Optimizing Reperfusion Outcomes in STEMIMinimizing right ventricular pacing: A new paradigm for cardiac pacing in sinus node dysfunction
Section snippets
Cardiac pacing in SND
The only effective treatment for symptomatic bradycardia is permanent cardiac pacing. Despite nearly 20 years of randomized clinical trials involving thousands of patients in North America and Europe, the optimal pacing mode and pacing system selection in SND, AVB, or among patients who qualify for implanted cardioverter/defibrillator (ICD) therapy but do not have an active indication for bradycardia support is unknown.
The historical precedent for these were 2 consecutive reports from Sweden in
The link between ventricular pacing and AF
The incidence of paroxysmal AF in patients with SND before pacemaker implantation has consistently been reported in the range of 40%-45%.12, 28, 29 In MOST, >50% of patients had at least 1 documented episode of paroxysmal AF before pacemaker implantation. The most recent episode of AF occurred <3 weeks before enrollment in 75% of patients.4 Pacemakers in 50%-65% of patients with SND detect AF and the incidence increases during long-term follow-up.30, 31 Paroxysmal AF detected by pacemakers in
The link between ventricular pacing and heart failure
The relationship between ventricular pacing and heart failure is considerably more complex. Risk of heart failure during pacing can be explained by interactions between substrate and promoters. Substrate is described by specific physiologic and clinical variables including atrial rhythm, AV conduction, ventricular conduction (QRS duration), ventricular function (ejection fraction [EF]), symptomatic heart failure, and myocardial infarction (MI). Promoters are specific to the implementation of
Future guidance in cardiac pacing for SND
Exploration of the link between the sequence of cardiac electrical activation and mechanical function is one of the most exciting contemporary areas of research in cardiac pacing. Optimal left ventricular pumping function requires a normal electrical activation sequence derived from the synchronized participation of the distal components of the specialized conduction system (the main bundle branches and their ramifications). The left ventricle normally contracts rapidly and synchronously with
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