Cardiomyopathy induced by artificial cardiac pacing: myth or reality sustained by evidence?
Implantable cardiac pacing systems are a safe and effective treatment for symptomatic irreversible bradycardia. Under the proper indications, cardiac pacing might bring significant clinical benefit. Evidences from literature state that the action of the artificial pacing system, mainly when the ventricular lead is located at the apex of the right ventricle, produces negative effects to cardiac structure (remodeling, dilatation) and function (dissinchrony). Patients with previously compromised left ventricular function would benefit the least with conventional right ventricle apical pacing, and are exposed to the risk of developing higher incidence of morbidity and mortality for heart failure. However, after almost 6 decades of cardiac pacing, just a reduced portion of patients in general would develop these alterations. In this context, there are not completely clear some issues related to cardiac pacing and the development of this cardiomyopathy. Causality relationships among QRS widening with a left bundle branch block morphology, contractility alterations within the left ventricle, and certain substrates or clinical (previous systolic dysfunction, structural heart disease, time from implant) or electrical conditions (QRS duration, percentage of ventricular stimulation) are still subjects of debate. This review analyses contemporary data regarding this new entity, and discusses alternatives of how to use cardiac pacing in this context, emphasizing cardiac resynchronization therapy.
São Lucas Hospital, Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
Andrés Di Leoni
AD
Ferrari
São Lucas Hospital, Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
Anibal Pires
AP
Borges
São Lucas Hospital, Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
Luciano Cabral
LC
Albuquerque
São Lucas Hospital, Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
Carolina
C
Pelzer Sussenbach
São Lucas Hospital, Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
Priscila Raupp da
PR
Rosa
São Lucas Hospital, Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
Ricardo Medeiros
RM
Piantá
São Lucas Hospital, Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
Mario
M
Wiehe
São Lucas Hospital, Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
Marco Antônio
MA
Goldani
D002037:Bundle-Branch Block / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects* / Q000379:methods; D002311:Cardiomyopathy, Dilated / Q000209:etiology* / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D012307:Risk Factors; D013318:Stroke Volume / Q000502:physiology; D018754:Ventricular Dysfunction / Q000503:physiopathology