnoses

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Aug 10, 2016 | Posted by in PEDIATRICS | Comments Off on Left Atrial Enlargement

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