BACKGROUND: Severing a limited number of second-order chordae to the anterior leaflet can improve ischemic mitral regurgitation (MR). Some concerns have been raised regarding possible influence on regional and global left ventricle (LV) function. We evaluated changes in cardiac function in 5 normal sheep with cutting of pre-instrumented chords in the beating heart to maintain constant load. METHODS AND RESULTS: Under cardiopulmonary bypass, wires were placed around the 2 central basal chordae and brought outside the heart, which was restarted. Hemodynamic and imaging data were collected before and after chordal cutting by radiofrequency ablation using those wires. Segmental contractility was assessed invasively using sonomicrometers and noninvasively using Doppler tissue velocity and strain rate (with strain rate viewed as less load-dependent than ejection fraction) at 6 sites: base, mid-ventricle, and apex along the anteroseptal and posterolateral walls. We found no changes from before to after chordal cutting in LV end-diastolic volume (47.2+/-3.3 after cutting versus 48.4+/-4.6 mL before cutting, P=0.66), end-systolic volume (21.5+/-1.2 versus 22.3+/-2.8 mL, P=0.68), ejection fraction (54.2+/-1.8 versus 54.2+/-2.7%, P=0.96), systolic ventricular elastance (7.28+/-1.68 versus 7.66+/-2.11 mm Hg/mL, P=0.64), preload-recruitable stroke work (46.6+/-7.7 versus 50.2+/-10.7 mm Hg, P=0.76), and LVdP/dt (1480+/-238 versus 1392+/-250 mm Hg/s, P=0.45). Doppler tissue velocities and longitudinal strain rates surrounding the papillary muscles were unchanged, as were sonomicrometer longitudinal and mediolateral absolute strains. No wall motion abnormalities were visible around the papillary muscles, and no MR developed. CONCLUSIONS: We find no evidence for acutely decreased global or segmental LV contractility with chordal cutting. This absence of adverse effects is consistent with long-term clinical experience with cutting these chords in valve repair.
BACKGROUND: Severing a limited number of second-order chordae to the anterior leaflet can improve ischemic mitral regurgitation (MR). Some concerns have been raised regarding possible influence on regional and global left ventricle (LV) function. We evaluated changes in cardiac function in 5 normal sheep with cutting of pre-instrumented chords in the beating heart to maintain constant load. METHODS AND RESULTS: Under cardiopulmonary bypass, wires were placed around the 2 central basal chordae and brought outside the heart, which was restarted. Hemodynamic and imaging data were collected before and after chordal cutting by radiofrequency ablation using those wires. Segmental contractility was assessed invasively using sonomicrometers and noninvasively using Doppler tissue velocity and strain rate (with strain rate viewed as less load-dependent than ejection fraction) at 6 sites: base, mid-ventricle, and apex along the anteroseptal and posterolateral walls. We found no changes from before to after chordal cutting in LV end-diastolic volume (47.2+/-3.3 after cutting versus 48.4+/-4.6 mL before cutting, P=0.66), end-systolic volume (21.5+/-1.2 versus 22.3+/-2.8 mL, P=0.68), ejection fraction (54.2+/-1.8 versus 54.2+/-2.7%, P=0.96), systolic ventricular elastance (7.28+/-1.68 versus 7.66+/-2.11 mm Hg/mL, P=0.64), preload-recruitable stroke work (46.6+/-7.7 versus 50.2+/-10.7 mm Hg, P=0.76), and LVdP/dt (1480+/-238 versus 1392+/-250 mm Hg/s, P=0.45). Doppler tissue velocities and longitudinal strain rates surrounding the papillary muscles were unchanged, as were sonomicrometer longitudinal and mediolateral absolute strains. No wall motion abnormalities were visible around the papillary muscles, and no MR developed. CONCLUSIONS: We find no evidence for acutely decreased global or segmental LV contractility with chordal cutting. This absence of adverse effects is consistent with long-term clinical experience with cutting these chords in valve repair.
Authors: Robert A Levine; Albert A Hagége; Daniel P Judge; Muralidhar Padala; Jacob P Dal-Bianco; Elena Aikawa; Jonathan Beaudoin; Joyce Bischoff; Nabila Bouatia-Naji; Patrick Bruneval; Jonathan T Butcher; Alain Carpentier; Miguel Chaput; Adrian H Chester; Catherine Clusel; Francesca N Delling; Harry C Dietz; Christian Dina; Ronen Durst; Leticia Fernandez-Friera; Mark D Handschumacher; Morten O Jensen; Xavier P Jeunemaitre; Hervé Le Marec; Thierry Le Tourneau; Roger R Markwald; Jean Mérot; Emmanuel Messas; David P Milan; Tui Neri; Russell A Norris; David Peal; Maelle Perrocheau; Vincent Probst; Michael Pucéat; Nadia Rosenthal; Jorge Solis; Jean-Jacques Schott; Ehud Schwammenthal; Susan A Slaugenhaupt; Jae-Kwan Song; Magdi H Yacoub Journal: Nat Rev Cardiol Date: 2015-10-20 Impact factor: 32.419
Authors: Alexander H Slocum; William R Bosworth; Anirban Mazumdar; Miguel A Saez1; Martin L Culpepper; Robert A Levine Journal: J Med Device Date: 2009-06-01 Impact factor: 0.582
Authors: Weiwei Shi; Bryant V McIver; Kanika Kalra; Eric L Sarin; Susan Schmarkey; Michael Duggan; Vinod H Thourani; Robert A Guyton; Muralidhar Padala Journal: J Cardiovasc Transl Res Date: 2017-06-02 Impact factor: 4.132