TCM is a rare disease, and its coexistence with transient high-degree AV block is very infrequent. AV block is reported in 2.9% of the total cases of TCM, and its relationship with TCM has not been clarified yet . The physiopathology is difficult to explain as TCM is supposed to have a magnified sympathetic tone and the apex, far away from the AV node, is the location of the most common wall segment motion abnormality. Diffuse spams in small coronary branches causing ischaemia and an increase in vagal tone are the hypothesized mechanisms of AV conduction disturbance .
The recovery of left ventricular dysfunction is not necessarily linked to the resolution of the AV conduction disturbances, suggesting different pathophysiologic mechanisms. In fact, in the majority of cases, AV block persists once the left ventricular function is normalized leading to a permanent pacemaker implantation. The indication and timing to place a permanent pacemaker is still a quandary, and decision should be individualized based on the lack of the conduction improvement or significative findings in the electrophysiological study [5, 6].
Although data from case series report that the majority of patients receive a permanent pacemaker , in our patient, due to the unexpected fast recovery of the normal AV conduction, even before of the left ventricular function normalization, we did not implant any device. Very few cases describe the normalization of AV conduction related to TCM [7,8,9], and this is the first case that reports it just a few hours after admission. Recent data suggest that advanced atrioventricular block is not associated with worse in hospital outcomes unlike what occurs with ventricular arrhythmias . Two years after the admission, the patient remains asymptomatic with a first-degree AV block on the electrocardiogram.