Role of routine chest xrays and device checks in detecting peri-procedural complications associated with cardiac device implantation: a UK tertiary centre experience

Introduction

Complications associated with Cardiac implantable electronic devices (CIEDs) are not uncommon, most of which occur in the perioperative phase. Until recently, guidance on implemented measures for early detection of peri-operative complications were lacking. The ESC guidelines on pacing recommend routine follow up of all newly implanted devices within 72 hours of implant. While the recently published EHRA expert consensus and practical guide on CIEDs recommend that a chest x-ray should be performed within 24 hours in all patients to rule out pneumothorax and document lead positions.

Purpose

At our tertiary centre for CIEDs, it is routine practice to perform CIEDs implantations on a day-case basis, targeting same day discharge for uncomplicated procedures. CXRs are performed 4 hours after the implant, and CIEDs are fully checked twice, once “on table” at the end of the procedure, and again after mobilisation and prior to discharge. In our analysis, we aimed to identify the yield of complications that could be detected early-on using these routine measures in all our implant procedures.

Methods

We performed a retrospective analysis of consecutive CIED implants performed between January and December 2019. The following information were collected; types and indications for device therapy, device checks reports, CXR reports, and clinical notes for documented symptoms or signs suggestive of peri-procedural complications.

Results

A total of 578 patients (Age 74±16 years, 68% male) were included in our analysis, for demographics see table. All patients had routine CXRs and 2 device checks. There were 16 (2.8%) peri-procedural complications associated with our device implants, 7 (1.2%) pneumothoraxes, 6 (1%) pericardial effusions, and 3 (0.5%) lead displacements.

In 4 out of the 7 peri-procedural pneumothoraxes, the operator reported difficulty gaining access. 2 patients with pneumothorax reported chest pain, 1 patient reported shortness of breath and 1 had low O2 saturations. There were 2 asymptomatic cases of pneumothorax after reportedly straightforward procedures and were only detected on the routine CXRs, one of them required chest drain insertion and the other treated conservatively.

2 out of the 3 lead displacements were detected on both CXRs and pre-discharge pacing checks and didn't require intervention, while 1 case of lead displacement occurred after the pacing checks and CXRs were reported to be satisfactory, further pacing checks triggered by patient's symptoms and bradycardia on the monitor revealed lead displacement requiring intervention prior to discharge.

Conclusion

Routine post CIED implantation CXRs can detect early – otherwise clinically silent-periprocedural complications and appropriately remains a requirement for all CIED implants. While repeat post mobilisation device checks has low yield of detection of complications and can be reasonably abandoned provided that initial “on-table” checks are satisfactory.

Funding Acknowledgement

Type of funding sources: None.

Application of recurrence plot analysis to characterise whole chamber propagation of atrial fibrillation

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): Oxford Biomedical Research Centre

Introduction

Non-contact charge density mapping allows visualisation of whole chamber propagation during atrial fibrillation (AF). The identification of regions with repetitive or, conversely, more complex patterns of wavefront propagation may provide clues to mechanisms responsible for AF maintenance and lead to improved outcomes from catheter ablation. Our novel mapping approach based on signal recurrence plots has never been applied to whole chamber, bi-atrial recording of atrial fibrillation.

Purpose

To apply recurrence analysis to characterise whole chamber bi-atrial AF propagation.

Methods

Non-contact dipole signals from left and right atrial maps were obtained during simultaneous bi-atrial charge density mapping of AF. Signals were converted to phase and mean phase coherence calculated for the generation of recurrence distance matrices for the whole chamber and each anatomical region (6x LA and 4x RA) over the 30-second recording duration, where a value of 1 (purple, see figure panel A) represents uniform repetitive conduction, and 0 (red), irregular, non-repetitive activity. Whole chamber and regional mean recurrence values were calculated and correlated with the frequency of wavefronts of localised irregular activation patterns.

Results

Maps were obtained prior to ablation in 21 patients (5 paroxysmal (pAF), 16 persistent AF (persAF)) undergoing de-novo catheter ablation procedures. Whole chamber recurrence was higher in patients with pAF (0.40 ± 0.08) than persAF (0.34 ± 0.05), p < 0.0005. There was an inverse correlation between regional recurrence values and the number of localised irregular activations detected (-0.7021, p < 0.0005, figure panel B) with the lateral LA and anterior RA demonstrating the highest recurrence values in each chamber (figure panel C).

Conclusion

Use of recurrence distance matrices characterises global AF propagation phenotypes. Regional values are inversely correlated with the frequency of localised irregular activation patterns identified demonstrating an anatomic dependence in the level of AF propagation complexity, greatest in the anterior LA and septal RA. Comparison of strategies targeting regions with maximal vs. minimal values during catheter ablation may define an optimal approach to treatment of persistent AF. Abstract Figure. Recurrence abstract figure

P1389Periodicity and Spatial Stability of Complex Propagation Patterns in Atrial Fibrillation

Introduction

Non-contact charge density mapping identifies complex wavefront propagation including localised rotational activation (LRA), localised irregular activation (LIA) and focal firing (FF). However, the duration of mapping required to reveal underlying patterns and their temporal stability is unknown.

Purpose

We sought to evaluate the variability in propagation patterns over increasing durations of recordings up to 30 seconds and examine the stability of these patterns between 2 separate maps with the aim of identifying the minimum duration required to reveal underlying patterns and how they represent the stable arrhythmia substrate.

Methods

Patients undergoing first time AcQMap guided catheter ablation were studied. 30s recordings of left atrial propagation were analysed. LIA, LRA, and FF were quantified for frequency, percentage time present and percentage surface area affected (for FF only frequency was assessed) at increasing durations up to 30s in 1s increments. At each incremental recording duration the percentage change in each variable was calculated. For occurrence frequency the results for every possible combination of maps of increasing duration within the 30s recording were compared whilst for occurrence time and surface area a 5s moving average at 1s increments was calculated. The point at which variability was seen to plateau represents the minimum optimal mapping duration. Spatial stability was assessed by correlating the frequency of patterns at each vertex of the anatomy over 2 separate 30s recordings. Stability of regions with the most repetitive patterns were compared using Cohen’s kappa statistic.

Results

15 patients were analysed (age 63 ± 9, 10 male, BMI 30 ± 5, CHA2DS2Vasc 1 ± 1.3, ejection fraction 54 ± 12%, left atrial diameter 46 ± 7mm, paroxysmal 1, persistent 14) with 11 included in the spatial stability analysis due to availability of recordings of sufficient duration. LRA demonstrated most variability followed by LIA and FF. Variability in LIA, LRA and FF decrease at increasing durations. LIA and FF variability plateau by 13 and 17s respectively. LRA plateaus at 23s. Variability of <10% is reached in all parameters at 18s.

LIA demonstrated the greatest stability with average R2 of 0.76 ± 0.14 (figure). Average R2 for LRA and FF were 0.45 ± 0.16 and 0.47 ± 0.12.  Low frequency focal firings were widely distributed across the atrial surface. For FF occurring at a frequency ≥10 over the 30s, average R2 value was 0.65 ± 0.14. Cohen kappa statistic was 0.70 for LIA and 0.45 for LRA.

Conclusion

Mapping durations of ≥23s are required to identify all temporally variable propagation patterns although shorter durations will identify less variable LIA and FF. 

LIA demonstrates high spatiotemporal stability and may best reflect disrupted conduction caused by the underlying atrial substrate and tissue architecture. Regions of high frequency FF are temporally stable and may represent important targets for ablation.

Abstract Figure 1

Safety and efficacy of multipolar pulmonary vein ablation catheter vs. irrigated radiofrequency ablation for paroxysmal atrial fibrillation: a randomized multicentre trial

Aims

The current challenge in atrial fibrillation (AF) treatment is to develop effective, efficient, and safe ablation strategies. This randomized controlled trial assesses the medium-term efficacy of duty-cycled radiofrequency ablation via the circular pulmonary vein ablation catheter (PVAC) vs. conventional electro-anatomically guided wide-area circumferential ablation (WACA).

Methods and results

One hundred and eighty-eight patients (mean age 62 ± 12 years, 116 M : 72 F) with paroxysmal AF were prospectively randomized to PVAC or WACA strategies and sequentially followed for 12 months. The primary endpoint was freedom from symptomatic or documented >30 s AF off medications for 7 days at 12 months post-procedure. One hundred and eighty-three patients completed 12 m follow-up. Ninety-four patients underwent PVAC PV isolation with 372 of 376 pulmonary veins (PVs) successfully isolated and all PVs isolated in 92 WACA patients. Three WACA and no PVAC patients developed tamponade. Fifty-six percent of WACA and 60% of PVAC patients were free of AF at 12 months post-procedure (P = ns) with a significant attrition rate from 77 to 78%, respectively, at 6 months. The mean procedure (140 ± 43 vs. 167 ± 42 min, P<0.0001), fluoroscopy (35 ± 16 vs. 42 ± 20 min, P<0.05) times were significantly shorter for PVAC than for WACA. Two patients developed strokes within 72 h of the procedure in the PVAC group, one possibly related directly to PVAC ablation in a high-risk patient and none in the WACA group (P = ns). Two of the 47 patients in the PVAC group who underwent repeat ablation had sub-clinical mild PV stenoses of 25–50% and 1 WACA patient developed delayed severe PV stenosis requiring venoplasty.

Conclusion

The pulmonary vein ablation catheter is equivalent in efficacy to WACA with reduced procedural and fluoroscopy times. However, there is a risk of thrombo-embolic and pulmonary stenosis complications which needs to be addressed and prospectively monitored.

ClinicalTrials.gov Identifier

NCT00678340.