Pulmonic stenosis: A clinical assessment of severity

The clinical, phonocardiographic, electrocardiographie, vectorcardiographic and tele-oroentgenographic findings in thirty-four patients with proved pulmonic stenosis with a normal aortic root are analyzed and points of reference enabling assessment of the severity of the stenosis are presented and tabulated. Patients with mild stenosis (right ventricular systolic pressure below 50 mm. Hg) present no effort incapacity. Characteristic findings include an early systolic click, an early peak of the systolic murmur, a normal pulmonic closure and an aortopulmonic interval between 0.04 and 0.06 second. The height of R in lead V 1 does not exceed 15 mm. The vectorcardiogram shows either clockwise or counter-clockwise direction of inscription of the QRS loop in the horizontal plane and a posterior deviation of T between +60 and +90 degrees in this plane. The cardiothoracic ratio is normal. Patients with moderate stenosis (right ventricular systolic pressure between 50 and 100 mm. Hg) show little effort incapacity if any, and have a soft and delayed pulmonic closure (aortopulmonic interval between 0.05 and 0.10 second) ; the height of R in lead V 1 does not exceed 23 mm.; the direction of inscription of the QRS loop in the horizontal plane is always clockwise and the posterior deviation of T in this plane between +75 and +122 degrees. The cardiothoracic ratio is still within normal limits. Patients with severe stenosis (right ventricular systolic pressure above 100 mm. Hg) show increasingly severe effort incapacity. The systolic murmur has a late peak and overrides the aortic closure whenever the right ventricular systolic pressure exceeds the systemic pressure. The pulmonic closure is not heard but may be recorded (aortopulmonic interval between 0.06 and 0.14 second). An increased fourth heart sound is common. The electrocardiographic findings include “pulmonary” P waves and T wave inversion beyond lead V 1. The vectorcardiogram shows marked posterior deviation of the T loop in the horizontal plane (between +80 and +170 degrees). The cardiothoracic ratio is increased. The different methods of examination are compared; the reliability of the phonocardiogram and the value of careful auscultation alone as a gauge of the right ventricular systolic pressure and in the bedside selection of the operable patients are stressed.