Impaired cardiorespiratory response to brief sudden strenuous exercise in the postoperative tetralogy of fallot patients: a ten-second pedaling test

Restrictive Physiology in Tetralogy of Fallot: Exercise and Arrhythmogenesis

The effect of right ventricular restrictive physiology on exercise capacity and arrhythmogenesis after correction of tetralogy of Fallot was assessed in 80 patients aged 7.9 ± 3.6 years. Right ventricular restrictive physiology was defined as the presence of an A wave across the pulmonary artery on 2-dimensional echocardiography. At the 6 month follow-up, 52 patients had restrictive physiology (group 1). A transannular patch was used in 36 patients in group 1 (62%) and in 19 (86%) of the 28 patients without restrictive physiology (group 2). Maximum heart rate attained (69% vs. 77%), maximum predicted heart rate (211 ± 12.6 vs. 226 ± 24.2 beats·min−1), and metabolic equivalents (7.6 ± 3.2 vs. 8.1 ± 2.6) were higher in group 2, but not significantly. The chronotropic index was similar in both groups. In group 1, 14% of patients presented with ventricular premature complexes at 6 months. No effect on exercise capacity and arrhythmogenesis could be attributed to restrictive physiology, but both groups had chronotropic incompetence compared to normal children.

Indications and timing of pulmonary valve replacement after tetralogy of Fallot repair

Surgical management of tetralogy of Fallot results in anatomic and functional abnormalities in the majority of patients. Although right ventricular volume load due to severe pulmonary regurgitation can be tolerated for years, there is now evidence that the compensatory mechanisms of the right ventricular myocardium ultimately fail and that if the volume load is not eliminated or reduced the dysfunction might be irreversible. In light of that data and with better understanding of risk factors for adverse outcomes late after tetralogy of Fallot repair, many centers are now recommending early pulmonary valve replacement before symptoms of heart failure develop. This article reviews the pathophysiology of chronic right ventricular volume load after tetralogy of Fallot repair and the risks and benefits of pulmonary valve replacement. Finally, recommendations for timing and indications for pulmonary valve replacement are given.