How does a pacemaker work and what happens during implantation surgery?

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1. 1

   Pacemaker (Wikipedia)

   WikipediaPublished Oct 15, 2026Checked Oct 17, 2026

   “A pacemaker, also known as an artificial cardiac pacemaker, is an implanted medical device that generates electrical pulses delivered by electrodes to one or more of the chambers of the heart. Each pulse causes the targeted chamber(s) to contract and pump blood, thus regulating the function of the electrical conduction system of the heart. The primary purpose of a pacemaker is to maintain an even heart rate, either because the heart's natural cardiac pacemaker provides an inadequate or irregular heartbeat, or because there is a block in the heart's electrical conduction system. Modern pacemakers are externally programmable and allow a cardiologist to select the optimal pacing modes for individual patients. Most pacemakers are on demand, in which the stimulation of the heart is based on the dynamic demand of the circulatory system. Others send out a fixed rate of impulses. A specific type of pacemaker, called an implantable cardioverter-defibrillator, combines pacemaker and defibrillator functions in a single implantable device.”

2. 2

   Natural pacemaker (Wikipedia)

   WikipediaPublished Sep 30, 2026Checked Oct 17, 2026

   “The natural pacemaker is the heart's natural rhythm generator. It employs pacemaker cells that produce electrical impulses, known as cardiac action potentials, which control the rate of contraction of the cardiac muscle, that is, the heart rate. In most humans, these cells are concentrated in the sinoatrial (SA) node, the primary pacemaker, which regulates the heart’s sinus rhythm. Sometimes a secondary pacemaker sets the pace, if the SA node is damaged or if the electrical conduction system of the heart has problems. Cardiac arrhythmias can cause heart block, in which the contractions lose their rhythm. In humans, and sometimes in other animals, a mechanical device called an artificial pacemaker (or simply "pacemaker") may be used after damage to the body's intrinsic conduction system to produce these impulses synthetically.”

3. 3

   Era of Synchronized Physiologic Leadless Pacing: A Novel Approach to Cardiac Pacing and Ongoing Development.

   Journal of clinical medicine (Shrestha et al.)Published Feb 4, 2026Checked Oct 17, 2026

   “Since the introduction of the first human single-chamber asynchronous leadless ventricular pacing in 2012, atrioventricular-synchronized single- or dual-chamber leadless pacing systems have been approved for clinical use since 2020. Leadless cardiac resynchronization therapy (CRT) has shown optimistic results in case series and awaits its full utility in real-world clinical practice. With the successful feasibility study of leadless conduction system pacing, we are eagerly awaiting long-term safety and efficacy data on a large scale. Another important frontier is the development of self-rechargeable LP, which may be an ideal pacemaker for the future and may reduce the burden of multiple device replacements as batteries near the end-of-service. Totally extravascular percutaneous leadless pericardial micro-pacemaker system implantation is under development. In this state-of-the-art review, we examine the evolution of cardiac pacing, emphasizing the development and utility of LP to meet maximum physiological pacing needs, optimize atrioventricular synchrony and cardiac resynchronization, and broaden its indications.”

4. 4

   Comparison of Outcomes of Leadless Versus Transvenous Pacemakers Following Tricuspid Valve Surgery.

   Journal of the American Heart Association (Shimoda et al.)Published Jul 10, 2026Checked Oct 17, 2026

   “Secondary outcomes included 2-year death.ResultsWe included 185 and 1336 patients in the leadless and transvenous groups, respectively. Use of leadless pacemakers increased from 6.3% in 2017 to 17.5% in 2021. Leadless pacemaker recipients more often underwent tricuspid valve replacement (29.2% versus 8.5%) while concomitant mitral surgery was less common (69.2% versus 86.8%). After adjustment, we found no evidence that in-hospital death (adjusted odds ratio, 1.82 [95% CI, 0.65-5.13] for leadless) and 2-year heart failure hospitalizations (subdistribution hazard ratio [HR], 0.88 [95% CI, 0.60-1.30] for leadless) differed between the 2 groups. We also found no evidence that 2-year death (adjusted HR, 1.04 [95% CI, 0.69-1.57] for leadless) differed between groups.ConclusionsNo statistically significant differences were detected between leadless versus transvenous pacemaker implantations after tricuspid valve surgery. However, CIs were wide, and a clinically meaningful difference in either direction cannot be excluded. The study may therefore be underpowered, and the absence of echocardiographic data limits assessment of tricuspid regurgitation, warranting prospective studies.”

5. 5

   Time to pacemaker insertion in older adults: A perspective on mortality and functional outcomes.

   Aging clinical and experimental research (Kazemerof et al.)Published Sep 23, 2026Checked Oct 17, 2026

   “Pacemaker insertion is common in older adults, yet the implications of procedural delays remain unclear. Nguyen and colleagues reported that longer time to implantation was associated with increased mortality over nearly five years. While this contribution is valuable, several methodological considerations warrant scrutiny before causal interpretations can be drawn. Infection may drive delay rather than result from it, as suggested by elevated neutrophils in the delayed group. Deconditioning, proposed as the mediating mechanism, was not directly measured. Residential aged care admission as a proxy for functional decline is influenced by social and caregiver factors independent of patient function. The 48‑hour threshold appears data‑driven rather than clinically justified. Finally, the absence of baseline frailty measures leaves residual confounding. Addressing these considerations would strengthen causal inference and refine clinical strategies.”