Physiological consequences of percutaneous pulmonary valve implantation: the different behaviour of volume- and pressure-overloaded ventricles.
OBJECTIVE
To investigate the early clinical and physiological consequences of relieving chronic right ventricular (RV) volume overload with percutaneous pulmonary valve implantation (PPVI).


RESULTS
We selected 17 patients (age 21.2 +/- 8.7 years), from a total of 125 who underwent PPVI, because they had important pulmonary regurgitation (PR) [regurgitant fraction > 25% on magnetic resonance (MR)] and an echocardiographic gradient < 50 mmHg across the RV outflow tract. Cardiopulmonary exercise testing, tissue Doppler and MR were performed before and within 3 months of PPVI. Following PPVI, PR (40.7 +/- 7.3 to 4.1 +/- 6.1%, P < 0.001) and RV end-diastolic volume fell (115.4 +/- 33.1 to 98.9 +/- 32.0 mL/m(2), P = 0.001); effective RV stroke volume increased (34.3 +/- 7.8 to 44.4 +/- 9.3 mL/m(2), P < 0.001). Left ventricular end-diastolic volume (66.6 +/- 18.0 to 73.4 +/- 16.5 mL/m(2), P = 0.014), stroke volume (38.4 +/- 11.1 to 46.4 +/- 10.2 mL/m(2), P = 0.001) and ejection fraction (57.8 +/- 8.1 to 63.5 +/- 5.2 mL/m(2), P = 0.001) increased. Pulmonary artery diastolic pressure (8.9 +/- 4.5 to 12.5 +/- 5.2 mmHg, P = 0.041) and mitral E/Ea increased (from 9.0 +/- 2.0 to 11.6 +/- 3.1, P = 0.003). Patients felt better, but standard measures of exercise capacity were unchanged.


CONCLUSIONS
PPVI relieves PR and restores compensatory cardiac performance. The lack of improvement in exercise parameters suggests that, in contrast to pressure overload, the contractile reserve of chronically volume-overloaded myocardium is limited.
Coats
Louise
L
UCL Institute of Child Health, London, UK.
Khambadkone
Sachin
S
Derrick
Graham
G
Hughes
Marina
M
Jones
Rod
R
Mist
Bryan
B
Pellerin
Denis
D
Marek
Jan
J
Deanfield
John E
JE
Bonhoeffer
Philipp
P
Taylor
Andrew M
AM
D000293:Adolescent; D000328:Adult; D002648:Child; D002908:Chronic Disease; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006350:Heart Valve Prosthesis; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011312:Pressure; D011664:Pulmonary Valve / Q000000981:diagnostic imaging / Q000473:pathology*; D011665:Pulmonary Valve Insufficiency / Q000000981:diagnostic imaging / Q000473:pathology*; D014463:Ultrasonography; D016276:Ventricular Function