CHB with CAD is a common combination especially in the elderly.
Which will you Intervene first ? Is the AV block related to CAD ?
How to differentiate Ischemic from degenerative AV block ?
Differentiating is often difficult.Even coronary angiogram may not answer the query unless it is totally normal . For AV block to occur usually LCX / RCA lesion is required. LAD lesion in isolation are rare to cause CHB .
How often re-vascularisation reverses ischemic CHB ?
Logically you expect more reversals.In real world it rarely happens.
Therapeutic options in combined CAD and CHB
- PCI and pace maker in the same sitting .
- PCI first followed by pace-maker at a later date.
- Pace maker first followed by PCI at a later date if required.
- CABG and epicardial pacemaker ( best option In all critical TVD and CHB)
- Pace maker followed by CABG later
- Pacemaker followed by medical management (CHB with Insignificant CAD)
Can worsening of ischemia occur after pacemaker ?
Very much possible . Since the patient has been benefited by low heart rate in terms of MVO2 consumption .(Inserting a pacemaker is like sudden withdrawal of beta blocker !)
Rate adoptive pacing can confer chronotropic competence which may bring back the angina.So,what was a insignificant lesion can become hemodynamicaly relevant and may require angioplasty later.
*The above clinical issue is applicable for sinus node dysfunction and CAD as well.
Final message
There is no fixed rule in the management strategy in combined CHB and CAD .
Generally , electrical therapy should be given preference .Symptom guided approach may be practical.
In this scientific era , one may argue to deal both issues together by simultaneous PCI and pacemaker , still option 3 and 6 remain clear favorites !
If angina occurs even in baseline bradycardia it is obvious the obstructive CAD is significant and needs immediate fixing .
Finally , though it looks an attractive concept , It is very rare for CHB to get reverted by PCI or CABG.
Dr.S.Venkatesan MD 