May 30, 2007International journal of cardiac imaging48 citationsOpen Access
An integrated approach to determine left atrial volume, mass and function in hypertrophic cardiomyopathy by two-dimensional echocardiography
Key Result
Hypertrophic cardiomyopathy patients had significantly higher left atrial mass (89.8 g vs 32.3 g) and augmented left atrial pump function compared to normal controls.
Study Design
Type
Case-Control (n=50)
Structured PICO
How does hypertrophic cardiomyopathy affect left atrial volume, mass, and function compared to controls as measured by two-dimensional echocardiography?
P
Population
50 subjects: 25 hypertrophic cardiomyopathy (HCM) patients (15 non-obstructive and 10 obstructive) and 25 controls.
C
Comparator
25 controls
O
Outcome
Left atrial (LA) volume, mass and function parameters (including LAD, LA mass, V max, V min, V pre-A, TA-SV, TA-EF, AA-SV, AA-EF, PA-SV, PA-EF, AEI, and LA-KE) assessed by two-dimensional echocardiographysurrogate
Hypertrophic cardiomyopathy is associated with increased left atrial size and augmented pump function, while conduit and reservoir functions are impaired specifically in the obstructive subtype.
Main Result
Absolute Event Rate: 89.8% vs 32.3%
p-value: p=<0.0001
Limitations
- Small sample size of HCM patients (n=25) due to low disease prevalence
- Assessment of LA mass by this formula needs validation by autopsy or magnetic resonance imaging
- Assessment of diastolic dysfunction relied only on transmitral flow by pulsed wave Doppler without tissue Doppler imaging
- Lack of long-term follow-up data to determine the prognostic value of atrial remodeling for developing atrial fibrillation
Abstract
METHODS: The study included 25 hypertrophic cardiomyopathy (HCM) patients (15 non-obstructive and 10 obstructive) and 25 controls for assessment of left atrial (LA) volume, mass and function by two-dimensional echocardiography. Measurement included mean LA diameter (LAD), LA mass = (mean LAD + anterior LA wall + posterior LA wall) 3 - mean LAD3 x 0. 8 + 0. 6, LA volume = (8/3 pi L. A1. A2), where L is LA length, A1 and A2 are LA area in 4-chambers and 2-chambers, respectively including maximum (V max), minimum (V min), and pre-atrial contraction (V pre-A), total atrial stroke volume (TA-SV), TA emptying fraction (TA-EF), active atrial SV (AA-SV), AA-EF, passive atrial SV (PA-SV), PA-EF, atrial expansion index (AEI), and LA kinetic energy (LA-KE) = (1/2) x AA-SV x P x V2. RESULTS: LAD, LA mass, V max, V min, and V pre-A were significantly higher in HCM than controls. TA-SV and TA-EF were comparable in both HCM subgroups and controls. AA-SV and LA-KE were significantly higher in both HCM subgroups than controls. LA-KE was significantly higher in obstructive HCM than non-obstructive (P < 0. 001). PA-EF and AEI were significantly lower in obstructive HCM than controls (P < 0. 05). CONCLUSION: HCM is associated with increased LA size and augmented LA pump function especially obstructive type. LA conduit and reservoir functions are impaired in obstructive HCM.
Cite This Study
Anwar et al. (2007) conducted a case-control in Hypertrophic cardiomyopathy (n=50). Two-dimensional echocardiography vs. Normal age-matched controls was evaluated on Left atrial mass (p=<0.0001). Hypertrophic cardiomyopathy patients had significantly higher left atrial mass (89.8 g vs 32.3 g) and augmented left atrial pump function compared to normal controls.