Scott

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Arrhythmias
Steven M. Costa, M.D. Assistant
Professor Department of Medicine Division of
Cardiology
Scott White Memorial Hospital and Clinic Texas
AM University Health Science Center
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Objectives

• Common Arrhythmias
• Sinus Tachycardia
• Atrial Fibrillation
• Atrial Flutter
• MAT
• VT

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CLUES

• Width? NCT vs WCT
• Regular? Irregular?
• Rate?
• P waves?
• No P waves
• Relation to QRS?
• Morphology (s)
• RP Interval

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Case 1
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Sinus Tachycardia

• General
• HR gt 100 bpm
• Upper Limits 220 age
• Behavior Warm up, Cool Down
• Etiology
• Hyperadrenergic States
• Hypovolemia
• Fever
• Pain
• Hyperthyroidism
• Treatment
• Correct underlying cause

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ECG 2

• Youve Just admitted at patient
• 68 y/o with CAP-Pneumonia
• h/o COPD
• You tuck him away
• Nurse calls you theyre Tachycardic

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MAT
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Multifocal Atrial Tachycardia

• General
• Seen in Elderly, Critically Ill pts
• Etiologies
• Pulmonary Disease
• COPD, Hypoxia
• Theophylline
• Electrolytes i K, Mg
• Infxns
• Metabolic Disturbances
• Acidosis

• ECG Recognition
• 3 different P wave morphologies
• Rate 100 180 bpm
• Treatment
• Treat the underlying cause!!!!

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Case 3

• 76 y/o WM
• HPI 3 hours history of fluttering in chest
  with SOB never had this before came on at rest
• No chest pain or symptoms consistent with heart
  failure
• PMHx significant for HTN (not on meds), Obesity,
  and Anxiety
• FHx positive for mother and two brothers with
  irregular heart rhythms
• Exam unremarkable except for irregularly
  irregular rhythm and BMI of 31

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ECG 3
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AFIB ECG
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A. Multiple-wavelet reentry Wavelets (indicated
by arrows) randomly reenter tissue previously
activated by them or by another wavelet. B.
Focal activation. The initiating focus often
lies within the region of the pulmonary veins.
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What are the important issues in managing this
gentleman?

• Etiology/Risk Factors
• Initial Rate control
• Do we anti-coagulate?
• Convert?
• Should we do other test?
• What medicines do we send him out on?

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Background

• Atrial fibrillation is the most common sustained
  arrhythmia
• Affects 2 million Americans
• 6 over the age of 65 experience it
• Responsible for 15 strokes
• Benjamin E Epidemiology of Atrial Fibrillation.
  In Falk RH, Podrida PJ, edsAtrial Fibrillation
  Mechanisms and Management. 2nd Ed,
  Lippincott-Raven Press, New York 1997, pp.1-22.

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Atrial Fibrillation Demographics by Age
U.S. populationx 1000
Population with AFx 1000
Population withatrial fibrillation
30,000 20,000 10,000 0
500 400 300 200 100 0
U.S. population
lt5
5-9
10-14
15-19
20-24
25-29
30-34
35-39
40-44
45-49
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85-89
90-94
gt95
Age, yr
Adapted from Feinberg WM. Arch Intern Med.
1995155469-473.
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Symptoms

• Inappropriate heart rate response
• Tachycardia induced cardiomyopathy
• Irregular rate
• Loss of atrial systolic function
• CHF- reduced EF
• Lots of patient have no symptoms
• present with Thromboembolic event

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Atrial Fibrillation Causes

• Cardiac
• Non-cardiac
• Lone atrial fibrillation

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Atrial Fibrillation Cardiac Causes

• Hypertensive heart disease
• Ischemic heart disease
• Valvular heart disease
• Rheumatic mitral stenosis
• Non-rheumatic aortic stenosis, mitral
  regurgitation
• Pericarditis
• Cardiac tumors atrial myxoma
• Sick sinus syndrome
• Cardiomyopathy
• Hypertrophic
• Idiopathic dilated (? cause vs. effect)
• Post-coronary bypass surgery

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Atrial Fibrillation Non-Cardiac Causes

• Pulmonary
• COPD
• Pneumonia
• Pulmonary embolism
• Metabolic
• Thyroid disease hyperthyroidism
• Electrolyte disorder
• Toxic alcohol (holiday heart syndrome)

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Lone Atrial Fibrillation

• Absence of identifiable cardiovascular,
  pulmonary, or associated systemicdisease
• Approximately 0.8 - 2.0 of patients with atrial
  fibrillation (Framingham Study)1
• In one series of patients undergoing electrical
  cardioversion, 10 had lone AF.2
• These patients have a favorable prognosis with
  respect to thromboembolism and mortality.

1 Brand FN. JAMA. 1985254(24)3449-3453. 2 Van
Gelder IC. Am J Cardiol. 19916841-46.
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RATE CONTROL

• Digoxin is NOT the first line of therapy
• Beta-blockers and nondihydropyridine CCBS are the
  first line of therapy
• Rare patient cant be controlled with meds - AV
  node ablation and pacing
• Tachycardia mediated cardiomyopathy
• Chicken or Egg

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New Onset AFib Work Up

• Work Up
• ECG - Telemetry
• TSH
• Electrolytes, Magnesium
• Echo TTE vs TEE
• Ingestion History EtOH, Cocaine
• PE Work up (if indicated)

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Other tests

• Echo
• Left atrial enlargement
• LV function
• Valvular Heart disease
• Shunt ie ASD is young
• Smoke (TEE)
• Poorly contractile LA appendage (TEE)

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Immediate Treatment

• Significant symptoms
• Restore NSR /- Antiarrhthymics
• Minimal symptoms
• Strongly Consider rate control
• AFFIRM Trial

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Afib Management

• Unstable
• Shock!

• Stable
• lt 48 Hrs gt 48 Hrs
• Rate Control Rate
• Anticoag Anticoag
• 1. TEE-DCCV
• CCV/DCCV 2. Coumadin
• /- DCCV

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Guidelines Definitions
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Therapeutic Approaches to Atrial Fibrillation

• Anticoagulation
• Antiarrhythmic Suppression
• Control of Ventricular Response
• Pharmacologic
• Catheter modification or ablation of the AV node.
• Curative Procedures
• Surgery
• Cox-Maze III
• Pulmonary Vein Isolation - Mini-Maze
• Catheter based ablation

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Benefit of Warfarin

• Absolute Risk of Stroke
• Age lt 65 years and no risk factors, lone AF
  ?1/yr.
• All others lowered to 1.5/yr by warfarin
• The Atrial Fibrillation Investigators Arch
  Intern Med 19941541449

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CHADS2 SCORECHF1, HTN1, Agegt 751, Diabetes1,
Stroke/TIA2

• Score Stroke Rate CHADS risk
• 0 1.9 Low
• 1 2.8 Low
• 2 4.0 Moderate
• 3 5.9 Moderate
• 4 8.5 High
• 5 12.5 High
• 6 18.2 High

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AF Anticoagulation - General Points

• Anticoagulation (INR 2.0 - 3.0) can reduce risk
  of stroke by 2/3 1,2
• Aspirin has little effect on risk of stroke due
  to AF lone AF consider ASA
• 1 Hylek EM and Singer DE. Arch Intern Med
  1994120897
• 2 Hylek EM et al. New Engl J Med 1966335540
• 3 The Atrial Fibrillation Investigators. Arch
  Intern Med 19971571237

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Stroke/Bleeding Risk
ACC/AHA Guidelines
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Anti-coagulation for AFib

• Afib accounts for 15 of strokes nationwide
• Chronic and Paroxysmal have the same risk
• 70 of strokes in Afib are cardioembolic
• Only 50-60 of qualified patients are on coumadin

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Stroke/Bleeding Risk
ACC/AHA Guidelines
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Cardioversion

• Acutely Yes, if
• Hemodynamically unstable
• CHF
• Angina
• Electively if pt remains symptomatic despite rate
  control
• Electrical vs Chemical

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Antiarrhythmic Drug Therapy
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AFib Summary

• Think about precipitating causes
• Rate control with beta blockers and calcium
  channel blockers
• Use safe, effective anti-dysrhythmic drugs
• Dont be afraid to anticoagulate
• EP guided ablation of Afib is slowly becoming a
  reality
• Aflutter can usually be easily ablated- remember
  Afib-Aflutter closely related
• Afib and Aflutter have similar stroke risks

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Case 4
Wide QRS complex tachycardia with cycle length
250ms. Mechanism of tachycardia cannot be
determined from this trace alone.
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• IV adenosine causes transient atrioventricular
  block and reveals the underlying atrial flutter.

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Wide complex tachycardia

• One of three things
• SVT w/ BBB or aberration
• SVT w/ conduction over accessory pathway
• VT important to differentiate
• CAD/LV dysfxn think VT gt 90

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• ECG 4

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Atrial Flutter

• (Macro) Reentrant Circuit located in the RA
• Typical Flutter Cavotricuspid Isthmus Dependent
• Atrial Rate 250-350 bpm
• Ventricular Rate Depends on degree of
  conduction

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Atrial Flutter (A-Flutter)

• Rapid and regular form of atrial tachycardia
• Usually paroxysmal
• Sustained by a macro-reentrant circuit
• Circuit is confined to the right atrium
• Episodes can last from seconds to years
• Chronic atrial flutter may progress to atrial
  fibrillation

Morady F. N Engl J of Med. 1999340534-544.
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Atrial flutter
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RF Ablation of Atrial Flutter
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ECG 5
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Ventricular Tachycardia

• Potentially lethal arrhythmias arising in
  ventricle
• Rate
• 100 280 bpm
• Usually 130 200 bpm
• Shape
• Monomorphic
• Polymorphic

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Monomorphic VT

• Heart rate 100 bpm or greater
• Rhythm Regular
• Usually secondary to structural heart disease
  such as healed tissue from old MI (scar)

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Polymorphic VT

• Heart rate Variable
• Rhythm Irregular
• Often due to myocardial ischemia in ACS setting
• Recognition
• Wide QRS with phasic variation
• Torsades de pointes

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Possible Causes PMVT

• Drugs that lengthen the QT
• Quinidine
• Procainamide
• Sotalol
• Ibutilide
• Physical
• Ischemia
• Electrolyte abnormalities

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Sustained vs. Nonsustained

• Sustained VT
• Episodes last at least 30 seconds
• Commonly seen in adults with prior
• Myocardial infarction
• Chronic coronary artery disease
• Dilated cardiomyopathy
• Non-sustained VT
• Episodes last at least 6 beats but lt 30 seconds

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Ventricular Tachycardia

• Etiology
• Ischemia (PMVT)
• CAD
• Structural Heart Disease
• DCM
• HoCM
• ARVD
• Infiltrative Disorders (Sarcoid, Amyloid)
• Channelopathies
• Idiopathic

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Underlying Arrhythmia of Sudden Death
Primary VF 8
Torsades de Pointes 13
VT 62
Bradycardia 17
Adapted from Bayés de Luna A. Am Heart J.
1989117151-159.
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Treatment

• Unstable
• Hemodynamics
• Sx
• Chest Pain
• SOB
• Pre-syncope

• Stable
• IV Amiodarone or IV Lidocaine
• Pacing
• Ablation

SHOCK!!!
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Implantable Cardioverter Defibrillator
First-line therapy for patients at risk for SCD

• Small devices, pectoral implant site
• Transvenous, single incision
• Local anesthesia conscious sedation
• Short hospital stays
• Few complications
• Perioperative mortality lt 1
• Programmable therapy options
• Single- or dual-chamber therapy
• Battery longevity up to 9 years
• 80,000 implants/year (2000 E)1

1Morgan Stanley Dean Witter. Investors Guide to
ICDs. 2000.
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Summary of Ventricular Dysrhythmia Management

• Amiodarone is no better than placebo at
  preventing sudden cardiac death
• LV dysfunction with EF lt 35 from any cause
  should be considered for EP referral for AICD
  placement

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ECG 6
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ECG 6
Toothbrush VT - Artifact
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Treatment

• Check patient

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SUMMARY

• Atrial fibrillation is a leading cause of stroke
• Anti-coagulation is underutilized in Atrial Fib
• Afib/flutter closely related
• Ventricular Tachycardia- cards eval
• SCD is common in post-MI patients and patients
  with CHF
• EF lt 35 should be considered for AICD, after
  medical therapy regardless of etiology
• Many, if not most, common rhythm problems can be
  ablated with catheter or surgical techniques