pacemaker
- related: Cardiology
- rate response: increase HR based on metabolic rate
| 1st | 2nd | 3rd |
|---|---|---|
| A | A | I |
| D | D | D |
| V | V | I |
- 1st letter: chamber pased, atrial, ventricular, dual
- 2nd letter: sensing, atrial, ventricular, dual
- 3rd letter: inhibition
- I: inhibit atrial on ventricular pacing
- D: lead in A, V. Sensing in A or V. Can pace in A or V. Can inihibit. Can trigger ventricular pacing based on atrium. AV nodal ablation
- Pacing:
- atrium: p waves
- RV: LBBB
- LV: RBBB
- AV: physiologic QRS
Indications for pacemaker
Current guidelines recommend implantable cardioverter-defibrillator (ICD) therapy for the primary prevention of sudden cardiac death (SCD) in patients with myocardial infarction (MI) with persistent left ventricular ejection fraction (LVEF) ≤30%, who are at least 40 days post-MI and 3 months post-revascularization (ie, coronary artery bypass grafting or percutaneous coronary intervention, if performed). It is also recommended in those with LVEF ≤35% and NYHA class II or III symptoms, regardless of prior MI.
This patient's MI was treated with percutaneous revascularization 4 months ago, and he is on optimal medical therapy. He has persistent left ventricular dysfunction with an ejection fraction of 25%. The most appropriate next step is to counsel and offer him ICD placement for primary prevention of SCD.