[Mitral prostheses with and without dysfunction: evaluation using 2-D Doppler echocardiography].

STUDY

OBJECTIVE

To evaluate the flow characteristics of normal and abnormal functioning mechanical and bioprosthetic (B) mitral valves.

DESIGN

Prospective study in patients submitted to mitral valve replacement.

SETTING

Laboratory of Echocardiography at Santa Marta Hospital.

PATIENTS: 61 consecutive and asymptomatic patients with normally functioning mitral prosthesis (prt)--37 Bjork-Shiley (B-S), 11 Carpentier-Edwards (C-E), 5 Hancok (HAN), 7 Ionescu-Shiley (I-S) and 1 Wessex--and 15 pts with abnormal prosthetic function (6 B-S, 5 Hall-Kaster, 2 C-E, 1 I-S and 1 HAN).

INTERVENTION: Prosthetic mitral flow record, using 2D-Doppler echocardiography, to analyse: peak velocity (PV), peak gradient (PG), mean gradient (MG), pressure half time (PHT), area (A) and presence of regurgitation (R).

RESULTS

Normally functioning prosthetic valves--PV ranged from 88 to 186 cm/s (134.6 +/- 24.3) in B-S prt and 133 to 198 cm/s (157.4 +/- 18.8) in B, p less than 0.0001. The prt B-S showed a greater PG (10.3 +/- 2.5 vs 7.6 +/- 2.6 mmHg), MG (3.1 +/- 1.1 vs 2.6 +/- 1 mmHg) and smaller area (2.3 +/- 0.4 vs 2.5 +/- 0.4 cm2) then Bioprosthetic ones, p less than 0.0001, p = 0.003, p = 0.003 respectively. There was a significant correlation between PG and MG: r = 0.84, r = 0.87, r = 0.84 respectively in B-S prt, Bioprosthesis and both, p less than 0.001. Mild regurgitation was present in 8 pts with prt B-S and 4 with B. Malfunctioning prosthetic valves--The mean of PV was 238.5 +/- 29.2 cm/s in prt B-S compared to 265.48.2 +/- 48.2 cm/s in B. Significant regurgitation, was detected by Doppler technic in 100% of B and 72% of mechanical prt. PV greater than 2 m/s has a 100% sensitivity and specificity to separate normal from abnormal prosthesis function.

CONCLUSIONS

These data may be useful as reference values to the follow-up of pts with these types of prt. The prt B-S seems to have more optimal hemodynamics profile than B ones. Protodiastolic transprosthetic PV greater than 2 m/s suggest abnormal functioning valve. PG is a significant determinant of MG.