Icd basic 042411(dr chang)

Basic ICD Treatment

張坤正醫師

中國醫藥大學內科副教授

中國醫藥大學附設醫院心臟內科主任

Advance EP Training

April/24/2011

ICD Concepts

ICD Automated Functions

Troubleshooting

ICD ConceptsOverview

•Evolution of ICDs•The ICD System•Components

– Device• Battery, Capacitors & Voltage• Circuitry• Connector Blocks

– Leads• Transvenous & Epicardial• Electrical Design• Connectors: IS-1 & DF-1

– Programmer

The Evolution of ICDs

1970

• Patent granted for first totally implantable defibrillator

• System used an intracardiac catheter and SQ patch with detection via RV pressure transducer

ICD Evolution

Michael Mirowski (1924-1990)

ICD Evolution

•1947 First human internal defibrillation •1956 First human external defibrillation•1969 First external canine prototype tested•1970 First implantable prototype (895 g)•1975 First implantable Defib in canines (250 g)•1980 First human implant @ Johns Hopkins•1985 ICD market released (350 units)

•1991 Non thoracotomy lead systems•1995 Pectoral ICD systems•1997 ICD & DDD•1998 ICD & DR•1999 ICD & Atrial Defibrillation•2001 ICD & Resynchronization Therapy

ICD Evolution

THE ICD SYSTEM

How it Works

The ICD System

*Animation

The ICD SystemHow it Works

Atrium & Ventricle• Bradycardia sensing • Bradycardia pacing• Antitachycardia

pacing

Ventricle• VT prevention• Antitachycardia pacing• Cardioversion• Defibrillation

Device Components

ICD

ICDDevice Components

c

c

c

Battery – Provides low voltage energy

High Voltage Shock – Delivered on demand

Capacitor – Stores high energy for use

Transformer – Multiplies Voltage

ICDHow High Voltage Is Created

How High Voltage Is Created

VoltageMultiplier

andTransformer High

VoltageCapacitor

High EnergyShocks(Up to 800 Volts)

Battery

Pacing Voltages

For Pacing

For Defibrillation

3.2 Volts

ICD

Battery Depletion

ICD

Battery DOWN

Charge Time UP

Both can Indicate Elective Replacement

(ERI)

Battery & Charge Time Relationship

Battery Voltage & Charge Time in an optimized ICD battery


The Importance of Charge Time

10 Seconds of VF

The longer the charge time, the longer this rhythm continues.

ICDConnector Block

ICD Connector Blocks

Components

23

New DF4 DR Header (2 set screws)

Today’s Current® DR RF Header (6 set screws)

COMPONENTS

High Voltage Leads

High Voltage Leads

Transvenous

Introduced into the heart through a vein.

Epicardial

Placed directly on the epicardium of the heart.

High Voltage Leads

Passive

Active

No Fixation

High Voltage LeadsTypes of Transvenous Leads

Transvenous

Endocardial Lead Systems

Passive Fixation (Tines)

Active Fixation (Screw)

Transvenous LeadsPlacement

Single Coil Dual Coil

Distal Coil

Proximal Coil

ConnectorPins

Typical Transvenous Lead

High Voltage Leads

Steroid Tip

Transvenous Lead

*Steroid not available in all leads

Benefits of Steroid:• Reduces acute Trauma and

Inflammation

• Rapid Tissue Damage Repair

• Reduced Fibrosis

Steroid Tip

Transvenous Lead


Lead Design

Optimal Tissue Contact

Transvenous Lead


Electrical Design

Lead Electrical Design

• High Voltage Leads can have 2 Circuits:

PACING & SENSING

SHOCKING

Circuits


Bipolar

Circuits

PACING & SENSING


•The electrical circuit for pacing and sensing includes:•Cathode – negative electrode (Tip)

•Anode: positive electrode (Ring or Coil)

Bipolar Configuration

Pacing/Sensing Circuit


True vs. Integrated

Circuits

Bipolar

PACING & SENSING

Polarity

Bipolaruses dedicated ring can as anode

Integrated Bipolaruses RV Coil can as anode

Pacing/Sensing Circuit

PolarityPacing/Sensing Circuit


High Voltage Coils

Circuits

True vs. IntegratedBipolar

PACING & SENSING

SHOCKING

Polarity

Single Coil• 1 high voltage coil per lead:

- RV (Right Ventricle)- Other extra HV Coils/Patches

• 1 or 2 Connector Pins - (HV only or P/S + HV)

Dual Coil• 2 High Voltage coils per lead:

- RV + SVC

• 3 Connector Pins (P/S + 2 HV)

Shocking Circuit

High Voltage Leads

Pace / Sense Connection = IS-1(International Standard)

High Voltage Defibrillation Connections = DF-1(Defibrillation Standard)

Connector Pins

Shocking Circuit

•The pathway in which high energy is delivered•Determined by electrodes used:

– HVA = active device– HVB = RV Coil– HVX = optional HV electrode (such as an SVC Coil)

Example: A > B

Vectors

A(Active Can)

B(RV HV Coil)

Shocking Circuit

Example: A > B(Active Can > RV HV Coil)

Vectors

Shocking Circuit

Example of Dual Coil: AX > B(Active Can + SVC HV Coil > RV HV Coil)

Vectors

Shocking Circuit

A > B AX > B

Vectors

COMPONENTS

Programmer

ICD Automated FunctionsOverview

• Sensing–The EGM Signal–The Sensing Circuit–Marker Channels

• Detection–Suspension (Magnet)–Rate & Duration (NID)–Detection Zones–SVT Discrimination

• Single Chamber• Dual Chamber

–Redetection

• Therapy –Tachyarrhythmia

• Anti-tachycardia Pacing (ATP)

• Cardioversion (Non-committed)

• Defibrillation (Committed)

–Bradyarrhythmia• Pacing Modes• Parameters• Other Brady Therapies

Low Power


Sensing

Sensing

• Sensing - what the device “sees”

• Electrical Activity - what the device is looking for

• Lead – contains the ‘eyeball’ of the device

SensingTrue vs. Integrated Bipolar

•Range of ‘eyeball’ is determined by polarityTrue Bipolar Sensing

Tip-to-ringSmaller surface areaMore “localized” sensing

Integrated Bipolar Sensing

Tip-to-coilLarger surface areaBroader sensing area

Sensing

•The ‘eye’ of the device– Constantly watches for electrical activity

– Sees or Senses all electrical signals that pass

– Signal produced by a passing electrical wave is called an IntracardiacElectrogram (EGM)

SENSING

The Intracardiac Electrogram EGM

Sensing

• Sensing is:

–The process of identifying cardiac depolarizations from an intracardiac electrogram

SensingThe EGM Signal

• The signal from a depolarization wave passing between sensing electrodes

Depolarization WaveProcessed by

Device

The EGM Signal

• Measured by:– Amplitude

• Peak-to-peak measurement (height) of deflection

• Measured in Millivolts (mV)

– Slew Rate• Speed of deflection change over time• Measured in volts per second (V/s)

The EGM Signal

• Measured Peak-to-Peak

Typical Ventricular EGM

• >5 mV for optimal sensing

Amplitude

The EGM Signal

• Measures Peak-to-Peak change in voltage over time

• R >.75 volts/sec for optimal sensing

Typical Ventricular EGM

Slew Rate = [V/s]

dVdt

Slew Rate

The EGM Signal

• Nearfield– Electrodes are close in range

• EGM Source = Tip-to-Ring / Tip-to-Coil

– Commonly a narrow signal (less myocardium in range)

– Used for arrhythmia detection • Devices are hardwired to nearfield for detection

Fields

The EGM Signal

EGM Source = Tip-to-Ring / Tip-to-Coil

Tip-to-Ring

(Bipolar)

Tip-to-Coil

(Integrated Bipolar)

Nearfield

The EGM SignalNearfield

Morphology Comparison

SINUS RHYTHM VT

EGM Source = Tip-to-Ring / Tip-to-Coil

The EGM Signal

•Nearfield– Electrodes are close in range

•EGM Source = Tip-to-Ring / Tip-to-Coil– Narrow signal – less myocardium in range– Used for arrhythmia detection

•Farfield–Electrodes are further in range

•EGM Source = Variable–More myocardium covered in range–Can resemble surface EKG

Fields

The EGM Signal

EGM Source = Variable

Can-to-RV Coil(HVA to HVB)

RV Coil-to-SVC Coil

(HVB to HVX)

Farfield

The EGM SignalFarfield

Morphology Comparison

EGM Source = Variable

SINUS RHYTHM VT

SENSING

The Sensing Circuit

The Sensing Circuit

• Upon being ‘seen,’ a signal is transported through the sensing circuit

The Sensing CircuitThe Amplifier

The Sensing CircuitThe Bandpass Filter

The Sensing CircuitRectifier

The Sensing CircuitLevel Detector

The Sensing Circuit

Sensitivity

•Minimum amplitude of electrical signal that registers as a sensed event

– Set in Millivolts (mV)– Programmable Setting

Sensitivity

If set at .15 mV

Programmed

SensitivityProgrammed

If set at .3 mVT-wave Not Sensed

SensitivityAuto-Adjusting

Sensitivity

• Allows sensing of fine VF waves

• Prevents sensing of T-waves, cross-chamberevents, and pacing artifacts

Auto-Adjusting

Auto-Adjusting SensitivityDecay Constant

Sensed Refractory

Max R-wave amplitude measured at 4 mV

Max R- wave amplitude measured at 7 mV

Threshold Start set to 50% of measured R-wave or 3 mV

2 mV 3 mV

R- wave is Sensed

Sensed Refractory

Maximum Sensitivity

Ventricular

Threshold Start

Decay Delay

• The Decay Delay holds the sensitivity threshold at the starting value for a programmable amount of time

60 ms

0 ms

R-wave

T-wave

Question?

What are the consequences of undersensing?

• Failure to sense VF, therefore, no therapy initiated

• Failure to treat VT that can accelerate to VF

• Can be fatal

Question?

What are the consequences of oversensing?

• Inappropriate therapies

• Potential for inducing fatal arrhythmias

• Patient suffering due to inappropriate therapy

SENSING

Marker Channels™

•Display:– Pace/Sense annotations

– ICD functional annotations:

• Sensing

• Detection

• Therapy

• Other information

Marker Channel™

* in Medtronic devices


Detection

Question?

What does “Detection” mean?

A device defined arrhythmia is present based on what is sensed.

Detection

• Confirms a sensed rhythm as an arrhythmia based on:– Rate – Duration

Detection

• Measured in:–Beat-to-beat intervals (milliseconds), or–Beats-per-minute (BPM)

Detection Rate

• 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

Detection

• Measured in:– Number of intervals to detect (NID), or– Length of time to detect

• Programmable by:– Beat or interval counters

• Consecutiveex: 16 beats within the detect zone

• Probabilistic (percentage or fraction) ex: 12 out of 16 beats within the detect zone

– Time in seconds

Detect Duration

Detection

Used for detection of VT

Consecutive Counter

Detection

NID = 12/16

Probabilistic Counter

Detection

Non-Sustained: Duration not met / No Detection

Sustained: Duration met / Detection Occurs

Detect Duration

Question?

What if the fast, sustained ventricular rhythm is the result of an SVT?

SVT Discriminators

•SVT Discriminators:– Prevent detection of tachyarrhythmias

caused by the presence of an SVT

– Prevent inappropriate, unnecessary therapy due to rapid SVT conduction

– Are present in some form in most ICDs

SVT Discriminators

•Discriminate based on:– Waveform morphology

• EGM Width (single chamber)

• Wavelet– Onset of arrhythmia– Stability of arrhythmia– Relationship between P- and R-waves

(dual chamber / requires an atrial lead)

SVT Discriminators

•Measures and stores the QRS characteristics of a normal sinus beat

•Identifies SVT vs. VT based on the QRS changes that occur in most VTs

SINUS RHYTHM

VT

Waveform Morphology

Electrical wavefronts generated by focus approach electrodes from different directions depending on the focus location.

Sinus

Supra-Ventricular

Ventricular

Classification: MD Morphology Discrimination

SVT Discriminators

•Match Threshold Programming– Lower %

• More likely to withhold appropriately; less likely to detect true VT

– Higher %• Less likely to appropriately withhold; more likely to detect true VT

Wavelet

SVT Discriminators

•Based on the premise that most VTs are characterized by a sudden onset

•Evaluates the acceleration of the ventricular rate

•Discriminates between:–Gradual rate increase–Abrupt rate increase

•Determines VT present if rateincrease is abrupt

Onset

SVT Discriminators

• When On:– Averages 4 beats and compares with an

average of previous 4 (multiplied by programmed Onset Percentage)

• Onset met if recent average is less than previous

Onset

SVT Discriminators

• Onset Percentage = 81%

530ms X 81% = 430ms

430ms ≠ 460ms = Onset Not Met

Onset


SVT Discriminators

•Based on the premise that AF conducts irregularly to the ventricles (and VT is a stable, regular rhythm)

•Discriminates regular from irregular intervals within a detect zone

Stability

SVT Discriminators

UnstableVaries >50 ms from previous 3

Stability = 50 msStability

SVT Discriminators

• Considers P and R relationship to discriminate SVT from VT

• Dual Chamber (requires an atrial and ventricular lead)

• Can be used in conjunction with other discriminators

Dual Chamber

Stability40 ms

V > AV = A

Compare atrial & ventricular frequency

V < A

Ventricular frequency > VT detection

Morphology45%

5 out of 8 AVA80 ms

Any

SVTOnVTOff

Bigeminal Avoidance

Morphology45%, 5/8ATU On

OnsetPassive

Optimized DR Discriminators

SVT Discriminators

•What it looks for:–Atrial Fibrillation / Flutter–Sinus Tachycardia–Other 1:1 SVTs (such as AVNRT)

•How it works:–Analyzes:

• Pattern (P:R wave relationship)• AV Association• Rate• Regularity (R waves)

PR Logic™

PR Logic™

•Distinguishes SVTs by analyzing P and R-wave:– Pattern: number and position of atrial events relative to ventricular events

Pattern

PR Logic™Example: Sinus Tachycardia

PR Logic™Example: Atrial Fibrillation

PR Logic™Example: AVNRT (Other 1:1 SVTs)

Junctional Zone

Question?

What about far-field R-wave sensing in the atrial channel?

PR Logic™

•Algorithm identifies and withholds therapy for:–Consistent, short-long pattern

Far-field R-wave Sensing

Question?

What happens when a magnet is applied over an ICD?

Tachy Detection

• ICDs of different manufacturers respond to magnets differently

•Use when:– EMI is present (surgery, TENS, etc.)– Temporary suspension is preferred over permanent programming

– Therapy is temporarily not desired

Magnet Mode


Therapy

Question?

Can you name some therapies delivered by an ICD?

ICD Therapies

• ICD Therapy– Low Power (Pacing Therapies)

• Anti-tachycardia Pacing (ATP)• Bradyarrhythmia Pacing

– High Power (Shock Therapies)• Cardioversion• Defibrillation

Anti-Tachycardia Pacing


Re-entry initiated

ATP delivered at a rate faster than tachyarrhythmia.Wavefronts collide.

Subsequent Pulse: Wavefronts collide closer to re-entry circuit

Subsequent Pulses: Wavefronts collide even closer to re-entry circuit

Arrhythmia terminated


•Has programmable:–Sequences – the number of times ATP will be applied upon re-detection


•Has programmable:

–Pulses – the number of pulses per sequence


•Has programmable:– Sequences – the number of times ATP will be applied upon re-detection (max = 10 in most)

–Pulses – the number of pulses per sequence (1-15)

–Rate of pulses delivered (percent or ms)


• Types:–Burst

•A series of pacing pulses delivered at equal intervals

•Interval decrement per sequence

Anti-Tachycardia PacingBurst


•Types:–Burst

•A series of pacing pulses delivered at equal intervals

•Interval decrement per sequence–Ramp

• A series of pacing pulses delivered at ever decreasing intervals

• Adds a pulse per sequence

Anti-Tachycardia PacingRamp

Anti-Tachycardia PacingBurst and Ramp Comparison

Programmed Values:

Number of S1 Pulses = 4Number of Sequences =

4R- S1% = 91%Decrement* = 10 ms

* Decrement between sequences

Programmed Values:

Number of S1 Pulses = 4Number of Sequences = 4R-S1% = 91%Decrement* = 10 ms

* Decrement between pulses

* Adds a pulse per sequence

ICD Therapies

•Tachyarrhythmia Therapy

–Cardioversion (CV)•Non-committed shock therapy (must synchronize to an R-wave to be delivered)

•Designed to treat 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

High Power

Cardioversion

•Delivers shock on an R-wave•Aborts if synchronization cannot be obtained due to arrhythmia termination

CardioversionProgramming

ICD Therapies

•Tachyarrhythmia Therapy

–Cardioversion (CV)•A non-committed shock (must synchronize to an R-wave to be delivered)

•Designed to treat organized tachyarrhythmias

–Anti-Tachycardia Pacing (ATP)•Pacing pulses delivered at a rate faster than the rhythm detected

•Can successfully terminate re-entrant tachycardias

Low Power

High Power

–Defibrillation Shock•A shock delivered to the heart to terminate a tachyarrhythmia

High Power

ICD Therapy

VT

FVT

VF

Benefits of Tiered Therapy

Defibrillation Programming

*Medtronic Programming Screen

Question?

When does the device call a therapy a success?

ICD Therapies

•“8 to terminate” rule–8 sinus and/or paced beats outside the slowed programmed detection zone

Termination/Redetection


ICD System Troubleshooting

Troubleshooting

•ICD System Issues–Lead System & Connections–Device–Other Issues (Patient, EMI)

Overview

ICD SYSTEM ISSUES

Lead Systems & Connections

Question?

In an ICD System, what component is generally known to be the source of most issues?a. device

b. lead

ICD System Issues

• Points of Failure– Acute (common suspects)

• Connector• Lead Dislodgement/Perforation

Leads

ICD System Issues

Points of Failure– Chronic (common suspects: High points of stress/pressure)

Lead fracture (commonly exhibits HIGH impedance/resistance)

Lead insulation break (commonly exhibits LOW impedance/resistance)

Leads

ICD System Issues

Points of Failure– Acute (common suspects)

Connector

What kinds of things can go wrong here?

Can you identify a problem?

Connector

Set screw is obstructing the bore

ICD System Issues

Connector

ICD System Issues

What might happen if a lead is connected?

ICD System Issues

What is going on here?

Set Screw Noise

Connector

ICD System Issues


• ConnectorLead dislodgement/perforation

How do we know when this occurs?

Common signs– Intermittent or loss of capture– Intermittent or loss or sensing– Inappropriate therapy during SVT

(in this example due to atrial lead dislodgement)

Lead Dislodgement

Atrial Dislodgement

ICD System Issues

Can you identify the dislodged lead(s)?

Lead Dislodgement

ICD System Issues

Lead Dislodgement

ICD System Issues

• Avoiding dislodgements– Ensure sufficient slack in lead– Use suture sleeves– Check lead tip stability during implant

ICD System Issues

• Occurs when:– Lead tip exits the heart, through the heart

Lead Perforation

ICD System Issues

•Diagnosing–Can be seen on x-ray–Definitive by Echo–Threshold and lead impedance may remain unchanged (due to possible continuous contact with tissue outside the heart)

•Possible patient symptoms–Change in pressure–Cardiac tamponade–Dyspnea

Lead Perforation

ICD System Issues


• Connector• Lead dislodgement/perforation

– Chronic (common suspects: High points of stress/pressure)

Lead fracture (commonly exhibits HIGH impedance)


1st Rib-Clavicle Crush (lead fracture)

ICD System Issues

Lead Crush

1st Rib & Clavicle Crush

Lead Fracture

ICD System Issues

Lead Fracture

ICD System Issues

Can you identify the fracture?

• Common behavior– Erratic sensing– Intermittent or loss of capture– High lead impedance

Lead Fracture

ICD System Issues

Lead Fracture

ICD System Issues

Example

ICD System Issues

• Points of Failure–Acute (common suspects)

• Connector• Lead dislodgement/perforation

– Chronic (common suspects: high points of stress/pressure)

Lead fracture (commonly exhibits HIGH impedance)

Lead insulation break (commonly exhibits LOW impedance)

Coaxial Inner Insulation Breach

Insulation Break

ICD System Issues

• Common Behavior–Lead impedance

• Low• Can be intermittent

–Capture threshold• Sudden rise or loss• Can be intermittent

–Sensing• Over/undersensing• Can be intermittent

Insulation Break

ICD System Issues

Example

ICD SYSTEM ISSUES

Device

ICD System Issues

• Common device issues:– Long charge times– Battery depletion

• Elective Replacement (ERI)• End of Life (EOL)

Device

– Inappropriate programmingAccelerationOver/UndersensingOutput

T-wave oversensing

Device

ICD System Issues


Device

ICD System Issues

Undersensing*Medtronic Programming Screen

Can you identify the problem?

Device

ICD System Issues

Undersensing

Can you identify the problem?

Infection/Erosion/Allergy

Allergy/Infection/Allergy

Allergy Test Kit Contents:

Polyurethane

Silicone

Titanium

Platinum Iridium

Polysulfone

EpoxyGold-sputtered devices

Infection/Erosion/AllergyAllergy Testing

Allergy Test Metals(included in kits)

Abandoned Leads

• Chatter between active and abandoned leads may cause inappropriate therapy

Electromagnetic Interference(EMI)

60 Hz (oversensing)

• The sensing of electrical signals other than those produced by the heart

Test Your Skills

What might you suspect from this EGM?

Case Study (Noise)

• Male 62 years• ICD Implant for VT/VF• Patient got 11 shocks

Fast Path Summary

Trends: Signal Amplitude

Trends: Lead Impedance

Impedance Decrease

Appropriate or Inappropriate Therapy?

Episode 52A/V lead 皆有noise

Case study (Morphology Change)

• Female 72 years old• ICD for VT episodes• Standard follow-up patient didn’t feel

anything.

FastPath Summary

Episode Directory

Episode 1: Appropriate or Inappropriate Therapy?

Morphology score low

Diagnostics

Therapy

MD Auto Update

Morphology auto update score increase to 100

Episode 3: Correct Diagnosis?

SVT Diagnosis

Diagnostics

After morphology update Correct Discreamation is SVT

Indications for ICD Therapy

Implantable Cardioverter-Defibrillators

ICD therapy is indicated in patients who are survivors of cardiac arrest due to ventricular fibrillation or hemodynamically unstable sustained VT after evaluation to define the cause of the event and to exclude any completely reversible causes.

ICD therapy is indicated in patients with structural heart disease and spontaneous sustained VT, whether hemodynamically stable or unstable.

ICD therapy is indicated in patients with syncope of undetermined origin with clinically relevant, hemodynamically significant sustained VT or VF induced at electrophysiological study.

III IIaIIaIIa IIbIIbIIb IIIIIIIIIIII IIaIIaIIa IIbIIbIIb IIIIIIIIIIII IIaIIaIIa IIbIIbIIb IIIIIIIIIIIaIIaIIa IIbIIbIIb IIIIIIIII



All primary SCD prevention ICD recommendations apply only to patients who are receiving optimal medical therapy and have reasonable expectation of survival with good functional capacity for more than 1 year.

ICD therapy is indicated in patients with LVEF less than or equal to 35% due to prior MI who are at least 40 days post-MI and are in NYHA functional Class II or III.

ICD therapy is indicated in patients with nonischemic DCM who have an LVEF less than or equal to 35% and who are in NYHA functional Class II or III.

ICD therapy is indicated in patients with LV dysfunction due to prior MI who are at least 40 days post-MI, have an LVEF less than or equal to 30%, and are in NYHA functional Class I.

ICD therapy is indicated in patients with nonsustained VT due to prior MI, LVEF less than or equal to 40%, and inducible VF or sustained VT at electrophysiological study.







ICD implantation is reasonable for patients with unexplained syncope, significant LV dysfunction, and nonischemic DCM.

ICD implantation is reasonable for patients with sustained VT and normal or near-normal ventricular function.

ICD implantation is reasonable for patients with HCM who have 1 or more major† risk factors for SCD.

ICD implantation is reasonable for the prevention of SCD in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) who have 1 or more risk factors for SCD.

ICD implantation is reasonable to reduce SCD in patients with long-QT syndrome who are experiencing syncope and/or VT while receiving beta blockers.

I IIaIIbIII


† See Section 3.2.4, “Hypertrophic Cardiomyopathy,” in the full-text guidelines for definition of major risk factors.

I IIaIIbIII

I IIaIIbIII

I IIaIIbIII

I IIaIIbIII


ICD implantation is reasonable for nonhospitalized patients awaiting transplantation.

ICD implantation is reasonable for patients with Brugada syndrome who have had syncope.

ICD implantation is reasonable for patients with Brugada syndrome who have documented VT that has not resulted in cardiac arrest.

ICD implantation is reasonable for patients with catecholaminergic polymorphic VT who have syncope and/or documented sustained VT while receiving beta blockers.

ICD implantation is reasonable for patients with cardiac sarcoidosis, giant cell myocarditis, or Chagas disease.

I IIaIIbIII

I IIaIIbIII

I IIaIIbIII

I IIaIIbIII

I IIaIIbIII



ICD therapy may be considered in patients with nonischemic heart disease who have an LVEF of less than or equal to 35% and who are in NYHA functional Class I.

ICD therapy may be considered for patients with long-QT syndrome and risk factors for SCD.

ICD therapy may be considered in patients with syncope and advanced structural heart disease in whom thorough invasive and noninvasive investigations have failed to define a cause.

ICD therapy may be considered in patients with a familial cardiomyopathy associated with sudden death.

ICD therapy may be considered in patients with LV noncompaction.

III IIaIIaIIa IIbIIbIIbIIIIIIIIIIII IIaIIaIIa IIbIIbIIbIIIIIIIIIIII IIaIIaIIa IIbIIbIIbIIIIIIIIIIIaIIaIIa IIbIIbIIb IIIIIIIII

I IIaIIbIII

I IIaIIbIII

I IIaIIbIII

I IIaIIbIII



ICD therapy is not indicated for patients who do not have a reasonable expectation of survival with an acceptable functional status for at least 1 year, even if they meet ICD implantation criteria specified in the Class I, IIa, and IIb recommendations above.

ICD therapy is not indicated for patients with incessant VT or VF.

ICD therapy is not indicated in patients with significant psychiatric illnesses that may be aggravated by device implantation or that may preclude systematic follow-up.

ICD therapy is not indicated for NYHA Class IV patients with drug-refractory congestive heart failure who are not candidates for cardiac transplantation or cardiac resynchronization therapy defibrillators (CRT-D).







ICD therapy is not indicated for syncope of undetermined cause in a patient without inducible ventricular tachyarrhythmias and without structural heart disease.

ICD therapy is not indicated when VF or VT is amenable to surgical or catheter ablation (e.g., atrial arrhythmias associated with the Wolff-Parkinson-White syndrome, RV or LV outflow tract VT, idiopathic VT, or fascicular VT in the absence of structural heart disease).

ICD therapy is not indicated for patients with ventricular tachyarrhythmias due to a completely reversible disorder in the absence of structural heart disease (e.g., electrolyte imbalance, drugs, or trauma).






ICDs in Pediatric Patients and Patients With Congenital Heart Disease

ICD implantation is indicated in the survivor of cardiac arrest after evaluation to define the cause of the event and exclusion of any reversible causes.

ICD implantation is indicated for patients with symptomatic sustained VT in association with congenital heart disease who have undergone hemodynamic and electrophysiological evaluation. Catheter ablation or surgical repair may offer possible alternatives in carefully selected patients.




ICDs in Pediatric Patients and Patients With Congenital Heart Disease

ICD implantation is reasonable for patients with congenital heart disease with recurrent syncope of undetermined origin in the presence of either ventricular dysfunction or inducible ventricular arrhythmias at electrophysiological study.

ICD implantation may be considered for patients with recurrent syncope associated with complex congenital heart disease and advanced systemic ventricular dysfunction when thorough invasive and noninvasive investigations have failed to define a cause.

All Class III recommendations found in Section 3 of the full-text guidelines, “Indications for Implantable Cardioverter-Defibrillator Therapy,” apply to pediatric patients and patients with congenital heart disease, and ICD implantation is not indicated in these patient populations.





Major Implantable Cardioverter-Defibrillator Trials for Prevention of Sudden Cardiac Death

Trial Year Patients(n)

LVEF Additional StudyFeatures

HazardRatio*

95% CI p

MADIT I 1996 196 < 35% NSVT and EP+ 0.46 (0.26-0.82) p=0.009

MADIT II 2002 1232 < 30% Prior MI 0.69 (0.51-0.93) p=0.016

CABG-Patch 1997 900 < 36% +SAECG and CABG 1.07 (0.81-1.42) p=0.63

DEFINITE 2004 485 < 35% NICM, PVCs or NSVT 0.65 (0.40-1.06) p=0.08

DINAMIT 2004 674 < 35% 6-40 days post-MI and Impaired HRV

1.08 (0.76-1.55) p=0.66

SCD-HeFT 2006 1676 < 35% Prior MI of NICM 0.77 (0.62-0.96) p=0.007

AVID 1997 1016 Prior cardiac arrest

NA 0.62 (0.43-0.82) NS

CASH† 2000 191 Prior cardiac arrest

NA 0.766 ‡ 1-sided p=0.081

CIDS 2000 659 Prior cardiac arrest, syncope

NA 0.82 (0.60-1.1) NS

* Hazard ratios for death from any cause in the ICD group compared with the non-ICD group. Includes only ICD and amiodarone patients from CASH.‡CI Upper Bound 1.112 CI indicates Confidence Interval, NS = Not statistically significant, NSVT = nonsustained ventricular tachycardia, SAECG = signal-averaged electrocardiogram.

Epstein A, et al. ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities. J Am Coll Cardiol 2008; 51:e1–62. Table 5.

Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION) Trial

• 1520 patients with NYHA Class III or IV HF, ischemic cardiomyopathy (ICM) or nonischemic cardiomyopathy (NICM) and QRS ≥ 120 ms

• Randomized 1:2:2 to optimal pharmacological therapy (OPT) alone or in combination with cardiac resynchronization therapy with either a pacemaker (CRT-P) or pacemaker-defibrillator (CRT-D)

• Both device arms significantly ↓ combined risk of all-cause hospitalization and all-cause mortality by ~20% compared with OPT

• CRT-D ↓ mortality by 36% compared with OPT (p=0.003)• Insufficient evidence to conclude that CRT-P inferior to

CRT-D

Bristow MR, Saxon LA, Boehmer J, et al. Cardiac-resynchronization therapy with or without an implantable defibrillator in advanced chronic heart failure. N Engl J Med 2004;350:2140-50.

Implantable Cardioverter-Defibrillators and Prevention of Sudden Cardiac Death in Hypertrophic Cardiomyopathy

• Multicenter registry study of implanted ICDs in 506 unrelated patients with HCM @ high risk for SCD (family hx of SCD, [septal thickness ≥ 30 mm], NSVT, syncope)

• Mean patient age 42 years (SD=17) and 87% had no or only mildly limiting symptoms

• Appropriate ICD discharge rates were 11% per year for 2o prevention and 4% per year for 1o prevention

• For 1o prevention, 35% of patients with appropriate ICD interventions had undergone implantation for only 1 risk factor

Maron BJ, Spirito P, Shen WK, et al. Implantable cardioverter-defibrillators and prevention of sudden cardiac death in hypertrophic cardiomyopathy. JAMA 2007;298:405-12.

Multicenter Automatic Defibrillator Implantation Trial II (MADIT II)

• 1232 patients ≥ 1 month post-MI and LVEF ≤ 30%• Randomized to ICD (n=742) or medical therapy (n=490)• No spontaneous or induced arrhythmia required for

enrollment• 6% absolute and 31% relative risk ↓ in all-cause mortality

with ICD therapy (p=0.016)

Moss AJ, Zareba W, Hall WJ, et al. Prophylactic implantation of a defibrillator in patients with myocardial infarction and reduced ejection fraction. N Engl J Med 2002;346:877-83.

Sudden Death in Heart Failure (SCD-HeFT) Trial

• 2521 patients with NYHA Class II or III HF, ICM, or NICM and LVEF ≤ 35%

• Randomized to 1) conventional rx for HF + placebo; 2) conventional rx + amiodarone; or 3) conventional rx + conservatively programmed shock-only single lead ICD

• No survival benefit for amiodarone• 23% ↓ in overall mortality with ICD therapy• Absolute ↓ in mortality of 7.2% after 5 y in the overall

populationBardy GH, Lee KL, Mark DB, et al. Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure. N Engl J Med 2005;352:225-37.

Defibrillator in Acute Myocardial Infarction (DINAMIT) Trial

• 674 patients 6 to 40 days post-MI with LVEF ≤ 35% and impaired cardiac autonomic function

• Randomized to ICD therapy (n=332) or no ICD therapy (n=342)

• Arrhythmic death ↓ in ICD group, but ↑ in nonarrhythmic death (6.1% per year vs. 3.5% per year, HR 1.75 (95% CI 1.11 to 2.76; p=0.016)

• No difference in total mortality

Hohnloser SH, Kuck KH, Dorian P, et al. Prophylactic use of an implantable cardioverter-defibrillator after acute myocardial infarction. N Engl J Med 2004;351:2481-8.

Defibrillators in Nonischemic Cardiomyopathy Treatment Evaluation (DEFINITE) Trial

• 458 patients with NYHA Class I to III, NICM, LVEF ≤ 35% and premature ventricular contractions (> 10/h) or NSVT

• Randomized to standard medical rx alone or in combination with single-chamber ICD

• Strong trend toward ↓ all-cause mortality with ICD therapy, although not statistically significant (p=0.08)

Kadish A, Dyer A, Daubert JP, et al. Prophylactic defibrillator implantation in patients with nonischemic dilated cardiomyopathy. N Engl J Med 2004;350:2151-8.

Notable Changes in 2008 ACC/AHA/HRS Guidelines

1. ICD recommendations are combined into a single list because of overlap between primary and secondary indications.

2. Primary prevention ICD indications in nonischemic cardiomyopathy are clarified using data from SCD-HeFT (i.e., ischemic and nonischemic cardiomyopathies and LVEF ≤35%, NYHA II-III) for support.

3. Indications for ICD therapy in inherited arrhythmia syndromes and selected nonischemic cardiomyopathies are listed.

4. MADIT II indication (i.e., ischemic cardiomypathy and LVEF ≤30%, NYHA I) is now Class I, elevated from Class IIa.

5. EF criteria for primary prevention ICD indications are based on entry criteria for trials on which the recommendations are based.

6. Emphasized primary SCD prevention ICD recommendations apply only to patients receiving optimal medical therapy and reasonable expectation of survival with good functional capacity for >1 year.

7. Independent risk assessment preceding ICD implantation is emphasized, including consideration of patient preference.

8. Optimization of pacemaker programming to minimize unneeded RV pacing is encouraged.9. Pacemaker insertion is discouraged for asymptomatic bradycardia, particularly at night.10. A section has been added that addresses ICD and pacemaker programming at end of life.

Icd basic 042411(dr chang)

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