Cardiac arrhythmias such as atrial fibrillation are abnormal heart rhythms that can cause complications like stroke if left untreated, but can be managed through approaches like rate control or rhythm control using medications, cardioversion, or catheter ablation procedures to restore normal sinus rhythm and prevent stroke. The document reviews the anatomy and electrical function of the normal heart, abnormalities that can occur, evaluation and diagnosis of arrhythmias, treatment options including for atrial fibrillation, and complications to be aware of such as the increased risk of stroke.

1. Cardiac Arrhythmias
Robert K. Altman, MD, FACC
Director, Clinical Cardiac Electrophysiology
Core Assistant Professor of Medicine
Hackensack-Seton Hall School of Medicine

2. Introduction to the Heart and the
Circulatory System
• A) How long is the circulatory system ? If we were to
connect all your arteries, veins and capillaries…….what
would the length be?
 60,000 miles
• B) How many times does the heart beat each day?
 100,000 times / each day; 35 million times / year; 2.5 billion
times / 70 years of life
• C) How many gallons of blood does the heart pump each
day?
 2000 gallons each day throughout the body

3. 4 chambers
– 2 upper (atrium)
– 2 lower (ventricle)
In cross-section:
Upper and lower
chambers are
separated by valves.
Three system of the heart
1. Pumping
2. Electricity
3. Blood Flow
Anatomy of the Heart

4. •In Sinus Rhythm, the
electrical impulse
originates at the Sinus
Node.
•It activates the upper
chambers to contract.
•When it reaches the AV
node it electrically
stimulates the lower
chambers of the heart to
contract.
•The heart beats as a 1:1
ratio in a coordinated
way.
Normal Sinus Rhythm

5. Measuring the Myocyte

6. The Cardiac Action Potential
Refractory period

7. 12 Lead Electrocadiogram:
Normal Sinus Rhythm

8. ECG

9. ECG
P
QRS
T

10. What could possibly go wrong?
• Arrhythmia
 Abnormality of the rhythm of the heart
 Too slow
• Bradyarrhythmia
• May require a pacemaker
 Too fast
• Tachyarrhythmia
• May originate in the upper or lower chambers
• May be treated with medications, defibrillators,
or procedures

11. Bradyarrhythmia
• Definition: Any ABNORMAL heart rate
from any cause that is less than 60 BPM
• At times bradycardia may be physiologic as
in athletes or during sleep
• Symptoms range from asymptomatic to
severely symptomatic with transient loss of
consciousness, cardiac arrest , fatigue,
shortness of breath
Treatment for most
symptomatic
bradyarrhythmias
is a pacemaker

12. Pacemaker Basics, A Brief History:
 1951 Paul Zoll: First external pacemaker
(plugged in)
 1957: Earl E. Bakken and Walton Lillehei
 Lillehei, cardiac surgeon designed pacing wires to be
used after congenital heart surgery.
 Bakken, electrical engineer, designed custom
hospital equipment with his company Medtronic
 After a power failure, Lillehei asked Bakken to design a
battery powered pacemaker
 He modified an electrical metronome and placed a battery in
a box.

13. Pacemaker Basics:
 Pulse generator: Delivers electrical impulses
 Battery to generate current and the circuitry.
 Lithium-iodine battery in which the lithium serves at the anode (source
of electrons),
 Battery varies depending on the frequency of use and the output
required to capture the (~10 years)
 Leads: Electrical conduits from generator to myocardium
 Most pacemaker leads are insulated with silicone, polyurethane, or a copolymer
of the two.

14. Pacemaker Basics:

15. What health condition does Howie Mandel Have?

16. What is Atrial Fibrillation (AF)?
• AF is the most common heart arrhythmia in the US
 Affects nearly 6 million people
 More than 160,000 new cases each year
 Eight people out of 100 over age 65 have AF
 More likely to develop AF if your parents had AF

18. Atrial Fibrillation
•In Atrial Fibrillation (AF)
the electrical impulses
originate in the atrium in a
chaotic fashion.
•May be as fast as 300-500
bpm.
•The upper chambers
quiver.
•Consequently, the heart
beat is irregular and fast

19. Difference in EKG Strips
Normal Sinus Rhythm
Atrial Fibrillation

20. Risk Factors
• Age >65
• Hypertension or high blood pressure
• Congestive heart failure
• Heart valve disease
• Previous open heart surgery
• Diabetes
• Sleep apnea
• Obesity

21. Symptoms of AF
• Symptoms vary widely, from being totally asymptomatic to
needing to be hospitalized.
• Most people complain of:
 Palpitations
 Fatigue
 Shortness of Breath
 Exercise intolerance
 Dizziness or lightheadedness

22. Stages or Types of AF
 Paroxysmal:
 Episodes start and stop on their own
 Usually last 7 days or less
 Terminates independently
 Usually initiated by rapid electrical firing from the pulmonary veins.
 Persistent atrial fibrillation:
 Episodes last longer than 7 days
 Requires medications and/or electrical cardioversion to achieve normal sinus
rhythm
 Initiation can originate in the pulmonary veins and areas in the left atrium
 Longstanding persistent
 Longer than one year

23. How is AF Diagnosed?
• EKG or Electrocardiogram
• Holter
• Event Monitor
• PCP or Cardiologist initially makes AF diagnosis
 Other diagnostic tests include
• ECHO
• Stress testing
• Thyroid testing

24. Learn how to check your pulse!
• Step 1
Turn your left hand palm-side up, then place
the first two fingers of your right hand along
the outer edge of your left wrist just below
where your wrist and thumb meet.
• Step 2
Slide your fingers toward the center of your
wrist. You should feel the pulse between the
wrist bone and the tendon.
• Step 3
Press down with our fingers until you feel your
pulse. Do not press too hard, or you will not
be able to feel the pulsation. Feel free to
move your fingers until the pulse is easiest to
feel.
• Step 4
Continue to feel your pulse for a full minute.
Concentrate on whether the beats are evenly
spaced, or whether they are erratic, with
missed beats, extra beats, or beats that are
too close together.

25. Why do we treat AF?
• Symptom
Management
• Stroke Prevention

26. Complications associated with AF
• AF alone is not life threatening.
• If untreated or undiagnosed complications
can arise.
 Stroke
 Organ damage caused by blood clots
 Fast heart rates can cause weakening of the
heart.

27. Stroke Risk with AF
• 795,000 strokes in US each year
• 15-20% of all strokes are caused by AF
• AF related strokes are severe and disabling
 23% die
 44% suffer from significant neurological damage
 Compared to only 8% mortality with strokes not caused by
AF.
• 30% of AF patients are unaware that they have AF
• 25% of AF related strokes- their was no prior diagnosis of
AF

28. TEE LAA thrombus

29. Stroke in Atrial Fibrillation

30. Anticoagulant Therapy in AF
Benefit

Harm

30

31. Risk Stratification in Atrial Fibrillation
• CHADS2-VASC:
 Congestive Heart Failure
 Hypertension
 Diabetes
 History of stroke (2 points)
 Vascular disease
 Age 65-74 (1 point)
 Age > 74 (2 points)
 Female sex
Chest. 2010;137(2):263-272
Chest. 2012;141(1):147
31

32. Medical Therapy for Atrial Fibrillation
Beyond Stroke Prevention:
Treatment dictated by multiple factors
 Symptoms
 Duration of Atrial Fibrillation
 Frequency of Atrial Fibrillation
 Underlying Disease or Co-morbidities
32

33. Medical Therapy for Atrial
Fibrillation
Rate Control Approach
• Goal is the slow the rate to <80 beats per
minute at rest and <110 beats per minute with
exertion.
• Achieving slowing of the heart rate in atrial
fibrillation which may often reduce symptoms
• Patients usually maintained in atrial fibrillation
with this approach as they usually tolerate
atrial fibrillation better with few symptoms
33

34. Rate Control Approach
 Most Common Side Effects
 Beta Blockers
 Fatigue and tiredness
 Lightheadedness
 Depression
 Sexual side effects
 Ca Channel Blockers
 Low BP/lightheadedness
 Constipation
 Lower extremity Swelling
34
Medical Therapy for Atrial
Fibrillation

35. Rhythm Control Approach
 Goal is the restore normal sinus rhythm
and maintain patient in normal sinus
rhythm
 Employed through a variety of
techniques
 Electrical Cardioversion
 Anti-Arrhythmic Medications
 Catheter Ablation
35
Medical Therapy for Atrial
Fibrillation

36. Rhythm Control Approach
 Multiple anti-arrhythmic medications available
 Have to be monitored carefully
 If anti-arrhythmic medications are not
tolerated or preferred
 Catheter ablation of atrial fibrillation is an
option
36
Medical Therapy for Atrial
Fibrillation

37. Pulmonary Vein Isolation
Cryoballoon
RF Ablation Catheter
Mapping Catheter
Courtesy of Medtronic, Inc

38. Affirm Study

39.  STROKE PREVENTION!!
 Rate Control vs Rhythm Control Approach
 Determining best medications
 Monitoring efficacy and for adverse effects
 Determination of timing to refer for Catheter Ablation
Medical Therapy for AF

40. Review
• AF is the most common arrhythmia.
• Patient with AF can be symptomatic or
asymptomatic.
• Most important aspects of treatment are stroke
prevention and rate/rhythm control.
• Know how to check your pulse.
• There are many treatment options available.