Gross anatomic relationship between the human left atrial appendage and the left ventricular summit region: implications for catheter ablation of ventricular arrhythmias originating from the left ventricular summit

PURPOSE

The left ventricular summit (LVS) is a source of difficult-to-treat arrhythmias because of anatomical limitations. The aim of this study was to perform detailed research of the left atrial appendage (LAA) anatomy of cadaveric hearts to analyze their complex anatomy and coverage of the LVS.

METHODS AND RESULTS

Eighty human formalin fixed hearts (mean age 44.4 ± 15.5, 27.5% females) were investigated. Each LAA size, type, and its relationship to the LVS were analyzed, as well as possible access sites for mapping/ablating electrode. Four types of LAA were observed over two LVS sites that are either accessible or not. The highest coverage over an inaccessible LVS area was observed in the Broccoli type, followed by the Windsock then the Chicken Wing and finally the Cactus types; over the accessible area of the LVS was observed in the Windsock, then in the Chicken Wing, then in the Cactus, and finally in the Broccoli types. The attainable coverage for electrode access is diminished from 25 to 65% because of the complex pectinate muscles and sharp angles. The highest density of the LAA floor made by pectinate muscles can be found in the Broccoli type (p < 0.005), while the Chicken Wing had the highest number of paper-thin-like pouches.

CONCLUSIONS

The LAA appears to be a promising entry for ablation-qualified patients with the LV summit originate arrhythmias. The complex internal structure of the LAA may complicate ablation procedures. More prominent appendages are promising in more extensive mapping areas over the LVS.

How to write an umbrella review? A step-by-step tutorial with tips and tricks

The number of meta-analyses (MA) and systematic reviews (SR) on various medical issues has increased during the last two decades. The MA and SR results may differ from one another due to a number of factors such as inaccurate or diverse searches through the databases, discrepancies in the extraction process or in statistical analysis, among others. Some results may even contradict one another, resulting in confusion among readers. Umbrella reviews (UR) have allowed the collection of all available data on a medical issue into one concise study, making it the source of evidence-based medical knowledge to the highest degree. Furthermore, UR can resolve those problems by collecting all data and taking into account both MA and SR, making it the superior tool for physicians. Although the pros of UR are clear and the overall popularity of these types of study has increased tremendously, there is no available step-by-step guide on how to conduct one. Therefore, the objective of the present study was to provide researchers with a detailed tutorial on how to conduct an UR. UR represent the next major step in the advancement of evidence-based medicine, with great practical potential for physicians looking for the most up-to-date data on their topic of interest. We hope that our step-by-step guide may be a useful tool for researchers conducting UR in the future.

Detailed radiological study of the patent ductus arteriosus: a computed tomography study in the Polish population

BACKGROUND

The aim of the study was to perform qualitative and quantitative computed tomography (CT) angiography-based evaluation of patent ductus arteriosus (PDA) morphology and its influence on morphology of the great vessels.

MATERIALS AND METHODS

Two-thousand twenty-two patients underwent 64-slice or dual-source CT and were retrospectively screened for the presence of PDA. Those who had presence of PDA underwent evaluation of its anatomy and morphology.

RESULTS

Thirty-two adult patients with PDA were evaluated (mean age 41.4 ± 17.4 years). Subjects with PDA had a higher value of aortic isthmus (p = 0.0148), main pulmonary artery (p < 0.0001), right (p =0.0007) and left (p = 0.0074) pulmonary arteries diameters than individuals from control group (16 adults, median age 43.3 ± 12.4 years). Types A, B, C, D, and E of PDA morphology occurred in 16 (50%), 3 (9%), 9 (28%), 2 (6%), and 2 (6%) patients, respectively. Subjects with the type A configuration of PDA tended to have a larger diameter at the aortic orifice (10.2 ± 5.2 mm vs. 6.4 ± 4.9 mm, p = 0.09) and a larger maximal diameter (10.3 ± 5.3 mm vs. 7.1 ± 4.7 mm, p = 0.14) compared to subjects with the type C configuration. The values of minimal, mean, and maximal diameters of PDA were 4.7 ± 1.9 mm, 7.0 ± 3.2 mm, and 9.4 ± 5.0 mm, respectively. The Spearman correlation coefficient between the main pulmonary artery and PDA diameters demonstrated a good correlation for minimal (r = 0.70, p < 0.001), mean (r = 0.62, p = 001), and maximal (r = 0.60, p = 0.0003) PDA diameters.

CONCLUSIONS

Computed tomography enables quantitative and qualitative evaluation of PDA, including its type of morphology, length, and diameters. In the evaluated adult population with PDA, the majority of patients had dilation of the aortic isthmus and pulmonary arteries. PDA diameters correlate with diameters of the pulmonary arteries and this correlation is strongest between PDA diameter at the narrowest site and main pulmonary artery.

P6557Permanent atrial fibrillation development in patients with DDD pacemaker -Rrisk factors and association with mortality in long-term

Background

In patients undergoing permanent DDD cardiac pacing, the maintenance of atrial contractility is important to ensure adequate ventricular filling and to guarantee an optimal ventricular ejection capacity. Atrial fibrillation (AF) is a major risk factor for thromboembolic events and is associated with increased cardiovascular and all-cause mortality.

Purpose

To analyse the risk factors for development of permanent AF in patients with DDD pacemaker and determine its association with all-cause mortality in long-term follow-up.

Methods

Retrospectively collected records comprised all consecutive patients who underwent primary DDD pacemaker implantation at single-centre between 1984–2014. Patients who were lost to follow-up after hospital discharge were excluded from analysis. Follow-up was completed on 31st August 2016. Definition of permanent AF was the occurence of AF which persisted until the end of follow-up. Data on patients' survival status and deceased patients' dates of death were collected from the national death registration system. Information of death date was available as of 31st August 2016. The endpoint was all-cause mortality.

Results

We included a total of 3771 patients and 24,432 patient-years of follow-up and exluded 157 (4%) patients who were lost to follow-up after hospital discharge. Mean follow-up was 78±62 months (max. 370 months), 1761 (47%) were female. Paroxysmal AF prior to DDD pacemaker implantation was detected in 1276 patients (34%). During entire follow-up 717 (19%) patients developed permanent AF in a mean period of 55±50 months. Analysis of risk factors for development of permanent AF is presented in Figure. Cox proportional hazards model with time-dependent covariate showed that development of permanent AF significantly increased mortality during follow-up (HR = 1.885, 95% CI, 1.654–2.148, P<0.001; with adjustment for age at implantation and sex: HR = 1.475, 95% CI, 1.294–1.682, P<0.001).

Permanent AF risk factors

Conclusions

Female sex protected against permanent AF development, whereas age at implantation, history of paroxysmal AF and apical position of RV lead increased the risk. Permanent AF was significantly increasing the all-cause mortality, even after adjustment for age at implant and gender.

Acknowledgement/Funding

None