Improvement of Myocardial Contractility with Leadless Endocardial Single-Lead Atrial Sensing Ventricular Pacing in Patients with Prolonged PQ Interval

Abstract

Aim: Micra AV represents a leadless endocardial pacing system able to detect atrial contractions providing atrioventricular synchrony. A reduction of myocardial contractility may be detected in case of first-degree atrioventricular block (AVB). Materials & methods: In six patients with first-degree AVB (PQ interval ≥220 msec) was evaluated the left ventricle global longitudinal strain (LV GLS) by speckle tracking (ST) echocardiography during single-lead atrial sensing ventricular pacing (VDD) stimulation as compared with spontaneous rhythm (SR), 24–48 h after Micra AV implantation. Results: A statistically significant difference between the two modalities was observed (LV GLS during SR: -14.7% [interquartile range (IQR) 5.5], LV GLS during VDD pacing: -16.1% [IQR 5.2]; p value = 0.041). Conclusion: Our preliminary results suggest an improvement of myocardial contractility with VDD pacing as compared with SR.

Plain language summary

What is this article about?

The Micra AV is an electronic device placed in the heart chambers capable to supply the electrical activity of the heart. A reduction of cardiac contractility may be observed in patients with electrical disorders of the heart.

What were the results?

In six patients affected by electrical cardiac disorders, we observed an improvement of cardiac contractility using Micra AV as compared with the spontaneous electrical activity of the heart.

What do the results of the study mean?

The results of this study suggest that in patients carrying this electronic device should be preferred a specific modality of activation of the device as compared with the spontaneous electrical activity of the heart in order to improve the contractility of the cardiac walls.

Tweetable abstract

An improvement of myocardial contractility was observed during VDD pacing as compared with spontaneous rhythm in 6 patients with first-degree AVB after 24–48 h from Micra AV implantation.

Keywords::

• atrioventricular block
• global longitudinal strain
• leadless pacemaker
• Micra AV
• speckle tracking echocardiography
• VDD pacing

Author contributions

AI Guaricci: writing – original draft, methodology, supervision; VE Santobuono: writing – review & editing, conceptualization; N Soldato: investigation, writing – original draft; P Basile: formal analysis and data curation, writing – review & editing; N Bozza: investigation, writing – original draft; MC Carella: investigation, writing – review & editing; P Siena: writing – original draft, investigation; C Forleo: conceptualization, writing – review & editing; G Pontone: methodology, writing – review & editing; MM Ciccone: writing – review & editing, conceptualization. All authors have read and approved the final version of the manuscript. The authors agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Financial disclosure

G Pontone received institutional grant and fee from GE Healthcare, Medtronic, Bracco, Heartflow. This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Competing interests disclosure

The authors have no competing interests or relevant affiliations with any organization or entity with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Writing disclosure

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Data sharing statement

The authors certify that this manuscript reports original clinical data. Individual, de-identified participant data that underlie the results reported in this article (text, tables, figures and appendices) are available from the corresponding author following publication upon reasonable request.

Additional information

Funding

G Pontone received institutional grant and fee from GE Healthcare, Medtronic, Bracco, Heartflow. This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.