The influence of iatrogenic interatrial septum leaks after left atrial appendage closure on cardiac function test results.

AIM: Left atrial appendage occlusion (LAAO) is a technique for preventing thromboembolism in patients with atrial fibrillation and a high risk of irreversible bleeding. In some patients, a spontaneous iatrogenic transseptal leak (ITL) remains after LAAO. The aim of this study was to assess the correlation between ITL incidence and the results of cardiac function tests in patients who underwent LAAO. METHODS AND RESULTS: LAOO was performed in 62 consecutive patients using the Amplatzer Amulet. Before and 3 months after LAA occlusion, the 6-min walking distance (6MWD) test was performed in all patients and oxygen consumption assessment (VO2max ) was performed in 32. All patients had transesophageal echocardiography before and 3 months after LAAO to assess ITL incidence. The patients were divided according to the presence and absence of ITL and the subgroup of patients with heart failure (HF) were further analyzed. In patients with HF and ITL, an increased VO2max (12.8 ± 5.2 vs 15.3 ± 4.7; P < 0.05) and 6MWD (350.1 ± 77.4 vs 414.3 ± 70.6; P < 0.05) was observed after the procedure comparing to the results before the procedure. The 6MWD was also significantly higher in the patients with transseptal leaks in comparison to those without (P < 0.0001). CONCLUSION: The presence of transseptal leaks after LAAO does not influence overall cardiac function test results. However, in patients with HF, there is an increase in oxygen consumption and 6MWD. These results indicate that ITLs in patients with HF decrease left atrial pressure, which is the key contributor to the symptoms of heart failure during physical activity.

Can we rely on machines? Device-detected atrial high rates correspond well with atrial arrhythmias in cardiac resynchronization recipients.

AIMS: The aim of the study was to verify in what proportion of patients, device-detected atrial high rate (AHR) episodes are indeed atrial arrhythmias (AAs). We investigated also the reasons for inappropriate arrhythmia classification and assessed if patients with misdiagnosed arrhythmias have distinct characteristics that would help to identify them. METHODS AND RESULTS: The study population consisted of 304 consecutive patients implanted with cardiac resynchronization therapy defibrillators (CRT-Ds) and subsequently monitored via remote monitoring for a median follow-up (FU) of 30.5 months. Intracardiac electrograms of every recorded AHR episode were assessed and classified (AA vs. no AA) by two experienced cardiologists. During FU, 14 386 episodes of AHR were recorded and classified in 176 (57.9%) patients. In 89.2% of them, these episodes were true AA (94% atrial fibrillation, 62% de novo). The reasons for AHR misdiagnosis were atrial far-field signals (89.5%) and noise (10.5%). The mean per cent of day spent in AHR (54.9 vs. 5.86%; P < 0.001) and the occurrence of periods with low CRT pacing (82.8 vs. 55%; P = 0.003) were significantly higher in AA subjects than in those with misdiagnosed AHR. Episode duration of properly detected AHRs was longer than that of misdiagnosed AHRs. Higher per cent of time spent in AHR was an independent marker of appropriate arrhythmia detection [adjusted hazard ratio (HR) 1.04; P = 0.023]. CONCLUSION: Nearly two-thirds of CRT-D patients had AHR episodes within 2.5 years after implantation. Almost 90% of AHRs were indeed AA. Misdetections were caused by far-field sensing or noise. A two-step diagnostic algorithm (>9% of time spent in AHRs and episode duration >36 s) allowed for proper detection of AA with a high hit-rate and specificity.

Two-dimensional versus three-dimensional transesophageal echocardiography in percutaneous left atrial appendage occlusion.

BACKGROUND: Real-time three-dimensional transesophageal echocardiography (RT3D TEE) enables better visualization of the left atrial appendage (LAA) and may be superior to real-time two-dimensional transesophageal echocardiography (RT2D TEE) for LAA occlusion (LAAO). The aim of this study was to assess inter- and intra-observer variability of RT2D TEE and RT3D TEE measurements of LAA, and to assess the accordance of RT2D TEE and RT3D TEE with appropriate occluder selection. METHODS: Transesophageal echocardiography was performed in 40 patients during LAAO. RT2D TEE and RT3D TEE measurements of the ostium and landing zone were performed independently by two echocardiographers. The appropriate choice of occluder was confirmed with fluoroscopic criteria. After the procedures, RT2D TEE and RT3D TEE evaluation were repeated separately by the same echocardiographers. RESULTS: The mean ostium diameters by RT2D TEE obtained by the two observers were 23.6 ± 4.2 vs. 24.8 ± 5.2 (p = 0.04), and the mean landing zone diameters were 17.7 ± 4.4 vs. 19.4 ± 3.9 (p < 0.01). In the case of RT3D TEE, the ostium diameters were 29.6 ± 5.3 vs. 29.4 ± 6.4 (p = not significant [NS]) and the landing zone diameters were 21.4 ± 3.8 vs. 21.6 ± 3.9 (p = NS). Intra-observer differences were absent in the case of RT3D TEE. The comparison of RT2D TEE vs. RT3D TEE analyses performed by the same echocardiographer revealed significant differences in the ostium and landing zone measurements (both p < 0.01). Agreement between the suggested device size was better for RT3D TEE (weighted kappa was 0.62 vs. 0.28, respectively). CONCLUSIONS: The results obtained with RT3D TEE showed significantly larger dimensions of the ostium and the landing zone. RT3D TEE showed lesser inter- and intra-observer variability and better agreement with the implanted device.