陽明大學附設醫院

心臟內科 黃嵩豪

First External Stimulation

Catharina Serafin

Increase in heart rate (140 bpm)

Hugo von Ziemssen (1882)

Stimulation: ON OFF

Right Ventricle

Left Ventricle

1827/46 Bradycardia as cause of syncope

(Adams, Stokes)

1882 First external stimulation (von Ziemssen)

1932 First external pacemaker (Hyman)

1952 External stimulation via surface electrodes

(Zoll)

1958 External stimulator with transvenous lead

(Furman, Robinson)

1958 First implantable PM with transvenous lead

(Elmquist, Senning)

Historical Milestones

First External Pacemaker Hyman (1932)

- Clockwork generator with manual power

- Transthoracic stimulation needle

- Handle turn to provide induction stimulus

Cardiac standstill

Stimulation 120 ppm

Transvenous External PM Furman and Robinson (1958)

Wearable Pulse Generator - Around Waist (1958 )

First Implantable Pacemaker Senning and Elmquist (1958)

Rune Elmquist

Engineer at Siemens-Elema

Ake Senning, Cardiac Surgeon

Karolinska Hospital Stockholm

First Implantable Pacemaker Senning and Elmquist (1958)

• 2 Transistors

• Pulse 2 V / 1.5 ms

• Rate 80 ppm

55 mm Ø , 16 mm thick

First Pacemaker Patient: Arne Larsson

1986

First Implantable Pacemaker

First Battery Powered PM

Chardack, Greatbatch (1960)

10 Zinc-Mercury Batteries

First Programmable PM Chardack, Greatbatch (1963)

with a screwdriver

Founded in 1949 as a

medical equipment

service company

History and Background History

• First external wearable pacemaker

Success With Implantable Pacemakers

In the United States, the first successful attempts at designing a totally implantable pacemaker were reported by Drs. William Chardack and Andrew Gage at the Veterans Administration Hospital in Buffalo, New York, and Wilson Greatbatch, an electrical engineer. The three men carried out more than two years of experimental work and testing, then published a paper about their work in 1960.

Medtronic's founders read the article with interest and soon contacted the New York researchers. Palmer Hermundslie flew his own plane to Buffalo to meet Dr. Chardack and Greatbatch, and signed a contract giving Medtronic exclusive rights to produce and market the Chardack-Greatbatch implantable pulse generator. Within two months of beginning production in late 1960, Medtronic had received orders for 50 of the $375 implantable units.

Co-founder Palmer Hermundslie often piloted his own plane to make emergency deliveries of pacemakers.

At the same time, Medtronic appointed Picker International Corporation of White Plains, New York, as its sole distributor outside the United States, exclusive of Canada. Picker's 72 foreign sales offices greatly expanded the marketing efforts of Medtronic, which had 14 sales representatives covering the United States and Canada.

In addition to the implantable pacemaker, the representatives sold seven other Medtronic products, including the Telecor, which visibly and audibly monitored heart activity; the Cardiac Sentinel, an automatic alarm that summoned aid when the patient's heart activity became critical and stimulated the heart with an electronically regulated pulse; and a Coagulation Generator, used to control bleeding during surgery without damaging nearby tissue.

Dr. C. Walton Lillehei with a child who received one of the early Medtronic external pacemakers

Atomic Pacemaker Plutonium powered PM (1967)

Implantable Electronic Cardiac Devices Historical Aspects

1932 1958 1964 1970 1980’s 1994

Hyman

Senning and Elmquist

1st implant of an electronic

PM

Mirowski

Development of the 1st ICD – implant in dogs

1st report of CRT

RECENTLY

Furman

1st endocardiac PM

Heart Failure control

Home Monitoring

Basic Concept of Pacemaker Over view

- Pacemaker System

- Pacemaker Function

- NBG Code

- Lead Impedance

- The magnet Mode & Electromagnetic Interference

- Information for patient ‘s pacemaker

What is a pacemaker ?

A device for increaseing a slow HR

A device used primarily to correct some types of bradycardia, or slow heart rhythms.

Who need it ?

Indications for Pacing

Sick Sinus Syndrome

Heart Block

Post RF Ablation

How does it work ? Attach the pacemaker system

Pulse generator

Sensing and Pacing leads

Make it into a circuit

Put the system into the body / under the skin and join to the

heart by pacing wire

Program it’s function by the programmer

Pacing Systems Pulse generator

Sensing and Pacing lead

The Pacemaker System

Patient

Lead

Pacemaker

Programmer

Lead

Pacemaker

Leads

Epicardial

Endocardial

Connection to Pacemaker

Just a Simple Lead

Lead System

A lead is the insulated wire used to connect the pulse

generator to the cardiac tissue

The lead transmits the energy to the myocardium and

relays intrinsic cardiac signals back to the sensing

circuit

Components of a Pacing Lead

Connector

Proximal Ring

Electrode

Lead

Body Active Fixation

Mechanism

Suture

Sleeve

Distal Tip

Electrode

Fixation Mechanisms

Active fixation Screw-in lead

Passive fixation Tined tip

Passive fixation Finned tip

Suture On

Sutureless

Epicardial Leads

Pacemaker Circuit

Unipolar VS Bipolar

Bipolar

Unipolar

Unipolar Vs. Bipolar

+ + -

Unipolar Configuration

Lead

Pacemaker Unipolar Pathway

-

+

Bipolar Configuration

Lead

Pacemaker

-

+

Bipolar Pathway

Unipolar Versus Bipolar

UNIPOLAR vs BIPOLAR

Unipolar Leads

Advantage

Smaller size

Easier to implant?

Larger spike on surface ECG

Theoretically more reliable

Disadvantages

Possibility of pocket stimulation

Possibility of myopotential inhibition

Susceptible to EMI

Susceptible to cross-talk

Bipolar Leads

Advantages

Torque control

Noise Rejection

Programming flexibility

No Pocket stimulation

Disadvantages

Larger Diameter

Stiffer

Small ECG Artifact in surface ECG

Lead Placement

Ventricular Lead

Right Ventricular Apex (RVA) or Right Ventricular Outflow Tract (RVOT) Ventricular Bradycardia Pacing

Sensing Intrinsic Rhythm

Atrial Lead

Right Atrial Appendage or Atrial Septal Wall Atrial Pacing

Atrial Sensing

Ventricular Lead Placement

Atrial Lead Placement

The atrial lead should be implanted on the septal wall of the atrial appendage

Once the lead is in the proper position it will have a “wagging” appearance

Atrial Endocardial Placement

Single Chamber Pacing

One Lead

One Circuit / Pacemaker

One Patient

Dual-Chamber Pacing

Basic Function

Energy

Output Parameters

Cardiac Stimulation Threshold

Impedance

Energy

Ohm's Law

Voltage

Current

Resistance

How to stimulate?

Ohm s Law: V = R x I

R = V

I

Voltage

Current = =

[V]

[A]

The higher the voltage and the lower the resulting current

the higher is the resistance.

V = Voltage, I = Current , R = Resistance

Voltage

The difference in potential energy between two points

Unit of measure = volt (V)

Current

The rate of transfer or flow of electricity

Unit of measure – milliampere (mA)

Resistance

The opposition to the flow of electrical current through a material

Unit of measure = ohm (Ω)

V = IR

V = IR

CONSTANT VOLTAGE

t (ms)

How to stimulate?

Pulse

Amplitude

Pulse Duration

U (V)

Pacemaker Pulse

Pacing Technology “Secret”

Pacemakers do only 2 things:

Pace

Sense

Capture

Definition : Cardiac depolarization and resultant contraction caused by pacemaker stimulus

Pacing (Stimulation) threshold

The lowest amount of energy to capture the myocardium 100 % of the time

How to stimulate?

Pulse Duration (ms)

Pulse

Ampli-

tude

(V)

Pulse Duration (ms)

Pulse

Ampli-

tude

(V)

How to stimulate?

Rheobase - Chronaxie

How to stimulate?

Pulse Duration (ms)

Pulse

Ampli-

tude (V)

Energy

(mJ)

How to stimulate?

E = R x I x t

E = x t (Joule) V2

R

Energy

V = R x I

V

R I =

E = V x x t V

R

How to stimulate?

E = x t (J) V2

R Energy

How to save energy?

- lower pulse amplitude (V²)

- lower pulse duration

- high impedance

Strength Duration Curve

pulse width (msec)

Voltage t

hre

shold

(V

)

Chronaxie

Rheobase

2 x Rheobase Most efficient pulse width

• The rheobase is the least voltage needed to

depolarise the heart at an infinite pulse duration.

• The chronaxie is the shortest pulse duration

required to depolarise the heart at a voltage twice

the rheobase.

Pacing Thresholds

Suggested Intraoperative Values

Atrium

Less than 1.5 Volts

Ventricular

Less than 1.0 Volts

Pacing Impedance

300-1500 Ω Depending on lead type

Acute To Chronic Threshold Change

Historically reported to occur between 2-8 weeks post implant

Thresholds may increase 2-5 times

Virtual Electrode - Myocardial Interface

Excitable Tissue

Non-Excitable Tissue

Virtual Electrode

Electrode

Chronic Electrode

Pacing Thresholds

Hayes, D. et. al. Cardiac Pacing and Defibrillation: A Clinical Approach.

Futura. Armonk, NY. 2000:7.

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

1 2 3 4 5 6 7 13 26 52

Time After Implant

Ch

ron

ic P

ac

ing

Th

res

ho

ld,

Pu

lse

Wid

th (

ms)

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

1 2 3 4 5 6 7 13 26 52

Time After Implant

Ch

ron

ic P

ac

ing

Th

res

ho

ld,

Pu

lse

Wid

th (

ms)

Steroid

No Steriod

Sensing

Definition: The ability of the pacemaker to sense an intrinsic electrical signal

Sensing

When programming sensitivity, as you lower the number you make the pacemaker more sensitive, (allow it “see” more).

1 mV 2 mV 5 mV

Sensing

Sensing

Sensing Threshold: indicates the minimum intracardiac signal that will be sensed by the pacemaker to initiate the pacemaker response (inhibited or triggered)

Sensing

X

= programmed

sensitivity

Amplifier

and Filter

Signal

processing

Signal

recording

How to sense?

0

5

10

15

20

25

1 3 5 10 30 50 100 300 1000

VES

R-wave

T-wave

Amplitude

Frequency (Hz)

P-wave Myopotentials

(mV)

How to sense?

Filtering of Intracardiac Signals

How to sense?

Sensitivity: 2.5 mV

Vs Vs

0

5

5

Intra-

cardiac

Signal

(mV)

Vs Vs Vs Vs

PM Marker

How to sense?

Sensitivity: 5.0 mV

Intra-

cardiac

Signal

(mV)

PM Marker

0

5

5

Vs Vs

Undersensing

Sensing Thresholds

Suggested Intraoperative Values

Atrium

Greater than 2.0 mV

Ventricular

Greater than 5.0 mV

The NASPE/BPEG Generic (NBG) Code

Position

Category

Letters Used

Manufac- turer’s Designation Only

I II III

Chamber(s) Paced

Chamber(s) Sensed

Response to Sensing

Rate modulation Multisite pacing

O-None P-Simple

Programmable

M-Multi- Programmable

C-Communicating R-Rate

modulation

O-None A-Atrium V-Ventricle D-Dual

(A+V)

S- Single (A or V)

S- Single (A or V)

O-None A-Atrium V-Ventricle D-Dual

(A+V)

O-None T-Triggered I-Inhibited D-Dual

(T+I)

O-None A-Atrium V-Ventricle D-Dual

(A+V)

IV V

Version 2001

Insulation Break Current is escaping

Decreased Resistance

Increased Current Drain

Pacing and sensing problems

Lead Fracture

Current cannot reach heart

Increased Resistance

Decreased Current Drain

Pacing and sensing problems

LiJ - Battery

Hybrid

Connectors

Titanium

housing

Components of the PM

Pacemaker Programming

Telemetry

Antenna

Pacemaker Power Source

Zinc-Mercury Lithium-Iodine

Pacemaker Power Source

Zinc-Mercury Lithium-Iodine

Time Time

Pacemaker Power Source

Pacemaker Power Source

Pulse Amplitude and Device Longevity Battery 1.1 Ah

Mode VVI VVI DDD DDD Amplitude (V) 5 2.5 5 2.5

Inhibited (µA) 11 11 12 12

Pacing V (µA) + 10 + 2,5 + 10 + 2,5

Pacing A (µA) - - + 10 + 2,5 Total (µA) 21 13,5 32 17

Longevity (yrs) 6,2 9,6 4,1 8,0

Lead Resistance/Impedance Changes

High Resistance

> 2500 ohms

Also called an “Open Circuit”

Chronic lead system

Fractured lead conductor coil

Acute lead system

Loss of contact between the terminal pin of the lead and the pacemaker header set screw

Low Resistance

< 250 ohms

Also called “Shorted Circuit”

Insulation Break-Down

Insulation cut by suture

Degradation of the insulation

Subclavian Crush Syndrome

Lead Resistance/Impedance

Changes

Implantable Cardioverter Defibrillator Anti-tachycardia Devices

First graphic documentation of ventricular fibrillation

ICD Evolution: 1850

Carl Ludwig (1816-1895)

1st documented termination of VF with elevated current

Their work went largely unnoticed for 30 years

ICD Evolution: 1899

• Reproduced electric current

termination of VF

• Done at the request of Bell

telephone to address

electrocution of line workers

(occurring at the rate of 1000/yr)

ICD Evolution: 1930

William Kouwenhoven (1886-1975)

What is ICD Therapy? • ICD therapy consists of

pacing, cardioversion, and

defibrillation therapies to

treat tachyarrhythmias. ICDs

also have programmable

diagnostic functions.

• An ICD system includes the

device, and the pacing,

sensing and defibrillation

lead(s).

1947

• First successful

defibrillation of

exposed human

heart

• Required

thoracotomy

ICD Evolution:

Early Medtronic Defibrillator 1950’s

Used in open heart surgeries

Applied directly to the heart

ICD Evolution

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

NEJM 1997;337;1576-83

Secondary Prevention of Sudden Arrhythmic Death

AVID Study

N of Patients at Risk ICD 742 502 (0.91) 274 (0.84) 110 (0.78) 9 Conventional 490 329 (0.90) 170 (0.78) 65 (0.69) 3

Moss AJ. N Engl J Med 2002;346:877-883

ICD

Conventional P = 0.007

1.0

0.9

0.8

0.7

0.6

0.0

Surv

ival

Pro

bab

ility

0 1 2 3 4 Years

0.78

0.69 -31%

Primary Prevention of Sudden Arrhythmic Death

MADIT II Study

Cardiac Resynchronization Therapy for Heart Failure

Ventricular Dysynchrony and Cardiac Resynchronization

• Ventricular Dysynchrony1 – Electrical: Inter- or

Intraventricular conduction delays typically manifested as left bundle branch block

– Structural: disruption of myocardial collagen matrix impairing electrical conduction and mechanical efficiency

– Mechanical: Regional wall motion abnormalities with increased workload and stress—compromising ventricular mechanics

• Cardiac Resynchronization

– Therapeutic intent of atrial synchronized biventricular pacing

• Modification of interventricular, intraventricular, and atrial-ventricular activation sequences in patients with ventricular dysynchrony

• Complement to optimal medical therapy

1 Tavazzi L. Eur Heart J 2000;21:1211-1214

Prevalence of Inter- or Intraventricular Conduction Delay

1 Havranek E, Masoudi F, Westfall K, et al. Am Heart J 2002;143:412-417 2 Shenkman H, McKinnon J, Khandelwal A, et al. Circulation 2000;102(18 Suppl II): abstract 2293 3 Schoeller R, Andersen D, Buttner P, et al. Am J Cardiol. 1993;71:720-726 4 Aaronson K, Schwartz J, Chen T, et al. Circulation 1997;95:2660-2667 5 Farwell D, Patel N, Hall A, et al. Eur Heart J 2000;21:1246-1250

IVCD 15%

IVCD >30%

General HF Population1,2

Moderate to Severe HF Population3,4,5

60%

70%

80%

90%

100%

0 60 120 180 240 300 360

Days in Trial

Cu

mu

lati

ve

Su

rviv

al

QRS Duration (msec)

<90

90-120

120-170

170-220

>220

Wide QRS – Proportional Mortality Increase

• NYHA Class II-IV patients

• 3,654 ECGs digitally scanned

• Age, creatinine, LVEF, heart rate, and QRS duration found to be independent predictors of mortality

• Relative risk of widest QRS group 5x greater than narrowest

1 Gottipaty V, Krelis S, Lu F, et al. JACC 1999;33(2) :145 [Abstr847-4].

Vesnarinone Study1 (VEST study analysis)

Clinical Consequences of Ventricular Dysynchrony

• Abnormal interventricular septal wall motion1

• Reduced dP/dt3,4

• Reduced pulse pressure4

• Reduced EF and CO4

• Reduced diastolic filling time1,2,4

• Prolonged MR duration1,2,4

1 Grines CL, Bashore TM, Boudoulas H, et al. Circulation 1989;79:845-853. 2 Xiao, HB, Lee CH, Gibson DG. Br Heart J 1991;66:443-447. 3 Xiao HB, Brecker SJD, Gibson DG. Br Heart J 1992;68:403-407. 4 Yu C-M, Chau E, Sanderson JE, et al. Circulation. 2002;105:438-445.

Click to Start/Stop

Longer

Shorter

Relaxed

Courtesy of Dr Kass, MD, Johns Hopkins University, Maryland.

SEPTUM BASE

APEX

SEPTUM BASE

Normal Dilated Cardiomyopathy

APEX

Left Ventricular Dysfunction Electromechanical Dyssynchrony

Summary of Proposed Mechanisms

Yu C-M, Chau E, Sanderson J, et al. Circulation 2002;105:438-445

Intraventricular

Synchrony

Atrioventricular

Synchrony

Interventricular

Synchrony

LA

Pressure

LV Diastolic

Filling

RV Stroke

Volume

LVESV LVEDV

Reverse Remodeling

Cardiac Resynchronization

MR

dP/dt, EF, CO

( Pulse Pressure)

Proposed Mechanisms: Improved Intraventricular Synchrony

Kass D Chen-Huan C, Curry C, et al. Circulation 1999;99:1567-73

PV loop tracings at right illustrate BiV/LV pacing produces: greater stroke work (area) and increased stroke volume (width), and a reduced systolic volume

0

40

80

120

0 100 200 300

0

40

80

120

0 100 200 300

0

40

80

120

0 100 200 300

0

40

80

120

0 100 200 300

LV

Pre

ss

ure

(m

m H

g)

LV

Pre

ss

ure

(m

m H

g)

LV Volume (mL) LV Volume (mL)

RV Apex RV Septum

LV Free Wall Biventricular

----- NSR Control - - - VDD Pacing

Adapted from Kass et al.

Proposed Mechanisms: Improved Intraventricular Synchrony

Click to Start/Stop

dP/dt 1,3,4 EF1,5

Pulse Pressure 3,4 SV&CO1, 2

Improved Intraventricular

Synchrony1,2

MR1

LVESV1

LA

Pressure1

1 Yu C-M, Chau E, Sanderson J, et al. Circulation 2002;105:438-445 2 Søgaard P, Kim W, Jensen H, et al. Cardiology 2001;95:173-182 3 Kass D Chen-Huan C, Curry C, et al. Circulation 1999;99:1567-73 4 Auricchio A, Ding J, Spinelli J, et al. J Am Coll Cardiol 2002;39:1163-1169 5 Stellbrink C, Breithardt O, Franke A, et al. J Am Coll Cardiol 2001;38:1957- 65

Proposed Mechanisms: Improved Atrioventricular Synchrony

Click to Start/Stop

1 Yu C-M, Chau E, Sanderson J, et al. Circulation 2002;105:438-445 2 Kindermann M, Frohlig G, Doerr T, et al. Pacing Clin Electrophysiol 1997; 20(I):2453-2462 3 Breithardt O, Stellbrink C, Franke A, et al. Am Heart J 2002;143:34-44 4 Søgaard P, Kim W, Jensen H, et al. Cardiology 2001;95:173-182

Improved Atrioventricular

Synchrony

LA1 Pressure

LV Diastolic Filling1,3

LVEDV1,4

Optimized AV Delay: Isovolumic Contraction Time1,2

MR1,4

1 Yu C-M, Chau E, Sanderson J, et al. Circulation 2002;105:438-445 2 Kerwin W, Botvinick E, O’Connel W, et al. JACC 2000;35:1221-7

Improved Interventricular

Synchrony1,2

LV Diastolic

Filling1

RV Stroke

Volume1

Courtesy of Ottawa Heart Institute

LV Wall

Endocardium

RV

Septum

LV

Proposed Mechanisms: Improved Interventricular Synchrony

Achieving Cardiac Resynchronization Mechanical Goal: Atrial-synchronized bi-ventricular pacing

• Transvenous Approach

– Standard pacing lead in RA

– Standard pacing or defibrillation lead in RV

– Specially designed left heart lead placed in a left ventricular cardiac vein via the coronary sinus

Right Atrial

Lead

Right Ventricular

Lead

Left Ventricular

Lead

Cardiac Resynchronization Atrio-biventricular Pacing

LV RV

Cleland et al, Eur Heart J 2006;27(16):1928-32

0 500 1000 1500 0

25

50

75

Days

P<0.0001 Event-

free S

urv

ival

5 71 192 321 365 404 8 89 213 351 376 409

Control

CRT

N of Patients at Risk

Medical Therapy

CRT

100 HF CF III/IV

EF<0.35

QRS>130ms

Cardiac Resynchronization

CARE-HF Study: Overall Mortality

Cardiac Resynchronization

CARE-HF Study: Sudden Mortality

Cleland et al, Eur Heart J 2006;27(16):1928-32

CRT

Medical Therapy

Su

rviv

al

Time (days)

Hazard ratio 0.54

(95% CI 0.35-0.84. P = 0.006)

CRT = 32 sudden deaths (7.8%)

Medical therapy = 54 sudden deaths (13.4%)

1.00

0.75

0.50

0.25

0.00

0 400 800 1200 1600

Cardiac Resynchronization + ICD

COMPANION Study: Overall Mortality

N Engl J Med 2005

CRT-D

CRT

TMO

Sobre

vid

a liv

re d

e e

vento

s (

%)

19%

12%

15%

N:1520