Comparison between transesophageal echocardiography and transthoracic echocardiography with harmonic tissue imaging for left atrial appendage assessment

Background: Transesophageal echocardiography (TEE) is the method of choice for evaluating both anatomy and function of left atrial appendage (LAA). In contrast, conventional transthoracic echocardiography (TTE) does not result in images of sufficient quality to explore LAA. Hypothesis: The aim of this study was to evaluate the potential role of TIE with harmonic frequency imaging (HFI) for assessing LAA normal anatomy and function. Methods: The study group comprised 25 patients, (9 men, 16 women, mean age 51 years, range 20-82). The TTE assessment of LAA both in fundamental frequency imaging (FFI) and HFI was performed using the apical two-chamber view; the longitudinal two-chamber view was used for TEE assessment of LAA. According to image quality, images were categorized into three classes: A: good quality, B: sufficient quality, C: poor quality. Results: Transthoracic echocardiography conventional imaging allowed sufficient LAA visualization (class B) in only 5 of 25 patients (20%); the HFI resulted in adequate LAA visualization in 23 of 25 patients (92%). Images were of good quality (class A) in 18 of 23 patients and of sufficient quality (class B) in 5 of 23 patients. Transesophageal echocardiography achieved good quality images in 24 of 25 patients (96%). Average LAA maximum area determined by HFI and TEE was 3.46±1.17 and 3.59±1.16 cm2, respectively; LAA minimum area was 1.81±0.98 and 1.77±0.97 cm2, respectively. Percent LAA area change was 51±16.5 and 50.9±16% with HFI and TEE, respectively. Statistical analysis showed no difference between the data obtained with the two methods. Conclusions: The results suggest that HFI TTE may be a useful tool for the exploration of LAA.