Comparison of first- and second-generation leadless pacemakers in patients with sinus rhythm and complete atrioventricular block

Simple electrocardiographic index for A4-wave amplitude of the VDD leadless pacemaker

Background

A4-wave amplitude (A4-amplitude) is a crucial factor determining the percentage of atrioventricular synchrony (%AVS) in a mechanical sensing-based VDD leadless pacemaker (VDD-LP). We hypothesized that 12-lead electrocardiographic (ECG) parameters related to right atrial (RA) excitation could predict A4-amplitude.

Objectives

We aimed to investigate the relationship between A4-amplitude and 12-lead ECG parameters reflecting RA excitation and assess its predictive power for achieving an appropriate A4-amplitude associated with high %AVS.

Methods

This single-center, retrospective, observational study enrolled consecutive patients undergoing VDD-LP implantation. The relationship between A4-amplitude and the positive peak amplitude of the P wave in lead II (P2), the positive peak amplitude of the P wave in lead V1 (V1P), and the sum of P2 and V1P (V1PP2) were assessed.

Results

Of the 67 patients undergoing VDD-LP implantation, 46 without atrial fibrillation bradycardia were enrolled. They had a data set of manual atrial mechanical sensing tests and 12-lead ECG. Among P2, V1P, and V1PP2, only V1PP2 was correlated with A4-amplitude (R 2=0.10; P=.029). In 30 patients in VDD pacing mode, the median %AVS was 67.8%. The A4-amplitude cutoff for %AVS ≥ 67.8% was 3.2 m/s2 (area under the curve [AUC] 0.81; P=.002). For A4-amplitude ≥ 3.2 m/s2, V1PP2 had moderate predictive power (AUC 0.72; P=.007). In 30 patients without sick sinus syndrome, the predictive power of V1PP2 for A4-amplitude ≥ 3.2 m/s2 was increased (AUC 0.80; cutoff value 110 μV; sensitivity 83%; specificity 71%; P=.011).

Conclusion

V1PP2, reflecting RA excitation, was related to A4-amplitude and had moderate predictive power. Notably, its predictive power increased when limited to patients without sick sinus syndrome. V1PP2 is a simple ECG predictor of A4-amplitude.

Different leadless pacemakers working in harmony (Aveir in the atrium/Micra AV2 in the ventricle) in a patient with dextrocardia and double outlet right ventricle after high-risk infected device extraction

INTRODUCTION

Patients with congenital heart disease are at increased risk for requiring cardiac pacing during their lifetime.

METHODS

We present the first described case of using two leadless pacing systems manufactured by separate companies implanted within the same patient to provide atrial and ventricular pacing due to complex congenital anatomy.

RESULTS

A 27-year-old male with dextrocardia with double outlet right ventricle, subaortic ventricular septal defect, and pulmonary stenosis status-post pulmonary valve replacement complicated by ventricular pacing dependence and subsequent atrial pacing dependence after atriotomy-based atypical flutter ablation developed recurrent mediastinitis and pocket infection with erosion despite prolonged antibiotic treatment. Due to atrial and ventricular pacing dependence, a comprehensive congenital care team concluded the need for lead extraction and replacement of pacemaker via leadless peacemaking device. Laser-lead extraction and temporary atrial pacemaker placement was performed. Afterward, a transesophageal echocardiogram guided implantation of both a Micra AV 2 (Medtronic) leadless pacemaker in the interventricular septum within the right ventricle and an Aveir (Abbott) leadless pacemaker in the superior base of the right atrial appendage was performed with successful pacing. Although there is no communication between these devices, atrial-mechanical ventricular pacing was reliable with good implant thresholds, impedances and sensing from both devices.

CONCLUSION

Our case demonstrates the feasibility of using dual leadless pacing modalities to simultaneously pace someone at complex, prohibitive risk for temporary permanent or permanent pacemaker devices.

The Use of Electrocardiogram Smartwatches in Patients with Cardiac Implantable Electrical Devices

Unlimited access to ECGs using an over-the-counter smartwatch constitutes a real revolution for our discipline, and the application is rapidly expanding to include patients with cardiac implantable electronic devices (CIEDs) such as pacemakers (PMs) and implantable cardioverter defibrillators (ICDs). CIEDs require periodic evaluation and adjustment by healthcare professionals. In addition, implanted patients often present with symptoms that may be related to their PMs or ICDs. An ECG smartwatch could reveal information about device functioning, confirm normal device function, or aid in the case of device troubleshooting. In this review, we delve into the available evidence surrounding smartwatches with ECG registration and their integration into the care of patients with implanted pacemakers and ICDs. We explore safety considerations and the benefits and limitations associated with these wearables, drawing on relevant studies and case series from our own experience. By analyzing the current landscape of this emerging technology, we aim to provide a comprehensive overview that facilitates informed decision-making for both healthcare professionals and patients.

Left atrial strain is a good predictor of atrio-ventricular synchrony in leadless pacemaker pacing

INTRODUCTION

The importance of atrio-ventricular synchrony pacing in sinus rhythm patients is known. To identify patients in whom leadless pacemakers are able to guarantee this atrio-ventricular synchrony, we explored correlations among echocardiographic measures of left atrial (LA) size and function (doppler parameter and strain) with A4 amplitude in patients implanted with new generation Micra-AV device.

METHODS

After implantation with Micra-AV system, patients underwent device interrogation to evaluate AV synchrony based on the sensing of atrial mechanics and echocardiographic exam to assess LA morphology and LA function.

RESULTS

In the 21 studied patients (14 males, 72 ± 13 years), the A4 wave amplitude values inversely correlated with LA antero-posterior diameter, LA volume, LA contraction strain and LA conduit strain, while they were positively related with LA reservoir strain.

DISCUSSION

Our results indicate a statistically significant relationship between morphological echocardiographic LA parameters and atrial contraction signal (A4), detected by leadless pacemakers and used to synchronize ventricular pacing with the atrium. Instantaneous LA function assessment obtained with LA strain provides incremental information over morphological parameters. LA strain evaluates atrial myocardial deformation during the whole cardiac cycle. We found higher value of A4 in patients that have grater absolute value of LAsr, LAscd and LAsct, that are simple and measurable parameters of LA functional capacity.

CONCLUSION

Preimplant echocardiographic evaluation of the atrial contractility may be useful in predicting adequate A4 sensing and consequently a good atrio-ventricular synchrony pacing. Echocardiography LA strain study seems promising in Micra-AV patient selection.