CONGENITAL HEART DISEASE Response to the Valsalva Maneuver After the Fontan Procedure for Tricuspid Valve Atresia, Single Ventricle or Pulmonic Valve Atresi

The Valsalva maneuver was performed during cardiac catheterization in 9 patients who had undergone a Fontan operation (Fontan group) and in 10 control subjects. The Fontan group had higher right atrial (RA) pressure (16 f 1 vs 4 f 0.5 mm Hg, p <O.OOi), lower cardiac index (2.5 f 0.1 vs 3.7 f 0.2 liters/min/m*, p <0.05), lower stroke index (32 f 2 vs 44 f 2 ml/beat/m*, p <0.05), and higher systemic vascular resistance (31 f 1 vs 24 f 1 units, p <0.05) than the control group. Four patients in the Fontan group had a normal 4-phase Valsalva response, and 5 did not (p <0.05). RA pressure was similar in those who responded normally and those who did not (16 f 0.5 vs 17 f 1 mm Hg), whe in those who responded normally cardiac index higher (2.9 f 0.2 vs 2.2 rf: 0.1 liters/min/m <0.05), stroke index was higher (36 f 1 vs 28 rt 1 ml/beat/m*, p <0.05), and systemic vascu sistance was lower (28 f 1 vs 31 f 1, p <0 is concluded that cardiac output is a better pr of a normal response to the Valsalva maneuver than RA pressure in patients after the Fontan procedure. A normal response to the supine Valsalva neuver suggests a cardiac index greater 2.4 liters/min/m* and stroke index greater tha ml/beat/m*. (Am J Cardiol 1985;56:905-