sudden cardiac death definition –death occurs within minutes –cardiac in nature –unwitnessed...
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Sudden Cardiac DeathSudden Cardiac Death
• Definition– Death occurs within minutes– Cardiac in nature– Unwitnessed death
• Incidence– 375,000 people suffer Sudden Cardiac
Death per year– Approximately 43 people every hour– 75,000 (20%) survive
• Definition– Death occurs within minutes– Cardiac in nature– Unwitnessed death
• Incidence– 375,000 people suffer Sudden Cardiac
Death per year– Approximately 43 people every hour– 75,000 (20%) survive
Sudden Cardiac ArrestSudden Cardiac Arrest
Magnitude of SCA in the U.S.Magnitude of SCA in the U.S.
1 U.S. Census Bureau, Statistical Abstract of the United States: 2001.2 American Cancer Society, Inc., Surveillance Research, Cancer Facts and Figures 2001.3 2002 Heart and Stroke Statistical Update, American Heart Association.4 Zheng Z. Circulation. 2001;104:2158-2163.
AIDS1
Breast Cancer2
Lung Cancer2
Stroke3
SCA4
SCA claims more lives each year than these other diseases combined
450,000
167,366
157,400
40,600
42,156
#1 Killer in the U.S.
Sudden Cardiac Arrest is one of the Leading Causes of Death in the U.S.
0
50,000
100,000
150,000
200,000
250,000
300,000
AIDS Breast Cancer Lung Cancer Stroke SCA
Source: Statistical Abstract of the U.S. 1998, Hoover’s Business Press, 118 th Edition
Sudden Cardiac DeathSudden Cardiac Death
• Causes– 80-90% are tachyarrhythmias– Only 10-20% are due to an acute
myocardial infarction or to bradyarrhythmias
• Causes– 80-90% are tachyarrhythmias– Only 10-20% are due to an acute
myocardial infarction or to bradyarrhythmias
PrimaryPrimaryVFVF8%8%
Underlying Arrhythmia of Sudden Cardiac Arrest
Adapted from Bayés de Luna A. Am Heart J. 1989;117:151-159.
TorsadesTorsadesde Pointesde Pointes
13%13%
Bradycardia17%
VTVT 62%62%
Coronary Heart DiseaseCoronary Heart Disease• An estimated 13 million people had CHD in the U.S. in 2002. 1
• Sudden death was the first manifestation of coronary heart disease in 50% of men and 63% of women. 1
• CHD accounts for at least 80% of sudden cardiac deaths in Western cultures.3
• An estimated 13 million people had CHD in the U.S. in 2002. 1
• Sudden death was the first manifestation of coronary heart disease in 50% of men and 63% of women. 1
• CHD accounts for at least 80% of sudden cardiac deaths in Western cultures.3
1 American Heart Association. Heart Disease and Stroke Statistics—2003 Update. Dallas, Tex.: American Heart Association; 2002.
2 Adapted from Heikki et al. N Engl J Med, Vol. 345, No. 20, 2001.
3 Myerberg RJ. Heart Disease, A Textbook of Cardiovascular Medicine. 6th ed. P. 895.
Etiology of Sudden Cardiac Death2,3
* ion-channel abnormalities, valvular or congenital heart disease, other causes
80%Coronary
Heart Disease
15%Cardiomyopathy
5% Other*
SCD
CAD Risk Factors
“Reduced left ventricular ejection fraction (LVEF) remains
the single most important risk factor for overall mortality
and sudden cardiac death.”1
“Reduced left ventricular ejection fraction (LVEF) remains
the single most important risk factor for overall mortality
and sudden cardiac death.”1
2119.8
14
10
7
16 16
129.4
28
1820
28
0
10
20
30
TRACE CAPRICORN EMIAT MADIT MUSTTInducible
MUSTTRegistry
MADIT II*
Con
trol
Gro
up M
orta
lity
at 2
year
s
Total Mortality
Arrhythmic Mortality
2119.8
14
10
7
16 16
129.4
28
1820
28
0
10
20
30
TRACE CAPRICORN EMIAT MADIT MUSTTInducible
MUSTTRegistry
MADIT II*
Con
trol
Gro
up M
orta
lity
at 2
year
s
Total Mortality
Arrhythmic Mortality
References in slide notes. * MADIT-II mortality values at 20 months.
SCD Rates in Post-MI Patients with LV Dysfunction
SCD Rates in Post-MI Patients with LV Dysfunction
Total Mortality ~20-30%; SCD accounts for ~50% of the total deaths.
Treatments to Reduce SCDTreatments to Reduce SCD
Correcting Ischemia– Revascularization
– Beta-blocker
Preventing Plaque Rupture
– Statin
– ACE inhibitor
– Aspirin
Stabilizing Autonomic Balance
– Beta-blocker
– ACE inhibitor
Correcting Ischemia– Revascularization
– Beta-blocker
Preventing Plaque Rupture
– Statin
– ACE inhibitor
– Aspirin
Stabilizing Autonomic Balance
– Beta-blocker
– ACE inhibitor
Improving Pump Function
– ACE inhibitor
– Beta-blocker
Prevention of Arrhythmias
– Beta-blocker
– Amiodarone
Terminating Arrhythmias
– ICDs
– AEDs
Prevent Ventricular Remodeling and Collagen Formation
– Aldosterone receptor blockade
Improving Pump Function
– ACE inhibitor
– Beta-blocker
Prevention of Arrhythmias
– Beta-blocker
– Amiodarone
Terminating Arrhythmias
– ICDs
– AEDs
Prevent Ventricular Remodeling and Collagen Formation
– Aldosterone receptor blockade
Zipes DP. Circulation. 1998;98:2334-2351.Pitt B. N Engl J Med. 2003;348:1309-1321.
MADIT II (1997-2002)Multicenter Automatic Defibrillator Implantation Trial II
MADIT II (1997-2002)Multicenter Automatic Defibrillator Implantation Trial II
• Objective - To evaluate the role of ICD vs. medical therapy in a group of patients with left ventricular dysfunction and MI
• Inclusion - Post MI patients with EF < 30%. No prior assessment of VT in the EP lab. Requirement for freq. PVC’s was dropped six months in to the study (only 23 pts enrolled).
• Exclusion - Approved indication for an ICD; Undergone coronary revascularization within 3-months; An MI within the past 1-month
• Objective - To evaluate the role of ICD vs. medical therapy in a group of patients with left ventricular dysfunction and MI
• Inclusion - Post MI patients with EF < 30%. No prior assessment of VT in the EP lab. Requirement for freq. PVC’s was dropped six months in to the study (only 23 pts enrolled).
• Exclusion - Approved indication for an ICD; Undergone coronary revascularization within 3-months; An MI within the past 1-month
Ann Noninvasive Electrocardiol. 1999;4:83-91
MADIT II Multicenter Automatic Defibrillator Implantation Trial II
MADIT II Multicenter Automatic Defibrillator Implantation Trial II
• Patients - 1,232 randomized in a 3:2 ratio to receive an ICD (752) or conventional medical therapy (490)
• Results - Over a 4-yr period with an average follow-up of 20-months, the ICD group resulted in a 5.6% absolute and 31% relative risk reduction in mortality over conventional group - 14.2% vs. 19.8% respectively– Study terminated early due to this favorable
result
• Patients - 1,232 randomized in a 3:2 ratio to receive an ICD (752) or conventional medical therapy (490)
• Results - Over a 4-yr period with an average follow-up of 20-months, the ICD group resulted in a 5.6% absolute and 31% relative risk reduction in mortality over conventional group - 14.2% vs. 19.8% respectively– Study terminated early due to this favorable
result
MADIT II Multicenter Automatic Defibrillator Implantation Trial II
MADIT II Multicenter Automatic Defibrillator Implantation Trial II
Probability of Survival
Moss, A. et. al. N Engl J Med 2002;877-83
60%60%
MUSTTMUSTT55
5 years5 years
54%54%
MADITMADIT44
2 years2 years
20%20%
CIDSCIDS33
3 years3 years
37%37%
CASHCASH22
2 years2 years
31%31%
AVIDAVID11
3 years3 years
Reductions in Mortality with ICDsCompared to Antiarrhythmic Drugs
0%0%
10%10%
20%20%
30%30%
40%40%
50%50%
60%60%
% M
orta
lity
Red
uctio
n%
Mor
talit
y R
educ
tion
1 The AVID Investigators. N Engl J Med. 1997;337:1576-1583.2 Kuck K. ACC98 News Online. April, 1998. Press release.
3 Connolly S. ACC98 News Online. April, 1998. Press release.4 Moss AJ. N Engl J Med. 1996;335:1933-1940.5 Buxton AE. N Engl J Med. 1999;341:1882-1890.
$0$0
$20$20
$40$40
$60$60
$80$80
$100$100
$120$120
$140$140
$160$160
$180$180
$200$200$L
YS
(X
100
0)$L
YS
(X
100
0)$L
YS
(X
100
0)$L
YS
(X
100
0)
Incremental Cost-Effectiveness Results ($LYS)*
Highly Cost EffectiveHighly Cost Effective
Cost EffectiveCost Effective
Borderline Cost EffectiveBorderline Cost Effective
ExpensiveExpensive
UnattractiveUnattractive
*Versus Conventional Therapy1 Kupersmith. Progress in Cardiovascular Disease. 1995. 2 Owens. Annals of Internal Medicine. 1997. 3 Kupperman. Circulation. 1990
CaptoprilCaptopril
$28,400$28,400
Post MIPost MIEF EF << .40 .4011
CardiacCardiac
$44,300$44,300
TransplantTransplantCHFCHF
TransplantTransplantCandidateCandidate11
PTCAPTCA
$91,500$91,500
Chronic CADChronic CADMild AnginaMild Angina1 VD LAD1 VD LAD11
Anticoag.Anticoag.
$174,100$174,100
Mitral Mitral StenosisStenosis
NSR, FemaleNSR, FemaleAge 35Age 3511
PeritonealPeritoneal
$57,300$57,300
DialysisDialysis33
CABGCABGChronic CADChronic CADMild AnginaMild Angina
3 VD3 VD11
$18,200$18,200
ICDICD
$27,000$27,000
TherapyTherapy22
GOAL OF ICD THERAPYGOAL OF ICD THERAPY
• 375,000 people suffer Sudden Death each year
• Only 20% survive• In 1985, the only indication for AICD
implantation was survival of 2 sudden death episodes
• Today, we are attempting to identify those patients who are at high risk and treat them prior to SCD
• 375,000 people suffer Sudden Death each year
• Only 20% survive• In 1985, the only indication for AICD
implantation was survival of 2 sudden death episodes
• Today, we are attempting to identify those patients who are at high risk and treat them prior to SCD
EF Clinic Program Patient Screening Pathway(The Ohio Heart & Vascular Center)
Determine EF
Does patient havehistory of cardiac
arrest, VF, orsymptomatic VT?
Non-Ischemic
Consult EP for possible CRT-D
Optimize therapies or consult HF specialist
EF ≤ 35%
Ischemic
PATIENT
40 days post MI with EF ≤ 30%
NYHA Class I CHF
EF > 35%
40 days post MI OR
3 months post revascularization
Consult EP for possible ICD
3 months post diagnosis
1. Consider referral to HF Specialist or HF Program.
2. Repeat diagnostics with change of symptoms.
Class III or IV CHFand QRS > 120 ms
Consult EP for possible ICD
Consult EP for possible ICD
Is patient on optimal medical
therapy?YES
YES
NO
Note: Pathway only begins after optimal medical therapy & coronary evaluation / intervention as appropriate
Consult EP for possible ICD
NYHA Class II or III CHF
This is a general protocol to assist in the management of patients. This protocol is not designed to replace clinical judgment or individual patient needs.
1. Cardiac Arrest–Due to VT or VF–Not due to transient or reversible cause
2. Spontaneous sustained VT–Structural heart disease must be present
3. Syncope of undetermined origin with:–Sustained VT that has clinical relevance and/or hemodynamic significance
–VF induced during EP study when drug therapy to
sustained VT is not preferred
1. Cardiac Arrest–Due to VT or VF–Not due to transient or reversible cause
2. Spontaneous sustained VT–Structural heart disease must be present
3. Syncope of undetermined origin with:–Sustained VT that has clinical relevance and/or hemodynamic significance
–VF induced during EP study when drug therapy to
sustained VT is not preferred
Class IClass I
Indications for ICDIndications for ICD
4. Nonsustained VT with:– Coronary disease– Prior MI– LV Dysfunction– Inducible VF or sustained VT
(Non-suppressible by antiarrhythmic drugs)
5. Spontaneous sustained VT– Not amenable to other treatments
4. Nonsustained VT with:– Coronary disease– Prior MI– LV Dysfunction– Inducible VF or sustained VT
(Non-suppressible by antiarrhythmic drugs)
5. Spontaneous sustained VT– Not amenable to other treatments
Class IClass I
Indications for ICDIndications for ICD
1. LVEF <30% at:–1 month post MI–3 months post coronary revascularization
1. LVEF <30% at:–1 month post MI–3 months post coronary revascularization
Class IIa
Class IIa
Indications for ICDIndications for ICD
1. Cardiac Arrest – Assumed due to VF
– EP test precluded by other medical conditions
2. Symptomatic sustained VT while awaiting cardiac transplant
3. Conditions with life-threatening risk
– Long QT Syndrome
– Hypertrophic cardiomyopathy
1. Cardiac Arrest – Assumed due to VF
– EP test precluded by other medical conditions
2. Symptomatic sustained VT while awaiting cardiac transplant
3. Conditions with life-threatening risk
– Long QT Syndrome
– Hypertrophic cardiomyopathy
Class IIb
Class IIb
Indications for ICDIndications for ICD
1. Syncope of undetermined origin
–Without structural heart disease
–No inducible VT or VF
2. Incessant VT or VF
3. VT or VF with an ablatable or surgically treatable cause
–WPW, LVOT VT, ILVT, Fascicular VT
4. Transient or reversible VT
–Due to AMI, electrolyte imbalance, drugs or trauma
1. Syncope of undetermined origin
–Without structural heart disease
–No inducible VT or VF
2. Incessant VT or VF
3. VT or VF with an ablatable or surgically treatable cause
–WPW, LVOT VT, ILVT, Fascicular VT
4. Transient or reversible VT
–Due to AMI, electrolyte imbalance, drugs or trauma
Class IIIClass III
Indications for ICDIndications for ICD
5.Psychiatric illness that may:
–Be aggravated by device implantation
–Preclude follow-up
6.Terminal illness
–<6 month life expectancy
5.Psychiatric illness that may:
–Be aggravated by device implantation
–Preclude follow-up
6.Terminal illness
–<6 month life expectancy
Class IIIClass III
Indications for ICDIndications for ICD
ICD EvolutionICD Evolution
Evolution of ICD TechnologyEvolution of ICD Technology
ICD EvolutionICD Evolution
THEN…THEN…•Required major surgery•Nonprogrammable•High-energy shock only• Indicated for 2X SCD
survivors only•1 ½ year longevity•< 1,000 implants/year
•Required major surgery•Nonprogrammable•High-energy shock only• Indicated for 2X SCD
survivors only•1 ½ year longevity•< 1,000 implants/year
ICD EvolutionICD Evolution
…and NOW…and NOW•Transvenous, single
incision•Local anesthesia,
conscious sedation•Programmable therapy
options•Single, dual and triple
chamber•Up to 9 years longevity•> 100,000
implants/year
•Transvenous, single incision
•Local anesthesia, conscious sedation
•Programmable therapy options
•Single, dual and triple chamber
•Up to 9 years longevity•> 100,000
implants/year
ICD EvolutionICD Evolution
How it WorksHow it Works
The ICD SystemThe ICD System
*Animation
The ICD SystemThe ICD SystemHow it WorksHow it Works
Atrium & Ventricle
• Bradycardia sensing
• Bradycardia pacing
• Antitachycardia pacing
Atrium & Ventricle
• Bradycardia sensing
• Bradycardia pacing
• Antitachycardia pacing
Ventricle• VT prevention• Antitachycardia
pacing• Cardioversion• Defibrillation
Ventricle• VT prevention• Antitachycardia
pacing• Cardioversion• Defibrillation
(Header)
(Used for Telemetry)
ICDICDDevice ComponentsDevice Components
Question?Question?
What is the function of an ICD?What is the function of an ICD?
•Sense•Detect•Therapy•Pace
•Sense•Detect•Therapy•Pace
Question?Question?
What is Sensing?What is Sensing?
• The process of identifying cardiac depolarizations from an intracardiac electrogram
• The process of identifying cardiac depolarizations from an intracardiac electrogram
• It’s what the device sees• It’s what the device sees
SensingSensing
• Sensing - what the device “sees”• Sensing - what the device “sees”
• Electrical Activity - what the device is looking for
• Electrical Activity - what the device is looking for
• Lead – contains the ‘eyeball’ of the device
• Lead – contains the ‘eyeball’ of the device
The EGM SignalThe EGM SignalFarfieldFarfield
Morphology ComparisonMorphology Comparison
EGM Source = VariableEGM Source = Variable
SINUS RHYTHM
SINUS RHYTHM VTVT
–TP = Anti-Tachycardia Pacing Initiated (ATP)
–CE = Charge End–CD = Charge Delivered
–TP = Anti-Tachycardia Pacing Initiated (ATP)
–CE = Charge End–CD = Charge Delivered
•Therapy:
Marker Channel™Marker Channel™
ICD Function AnnotationsICD Function Annotations
* in Medtronic devices
DetectionDetection
•Measured in:–Beat-to-beat intervals (milliseconds), or–Beats-per-minute (BPM)
•Measured in:–Beat-to-beat intervals (milliseconds), or–Beats-per-minute (BPM)
Detection RateDetection Rate
•Classifies rhythm by detection zone:–VT = Ventricular Tachycardia
–VF = Ventricular Fibrillation
•Classifies rhythm by detection zone:–VT = Ventricular Tachycardia
–VF = Ventricular Fibrillation
•Programmable in ranges of ratesExample: VT = 162 bpm – 188 bpm
VF = 188 bpm and faster
•Programmable in ranges of ratesExample: VT = 162 bpm – 188 bpm
VF = 188 bpm and faster
Question?Question?
Can you name some therapies delivered by an ICD?Can you name some therapies delivered by an ICD?
ICD TherapiesICD Therapies
• ICD Therapy– Low Power (Pacing Therapies)
• Anti-tachycardia Pacing (ATP• Bradyarrhythmia Pacing
– High Power (Shock Therapies)• Cardioversion • Defibrillation
• ICD Therapy– Low Power (Pacing Therapies)
• Anti-tachycardia Pacing (ATP• Bradyarrhythmia Pacing
– High Power (Shock Therapies)• Cardioversion • Defibrillation
ICD TherapiesICD Therapies
•Tachyarrhythmia Therapy•Tachyarrhythmia Therapy–Anti-Tachycardia Pacing (ATP)
•Pacing pulses delivered at a rate faster than the rhythm detected
•Can successfully terminate re-entrant tachycardias
–Anti-Tachycardia Pacing (ATP)•Pacing pulses delivered at a rate faster than the rhythm detected
•Can successfully terminate re-entrant tachycardias
Low Power
Anti-Tachycardia PacingAnti-Tachycardia Pacing
*Animation
Click image to view animation
Anti-Tachycardia PacingAnti-Tachycardia Pacing
Re-entry initiatedRe-entry initiated
ATP delivered at a rate faster than
tachyarrhythmia.Wavefronts collide.
ATP delivered at a rate faster than
tachyarrhythmia.Wavefronts collide.
Subsequent Pulse: Wavefronts collide closer to re-entry
circuit
Subsequent Pulse: Wavefronts collide closer to re-entry
circuit
Subsequent Pulses: Wavefronts collide even closer to re-entry circuit
Subsequent Pulses: Wavefronts collide even closer to re-entry circuit
Arrhythmia terminatedArrhythmia terminated
CardioversionCardioversion
•Delivers shock on an R-wave•Aborts if synchronization cannot be obtained due to arrhythmia termination
•Delivers shock on an R-wave•Aborts if synchronization cannot be obtained due to arrhythmia termination
DefibrillationDefibrillation
*Animation
Click image to view animation
ICD TherapyICD Therapy
VT
FVT
VF
Benefits of Tiered TherapyBenefits of Tiered Therapy
Bradyarrhythmia TherapyBradyarrhythmia Therapy
•Most ICDs offer:–Single Chamber Pacing
•AAI(R), VVI(R) and VOO
–Dual Chamber Pacing•DDD(R), DDI(R), DOO and ODO•Mode Switch
–Separate post-shock pacing programming•Ensures capture
•Most ICDs offer:–Single Chamber Pacing
•AAI(R), VVI(R) and VOO
–Dual Chamber Pacing•DDD(R), DDI(R), DOO and ODO•Mode Switch
–Separate post-shock pacing programming•Ensures capture
Pacing ModesPacing Modes