Page 66 - The role of advanced echocardiography in patients with ischemic heart disease - Rachid Abou

Chapter three. Age related left atrial remodeling
DISCUSSION
The present study reports the values of PWD, PA-TDI and LA reservoir strain across a wide age range in a large group of individuals without structural heart disease. With increasing age, the LA conduction becomes slower and the LA compliance reduces, suggesting the presence of age-related fibrotic changes of the LA wall. In addition, larger body mass index and LA volume index were independently associated with reduced LA reservoir strain.
Ageing is related to structural remodeling of the LA myocardium.3-5 This structural remodeling may become pathologic and form the substrate for the occurrence of atrial fibrillation or lead to heart failure.6,15 Differentiation between physiological and pathological LA structural remodeling is challenging. Current non-invasive imaging modalities permit evaluation of LA dimensions and geometry and LA myocardial tissue characterization. Dilated LA and the presence of macroscopic fibrosis on magnetic resonance imaging are the hallmark of LA structural remodeling.16 However, dilatation of the LA is rather unspecific and not always pathologic (for example, in endurance athletes) and detection of macroscopic fibrosis with late gadolinium contrast enhanced magnetic resonance requires high expertise in image acquisition and post-processing and its availability remains low.
The present study proposed 3 parameters that characterize the LA structural remodeling combining electromechanical properties of the LA wall and evaluated the age-related changes of these parameters and their correlates. The increased collagen deposition and myocardial fibrosis of the LA myocardium associated with ageing lead to slow conduction of the action potential which is reflected by prolongation of the PWD on ECG and PA-TDI duration on echocardiography. In addition, this increased myocardial fibrosis may result in reduced LA compliance which is reflected by reduced LA reservoir strain on echocardiography.
There is accumulating evidence concerning the potential role of PWD, PA-TDI and LA reservoir strain for risk stratification of patients with various cardiovascular pathologies. However, reference values indicating normal LA physiological properties have not been well established. Data from the Framingham Heart Study including 295 patients (age range between 25 and 85 years, 52% male) showed a median PWD of 34 ms ( interquartile range 28-43 ms).17 In addition, a recent meta-analysis including 80 studies with a total of 6,827 healthy participants aged between 25 and 45 years, reported a weighted mean value of PWD of 33.46 ± 9.65 ms.18 The present study reports slightly
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