Atrioventricular Valve Dyssynchrony Resulting From Severe Mitral Regurgitation

Abstract

A nearly 4-year-old Ethiopian girl with a 1-year history of weight loss and rapid breathing who had just immigrated to the United States presented to the emergency department with respiratory distress and increasing lethargy. Over the preceding year, she had been found to have increasing tachypnea, anorexia, a 5-kilogram weight loss, fatigue, intermittent emesis, and decreased urine output. There were multiple notable findings on the physical examination. Abnormalities of the vital signs included a respiratory rate of 52 breaths per minute, blood pressure of 70/53, and an oxygen saturation of 85% on room air. In general, she was cachectic and lethargic. There was jugular venous distension with accentuated a waves. There were diffuse fine inspiratory crackles across the lung fields. There was asymmetrical protrusion of the left anterior chest with a visible, dynamic cardiac impulse. On auscultation, there was a regular rhythm with an S3 present. There was a III/VI, holosystolic, midfrequency, blowing murmur in the 5th intercostal space at the midclavicular line with radiation to the apex and the left axilla. A diastolic rumble was not appreciated. The liver edge was 4 centimeters below the right costal margin. Pulses were normal at the brachia and femoral arteries, bilaterally. There was no peripheral edema or clubbing. Blood work revealed a negative troponin and a B natriuretic peptide of 2761 picograms per milliliter. A chest radiograph was performed, which showed cardiomegaly with enlargement of the left superior cardiac border, bilateral pulmonary edema, and superior deviation of the left mainstem bronchus suggestive of left atrial dilatation (Figure 1). A 15-lead electrocardiogram demonstrated sinus rhythm with left atrial enlargement and ST segment elevation in the anterior precordial leads (Figure 2). Figure 1. A chest radiograph taken in an anteroposterior projection demonstrates: pronounced cardiomegaly with a cardiothoracic ratio of 71%; a double contour of …