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Changes in left ventricular diastolic function 6 months after nonsurgical septal reduction therapy for hypertrophic
S F Nagueh1, N M Lakkis, K J Middleton
1Department of Medicine, Cardiology Section, Baylor College of Medicine, Houston, Tex 77030, USA. sherifn@bcm.tmc.edu
Insights
Nonsurgical septal reduction therapy (NSRT) improves diastolic function in hypertrophic obstructive cardiomyopathy (HOCM) patients by enhancing left ventricular relaxation and compliance. This contributes to reduced outflow tract gradients and better symptom relief.
Area of Science:
- Cardiology
- Cardiac Surgery
- Medical Devices
Background:
- Nonsurgical septal reduction therapy (NSRT) is used to treat hypertrophic obstructive cardiomyopathy (HOCM).
- NSRT effectively reduces the left ventricular outflow tract (LVOT) gradient and alleviates symptoms in HOCM patients.
- The impact of NSRT on left ventricular (LV) diastolic function remains largely unknown.
Purpose of the Study:
- To investigate the effects of NSRT on left ventricular diastolic function in patients with HOCM.
- To assess changes in LV relaxation, compliance, and volumes following NSRT.
Main Methods:
- A cohort of 29 HOCM patients underwent Doppler echocardiography before and 6 months after NSRT.
- Key parameters assessed included LV volume, pre-A-wave pressure, early diastolic mitral annulus velocity (Ea), and diastolic relaxation time constant (tau).
Main Results:
- NSRT significantly reduced the LVOT gradient (53.6 to 6 mm Hg) and improved exercise duration and NYHA class.
- Patients showed decreased pre-A pressure (18 to 14 mm Hg) and tau (62 to 51 ms), indicating improved LV relaxation.
- Early diastolic mitral annulus velocity (Ea) and LV end-diastolic volume increased, suggesting enhanced LV compliance and filling.
Conclusions:
- Nonsurgical septal reduction therapy positively impacts left ventricular diastolic function in HOCM patients.
- Improved LV relaxation and compliance following NSRT contribute to the observed symptomatic improvements and reduced LVOT gradients.
Background:
Nonsurgical septal reduction therapy (NSRT) decreases left ventricular outflow tract (LVOT) gradient and improves symptoms in patients with hypertrophic obstructive cardiomyopathy (HOCM). NSRT effects on LV/left ventricular diastolic function are currently unknown.
Methods And Results:
HOCM patients (n=29) had Doppler echocardiography at baseline and 6 months after NSRT to evaluate changes in LV volume, pre-A-wave pressure, early diastolic mitral annulus velocity (Ea) by tissue Doppler, and tau. At 6 months, a significant reduction in LVOT gradient (from 53.6+/-15 to 6+/-5 mm Hg; P<0.001) was accompanied by improvement in exercise duration (from 284+/-147 to 408+/-178 seconds; P=0.04) and New York Health Association class (from III to I; P<0.001). Pre-A pressure (18+/-6 to 14+/-5 mm Hg; P<0.01) and tau (62+/-8 to 51+/-8 ms; P<0.01) decreased, whereas Ea (5.8+/-1.8 to 8+/-1.8 cml/s; P<0.01) and LV end-diastolic volume (117+/-16 to 130+/-22 mL; P<0.01) increased.
Conclusions:
NSRT improves LV relaxation and compliance, which contributes to the symptomatic relief seen at 6 months.