Left atrial anatomy relevant to catheter ablation

The rapid development of interventional procedures for the treatment of arrhythmias in humans, especially the use of catheter ablation techniques, has renewed interest in cardiac anatomy. Although the substrates of atrial fibrillation (AF), its initiation and maintenance, remain to be fully elucidated, catheter ablation in the left atrium (LA) has become a common therapeutic option for patients with this arrhythmia. Using ablation catheters, various isolation lines and focal targets are created, the majority of which are based on gross anatomical, electroanatomical, and myoarchitectual patterns of the left atrial wall. Our aim was therefore to review the gross morphological and architectural features of the LA and their relations to extracardiac structures. The latter have also become relevant because extracardiac complications of AF ablation can occur, due to injuries to the phrenic and vagal plexus nerves, adjacent coronary arteries, or the esophageal wall causing devastating consequences.

Left atrial appendage: anatomy and imaging landmarks pertinent to percutaneous transcatheter occlusion

Percutaneous left atrial appendage (LAA) closure represents a complementary option and effective treatment for patients at risk of thromboembolism, especially in patients for whom it may be difficult to achieve satisfactory anticoagulation control or where anticoagulation treatment is not possible or desirable. Effective and safe transcatheter LAA occlusion requires a detailed knowledge of crucial anatomic landmarks and endocardial morphologic variants of the LAA and its neighbouring structures.1 ,2 w1–w3 Our aim in this article is to provide the basic anatomic information that is important for the interventional cardiologist to know when planning an LAA occlusion procedure.

LA Size in Former Elite Athletes

A recent meta-analysis by Iskandar et al. (1) nicely showed that endurance athletes have larger left atrial (LA) diameters compared with control subjects. Yet only 9 of 54 studies included in their analysis reported LA volume values corrected for body surface area (BSA). In fact, few studies have determined LA volume in young athletes, and, to the best of our knowledge, no study has reported this variable in older athletes. This is an important question given the growing debate about the potential deleterious effects of long-term strenuous endurance exercise on the human heart, notably the higher risk of atrial fibrillation (AF), a condition for which both atrial dilation and the normal aging process are thought to be potential causative mechanisms (2). Thus, we aimed to assess the long-term consequences of endurance exercise on LA volume in athletes who were highly competitive at younger ages and are still active. To this end, we compared BSA-corrected LA volumes determined with late gadolinium enhancement magnetic resonance imaging (LGE-MRI) in former elite endurance athletes and sedentary control subjects.

Heart dimensions may influence the occurrence of the heart rate deflection point in highly trained cyclists

To determine whether the heart rate (HR) response to exercise in 21 highly trained cyclists (mean (SD) age 25 (3) years) was related to their heart dimensions. Methods—Before performing an incremental exercise test involving a ramp protocol with workload increases of 25 W/min, each subject underwent echocardiographic evaluation of the following variables: left ventricular end diastolic internal diameter (LVIDd), left ventricular posterior wall thickness at end diastole (LVPWTd), interventricular septal wall thickness at end diastole (IVSTd), left ventricular mass index (LVMI), left atrial dimension (LAD), longitudinal left atrial (LLAD) and right atrial (LRAD) dimensions, and the ratio of early to late (E/A) diastolic flow velocity. Results—The HR response showed a de- flection point (HRd) at about 85% V~ O2MAX in 66.7% of subjects (D group; n = 14) and was linear in 33.3% (NoD group; n = 7). Several echocardiographic variables (LVMI, LAD, LLAD, LRAD) indicative of heart dimensions were similar in each group. However, mean LPWTd (p<0.01) and IVSTd (p<0.05) values were signifi- cantly higher in the D group. Finally, no significant diVerence between groups was found with respect to the E/A. The HR response is curvilinear during incremental exercise in a considerable number of highly trained endurance athletes—that is, top level cyclists. The departure of HR increase from linearity may predominantly occur in athletes with thicker heart walls.

Standardized review of atrial anatomy for cardiac electrophysiologists

2.691 JCR (2013) Q2, 50/125 Cardiac & cardiovascular systems, 51/122 Medicine, research & experimental

Centenarians and their hearts: a prospective registry with comprehensive geriatric assessment, electrocardiogram, echocardiography, and follow-up

Background Data on the cardiac characteristics of centenarians are scarce. Our aim was to describe electrocardiogram (ECG) and echocardiography in a cohort of centenarians and to correlate them with clinical data. Methods We used prospective multicenter registry of 118 centenarians (28 men) with a mean age of 101.5 ± 1.7 years. Electrocardiogram was performed in 103 subjects (87.3%) and echocardiography in 100 (84.7%). All subjects underwent a follow-up for at least 6 months. Results Centenarians with abnormal ECG were less frequently females (72% vs 93%), had higher rates of previous consumption of tobacco (14% vs 0) and alcohol (24% vs 12%), and scored lower in the perception of health status (6.8 ± 2.0 vs 8.3 ± 6.8). Centenarians with significant abnormalities in echocardiography were less frequently able to walk 6 m (33% vs 54%). Atrial fibrillation/flutter was found in 27 subjects (26%). Mean left ventricular (LV) ejection fraction was 60.0 ± 10.5%. Moderate or severe aortic valve stenosis was found in 16%, mitral valve regurgitation in 15%, and aortic valve regurgitation in 13%. Diastolic dysfunction was assessed in 79 subjects and was present in 55 (69.6%). Katz index and LV dilation were independently associated with the ability to walk 6 m. Age, Charlson and Katz indexes, and the presence of significant abnormalities in echocardiography were associated with mortality. Conclusions Centenarians have frequent ECG alterations and abnormalities in echocardiography. More than one fifth has atrial fibrillation, and most have diastolic dysfunction. Left ventricular dilation was associated with the ability to walk 6 m. Significant abnormalities in echocardiography were associated with mortality.