Diagnosis
4
Figure 1. Atrial Tachycardias
Macroreentrant Atrial Tachycardia/
Atrial Flutter
• Constant regular P-wave/
flutter wave morpholog y
• Rate typically >250 bpm
a
• Mechanism: Macroreentry
Focal Atrial Tachycardia
• Discrete P-waves with isoelectric
segment
• Rate typically 100-250 bpm
a
• Mechanisms: Microreentry
or automaticity
Typical Atrial
Flutter
Counterclockwise Atrial Flutter
• ECG flutter waves
a
:
▶ Negative in II, III, aVF
▶ Postitive in V1
Clockwise Atrial Flutter
(reverse typical Atrial Flutter)
• ECG flutter waves
a
:
▶ Positive in II, III, aVF
▶ Negative in V1
V1 typically opposite in polarity to
inferior leads
Right Atrial
Example: Reentry around healed
surgical incision in the free wall of
the RA aer repair of congenital
heart disease
Le Atrial
• Perimitral flutter
• LA roof dependent flutter
• Others
ECG
a
: Atypical
flutter suggested
by P-wave polarity
that does not fit
typical atrial flutter
(e.g., concordant
P-wave polarity
between V1 and
inferior leads)
a
Exceptions to P-wave morpholog y and rate are
common in scarred atria.
Not Cavotricuspid Isthmus Dependent
("Atypical Atrial Flutter")
• Reentry that is not dependent on conduction
throught the cavotricuspid isthmus
• The circuit is usually defined by atrial scars
from prior heart surgery, ablation,
or idiopathic
• Location determines ablation approach
and risks
• Multiple reentry circuits can be present
Cavotricuspid Isthmus
Dependent
• RA reentry dependent on
conduction through the
cavotriscuspid isthmus
• Can be cured by ablation
creating conduction block in
the cavotricuspid isthmus
