Effect of Left Ventricular Outflow Tract Obstruction on Left Atrial Mechanics in Hypertrophic Cardiomyopathy

Table 6

Effects of septal myectomy on LA volumes and mechanics.

	Premyectomy ()	Postmyectomy ()	value
NYHA I/II/III/IV (%)	0/0/100/0	80/20/0/0	<0.0001
LVOT resting (mmHg)	68.1 ± 40	11.0 ± 6	<0.0001
LVOT provocable (mmHg)	98.3 ± 27	21.2 ± 14	<0.0001
MR: trivial/mild/moderate/severe (%)	10/40/40/10	40/60/0/0	0.0004
LVEF (%)	65.9 ± 8	61.4 ± 9	0.08
LA volume indices
(mL/m^2)	66.2 ± 23	49.8 ± 20	<0.0001
(mL/m^2)	53.2 ± 24	39.3 ± 18	<0.0001
(mL/m^2)	40.5 ± 23	26.6 ± 16	<0.0001
Left atrial ejection/emptying fraction (%)	41.6 ± 13	48.4 ± 10	0.006
Left ventricular stroke volume (mL/m^2)	55.5 ± 11	48.0 ± 10	0.01
Conduit volume	57.2 ± 21	47.3 ± 20	0.066
Reservoir function
Expansion index (%)	80.5 ± 44	100.1 ± 36	0.01
Longitudinal reservoir strain (%)	14.1 ± 6	17.3 ± 7	0.01
SRs (%/sec)	0.51 ± 0.2	0.57 ± 0.2	0.15
Conduit function
Passive emptying index/fraction (%)	21.4 ± 9	22.2 ± 9	0.66
SRe (%/sec)	−0.27 ± 0.2	−0.27 ± 0.2	0.98
Booster function
Active emptying index/fraction (%)	26.4 ± 11	33.7 ± 8	0.002
Longitudinal booster strain (%)	6.8 ± 4	9.8 ± 5	0.0001
SRa (%/sec)	−0.48 ± 0.2	−0.68 ± 0.2	0.001

denotes between pre- and postmyectomy values.