Acute volume reduction with aortic valve replacement immediately improves ventricular mechanics in patients with aortic regurgitation.
OBJECTIVE
Few data have been available regarding the immediate response in ventricular mechanics to acute volume reduction caused by aortic valve replacement for aortic regurgitation.


METHODS
We studied 9 patients in the operating room immediately before and after the institution of cardiopulmonary bypass. Left ventricular pressure and cross-sectional area (a surrogate of left ventricular volume) were measured with a catheter-tip manometer and a transesophageal echocardiographic system equipped with automated border-detection technology. Left ventricular pressure-area loops were constructed, and the caval occlusion method was used to obtain the slope of the end-systolic pressure-area relationship and the end-systolic area associated with 100 mm Hg. From the steady-state beats, stroke area was obtained by subtracting the minimum area from the maximum area. Effective arterial elastance, a measure of ventricular afterload, was calculated from end-systolic pressure, and stroke area as follows: effective arterial elastance equals end-systolic pressure divided by stroke area.


RESULTS
Reductions in maximum area (21.0 +/- 8.5 to 16.0 +/- 6.8 cm(2) [SD])and minimum area (15.3 +/- 8.4 to 12.0 +/- 6.1 m(2)) shifted the baseline pressure-area loops to the left. The slope of the end-systolic pressure-area relationship (11.6 +/- 4.8 to 16.0 +/- 7.5 mm Hg/cm(2)) and afterload (effective arterial elastance, 17.9 +/- 11.6 to 26.3 +/- 16.4 mm Hg/cm(2)) were increased, and the end-systolic area associated with 100 mm Hg was reduced (18.3 +/- 10.0 to 13.7 +/- 5.8 cm(2)).


CONCLUSIONS
Correction of volume overload reduced preload (minimum area), shifted the end-systolic pressure-area relationship to the left (decreased end-systolic area), and improved ventricular contractility (increased slope of the end-systolic pressure-area relationship). The result indicated that acute volume reduction favorably influenced ventricular mechanical parameters immediately after the operation.
Morita
Shigeki
S
Department of Cardiovascular Surgery, Faculty of Medicine, Kyushu University, Fukuoka, Japan. morita@heart.med.kyushu-u.ac.jp
Ochiai
Yoshie
Y
Tanoue
Yoshihisa
Y
Hisahara
Manabu
M
Masuda
Munetaka
M
Yasui
Hisataka
H
D000328:Adult; D000368:Aged; D001022:Aortic Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D006328:Cardiac Catheterization; D002302:Cardiac Output; D002315:Cardiopulmonary Bypass; D017548:Echocardiography, Transesophageal; D019918:Heart Valve Prosthesis Implantation / Q000379:methods; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D011669:Pulmonary Wedge Pressure; D013318:Stroke Volume; D013815:Thermodilution; D016896:Treatment Outcome; D014655:Vascular Resistance; D016277:Ventricular Function, Left; D017725:Ventricular Pressure