Himalayan P-Waves in a Patient With Tricuspid Atresia
An 8-month-old female infant was diagnosed with tricuspid atresia in utero by an ultrasound and the diagnosis was confirmed at birth. She underwent a modified Blalock-Tausig shunt at the age of 2 months to treat increasing cyanosis. She did well and is waiting to complete single ventricle palliation.
On her recent follow-up, she was asymptomatic, with a systemic arterial saturation of 80% at room air. On examination, she had normal and symmetric pulses in her extremities, a normal S1, single S2, a grade 3/6-continuos murmur (due to shunt) at base, and a grade 2/6 ejection systolic murmur at the mid-left sternal border. Her abdominal examination was normal. Her cardiothoracic ratio was 0.60 on chest X-ray.
Her recent 12-lead ECG (Figure) demonstrates important diagnostic information and classic signs of tricuspid atresia. It shows a normal sinus rhythm, superior axis (−15), right atrial enlargement, and an adult pattern of QRS progression over the precordial leads (V1 through V6). This pattern of QRS is characterized by absent right ventricular forces and well-developed left ventricular forces consistent with left ventricular hypertrophy. The P-waves are tall (>5 mm) and peaked in lead II. These types of P-waves are called giant P-waves or Himalayan P-waves and are indicative of a dilated right atrium due to a restrictive atrial communication.
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The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.