Risk of Pacing-induced Cardiomyopathy
Condition: Pacemaker DDD; Atrioventricular Block; Pacing-Induced Cardiomyopathy
MeSH terms: Cardiomyopathies; Atrioventricular Block
Study type: Observational

Summary: 
      This study will evaluate the association between right ventricular pacing and the risk of
      pacing-induced cardiomyopathy.
    

Detailed description: 
      Background:

      Right ventricular (RV) pacing may lead to pacing-induced cardiomyopathy (PICM) and heart
      failure (HF). The detrimental effects of RV pacing have been attributed to the abnormal and
      dyssynchronous electrical and mechanical activation of the myocardium. The activation is
      affected by the RV pacing site. Understanding the consequences of different RV pacing sites
      and the patterns of dyssynchrony may help to choose the optimal treatment for the individual
      patient.

      Aim and objectives:

      The overall aim of this project is to investigate the association between RV pacing site and
      the risk of PICM. Contrast enhanced cardiac computed tomography (CT) will be applied for
      precise localization of the RV pacing. Furthermore, investigation of the association between
      PICM and different mechanical and electrical myocardial activation patterns during RV pacing
      will be conducted using new echocardiographic and electrocardiographic methods.

      Methods:

      The study is designed as a retrospective cohort study with clinical follow-up. Patients with
      prior pacemaker implantation due to advanced atrioventricular block will be included. The
      study baseline is retrospective and defined as time of pacemaker implantation and follow-up
      is time of inclusion. Baseline data will be extracted from the Danish Pacemaker- and ICD
      Registry, electronic medical records (EMR) and review of echocardiographs. Follow-up data
      will be extracted from existing data in the EMRs as well as generated during a follow-up
      visit with a clinical examination. For assessment of cardiac function, RV lead position and
      electrical and mechanical activations patterns, the examination will include a transthoracic
      echocardiography, an electrocardiogram, a 3-dimensional chest photo, and a contrast-enhanced
      cardiac CT. Data will be analysed for differences between those who develop PICM and those
      who do not.

      Expected outcomes and perspectives:

      The hope is that this project will generate knowledge and awareness on pacemaker treatment
      and the risk of PICM. Understanding the pathophysiology behind PICM is key to learning how to
      prevent it. Accordingly, this project has the potential to contribute to improving pacemaker
      treatment and the quality of care for the large and still growing PM population.
    

Intervention name(s): Right ventricular pacing
Intervention type(s): Device
Intervention description(s): Right ventricular pacing from a DDD pacemaker implanted due to high-degree AV block
Observational model: Cohort
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        Subjects with a normal or near-normal ejection fraction prior to pacemaker implantation who
        received a DDD-pacemaker due to high-degree AV block ≥ 1 years prior to screening.