ECG in a cyanotic 22-year-old woman who had a cardiac operation in early childhood.
The upright P wave before each QRS in leads I, II, and III indicates sinus rhythm. The large ([greater than or equal to] 0.1 mV and [greater than or equal to] 0.04s) negative terminal portion of the P wave in lead [V.sub.1] is a sign of left atrial enlargement, and the P wave amplitude [greater than or equal to] 0.25 mV in lead II suggests right a trial enlargement. The QRS is negative in lead I and positive in lead aVF, indicating right axis deviation, and a QRS more negative in lead I than in aVR suggests that the QRS axis is closer to + 120[degrees] than to + 90[degrees]. Several criteria indicate left ventricular hypertrophy: [RV.sub.6] > [RV.sub.5]; [RV.sub.6] > 2.0 mV; and [SV.sub.3] + RaVL > 2.0 mV. Right axis deviation in the presence of left ventricular hypertrophy indicates coexisting right ventricular hypertrophy, which diagnosis is supported by the isoelectric QRS in lead V1. Repolarization changes in the lateral precordial leads are signs of left ventricular hypertrophy, and those in the inferior leads suggest right ventricular hypertrophy.
Congenital malformations that can result in cyanosis, increased pulmonary blood flow, and biventricular enlargement on electrocardiogram include transposition of the great arteries with pulmonary hypertension, single ventricle, truncus arteriosus, ventricular septal defect with moderate pulmonic stenosis, and occasionally pulmonary atresia with an intact ventricular septum and a large patent ductus arteriosus or significant tricuspid regurgitation. (1-3) In addition, cyanotic conditions that have been palliated with a systemicto-pulmonary arterial shunt have a cause for both increased pulmonary blood flow and left ventricular hypertrophy.
The current patient's cardiac malformation, pulmonary atresia, was palliated with a Waterston shunt (side-to-side anastomosis of the ascending aorta to the right pulmonary artery). Unfortunately, the anastomosis was too large, pulmonary arterial pressure was identical with systemic arterial pressure, and she has developed Eisenmenger physiology. (4) The palliative Potts shunt (side-to-side anastomosis of the descending aorta to the left pulmonary artery) also can result in too large an anastomosis and Eisenmenger's reaction. In contrast, with a Blalock-Taussig shunt (end-to-side anastomosis of a subclavian artery to the ipsilateral pulmonary artery) the size of the anastomosis and left-to-right shunt is limited by the size of the subclavian artery, and Eisenmenger's reaction virtually never occurs.
(1.) Gamboa R, Gersony WM, Nadas AS. The electrocardiogram in tricuspid atresia and pulmonary atresia with intact ventricular septum. Circulation 1966; 34:24-37.
(2.) Park MK, Guntheroth WG. How to read pediatric ECGs, 3rd edition. St. Louis: Mosby Year Book; 1992:235.
(3.) Surawicz B, Knilans TK. Chou's Electrocardiography in Clinical Practice: Adult and Pediatric, 5th edition. Philadelphia: WB Saunders; 2001:666.
(4.) Wood P. The Eisenmenger syndrome or pulmonary hypertension with reversed central shunt. Br Med J 1958; 2:701-709, 755-762.
D. Luke Glancy, MD; Vijayendra R. Jaligam, MD
Dr. Glancy is a Professor and Dr. Jaligam is an Assistant Professor in the Sections of Cardiology, Department of Medicine, Louisiana State University Health Sciences Center and the Interim LSU Hospital, New Orleans.
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|Title Annotation:||ECG of the Month|
|Author:||Glancy, D. Luke; Jaligam, Vijayendra R.|
|Publication:||The Journal of the Louisiana State Medical Society|
|Article Type:||Case study|
|Date:||Jul 1, 2013|
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