Pacemaker syndrome arises from adverse electrophysiological and haemodynamic consequences of pacing— in particular ventricular pacing—despite normal pacemaker function [1, 2]. The symptoms are diverse, ranging from breathlessness, syncope, palpitations, neck pressure, dizziness and flushing to more vague symptoms of lethargy and impaired exercise tolerance. Clinical signs include cannon ‘a’ wav...

Pacing from the right ventricular apex has been the clinical standard for decades but has recently come into question with a growing trend towards reducing ventricular pacing as much as possible. The earliest devices provided asynchronous ventricular pacing in patients whose indication for pacing was asystolic complete heart block. RV apical pacing was literally the difference between life and ...

Various pacing technologies have been developed during the past 50 years since the first pacemaker was implanted in 1958. Dual-chamber pacing, rate responsiveness, programmable and rate-responsive atrioventricular (AV) intervals, alternative-site pa0cing, and new multichamber pacing devices are all attempts to mimic normal cardiac physiology as much as feasible. The categories of alternative-si...

The goal of the present study was to assess the effects of left ventricular (LV) pacing sites (apex vs. free wall) on radial synchrony and global LV performance in a canine model of contraction dyssynchrony. Ultrasound tissue Doppler imaging and hemodynamic (LV pressure-volume) data were collected in seven anesthetized, opened-chest dogs. Right atrial (RA) pacing served as the control, and cont...

Cardiac resynchronization therapy (CRT) with biventricular pacing (BVP) is well-established in patients reduced left ventricular ejection fraction (LVEF), heart failure and wide QRS or indication for pacing. BVP achieves CRT through non-physiological fusion of paced wave-fronts from the RV endocardium LV epicardium. Conduction system utilizing bundle branch area has recently shown to be a safe ...

Selegiline is a centrally acting sympatholytic agent with neuroprotective properties. It also has been shown to promote sympathetic reinnervation after sympathectomy. These actions of selegiline may be beneficial in heart failure that is characterized by increased sympathetic nervous activity and functional sympathetic denervation. Twenty-seven rabbits with rapid cardiac pacing (360 beats/min, ...

Transvenous cardiac pacemakers definitely improve quality of life and reduce mortality in at-risk patients, but they are associated with several potential device-related complications. Approximately 10% of patients experience complications related to transvenous implantation of the pacemaker. These may be attributable to either the pulse generator (hematoma, skin breakdown, pocket infection) or...

The cardiac pacemaker lead, the "Achilles heel" of pacing hardware, is a relatively fragile cable of insulated conductor wire implanted into the hostile environment of the human body [1]. The ideal pacing lead remains an elusive goal. Important lead characteristics include ease of surgical insertion with safe and reliable fixation in the myocardium and a high level of electrical performance [2]...