Normal splitting of the second heart sound in significant valvular pulmonic stenosis

Abstract Normal splitting of the second heart sound in two patients with significant valvular pulmonic stenosis is described. In 30 other patients with moderate to severe valvular pulmonic stenosis, second sound splitting was abnormally wide. A normal expiratory duration of the A 2 -P 2 interval has been considered a reliable indicator of the absence of significant pulmonic stenosis. This report demonstrates that exceptions to this rule may occur. The possible causes of normal splitting of the second sound with significant valvular pulmonic stenosis are discussed.