| Clinical Evaluation of SJM Prosthetic
Aortic Valve by Doppler Echocardiography: Application of Energy
Loss Index (ELI) as a New Index of Aortic Prosthetic Valve Function |
(The Department of Surgery II, Miyazaki Medical
College, Miyazaki, Japan)
| Kunihide Nakamura |
Mitsuhiro Yano |
Yoshikazu Yano |
| Tomokazu Saitoh |
Katsuhiko Niina |
Kohji Furukawa |
| Yusuke Enomoto |
Masanori Nishimura |
Toshio Onitsuka |
|
Although the pressure gradient (PG)
and the effective orifice area (EOA) have been used as indices
of prosthetic valve function, these values show correctly neither
energy loss, nor increased workload. This study aimed to evaluate
the prosthetic valve function using echocardiography and PG,
EOA and energy loss index, a new index advocated by Garcia et
al. These were calculated for 40 patients with aortic prosthetic
valve replacement by SJM valve (19HP, 6 cases; 21mm, 16 cases;
23mm, 14 cases; 25mm, 4 cases). Preoperative and postoperative
echocardiographic measurements and their variations were analyzed
and compared according to the size of implanted valve. In the
comparison before and after aortic valve replacement, left ventricular
mass (383}151g vs 288}113g, p0.01), SV1{RV5 on ECG (5.07}1.73mV
vs 3.83}1.5mV, p0.01), and diastolic left ventricular
posterior wall thickness (14.4}3.7mm vs 12.9}2.8mm, p0.05)
decreased significantly after the operation. However, there was
no significant difference according to the size of the prosthetic
valve in these reduction rates caluculated by (preoperative value|postoperative
value)/preoperative value. Small size prosthetic valves were
used for patients with small diameter of left ventricular outflow
tract (LVOT) (19HP, 18}2mm; 21mm, 21}2mm; 23mm, 23}4mm; 25mm,
27}3mm; p0.01) and small body surface area (19HP, 1.5}0.2m²;
21mm, 1.5}0.2m²; 23mm, 1.7}0.1m²; 25mm, 1.8}0.1m²;
p0.01) in our study. There was a significant difference
in EOA (19HP, 1.2}0.4cm²; 21mm, 1.9}0.7cm²; 23mm, 2.2}0.9cm²;
25mm, 3.5}1.1cm²; p0.01), but not in ELI (19HP,
1.01}0.41cm²/m²; 21mm, 1.87}1.03cm²/m²; 23mm,
1.83}1.09cm²/m²; 25mm, 3.08}1.21cm²/m²; p0.055)
according to the size of the prosthetic valve. Small size prosthetic
valves had small EOA, but showed satisfactory valve function
in decreasing left ventricular hypertrophy and reducing LVM and
ELI of small size was similar to that of large size.
@Jpn. J. Cardiovasc. Surg. 33: 77-80 (2004) |
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