Balloon mitral valvuloplasty: comparison of haemodynamic and echocardiographic assessment of mitral stenosis at different heart rates in the catheterisation laboratory

Aims: To compare echo-Doppler, Gorlin equation and haemodynamic methods of measuring mitral valve stenosis during right ventricular pacing-induced tachycardia before and after Inoue balloon mitral valvuloplasty to determine which method gave the most consistent results. Methods and results: Measurements were made before and after valvuloplasty at: baseline heart rates, paced at 115 and then 145 beats/min. Mitral valve area by echo-Doppler was 1.1(±0.1) cm2 (mean±S.E.) before and 1.8(±0.2) cm2 after valvuloplasty; and by Gorlin equation: 0.9(±0.1) cm2 before and 1.5(±0.1) cm2 after. Echo-Doppler measurements were heart rate dependent but those by Gorlin measurements were not. At baseline, cardiac index was 2.08(±0.2) l min−1, left atrial pressure 23.3(±7.9) mmHg and mean mitral diastolic gradient 16.9(±9.9) mmHg. After valvuloplasty, cardiac index was 2.31(±0.1) l min−1, left atrial pressure fell to 19.2(±5.6) mmHg and mean diastolic gradient was reduced to 8.5(±1.8) mmHg. Conclusions: The Gorlin mitral valve area appeared to be the most heart rate independent indicator of success following valvuloplasty.