Anatomical analysis of incidental left atrial diverticula in patients with suspected coronary artery disease using 64-channel multidetector CT

A meta-analysis of the accessory left atrial appendage and the left atrial diverticulum

Left atrial (LA) structures, including the accessory left atrial appendage (aLAA) and left atrial diverticulum, have been studied based on their prevalence, shape, and association with arrhythmia and thrombi formation. A pooled prevalence with morphometric data has not been determined in previous research. Our goal is to provide structured, clinically relevant information on said structures for clinical practitioners to use in their daily work. We propose that morphometric data of additional LA structures is necessary when considering the possible complications during cardiac interventions. We conducted a meta-analysis of all relevant studies which used electrocardiogram (ECG)-gated computed tomography (CT) imaging to determine the prevalence of LA structures and record their morphometric characteristics as well as the presence of thrombi. Data were extracted from 19 studies (n = 6643 hearts). The pooled prevalence estimate of left atrial diverticulum and/or aLAAs were reported from 14 studies and was 28.8%. The most common location noted was anterosuperior in the LA with 70.2% of structures found there. Data regarding thrombi presence in left atrial diverticulums or aLAAs were extracted from 11 studies and a thrombus was present in 0.2%. The prevalence rates of aLAAs and left atrial diverticulums are essential in performing uncomplicated cardiac interventions and reducing risk of electrophysiological procedures. Our findings show a considerable prevalence of LA structures in varying populations, provides information regarding the general characteristics of said structures, and does not support the previously theorized associated risk of thrombus formation in relation to LA structure presence.

The characteristics of left atrial diverticula in normal sinüs rhythm patients

PURPOSE

The purpose of this study was to evaluate the prevalence, location, size and morphological characteristics of left atrial diverticula using electrocardiographically gated multi-detector computed tomography in patients with normal sinus rhythm.

METHODS

Electrocardiographically gated cardiac multi-detector computed tomography was performed in 93 patients with normal sinus rhythm. The prevalence, number, size, morphological characteristics and location of left atrial diverticula were recorded.

RESULTS

A total of 72 left atrial diverticula were diagnosed in 45 (48.4%) of the 93 patients in this study. Of these 72 diverticula, 66 (91.7%) were cystiform and 6 (8.3%) were tubiform. Anterosuperior wall, left lateral wall and septum were the most common locations of these left atrial diverticula (n = 42, 58.3%; n = 22, 15.3% and n = 7, 9.7%, respectively).

CONCLUSION

Diverticula are common variations. The discovery of these structures is relatively new and their clinical significance remains unclear. They are generally asymptomatic but although not supported by many studies, in some case reports they are claimed to be associated with arrhythmias and thromboembolism. In addition, it is theoretically reasonable to think that they may cause complications during interventional procedures. Better understanding of these structures has the potential to improve management strategies and reduce potential complications. Therefore, they should be reported during routine cardiac computed tomography.

The Role of Magnetic Resonance Imaging and Cardiac Computed Tomography in the Assessment of Left Atrial Anatomy, Size, and Function

In the last decade, there has been increasing evidence that comprehensive evaluation of the left atrium is of utmost importance. Numerous studies have clearly demonstrated the prognostic value of left atrial volume for long-term outcome. Furthermore, advances in catheter ablation procedures used for the treatment of drug-refractory atrial fibrillation require the need for detailed knowledge of left atrial and pulmonary venous morphology as well of atrial wall characteristics. This review article discusses the role of cardiac magnetic resonance and computed tomography in assessment of left atrial size, its normal and abnormal morphology, and function. Special interest is paid to the utility of these rapidly involving noninvasive imaging methods before and after atrial fibrillation ablation.

Anatomical features and clinical importance of left atrial diverticula: MDCT findings

To assess the anatomical features and clinical importance of left atrial diverticula and atrial accessory appendages in patients undergoing cardiac computed tomography with multidetector computed tomography. A total of 1305 consecutive patients (385 female, 29.5%; 920 male, 70.5%) were assessed using electrocardiogram-gated computed tomography between May 2010 and June 2013. The anatomical features and the prevalences of left atrial diverticula and left atrial accessory appendages were retrospectively assessed by four radiologists. The relationships between the prevalence and size of the diverticula and the age and gender of the patients were assessed. Among the 1305 patients, 610 (46.7%) exhibited 708 left atrial diverticula, and 62 (4.8%) exhibited left atrial accessory appendages. The most common locations of the left atrial diverticula were the right anterior superior wall (n = 328, 46.3%) and the lateral superior wall (n = 96, 13.5%). In addition to classical cystic and tubular diverticula, 49 (3.7%) of the patients exhibited mixed (cystic-tubular), conical, or hook-shaped diverticula and diverticular forms containing mural calcifications. There was no significant relationship between the prevalence of diverticula and the age and gender of the patients (P > 0.05). In addition to tubular and cystic diverticula, the left atrial wall can host different diverticular forms (such as mixed, conical, calcific, and hook shaped). It could be beneficial to assess the left atrium using MDCT to determine the source of emboli in cryptogenic embolism and to reduce complications associated with interventional procedures performed for left atrial arrhythmias.

Congenital absence of the pericardium and its mimics

Congenital absence of the pericardium is a rare entity, with less than 400 cases reported in the literature. Pericardial absence is typically left sided, which results in herniation of the great vessels or portions of the heart. Patients may be asymptomatic, typical for complete defects, or can present with various degrees of chest pain in the setting of partial absence and strangulation. The finding may be isolated or associated with complex heart disease. We present a number of cases of pericardial absence that show isolated right- and left-sided defects, as well as entities in the differential diagnosis. Early recognition may decrease morbidity and mortality, resulting from delay in proper treatment.