CLINICIAN DEVICE GUIDE · SECTION 2 OF 3
Identify device needs, gather referral information, and recognize the urgent patient.
Unstable bradycardia, new Mobitz II/high-grade/complete AV block, ongoing sustained VT, or suspected arrhythmic syncope with concerning findings requires urgent monitored or emergency evaluation. An outpatient device appointment is not the next step for an unstable patient.[1], [2]
For a patient recovering from VT/VF arrest or sustained VT, coordinate prompt EP assessment of the cause and secondary-prevention options.[2]
Symptomatic sinus node dysfunction or significant AV conduction disease.
Prior dangerous ventricular arrhythmia or a qualifying risk of sudden arrhythmic death.
Heart failure with electrical dyssynchrony or concern about frequent ventricular pacing.
Some patients need more than one function. EP determines whether a pacemaker, ICD, CRT-P, CRT-D, or another pacing strategy best meets those needs.
Document symptoms, EKG findings, and medication/reversible-cause review. For sinus node dysfunction, correlate fatigue, exercise intolerance, dizziness, or syncope with bradycardia or pauses when possible.
Significant acquired AV block may require pacing even without symptoms. Do not postpone assessment of dangerous block while trying to establish symptom correlation.[1]
VT/VF arrest or sustained VT without a reversible explanation should prompt EP assessment. A recovered EF does not by itself remove a secondary-prevention indication. Evaluate the underlying substrate, event circumstances, overall health, and goals.[2]
Persistently reduced EF despite guideline-directed therapy should trigger cardiology/EP review. A common profile is LVEF ≤35%, NYHA II–III symptoms, and expected meaningful survival beyond one year. Other qualifying profiles and disease-specific risks exist.[3]
Routine primary-prevention implant decisions allow time for recovery and reassessment. In ischemic cardiomyopathy, usual thresholds include at least 40 days after MI and at least 90 days after revascularization, with appropriate medical therapy.
These timelines should not automatically be applied to secondary prevention or urgent pacing needs. Referral can begin while treatment is optimized; the EP determines implant timing and whether interim protection is appropriate.[2]
Look for persistent heart failure symptoms, reduced EF, and a wide QRS—especially LBBB. The strongest common CRT profile is LVEF ≤35%, sinus rhythm, LBBB ≥150 ms, and NYHA II, III, or ambulatory IV symptoms on guideline-directed therapy. Other patterns may also qualify.[3]
Patients likely to require frequent ventricular pacing also need strategy review. With LVEF 36–50% and substantial anticipated ventricular pacing, cardiac physiologic pacing is reasonable to reduce pacing-induced cardiomyopathy risk. His bundle/left bundle branch area pacing or CRT may be selected according to the clinical situation.[4]
New LV dysfunction or worsening heart failure with substantial RV pacing should prompt device/EP review for a possible upgrade, alongside assessment of other causes.[4]
Pacing, ICD protection, resynchronization, or possible upgrade.
12-lead EKG, QRS duration/morphology, monitor strips, and arrest/VT records when applicable.
Available echo/imaging report, EF, and study date; the specialist can coordinate reassessment.
Medication doses, tolerance, duration, and MI/PCI/CABG dates.
Symptoms, functional status, major comorbidities, preferences, and existing device interrogation if available.
Refer the clinical problem; the specialist selects the device. A low EF or a wide QRS is a reason to assess candidacy, not an automatic implant decision.
For clinician education. Apply clinical judgment, current specialist guidance, and local emergency pathways.