Improvement in left ventricular filling properties after relief of right ventricle to pulmonary artery conduit obstruction: contribution of septal motion and interventricular mechanical delay.
OBJECTIVE
To investigate the impact of relief of right ventricle (RV) to pulmonary artery (PA) conduit obstruction on septal motion and ventricular interaction and its functional implications for left ventricular (LV) filling properties.


RESULTS
In 20 consecutive patients with congenital heart disease and RV to PA conduit obstruction, the following were prospectively assessed before and after percutaneous pulmonary valve implantation (PPVI): the septal curvature and LV volumes throughout the cardiac cycle by magnetic resonance imaging; RV to LV mechanical delay by 2D-echocardiographic strain imaging; and objective exercise capacity. Percutaneous pulmonary valve implantation led to a reduction in RV to LV mechanical delay (127.9 +/- 50.9 vs. 37.7 +/- 35.6 ms; P < 0.001) and less LV septal bowing in early LV diastole (septal curvature: -0.11 +/- 0.11 vs. 0.07 +/- 0.13 cm(-1); P < 0.001). Early LV diastolic filling (first one-third of diastole) increased significantly (17.5 +/- 9.4 to 30.4 +/- 9.4 mL/m(2); P < 0.001). The increase in early LV diastolic filling correlated with the reduction in RV to LV mechanical delay (r = -0.68; P = 0.001) and change in septal curvature (r = 0.71; P < 0.001). In addition, the improvement in peak oxygen uptake (56.0 +/- 16.0 vs. 64.1 +/- 13.7% of predicted; P < 0.001) was associated with the increase in early LV diastolic filling (r = 0.69; P = 0.001).


CONCLUSIONS
Relief of RV to PA conduit obstruction significantly improves early LV filling properties. This is attributed to more favourable septal motion and reduction in interventricular mechanical delay.
Lurz
Philipp
P
Cardiac Unit, UCL Institute of Child Health and Great Ormond Street Hospital for Children, Great Ormond Street, London WC1N 3JH, UK. philipp.lurz@gmx.de
Puranik
Rajesh
R
Nordmeyer
Johannes
J
Muthurangu
Vivek
V
Hansen
Michael S
MS
Schievano
Silvia
S
Marek
Jan
J
Bonhoeffer
Philipp
P
Taylor
Andrew M
AM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000209:etiology* / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology; D001807:Blood Vessel Prosthesis; D002648:Child; D004452:Echocardiography; D005260:Female; D006083:Graft Occlusion, Vascular / Q000503:physiopathology / Q000601:surgery*; D006346:Heart Septum / Q000502:physiology; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods; D006352:Heart Ventricles / Q000002:abnormalities* / Q000601:surgery; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000002:abnormalities* / Q000601:surgery; D011664:Pulmonary Valve / Q000601:surgery; D011665:Pulmonary Valve Insufficiency / Q000209:etiology / Q000503:physiopathology / Q000601:surgery; D011666:Pulmonary Valve Stenosis / Q000503:physiopathology / Q000601:surgery*; D013314:Stress, Mechanical; D055815:Young Adult