Pulmonary effects on exercise testing in tetralogy of Fallot patients repaired with a transannular patch.

Powell AW, Mays WA, Knecht SK, Chin C;

Cardiol Young. 2018 Nov 26:1-7. doi: 10.1017/S1047951118001920. [Epub ahead of
print]

BACKGROUND: A transannular patch is often used in the contemporary surgical
repair of tetralogy of Fallot. This can lead to significant pulmonary
insufficiency and increased right ventricular volumes and ultimately pulmonary
valve replacement. Cardiopulmonary exercise testing is used to assess exercise
capacity in tetralogy of Fallot patients before pulmonary valve replacement.
There is only few published literatures on how lung function affects functional
capacity in tetralogy of Fallot patients repaired with a transannular patch.
METHODS: A retrospective chart review was done from 2015 to 2017 on patients with
tetralogy of Fallot who underwent maximal effort cardiopulmonary exercise testing
with cycle ergometry and with concurrent pulmonary function testing. Tetralogy of
Fallot patients repaired with a transannular patch without pulmonary valve
replacement were compared with age, gender, and size-matched normal controls.
RESULTS: In the tetralogy of Fallot group, 24 out of 57 patients underwent
primary repair with a transannular patch. When compared to the normal controls,
they demonstrated abnormal predicted forced expiratory volume in one second (79 ±
23.1% versus 90.7 ± 14.1%, p<0.05), predicted maximal voluntary ventilation (74 ±
18% versus 90.5 ± 16.2%, p<0.05) while having low-normal predicted forced vital
capacity (80.5 ± 17.2% versus 90.2 ± 12.4%, p<0.05) and normal breathing reserve
percentage (50.3 ± 11.3% versus 47.5 ± 17.3%, p = 0.52). Cardiopulmonary exercise
testing abnormalities included significantly lower percent predicted oxygen
consumption (63.2 ± 12.2% versus 87 ± 12.1%, p<0.05), maximal heart rate (171.8 ±
18.9 versus 184.6 ± 13.6, p<0.05), and percent predicted maximum workload (61.7 ±
15.9% versus 88.3 ± 21.5%, p<0.05).
CONCLUSIONS: Tetralogy of Fallot patients repaired with a transannular patch can
have abnormal pulmonary function testing with poor exercise capacity in addition
to chronotropic incompetence and impaired muscular power.