EXERCISE HAEMODYNAMIC PERFORMANCE OF THE PULMONARY AUTOGRAFT FOLLOWING THE ROSS PROCEDURE
G. Porter*, P. Skillington, A. Bjorksten, L. Grigg, A. Yapanis, J. Morgan, D. Blake.
Departments of Cardiology, Cardiac Surgery and Anaesthesia, The Royal Melbourne, Hospital, Melbourne, Victoria.
Background: The Ross procedure, in which the aortic valve is replaced with the patient's own pulmonary valve (pulmonary autograft [PAU]), is considered the best repair for young patients with isolated aortic valve disease. Rest PAU haemodynamics are excellent but exercise haemodynamic data are lacking.
Aim: To measure the haemodynamic performance of the PAU with exercise Doppler echocardiography (DE).
Methods: Twenty-four Ross patients (male 20) age 46±11 yrs were studied 25±14 months following aortic valve replacement with a PAU. The indication was aortic stenosis in 9, aortic incompetence in 7, and mixed disease in 8. Patients had baseline supine DE to measure maximum velocity (Vmax) and the mean pressure gradient (DP) across the PAU. Effective orifice area (EOAi) was calculated from the continuity equation and indexed to body surface area. Patients then underwent symptom-limited upright bicycle exercise with supine DE repeated immediately on stopping exercise. For comparison we studied 10 normal volunteers (NV) age 41±10 yrs and 5 bi-leaflet mechanical aortic valve (MAV) patients age 55±9.6 yrs.
Results:
|
Doppler echocardiography results of the 24 Ross patients |
|||
|
Variable |
Rest |
Exercise |
%D |
|
Heart rate (bpm) |
72±12 |
125±22 |
75±25 |
|
Cardiac index I/min/m2 |
2.6±0.7 |
4.6±1.4 |
83±38* |
|
Vmax (m/s) |
1.2±0.2 |
1.8±0.4 |
57±30* |
|
DP (mmHg) |
4±1 |
8±4 |
145±96* |
|
EOAi (cm2/m2) |
1.7±0.4 |
1.6±0.8 |
-4±19 |
*p<0.001 for the % D from rest to exercise
The NV had similar rest and exercise Vmax, DP, and EOAi to the Ross patients, whereas the 5 patients with MAV had significantly higher rest and exercise Vmax (rest 2.5±0.2m/s exercise 3.4±0.3 p<0.001) and rest and exercise DP (rest 14±3mmHg exercise 30±5 p<0.001) than the NV and Ross patients.
Conclusion: These results confirm excellent rest PAU haemodynamic performance and suggest that exercise PAU haemodynamic performance following the Ross procedure is similar to the native aortic valve.
