Individuals with low levels of adenosine are susceptible to sudden surges in adenosine levels which act on the AV node and cause episodes of presyncope or syncope. This would be seen on an ECG as a sudden increase in sinus rate with narrow QRS complexes just prior to the period of asystole.
Paroxysmal AV Block Extrinsic Idiopathic AV Block
Paroxysmal AV Block Intrinsic AV Block
Paroxysmal AV Block Extrinsic Vagal AV Block
AVNRT Slow/Fast
Fascicular VT
Second degree AV block
First degree AV block
Third degree AV block