BACKGROUND: Small valve size and prosthetic patient mismatch are both considered to have harmful effects on residual left ventricular hypertrophy after aortic valve replacement for aortic stenosis. In general, it is believed that the effective orifice area index of the prosthesis must not be less than 0.85 cm(2)/m(2) in order to avoid prosthetic patient mismatch. On the other hand, studies have shown that valve type and valve size had no effects on postoperative left ventricular mass (LVM). The objective of this report was to examine the relationships between patient characteristics or the prosthetic valve and postoperative LVM. METHODS: To evaluate the factors that influence postoperative LVM, we formulated the hypothesis that postoperative LVM is proportional to the sum total of pressure at the prosthetic valve orifice and inner surface area of the left ventricle in systole. We present a conceptually new index for postoperative LVM and compare the index with postoperative LVM. RESULTS: The results indicated a strong correlation between the new index and postoperative LVM six years after surgery (r(2) =0.67, p < 0.0001). As might be expected, LVM increased gradually as the value of the new index increased. CONCLUSIONS: The results of the present study indicate that postoperative left ventricular hypertrophy can be avoided by preventing postoperative hypertension in patients without left ventricular dilatation and an effective orifice area index is greater than 0.77 cm(2)/m(2). 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.
BACKGROUND: Small valve size and prosthetic patient mismatch are both considered to have harmful effects on residual left ventricular hypertrophy after aortic valve replacement for aortic stenosis. In general, it is believed that the effective orifice area index of the prosthesis must not be less than 0.85 cm(2)/m(2) in order to avoid prosthetic patient mismatch. On the other hand, studies have shown that valve type and valve size had no effects on postoperative left ventricular mass (LVM). The objective of this report was to examine the relationships between patient characteristics or the prosthetic valve and postoperative LVM. METHODS: To evaluate the factors that influence postoperative LVM, we formulated the hypothesis that postoperative LVM is proportional to the sum total of pressure at the prosthetic valve orifice and inner surface area of the left ventricle in systole. We present a conceptually new index for postoperative LVM and compare the index with postoperative LVM. RESULTS: The results indicated a strong correlation between the new index and postoperative LVM six years after surgery (r(2) =0.67, p < 0.0001). As might be expected, LVM increased gradually as the value of the new index increased. CONCLUSIONS: The results of the present study indicate that postoperative left ventricular hypertrophy can be avoided by preventing postoperative hypertension in patients without left ventricular dilatation and an effective orifice area index is greater than 0.77 cm(2)/m(2). 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.