Spontaneous recovery of complete atrioventricular block complicating acute anterior wall ST elevation myocardial infarction

Abstract

Coronary angiography provides invaluable information for decision making in such clinical scenarios. Complete atrioventricular block due to reversible ischaemia produced by reocclusion of an infarct-related artery should be reversible by percutaneous coronary angioplasty of the infarct-related artery. We suggest that reversible causes be considered before attributing atrioventricular block to irreversible damage, which would require a permanent pacemaker implantation. This would be more significant in most of the developing world, where resources are scarce.

Total atrioventricular block in patient with late onset acute inferior myocardial infarction

“…Spontaneous recanalization or dual arterial blood supply explains the absence of necrosis. [14][15][16] The existence of a protective mechanism of AV node against ischaemia also increases the likelihood of spontaneous resolution, because the collateral blood vessels work properly and the AV node is rich in glycogen. 7,8 In addition, the AV node becomes relatively resistant to ischemia and can restore function more rapidly than the other area of myocardium, once the ischemia has subsided.…”

“…7,8 In addition, the AV node becomes relatively resistant to ischemia and can restore function more rapidly than the other area of myocardium, once the ischemia has subsided. 15 Another possibility is that the ongoing thrombotic process can be stopped by reperfusion, either invasively or pharmacologically. In our patient, due to limited resources and patient delay, reperfusion therapy was not performed either invasively or pharmacologically.…”

Inferior ST-elevation myocardial infarction managed with a pharmacoinvasive strategy and conservative management of delayed atrioventricular block: classical case report

“…The development of high-degree AV block after reperfusion, as with our case, is also not uncommon and has in fact been proposed to suggest successful reperfusion. 17 , 18 Microvascular obstruction, a form of reperfusion injury, has also been suggested as a mechanism for ongoing ischaemia of specialized conduction tissue despite patent epicardial coronary arteries. 19 Additionally, flow restoration may facilitate leucocyte migration to the infarcted area with stimulation of vagal nerve endings in the infero-posterior LV wall with resultant AV block.…”

“… 19 Additionally, flow restoration may facilitate leucocyte migration to the infarcted area with stimulation of vagal nerve endings in the infero-posterior LV wall with resultant AV block. 18 Due to increased vagal afferents within the posterior ventricular myocardium, this manifestation of AV block is thought to be more common in inferior MI. 17 , 18 Interestingly, the delayed resolution of AV block in these patients suggests that there may be more complex or multiple mechanisms that contribute to the development of AV block with reperfusion.…”

“… 18 Due to increased vagal afferents within the posterior ventricular myocardium, this manifestation of AV block is thought to be more common in inferior MI. 17 , 18 Interestingly, the delayed resolution of AV block in these patients suggests that there may be more complex or multiple mechanisms that contribute to the development of AV block with reperfusion. As the effects of increased vagal tone are expected to be short-lived, transient ischaemia-related AV nodal dysfunction seems to be the more likely aetiology.…”