How do you decide the type of pacemaker (Permanent Artificial Cardiac Pacemaker) to use for a patient?

Pacemaker Type Selection

For sinus node dysfunction with intact AV conduction, use dual-chamber (DDD) or single-chamber atrial (AAI) pacing; for AV block, use dual-chamber pacing as first-line; for permanent atrial fibrillation, use single-chamber ventricular (VVI) pacing. 1

Primary Decision Algorithm

Step 1: Identify the Underlying Rhythm Disorder

Sinus Node Dysfunction (SND):

• Dual-chamber pacing (DDD) is recommended over single-chamber ventricular pacing (VVI) in patients with intact AV conduction (Class I, Level of Evidence A) 1
• Dual-chamber pacing is superior to ventricular pacing for reducing atrial fibrillation risk, preventing pacemaker syndrome, and improving quality of life 1
• Single-chamber atrial pacing (AAI) may be considered in highly selected patients with normal AV and ventricular conduction (Class IIb) 1
• Avoid dual-chamber or atrial pacing in patients with permanent or longstanding persistent AF where rhythm restoration is not planned (Class III) 1

AV Block:

• Dual-chamber pacing is recommended as first-line therapy (Class I, Level of Evidence C) 1
• Single-chamber ventricular pacing is acceptable in specific situations: sedentary patients, significant medical comorbidities limiting life expectancy, or technical limitations like vascular access problems (Class I, Level of Evidence B) 1
• Single-lead VDD pacing can be useful in patients with normal sinus node function and AV block, particularly younger patients with congenital AV block (Class IIa) 1
• VVI pacing is appropriate following AV junction ablation or when ablation is planned for AF rate control (Class IIa) 1

Step 2: Assess AV Conduction Status

For patients with SND:

• Document intact AV conduction before selecting AAI mode 1
• If AV conduction is questionable or likely to deteriorate, choose dual-chamber over single-chamber atrial pacing (Class I, Level of Evidence B) 1
• Consider future progression: patients may develop AV block from natural disease progression, drug therapy, or catheter ablation 1

Step 3: Evaluate for Chronotropic Incompetence

Rate-adaptive pacing indications:

• Rate-adaptive pacing can be useful in patients with significant symptomatic chronotropic incompetence (Class IIa, Level of Evidence C) 1
• Chronotropic incompetence exists when heart rate fails to reach 100 beats/min during exercise testing 1
• The need for rate response should be reevaluated during follow-up 1

Step 4: Consider Special Clinical Scenarios

Permanent Atrial Fibrillation:

• Use single-chamber ventricular (VVI) pacing when there is no significant atrial hemodynamic contribution (Class I) 1
• Dual-chamber pacing should not be used in permanent AF where rhythm restoration is not planned (Class III) 1

Hypersensitive Carotid Sinus Syndrome:

• Dual-chamber or single-chamber ventricular pacing can be useful (Class I, Level of Evidence C) 1
• AAI pacing is not recommended (Class IIa) 1

Neurocardiogenic Syncope:

• Dual-chamber pacing can be useful (Class I, Level of Evidence C) 1
• AAI pacing is not recommended (Class IIa) 1

Long QT Syndrome:

• Dual-chamber or atrial pacing is recommended over ventricular pacing for symptomatic or high-risk patients (Class I, Level of Evidence C) 1

Hypertrophic Cardiomyopathy:

• Dual-chamber pacing can be useful for medically refractory, symptomatic patients with significant resting or provoked LVOT obstruction (Class I, Level of Evidence C) 1

Key Factors Influencing Device Selection

Patient-specific considerations: 1

• Cardiac conduction abnormality type and severity
• Presence and severity of comorbidities
• Coronary heart disease and angina status
• Degree of left ventricular dysfunction
• Current and anticipated future drug therapy
• Anticipated activity level
• Patient age and life expectancy

Technical considerations: 1

• Vascular access limitations
• Availability of follow-up services
• Expertise of implant team
• Cost considerations

Important Caveats

Pacemaker Syndrome:

• Occurs with loss of AV synchrony in ventricular pacing, causing symptoms like lightheadedness or syncope 1
• In the PASE trial, 26% of patients assigned to ventricular pacing crossed over to dual-chamber pacing due to pacemaker syndrome 2
• This is a critical reason to avoid VVI pacing in patients with intact atrial function

Minimizing Ventricular Pacing:

• In patients with SND and intact AV conduction, program dual-chamber pacemakers to minimize ventricular pacing for AF prevention (Class IIa, Level of Evidence B) 1
• Excessive right ventricular pacing may promote atrial fibrillation 3

Future Considerations:

• Select a pacemaker with capabilities that may be needed in the future, even if not required at implantation 1
• Consider upgrading to CRT-P or CRT-D if the patient is likely to qualify shortly (e.g., post-MI with extremely low LVEF) 1