Left Atrial Septal Pouch-Is it Really a New Risk Factor for Ischemic Stroke?: Subanalysis of the ASSAM Study

PURPOSE

The atrial septal pouch is an anatomic variant of the interatrial septum caused by incomplete fusion of the septum primum and secundum. It is debatable whether coexistence of septal pouch and atrial fibrillation (AF) increases the risk of stroke. Thus, the aim of the study was to evaluate the coexistence of left atrial septal pouch (LASP) and AF in patients with a history of stroke in comparison with those without an earlier history of stroke.

MATERIALS AND METHODS

We analyzed 145 patients with AF (68 in the study group, 77 in the control group). The study group consisted of patients with previous stroke and AF; control group consisted of patients scheduled for AF ablation. All patients underwent computed tomography with the assessment of atrial septum morphology and presence of LASP. The study was a subanalysis of the ASSAM (AssesSment of the left atrial appendage morphoLogy in patients aAfter ischaeMic Stroke) study.

RESULTS

The prevalence of LASP in the entire group was 38.6%. There were no significant differences in the prevalence of LASP between the study and control groups (33.8% vs. 42.9%, P=0.265). Mean longitudinal and transverse dimensions of LASP were 9.34±3.27 and 2.4±0.6 mm, respectively, and there was no significant difference between the study and controls. Patients from the stroke group were older (P<0.0001), had a higher CHA2DS2-VASc score (5.41±1.93 vs. 1.62±1.46, P<0.0001) compared with controls.

CONCLUSIONS

Presence of LASP is not more prevalent in patients with a history of stroke. Additional information on the presence of LASP do not improve accuracy of risk stratification for stroke in patients with AF.

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.