Christophe Garweg1, Surinder Kaur Khelae2, Clemens Steinwender3, Joseph Yat Sun Chan4, Philippe Ritter5, Jens Brock Johansen6, Venkata Sagi7, Laurence M Epstein8, Jonathan P Piccini9, Mario Pascual10, Lluis Mont11, Rik Willems12, Todd Sheldon13, Vincent Splett13, Kurt Stromberg13, Nicole Wood13, Larry Chinitz14. 1. University Hospitals Leuven, Leuven, Belgium. Electronic address: christophe.garweg@uzleuven.be. 2. Institut Jantung Negara, Kuala Lumpur, Malaysia. 3. Kepler University Hospital Linz, Linz, Austria; Paracelsus Medical University Salzburg, Salzburg, Austria. 4. Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong. 5. Hôpital Haut-Lévêque-CHU de Bordeaux, Pessac, France. 6. Odense University Hospital, Odense, Denmark. 7. Medical Center, Jacksonville, Florida. 8. North Shore University Hospital, Manhasset, New York. 9. Duke University Medical Center and Duke Clinical Research Institute, Durham, North Carolina. 10. Baptist Hospital, Miami, Florida. 11. Institut Clinic Cardiovascular (ICCV), Hospital Clínic, Universitat de Barcelona, Catalonia, Barcelona, Spain. 12. University Hospitals Leuven, Leuven, Belgium. 13. Medtronic, Inc., Mounds View, Minnesota. 14. NYU Langone Medical Center, New York, New York.
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. RESULTS: In univariate analysis, low A4 amplitude was inversely related to atrial function assessed by E/A ratio and e'/a' 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. E/A ratio and SDSD were multivariable predictors of high AVS, with >90% probability if E/A <0.94 and SDSD <5 bpm. CONCLUSION: Clinical parameters and echocardiographic markers of atrial function are associated with A4 signal amplitude. High AVS can be predicted by E/A ratio <0.94 and low sinus rate variability at rest.
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. RESULTS: In univariate analysis, low A4 amplitude was inversely related to atrial function assessed by E/A ratio and e'/a' 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. E/A ratio and SDSD were multivariable predictors of high AVS, with >90% probability if E/A <0.94 and SDSD <5 bpm. CONCLUSION: Clinical parameters and echocardiographic markers of atrial function are associated with A4 signal amplitude. High AVS can be predicted by E/A ratio <0.94 and low sinus rate variability at rest.
Authors: Kelly Arps; Jonathan P Piccini; Rebecca Yapejian; Rhonda Leguire; Brenda Smith; Sana M Al-Khatib; Tristram D Bahnson; James P Daubert; Donald D Hegland; Kevin P Jackson; Larry R Jackson; Robert K Lewis; Sean D Pokorney; Albert Y Sun; Kevin L Thomas; Camille Frazier-Mills Journal: Heart Rhythm O2 Date: 2021-08-23