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Miguel Chaput

Publications and source records attributed to Miguel Chaput.

4 recordsLinked to original sources
PubMed2006

Chordal cutting does not adversely affect left ventricle contractile function.

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.

Animals↗
PubMed2006

Dynamic right ventricular outflow tract obstruction in cardiac surgery.

BACKGROUND: Right ventricular outflow tract obstruction can be a cause of hemodynamic instability but it has not been described in non-congenital cardiac surgery. METHODS: The prevalence of right ventricular outflow tract obstruction was retrospectively studied in 670 consecutive patients undergoing cardiac surgery. Significant right ventricular outflow tract obstruction was diagnosed if the right ventricular systolic to pulmonary artery peak gradient was more than 25 mm Hg. The diagnosis was based on measurement of the right ventricular and pulmonary artery systolic pressure through the paceport and distal opening of the pulmonary artery catheter. To further validate the prevalence and the importance of right ventricular outflow tract obstruction, 130 patients were prospectively studied over a 12-month period. RESULTS: In the retrospective cohort, 6 patients (1%) undergoing various types of cardiac surgical procedures were found to have significant dynamic right ventricular outflow tract obstruction with a mean gradient of 31 +/- 4 mm Hg (26 to 35 mm Hg). In the prospective study significant dynamic right ventricular outflow tract obstruction was identified in 5 patients (4%) (average peak: 37 +/- 15 mm Hg; range: 27 to 60 mm Hg). The typical transesophageal echocardiography finding was end-systolic obliteration of the right ventricular outflow tract. In patients with significant dynamic right ventricular outflow tract obstruction, hemodynamic instability was present in 10/11 patients (91%). CONCLUSIONS: Right ventricular outflow tract obstruction is easily diagnosed using the paceport of the pulmonary artery catheter and should be considered as a potential cause of hemodynamic instability especially when transesophageal echocardiography reveals systolic right ventricular cavity obliteration.

Aged↗
PubMed2005

Conversion to sinus rhythm does not improve long-term survival after valve surgery: insights from a 20-year follow-up study.

OBJECTIVE: Atrial fibrillation (AF) is frequently associated with valvular heart disease and a common complication of valve surgery. Its contribution to long-term mortality and morbidity remains debated. Our objective was to determine the impact of AF on long-term mortality and embolic complications after valvular surgery and the benefit of conversion to sinus rhythm. This may provide insight to the clinical advantages of surgical anti-AF procedures. METHODS: Data concerning rhythm status, mortality and embolic complications were prospectively collected for 5466 patients with valve surgery. Patients had surgery between 1979 and 2003. Follow-up was complete and all patients had a yearly EKG. RESULTS: Patients with preoperative AF had poorer long-term survival than patients without preoperative AF (20-year survival 23.7 and 33.4%, respectively, P<0.0001). However, preoperative AF was not an independent risk factor of long-term mortality (HR=1.04, P=0.6). In patients with preoperative sinus rhythm, postoperative development of AF had an impact on long-term mortality (HR=1.46, P=0.0012). In patients with preoperative AF, postoperative rhythm did not influence mortality when adjusted for other variables (AF vs. sinus rhythm, HR=1.07, P=0.5709). Mitral valve surgery (HR=1.55, P=0.0270) but not preoperative or postoperative AF had a significant impact on the advent of embolic complications. CONCLUSIONS: The conversion to sinus rhythm did not improve long-term survival or reduce the incidence of embolic complications after valve surgery. Patients with preoperative AF had poorer survival than patients without preoperative AF. AF may be a marker of advanced disease in these patients.

Aortic Valve↗