0071643192.pdf

ECG FINDINGS(SEEFIGURE1.12)

■ Narrow QRS complexes at rate of 120–200 bpm
■ Absence of visible P waves
■ Retrograde P waves are buried in QRS.
■ Regular rhythm

TREATMENT

■ If patient unstable →electrical cardioversion:
■ Synchronized
■ Begin with 50–100J
■ Other therapy focused on interrupting circuit within AV node
■ Vagal maneuvers
■ Valsalva
■ Carotid sinus massage
■ Be wary in elderly.
■ Ensure no carotid bruits first.
■ Immerse face in cold water →dive reflex (more effective in infants).
■ AV-node blockers
■ Adenosine
■ Diltiazem
■ β-Blockers

WOLFE-PARKINSON-WHITESYNDROME(WPW)

A very small percentage of the population has an accessory pathway that allows
sinus impulses to bypass the AV node and be conducted directly to the ventri-
cles. WPW is the most common accessory pathway syndrome.

In WPW, the accessory tract = bundle of Kent

RESUSCITATION
TABLE 1.7. CHADS2 Score to Predict Risk of Stroke in Patients With Chronic Atrial Fibrillation

VARIABLE POINTS

C CHF 1

H Hypertension 1

A Age> 75 years 1

D Diabetes 1

S Prior TIA or Stroke 2

Low risk (0–1 points): Aspirin

Moderate risk (2 points): Aspirin or warfarin

High risk (≥3 points): Warfarin (aspirin, if warfarin contraindicated)

FIGURE 1.12. AV-nodal reentrant tachycardia.

Adenosine will be effective in

the vast majority of patients

with AVNRT.

WPW accessory pathway =

bundle of Kent, connecting the

atrium directly to the ventricle.