A pacemaker is an electronic device inserted in an individual’s chest to control the heartbeat. It is also known as a cardiac pacing device. By using intrinsic cardiac Pacemakers, we can support the patient. By subcutaneous electrodes, we can accomplish the pacing of the heart and maintain it for a short period. The Pacemaker has significantly developed over time, and at present, a permanent Pacemaker is inserted in the patient’s chest

 Types: Following are three types of Pacemaker;

  • Single Chamber Pacemaker: This type normally takes electrical impulses to the right side of your heart.
  • Dual Chamber Pacemaker: It takes the electrical ventricle to your heart’s right side and right atrium to control the two chambers’ contractions.
  • Biventricular Pacemaker: This type is also known as resynchronization therapy. It is used for people having Heartbeat problems and Heart failure. It stimulates both the left ventricle as well as the right ventricle. 

Pacemaker Indications:

A Pacemaker is a device through which electrical impulses are stimulated to maintain a heartbeat. Initially, Pacemaker was externally used to place different electrodes in patients. The complete heart defects were treated by attaching electrodes directly to the heart. There is a considerable advancement in Pacemakers, and now a day, permanent Pacemakers are placed on patients. It shows the indications and contraindications of Pacemaker. Most usual indications for a permanent Pacemaker are the implantation of (SND) sinus node dysfunction and (AV) atrioventricular block, which is very high in grade. American college of cardiology has established different recommendations for the implantation of cardiac Pacemakers. The medical hospitals of Cardiology have also shown the same advice for Pacemakers. The indications of pacemaker implantation have divided into three different types, which are as follows: 

  • Type 1: In this type, the implantation of a Pacemaker is considered very Favorable and essential. 
  • Type 2: The placement of the Pacemaker is indicated in this type, but there is a lot of clash or divergence of opinion.
  • Type 3: In this type, the permanent Pacemaker is not recommended, and it can cause harmful effects rather than benefits. 

For the insertion of the Pacemaker, the circumstances of ACC/AHA/HRS are discussed below:

  1. Sinus Node Dysfunction
  • Type one indications: In addition to immediate sinus pauses, the sinus bradycardia of documented symptomatic gives rise to symptoms and bradycardia for medical state results in drug therapy. 
  • Type two indications: There is no relationship between the symptoms of Pacemaker or bradycardia. In this indication, sinus node functions will be located where syncope is unexplained in clinically significant abnormalities. It will give rise to Electrophysiological studies.
  1. Acquired Atrioventricular block:
  • Type one indications:
  • Acquired atrioventricular block with or without symptoms which is complete third degree.
  • Mobitz class one and two is the second degree of atrioventricular block.
  • The second and third degrees of AV block was discovered in the absence of myocardial infarction. 
  • Mobitz class two is the most complex and narrow QRS.
  • Type two indications:
  • It is a narrow, complex QRX. 
  • It is an asymptomatic Mobitz that falls in type II.
  • It is a first-degree AV block.
  • In Ep studies, infra levels are second in the degree of AV block.  
  • Chronic Bifascicular block
  • Type one indications:
  • It is the second or third degree of AV block.
  • It is a second-degree class two AV block.
  • Type two indications:
  • Some patients suffering from Coma should not be discovered to have AV block, especially in Ventricular Tachycardia. Other likely diseases have been excluded.
  • It is a markedly prolonged HV interval incidental finding in the EP study. AV node is used to determine the conduction time.
  • The bifascicular (with or without symptoms) is considered for patients with neuromuscular diseases. 
  1. Acute Phase of Myocardial Infarction
  • Type one indications
  • The alternating branch of the third degree is persistent for second degree AV block in permanent ventricular.
  •  AV block is located below the Purkinje.
  •  The advanced degrees for permanent ventricular pacing intranodal AV block are the second and third degrees associated with bundle branch block.
  • The symptomatic degrees of AV block, which are persistent for pacing permanent ventricular, are second and third degrees.
  • Type two Indications:
  • Third-degree AV blocks are persistent for pacing asymptomatic permanent ventricular pacing.
  • Neurocardiogenic syncope and Hypersensitive carotid sinus syndrome:
  • Type one indications:
  • Carotid sinus stimulation is generally caused by recurrent syncope, while, Ventricular asystole is caused by carotid sinus, which occurs for more than three seconds.
  • Type two indications: 
  • Cardio Inhibitory occurs in patients for more than three seconds.
  • The table tilt testing occurs for symptomatic neurocardiogenic syncope. It is believed that syncope is immediately associated with bradycardia automatically.
  • Post Cardiac Transplantation:
  • Type one indications:
  • It is believed that bradycardia constantly holds rehabilitation or release after postoperative recovery.
  • Bradycardia was not discovered after cardiac transplantation, which can be considered syncope.
  • Hypertrophic Cardiomyopathy (HCM):
    • Type one indications: In this indication, sinus node dysfunction and AV blocks have been discovered in some patients. 
  • Type two indications: It is believed that the ventricular outflow tract is a barrier in some medically refractory symptomatic patients and severe resting.
  • Congenital Heart disease: 
  • Type one indications: 
  • In advanced second and third-degree AV block, ventricular dysfunction or low cardiac has been observed. These degrees are not likely to resolve or continue after cardiac surgery.
  • In age-appropriate bradycardia, sinus node dysfunction symptoms will be observed.
  • Infants and adults with congenital heart disease have a ventricular rate less than or equal to the normal rate of ventricular.
  • Type two indications:
  • Sinus Bradycardia is typically used to prevent the recurrent shocks of intra-atrial-entrant tachycardia. 
  • Likewise, Sinus node dysfunction is used to treat patients with congenital heart diseases.
  • The average heart rate is less than 50 bpm for congenital third-degree AV block after the first year of life.
  • Pacing to prevent Tachycardia:
  • Type one indications: Constant interruption occurs, which depends on VT and QT extension.
  • Type two indications:
  • Congenital QT syndromes are favorable for high-risk patients.
  • In a patient with sinus node dysfunction, recurrent atrial fibrillation is helpful for the blockage of symptomatic drug-refractory.

  

 

 

 

References: 

    • https://www.ncbi.nlm.nih.gov/books/NBK507823/
  • https://emedicine.medscape.com/article/1839735-overview
  • https://www.msdmanuals.com/professional/multimedia/table/indications-for-permanent-pacemakers