Guideline Recommendations for VVI Mode Programming at 65 bpm in Patients with Atrial Lead Failure

Mode Definition

The VVI pacing mode delivers ventricular‑only pacing, senses intrinsic ventricular activity, and inhibits pacing when spontaneous ventricular depolarizations are detected. [1][2]

Programming a VVI backup rate of 65 bpm provides a safety net that prevents symptomatic bradycardia while minimizing unnecessary ventricular pacing. [1][2]
The device will only deliver a pacing pulse when the intrinsic ventricular rate falls below 65 bpm. 3

Loss of atrioventricular (AV) synchrony after atrial‑lead disconnection can reduce cardiac output by up to 50 % because atrial contribution to ventricular filling is eliminated. [3][4]
“Pacemaker syndrome,” characterized by fatigue, dyspnea, dizziness, orthostatic hypotension, and cannon A‑waves, occurs in 30–50 % of patients who retain intact atrial function when AV synchrony is lost. [1][2]5
In patients with ventricular dysfunction, the absence of AV synchrony is especially deleterious because their hemodynamics rely heavily on optimized preload. 4

VVI at 65 bpm is not optimal for patients with a functioning sinus node; AV synchrony should be restored by replacing the atrial lead and programming a dual‑chamber mode (VDD or DDD). [3][4]
In the presence of a normal sinus rhythm, VVI pacing can precipitate or worsen heart‑failure symptoms, particularly in those with dilated ventricles. 4

Permanent atrial fibrillation when rhythm restoration is not planned. [3][4]
Giant atria that provide no significant hemodynamic contribution. [1][2]
Absence of retrograde ventriculo‑atrial conduction. 1
Situations where simplicity is paramount (e.g., terminal illness, advanced age, remote living conditions). [1][2]

Do not assume VVI is appropriate solely because the atrial lead has failed; if sinus node function is preserved, maintaining AV synchrony is essential for adequate hemodynamics. [3][4]
Do not overlook symptoms of pacemaker syndrome (fatigue, dyspnea, dizziness, orthostatic hypotension, cannon A‑waves); these warrant reassessment of pacing strategy. [1][2]5
Do not rigidly keep the backup rate at 65 bpm if the patient develops symptoms; consider increasing to 70–80 bpm or switching to a rate‑responsive mode (VVIR) when chronotropic incompetence is present. [1][4]

The American College of Cardiology describes the VVI pacemaker code, where the first V indicates the pacemaker delivers electrical impulses to the ventricle, the second V indicates the device senses intrinsic ventricular electrical activity, and I indicates the pacemaker is inhibited by sensed ventricular activity 6, 7
The VVI pacing mode is characterized by ventricular pacing being inhibited by sensed spontaneous ventricular activity, making it a classic prototypical pacing mode 7

The American College of Cardiology recommends VVI pacing for symptomatic bradyarrhythmias when there is no significant atrial hemodynamic contribution, pacing simplicity is a priority, or there is absent retrograde ventriculoatrial conduction 6, 7
The pacemaker continuously monitors for intrinsic ventricular depolarization, and if the patient's own ventricular rate exceeds the programmed lower rate limit, the pacemaker remains inhibited and does not pace 8
If no ventricular activity is sensed within the programmed interval, the pacemaker delivers a ventricular pacing stimulus 6

The American College of Cardiology states that VVI pacing is contraindicated when pacemaker syndrome is present or anticipated, and dual-chamber pacing modes that preserve AV synchrony should be considered instead 6, 7