Bradycardia and Narrow Complex Tachycardia

1
Bradycardia and Narrow Complex Tachycardia

• Smriti Banthia
• CCU Lecture Series

2
Conduction System Anatomy

• Sinus node is supplied by the RCA in 60 of
  people and by the LCX in 40.
• AV node is supplied by the RCA in 90 and by the
  LCX in 10 of patients.
• Right bundle supplied by LAD
• Left bundle supplied by branches of the RCA and
  LAD

Zimetbaum PJ, Josephson ME. NEJM, 2003
Taken from www.baptistoneword.org
3
Pacemaker?

• Progressive shortening of PP interval before it
  blocks
• Pause is less than 2 of the preceding PP
  intervals

4
Pacemaker?
5
WHAT NEXT?
52 year-old obese man who presents with
cellulitis. Above seen on telemetry during
hospitalization.
6
Page. HR 30. WHAT NEXT?
7
WHAT IS THIS?

8
WHAT NEXT?
80 year-old man presents with syncope.
9
Whats the rhythm?
NSR with first degree AV block
10
Pause duration to meet criteria for pacemaker
implantation?
3 seconds
11
Post cath, holding groin pressure. Pt dizzy now.
WHAT NEXT?
Sinus Bradycardia. Vagal response. Give Atropine.
12
What is the rhythm?
ATRIAL FIBRILLATION
13
Management of AF

• Maintenance of normal sinus rhythm
• No treatment
• Pharmacologic therapy (AAD, anticoagulants)
• Non-pharmacologic therapy (Ablation, PPM)
• Ventricular rate control
• Pharmacologic therapy (BB, CCB, Digoxin)
• Non-pharmacologic therapy (AVN ablation)
• Reduction of thromboembolic risk

14
Whats wrong?
15
AFIB AND STROKE

• Leading cause of stroke from embolism
• AF increases stroke risk
• 17x Rheumatic heart Dz
• 5x in non-valvular
• Risk of stroke 5/yr
• Proportion of strokes attributable to AF
  increases with age

16
When Rx Coumadin?
17
(No Transcript)
18
Problem What about pt with prior hx of CVA but
no other RF? Classified as moderate risk when in
fact may be high risk. Thus, the ACC/AHA
guidelines differ in the following way
19
ACC/AHA Guidelines for Anticoagulation
20
Tachy-Brady Syndrome
21
WHAT NEXT???
32 year-old female with palpitations
22
After Adenosine 6mg IV
23
Retrograde p waves
CSM/Vagal Maneuvers Adenosine BB/CCB Ablation
24
AVNRT Mechanism?
25
(No Transcript)
26
Aflutter with variable conduction
27
MAT
28
Aflutter with 41 Block
Most cases of atrial flutter are caused by a
large reentrant circuit in the wall of the right
atrium EKG Characteristics Biphasic sawtooth
flutter waves at a rate of 300 bpm Flutter
waves have constant amplitude, duration, and
morphology through the cardiac cycle There is
usually either a 21 or 41 block at the AV node,
resulting in ventricular rates of either 150 or
75 bpm
29
Unmasking of Flutter Waves
In the presence of 21 AV block, the flutter
waves may not be immediately apparent. These can
be brought out by administration of adenosine.
30
Atrial Tachycardia
31
Atrial tachycardia

• P wave upright lead V1 and negative in aVL
  consistent with left atrial focus.
• P wave negative in V1 and upright in aVL
  consistent with right atrial focus.
• Adenosine may help with diagnosis if AV block
  occurs and continued arrhythmia likely atrial
  tachycardia
• 70-80 will also terminate with adenosine.

32
WHAT IS THIS?
33

• A. Emergent cardioversion for polymorphic VT.
• B. I.V. procainamide
• C. I.V. lidocaine
• D. diltiazem drip to obtain rate control.

34
WPW epidemiology

• Present in 0.3 of the population
• Risk of sudden death 1 per 1000 patient-years
• Sudden death due to atrial fibrillation with
  rapid ventricular conduction
• Atrial fibrillation often induced from rapid ORT

ORT(orthodromic reciprocating tachycardia
35
Atrial Fibrillation and WPW

• AV nodal blocking agents may paradoxically
  increase conduction over accessory pathway by
  removing concealed retrograde penetration into
  accessory pathway.

Concealed penetration into the pathway causes
intermittent block of pathway conduction
36
Management of Atrial Fibrillation with WPW

• Avoid AV nodal blockers
• IV procainamide to slow accessory pathway
  conduction
• Amiodarone if decreased LVEF
• DC cardioversion if symptomatic with hypotension