Sudden Cardiac Death Definition –Death occurs within minutes –Cardiac in nature –Unwitnessed...

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


• 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



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



Is patient on optimal medical

therapy?YES

YES

NO

Note: Pathway only begins after optimal medical therapy & coronary evaluation / intervention as appropriate


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


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


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


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


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


ICD EvolutionICD Evolution

Evolution of ICD TechnologyEvolution of ICD Technology


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


…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

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

Sudden Cardiac Death Definition –Death occurs within minutes –Cardiac in nature –Unwitnessed...

Documents

Transcript of Sudden Cardiac Death Definition –Death occurs within minutes –Cardiac in nature –Unwitnessed...