Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jan 17;6(4):519-527.
doi: 10.1016/j.hroo.2025.01.006. eCollection 2025 Apr.

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

Takafumi Oka  1 , Koki Tanabiki  2 , Takayuki Sekihara  1 , Akira Yoshida  1 , Kentaro Ozu  3 , Tomoaki Nakano  1 , Hibiki Mima  1 , Yasuhiro Akazawa  1 , Fusako Sera  1 , Shigetaka Kusumoto  2 , Masaki Takashina  2 , Tomohito Ohtani  1 , Yasushi Sakata  1
Affiliations

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

Takafumi Oka et al. Heart Rhythm O2. .

Abstract

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.

Keywords: 12-Lead electrocardiogram; Atrioventricular block; Atrioventricular synchrony; Leadless pacemaker; P-wave; Sick sinus syndrome.

PubMed Disclaimer

Figures

None
Graphical abstract
Figure 1
Figure 1
Study flowchart. Sixty-seven patients who undergo VDD leadless pacemaker implantation at Osaka University Hospital are retrospectively enrolled in this study. After excluding 21 patients, 46 are included. AF = atrial fibrillation; MAM = manual atrial mechanical.
Figure 2
Figure 2
Measurement method of the P-wave positive amplitude in leads II and V1. A: Standard 12-lead electrocardiogram with 1.0 mV/10 mm voltage calibration. B: Leads II and V1 with 1.0 mV/40 mm voltage calibration. C: P-wave positive amplitude (positive peak to isoelectric line) is manually measured with an electric caliper.
Figure 3
Figure 3
Distribution of A4-amplitude and P-wave positive peak amplitude in leads II and V1. A: Distribution of A4-amplitude (m/s2). B: Distributions of V1PP2, P2, and V1P. C: Correlation between P2 and A4-amplitude. D: Correlation between V1P and A4-amplitude. E: Correlation between P2 and V1P. F: Correlation between V1PP2 and A4-amplitude. The blue line represents the regression line; the light blue curve represents the 95% confidence interval; and the orange curve represents the 95% prediction interval. A4-amplitude = A4-wave amplitude; P2 = positive P-wave amplitude in lead II; V1P = positive P-wave peak amplitude in lead V1; V1PP2 = positive P-wave amplitude in lead II plus positive P-wave peak amplitude in lead V1.
Figure 4
Figure 4
Predictive power of V1PP2 for A4-amplitude. A: ROC analysis (n = 21) of A4-amplitude for high %AVS ≥ 67.8%, which was the median %AVS in the 21 patients. B: ROC analysis of V1PP2 for A4-amplitude ≥ 3.2 m/s2. C: Comparison of V1PP2 between patients with and without sick sinus syndrome. D: ROC curves of V1PP2 for 3.2 m/s2 of A4-amplitude in patients without sick sinus syndrome (n = 21). A4-amplitude = A4-wave amplitude; AUC = area under the curve; %AVS = percentage of atrioventricular synchrony; P2 = positive P-wave amplitude in lead II; ROC = receiver operating characteristic; V1P = positive P-wave peak amplitude in lead V1; V1PP2 = positive P-wave amplitude in lead II plus positive P-wave peak amplitude in lead V1.
Supplementary Figure 1
Supplementary Figure 1
Supplementary Figure 2
Supplementary Figure 2
Supplementary Figure 3
Supplementary Figure 3
Supplementary Figure 4
Supplementary Figure 4
Supplementary Figure 5
Supplementary Figure 5
See this image and copyright information in PMC

References

    1. Chinitz L., Ritter P., Khelae S.K., et al. Accelerometer-based atrioventricular synchronous pacing with a ventricular leadless pacemaker: results from the Micra atrioventricular feasibility studies. Heart Rhythm. 2018;15:1363–1371. - PubMed
    1. Garweg C., Splett V., Sheldon T.J., et al. Behavior of leadless AV synchronous pacing during atrial arrhythmias and stability of the atrial signals over time—results of the MARVEL Evolve subanalysis. Pacing Clin Electrophysiol. 2019;42:381–387. - PubMed
    1. Steinwender C., Khelae S.K., Garweg C., et al. Atrioventricular synchronous pacing using a leadless ventricular pacemaker: results from the MARVEL 2 Study. JACC Clin Electrophysiol. 2020;6:94–106. - PubMed
    1. Saunders J.L., Calatayud J.B., Schulz K.J., Maranhao V., Gooch A.S., Goldberg H. Evaluation of ECG criteria for P-wave abnormalities. Am Heart J. 1967;74:757–765. - PubMed
    1. Kligfield P., Gettes L.S., Bailey J.J., et al. Recommendations for the standardization and interpretation of the electrocardiogram: part I: the electrocardiogram and its technology: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society: endorsed by the International Society for Computerized Electrocardiology. Circulation. 2007;115:1306–1324. - PubMed

LinkOut - more resources