Evolving Indications for Conventional Pacing

Abstract

Official guidelines for the indications of conventional permanent pacing are being updated periodically as the indications evolve continually. Also nontraditional indications for pacing emerge, such as marked first-degree AV block, malignant vasovagal syncope, obstructive hypertrophic cardiomyopathy, and paroxysmal atrial fibrillation. A critical review and analysis of these indications is undertaken in this review article. I N T R O D U C T I O N The indications for conventional pacing evolve continually with periodic upgrading of the well-known ACC/AHA/NASPE guidelines and the development of nontraditional indications such as marked first-degree AV block, malignant vasovagal syncope, obstructive hypertrophic cardiomyopathy, and paroxysmal atrial fibrillation. Rapid advances in pacemaker technology have provided improved systems to match the needs of patients in the aforementioned special situations. 2 0 0 2 A C C / A H A / N A S P E G U I D E l I N E S C O m P l E T E AV B l O C k The 2002 ACC/AHA/NASPE guidelines designate, like the previous ACC/AHA recommendations, asymptomatic complete AV block (in the absence of co-morbidity) with ventricular escape rates >40 bpm as a class II indication for pacing. The rate criterion of >40 bpm is arbitrary and unnecessary. It is not the escape rate that is critical to stability, but rather the site of origin of the escape rhythm (junctional or ventricular). Rate instability may not be predictable or obvious. Irreversible acquired complete AV block should be a class I indication for pacing. T y P E I S E C O N D D E G R E E AV B l O C k The 2002 ACC/AHA/NASPE guidelines state that type I second-degree AV block is usually due to delay in the AV node irrespective of QRS width. Type I seconddegree AV block with bundle branch block (far less common than narrow QRS type I block) must not be automatically labeled as AV nodal on the basis of this statement. REVIEw University of South Florida College of Medicine, Tampa, Florida, USA HOSPITAL CHRONICLES 2008, 3(1): 16–24 Correspondence to: S. Serge Barold, MD University of South Florida College of Medicine Tampa, Florida, USA E-mail: ssbarold@aol.com kEy wORDS: permanent pacemakers, atrioventricular block, vasovagal syncope, hypertrophic cardiomyopathy,