A pacemaker is a medical device implanted into the patient’s chest and transmits tiny electrical impulses to the heart through leads to assist it in beating. Pacemaker treatment is an interventional approach that may be considered for individuals who develop clinically severe bradyarrhythmias. These arrhythmias are characterized by a heart rate of fewer than sixty beats per minute and an irregular rhythm. A pacemaker device helps to either restore atrioventricular (AV) synchronization or maintain an appropriate heart rhythm for the body to satisfy its demands (Hai et al., 2020). Hence, pacemaker leads are inserted into the appropriate chambers of the heart to activate the cardiac tissue.
The sinoatrial node is a normal pacemaker inside the heart that controls the regular heartbeat. The electronic impulse created by the sinoatrial node causes the whole heart to contract. Originally, pacemakers used to be external and required subcutaneous electrode insertion for individuals with incorrect intrinsic heart pacemaker function (Dalia & Amr, 2022). The complete cardiac block was corrected by directly attaching electrodes to the heart. Eventually, a completely implanted pacemaker was created as the pacemaker advanced. There have been numerous developments in pacemakers since then, and the permanent pacemaker of today is implanted subcutaneously.
The pacemaker system consists of the pacemaker as well as the cables connecting it to the heart. The pacemaker device has both a battery as well a computer circuitry system. The computer circuits track the patient’s underlying cardiac rhythm and transmit an electrical impulse to induce the heart rate at the desired pace. According to Trohman et al. (2020), numerous pacemakers implanted presently may include rate responsiveness characteristics that provide periodic heartbeat pacing faster while exercising. When a patient has a dual-chamber pacemaker, two wires are linked to the heart, while a single-chamber pacemaker only has one wire.
The most frequent indications for lifelong pacemaker placement are sinus node dysfunction (SND), high-grade atrioventricular (AV) block, and post-myocardial infarction. SND is characterized by a range of cardiac arrhythmias, such as sinoatrial block, sinus bradycardia, and paroxysmal supraventricular tachycardia, which commonly alternates with intervals of either bradycardia or asystole. Symptoms may be caused by paroxysmal supraventricular tachycardia, bradycardia, or both. Although SND is the most prevalent cause of pacemaker implantation, long-term pacing in these clients may not increase longevity despite eliminating symptoms and enhancing the quality of life (Russell et al., 2019). Atrial-based pacing is sometimes preferred in individuals with the malfunction of the sinus node.
Additionally, all individuals with total cardiac block may be candidates for permanent pacemaker placement. Even if the person is asymptomatic, lifelong pacemaker placement should be explored if the ventricular heart rate is greater than 40. The indication is increased if individuals with total heart block or severe second-degree Atrioventricular (AV) block have heart failure, a ventricular rate of less than 40 and bradycardia-induced ventricular arrhythmias (Russell et al., 2019). Electrophysiology (EP) investigations should be performed if an individual with an asymptomatic AV block of the second degree does not meet the criteria above.
The criteria for lifelong pacemaker insertion in individuals with myocardial infarction and Atrioventricular block do not rely on the occurrence of symptoms. The long-term outcome for Acute Myocardial Infarction (AMI) survivors with AV block mostly depends on the severity of myocardial damage and the nature of intraventricular conduction abnormalities (Sundbøll et al., 2018). A Pacemaker should be indicated for all AMI clients with the symptomatic and persistent second or third-degree Atrioventricular block.
Ultimately, a number of bradyarrhythmias may be effectively treated using cardiac pacemakers. By delivering an adequate heart rate, cardiac pacing may restore effective circulation and regulate hemodynamics affected by a decreased heart rate. Despite the plethora of clinical conditions in which permanent cardiac pacing is explored, most choices about lifelong pacemaker insertion are influenced by the correlation of symptoms with bradyarrhythmia. High-grade atrioventricular (AV) block, sinus node dysfunction (SND), and post-myocardial infarction are the most common reasons for inserting a permanent pacemaker.
References
Dalia, T., & Amr, B. S. (2022). Pacemaker Indications. Nih.gov; StatPearls Publishing.
Hai, J., Chan, Y., Lau, C., & Tse, H. (2020). Single‐chamber leadless pacemaker for atrial synchronous or ventricular pacing.Pacing and Clinical Electrophysiology, 43(12), 1438–1450.
Russell, M. R., Galloti, R., & Moore, J. P. (2019). Initial experience with transcatheter pacemaker implantation for adults with congenital heart disease.Journal of Cardiovascular Electrophysiology, 30(8), 1362–1366.
Sundbøll, J., Horváth-Puhó, E., Adelborg, K., Schmidt, M., Pedersen, L., Bøtker, H. E., Henderson, V. W., & Toft Sørensen, H. (2018). Higher Risk of Vascular Dementia in Myocardial Infarction Survivors.Circulation, 137(6), 567–577.
Trohman, R. G., Huang, H. D., Larsen, T., Krishnan, K., & Sharma, P. S. (2020). Sensors for rate‐adaptive pacing: How they work, strengths, and limitations.Journal of Cardiovascular Electrophysiology, 31(11), 3009–3027.