Predictors of atrial mechanical sensing and atrioventricular synchrony with a leadless ventricular pacemaker: Results from the MARVEL 2 Study

Abstract

BACKGROUND The MARVEL (Micra Atrial TRacking Using a Ventricular AccELerometer) 2 study assessed the efficacy of atrioventricular (AV) synchronous pacing with a Micra leadless pacemaker. Average atrioventricular synchrony (AVS) was 89.2%. Previously, low amplitude of the Micra-sensed atrial signal (A4) was observed to be a factor of low AVS.OBJECTIVE The purpose of this study was to identify predictors of A4 amplitude and high AVS.METHODS We analyzed 64 patients enrolled in MARVEL 2 who had visible P waves on electrocardiogram for assessing A4 amplitude and 40 patients with third-degree AV block for assessing AVS at rest. High AVS was defined as .90% correct atrial-triggered ventricular pacing. The association between clinical factors and echocardiographic parameters with A4 amplitude was investigated using a multivariable model with lasso variable selection. Variables associated with A4 amplitude together with premature ventricular contraction burden, sinus rate, and sinus rate variability (standard deviation of successive differences of P-P intervals [SDSD]) were assessed for association with AVS. RESULTSIn univariate analysis, low A4 amplitude was inversely related to atrial function assessed by E/A ratio and eʹ/aʹ ratio, and was directly related to atrial contraction excursion (ACE) and atrial strain (Ɛa) on echocardiography (all P .05). The multivariable lasso regression model found coronary artery bypass graft history, E/A ratio, ACE, and Ɛa were associated with low A4 amplitude.

Long-term synchronization of old transvenous dual-chamber pacemaker and newly implanted leadless ventricular pacemaker with atrial sensing capability

“…Several additional factors may positively influence the amount of successful atrial sensing of the Micra AV, including low sinus rate variability and low E/A ratio. 5 Atrial pacing by definition has 0 heart rate variability, thus enhancing atrial sensing by the Micra AV leadless pacemaker. Additionally, history of the aortocoronary bypass was demonstrated in this study 5 as a risk factor for low AV synchrony.…”

“… 5 Atrial pacing by definition has 0 heart rate variability, thus enhancing atrial sensing by the Micra AV leadless pacemaker. Additionally, history of the aortocoronary bypass was demonstrated in this study 5 as a risk factor for low AV synchrony. Our patient underwent coronary bypass surgery and mitral valve replacement, which can explain the initial difficulty to achieve appropriate atrial sensing by Micra AV.…”

Nontransvenous Cardiovascular Implantable Electronic Device Technology—A Review for the Anesthesiologist

“…7 Unlike conventional AV synchronous pacing, which requires a dual-chamber transvenous pacemaker (accurate atrial signal detection with a right atrial lead), the reliance on atrial myocardial contraction strength by the accelerometer frequently reduces the effectiveness of Micra AV synchronous pacing. 8 For example, AV synchronous pacing during thoracic surgical procedures may be ineffective because the Micra may track surgery-related tissue motion and may pace the right ventricle asynchronous to the sinus node. The Micra AV also has two automated mode-switching features (activity mode switch and AV conduction mode switch) that can improve hemodynamics and preserve battery life.…”

Gerätebasierte rhythmologische Diagnostik und Therapie in COVID-19-Zeiten

“…Echokardiographische Parameter, wie z. B. ein E/A-Verhältnis < 0,94 und eine geringe Variabilität der Sinusrate in Ruhe, korrelieren mit einer hohen AV-sequenziellen Stimulationsrate [ 15 ].

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