Comparison of clockwise and counterclockwise right atrial flutter using high-resolution mapping

Background

To the best of our knowledge, few studies have been performed that explore the electrophysiological differences between clockwise (CW) and counterclockwise (CCW) right atrial (RA) cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) using the high-resolution Rhythmia mapping system. Objectives. Accordingly, our prospective cohort study, sought to compare CW and CCW CTI-dependent AFL in preselected pure right AFL patients (pts) using the ultra-high-definition (ultra-HD) Rhythmia mapping system. The study also aimed to mathematically develop a cartography model based on automatic velocity RA measurements to identify electrophysiological AFL specificities.

Methods and results

Between October 2019 and July 2020, 33 patients were recruited. The mean age was 71±13 years old. No difference was found concerning clinical variables between CCW AFL and CW AFL or regarding left ventricular ejection fraction (LVEF) (55.5±10 vs. 56.6±12; p=0.76). The AFL cycle length was very similar (248±20 vs. 252±28 ms; p=0.6). The sinus venosus (SV) block line was present in 32/33 of cases (97%) and no significant difference was found between CCW and CW CTI AFL (100% vs. 91%; p=0.7). No line was localized in the region of the crista terminalis (CT). A superior gap was present in the posterior line in 14/31 (45.2%) but this was similarly present in CCW AFL, when compared to CW AFL (10/22 [45.5%] vs. (4/10 [40%]); p=0.9). When present, the extension of the posterior line of block was observed in 18/31 pts (58%) without significant differences between CCW and CW CI AFL (12/22 [54.5%] vs. (6/10 [60%]) (p=.9) The Eustachian ridge line of block was similarly present in both groups (82% [18/22] vs. 45.5% [5/11]; p=0.2). The absence of the Eustachian ridge line of block led to significantly slowed velocity in this area (28±10cm/s; n=8),and the velocities were similarly altered between both groups (26±10 [4/22] vs. 29.8±11cm/s [4/11]; p=0.6). We created mathematical, three-dimensional RA reconstruction-velocity model measurements. In each block localization, when the block line was absent, velocity was significantly slowed (≤20cm/s). A systematic slowdown in conduction velocity was observed at the entrance and exit of the CTI in 100% of cases. This alteration to the conduction entrance was localized at the lateral side of the CTI for the CCW AFL and at the septal side of the CTI for CW AFL. The exit-conduction alteration was localized at the CTI septal side for the CCW AFL and at the CTI lateral side for the CW AFL. The only differences between CW and CCW AFL concerned activation patterns.

Conclusions

The ultra-HD Rhythmia mapping system confirmed the absence of significant electrophysiological differences between CCW and CW AFL. The mechanistic posterior SV and Eustachian ridge block lines were confirmed in each arrhythmia. A systematic slowing down at the entrance and exit of the CTI was demonstrated in both CCW and CW AFL, but in reverse positions.

Funding Acknowledgement

Type of funding sources: None.

Is transesophageal echocardiogram mandatory for patients undergoing ablation for right atrial flutter with uninterrupted anticoagulants? A prospective single registry

Funding Acknowledgements

Type of funding sources: None.

Background. Limited data exist regarding the prevalence of left atrial appendage (LAA) thrombi and spontaneous echocardiographic contrast (SEC) in patients with atrial flutter (AFL). Objectives. Our prospective single-center observational study sought to evaluate the prevalence of LAA thrombi in patients referred for AFL ablation, compared to those requiring atrial fibrillation (AFib) ablation during the same time period, as well as to determine the predictive factors of LAA thrombi in terms of arrhythmia etiology. Methods and Results. From July 2019 to August 2020, 321 consecutive patients who were referred for either AFib ablation (n = 229) or AFL ablation (n = 92) were included in the study, with a thrombus detected by transesophageal echocardiography (TEE) in 3.22% (12/321). Prior to ablation under anticoagulants, the percentage of thrombi was similar between patients referred for AFL ablation and those referred for AFib ablation (5.4% [n = 5/92] vs. 3.1% [n = 7/229]; p = 0.3). In the overall population, patients with LAA thrombi had a higher CHA²DS²-VASc score (3 ± 2 vs. 2 ± 1.5; p = 0.048) and a higher presence of valvular prothesis (25% vs. 4.9%; p = 0.003), with relevant left atrial remodeling  more often observed, such as demonstrated by a higher left atrium (LA) volume (57 ± 19 vs. 46 ± 17 ml/m²; p = 0.04), a lower LAA velocity (0.41 ± 0.3 vs. 0.55 ± 0.2; p = 0.04) and a more severe LAA echo contrast (83.3% vs. 3.2%; p <0.0001). In the subset of patients with right AFL, patients with LAA thrombi had a higher CHA²DS²-VASc score (4.4 ± 1 vs. 2.5 ± 1.5; p = 0.008), had more often hypertension (100% vs. 53%; p = 0.04) and more often diabetes mellitus (60% vs. 18.4%; p = 0.03), and a more severe LAA echo contrast (80% vs. 5.7%; p <0.0001). Predictive factors of atrial thrombi evaluated by crude odds ratios were the presence of valvular prosthesis (OR = 6.53; [1.60, 26.65] ; p = 0.009), the CHA²DS²-VASc score (OR = 1.41 [0.99, 2.01] ; p = 0.05), the LAA velocity (cm/s) (OR = 0.03; [0.001, 0.79]; p = 0.04) and presence of severe LAA contrast (OR = 188 ; [35.32, 1002.02] ; <0.0001) rather than the atrial arrhythmia itself. Conclusions. Patients referred for ablation with right AFL have a similar risk of LAA thrombi, compared to those with AFib. The risk of LAA thrombi is better related to the presence of valvular prosthesis, CHA²DS²-VASc score and LA remodelling than the atrial arrhythmia itself. Accordingly, TEE should be recommended before right AFL ablation, especially in case of a valvular prosthesis, high CHA²DS²-VASc score or LA alteration.

Pulmonary Embolism in Covid-19 patients: A French Multicentre Cohort Study

Background

While pulmonary embolism (PE) appears to be a major issue in Covid-19, data remain sparse.

Purpose

We aimed to describe the risk factors and baseline characteristics of patients with PE in a large cohort of Covid-19 patients.

Methods

In a retrospective multicentric observational study, we included consecutive hospitalised patients for Covid-19. Patients without computed tomography pulmonary angiography (CTPA)-proven PE diagnosis, those who were directly admitted to an intensive care unit (ICU), and those still hospitalised without PE experience were excluded.

Results

Among 1240 patients (58.1% men, mean age 64 ± 17 years), 103 (8.3%) patients had PE confirmed by CTPA. The ICU transfer requirement and mechanical ventilation requirement were significantly higher in the PE group (P < 0.001 and P < 0.001, respectively). In an univariable analysis, traditional venous thromboembolic risk factors were not associated with PE (P > 0.05), while patients under therapeutic-dose anticoagulation before hospitalisation or prophylaxis-dose anticoagulation introduced during hospitalisation had lower PE occurrence (OR 0.40, 95%CI(0.14-0.91); P = 0.04 and OR 0.11, 95%CI(0.06-0.18); P < 0.001, respectively). In a multivariable analysis, the following variables (also statistically significant in univariable analysis) were associated with PE: male gender (OR 1.03, 95%CI(1.003-1.069); P = 0.04), anticoagulation with prophylaxis-dose (OR 0.83, 95%CI(0.79-0.85), P < 0.001) or therapeutic-dose (OR 0.87, 95%CI(0.82-0.92), P < 0.001), C-reactive protein (OR 1.03, 95%CI(1.01-1.04), P = 0.001) and time from symptom onset to hospitalisation (OR 1.02, 95%CI(1.006-1.038), P = 0.002) (Table 1).

Conclusion

Pulmonary embolism risk factors in Covid-19 context do not include traditional thromboembolic risk factors but rather independent clinical and biological findings at admission, including a major contribution to inflammation.