- Ectopic atrial tachycardia with block suggests digitalis excess. Don’t forget to find for the inverted P waves !
- Endless loop tachycardia in dual chamber pacemakers
– Normally when intrinsic P wave is detected, the atria pacemaker is inhibited and the ventricle’s one fires.
– However, if there is an alternate pathway enabling the retrograde conduction of the ventricular impulse, it will be misinterpretated as P wave. Atrial discharge is blocked but the ventricular pacemaker fires.
– Endless loop = ventricles -> atria -> ventricles -> atria -> ventricles -> atria……..
– Look for the pacemaker spike, it can small !
- Grouped Aflutter beats: think of bilevel AV block.
– This nice example is gotten from Dr Nelson’s slide in may 2015.
– In upper level, there is 2:1 conduction. In lower level, there is 3:2 conduction.
– Clinical significance: when you are trying to treat AFT with AVNB it may cause Wenckebach to develop below the upprer filter. It is perfectly okay, and not something to be worried about.