To determine the change in left atrial (LA) volume following alcohol septal ablation in patients with hypertrophic cardiomyopathy (HCM). Alcohol septal ablation is performed to relieve symptoms caused by left ventricular outflow tract (LVOT) obstruction in HCM.
We retrospectively reviewed the clinical and echocardiographic data of 109 patients with alcohol septal ablation performed from January 2003 to December 2007. Of these, 58 had both pre and post echocardiograms performed. LA volumes were traced by a single observer and verified by 2 observers.
58 patients (mean age 62.8 years, 56.9% female) were included. They had echocardiograms performed within (median 2, range 0–148) days before and (median 87, range 1–481) days after the procedure. There was a mean decrease in LA volume index of 9.3 (95% CI 6.7–11.9; p < 0.0001) cc/m2. The resting LVOT gradient decreased by a mean of 43.9 (95% CI 32.0–55.8; p < 0.0001) mm Hg. Median mitral regurgitation grade decreased from moderate to mild (p < 0.001). Changes in diastolic function parameters were also noted.
There is a decrease in LA volume index of around 16% in patients following alcohol septal ablation for HCM following relief of the gradient. This may be a result of decreased left atrial pressures, decreased mitral regurgitation and improved diastolic function.
Previous studies have revealed that there is a decrease in left atrial dimension following alcohol septal ablation. However, volumetric changes in left atrial size have not been studied extensively. The American Society of Echocardiography recommends volumetric determinations of LA size over linear dimensions because these allow accurate assessment of asymmetric remodeling. The observed decrease in LA volume may be a result of decreased left atrial pressures, decreased mitral regurgitation and improved diastolic function. In HCM patients, increased LA size is associated with increased risk of atrial fibrillation, decreased exercise capacity, increased stroke incidence, sudden death and increased heart failure mortality and therefore, this decrease may portend better outcomes.
Gautam Kumar, No Financial Disclosure Information; No Product/Research Disclosure Information