Download Most relevant technological advancements in cardiac pacing

Most Relevant Technological
Advancements of Recent Years in
Cardiac Pacing
Dr. Sebastian Gallino
Electrophysiology Sector. Cardiology Service.
Cosme Argerich Hospital
Evolution of implantable cardiac devices
Most relevant technological advancements in cardiac
pacing
1) Control and follow up all the time and
from anywhere in the world. Remote
monitoring from a distance of
pacemakers and cardioverter
defibrillators.
Remote monitoring from a distance of pacemakers
and cardioverter defibrillators
• This new technology applied to medicine
permits monitoring in a remote way, the
cardiac rhythm of the patient through such
device, which can send automatically once
a day and immediately in the case of a
critical event, by a cell phone network
(GPRS system), the information stored for
a while, or when cardiac rhythm
disturbances appear
Remote monitoring from a distance of pacemakers
and cardioverter defibrillators
• This medical and technical information is
sent to a service center, where it becomes
a brief report that is immediately submitted
through the Internet, SMS or by fax, to the
attending physician, which allows to the
latter, to be in touch with the patient and
better monitor cardiac rhythm and the
capacity of operation of the device
implanted in each patient
Remote monitoring from a distance of pacemakers
and cardioverter defibrillators
• As an additional feature, the system also
detects possible technical failures in the
device, such as for instance, low signal
quality that could interfere with the
accuracy of a future management.
• Another interesting item of this technology
is the possible improvement of life span of
the ICD as a result of a decreased number
of unnecessary electrical shocks.
Remote monitoring from a distance of pacemakers
and cardioverter defibrillators
Benefits:
- Early diagnosis of asymptomatic atrial
fibrillation, appropriate and inappropriate
shocks, alterations in catheter state and the
battery.
Reduced controls in person without increasing risk
(1)
-Early management when faced with pathologic
findings without waiting for the next scheduled
routine follow up.
(1) Circulation. 2010;122:325-332. Efficacy and safety of automatic remote
monitoring for implantable cardioverter-defibrillator follow-up . The Lumos-T
safely reduces routine office device follow-up (TRUST) trial
Remote monitoring from a distance of pacemakers
and cardioverter defibrillators
Remote monitoring from a distance of pacemakers
and cardioverter defibrillators
Remote monitoring from a distance of pacemakers
and cardioverter defibrillators
Remote monitoring from a distance of pacemakers
and cardioverter defibrillators
Most relevant technological advancements in
cardiac pacing
2) Early detection of Atrial Fibrillation and
Ventricular Arrhythmia.
Storing of atrial fibrillation recordings (AF load),
ventricular arrhythmias, etc.
“Stored electrograms”
Stored electrograms
The contribution to routine telemetric
controls, allows storing information with
clinical relevance for making daily
decisions faced with the patient
Storage of EGMs
• magnet
• pacemaker-mediated
• tachy-atrial response
• tachy-atrial detection
(rate/duration)
• sudden response to brady
• ventricular tachycardia
(rate/duration)
• NSVT (3 or more PVC)
tachycardia
Storage of information
Atrial Fibrillation Detection
Example: Syncopal ventricular tachycardia
Example: Atrial flutter
Stored episode of atrial arrhythmia at 200 bpm.
50 mm/sec
Patient dependent on ventricular pacing
9 seconds
Most relevant technological advancements in
cardiac pacing
3) Decrease of shocks and their deleterious
effect. Anti-tachycardia pacing of
ventricular tachyarrhythmias in patients
carriers of ICD.
• Cardioverter defibrillators have a primary
function, i.e. prevention of sudden cardiac
death by interrupting ventricular
tachyarrhythmias
• This function is made by intracavitary
electric shock or by non-painful therapy
known as anti-tachycardia pacing
• This system paces the ventricle at heart rates
slightly greater than the cycle length of
tachycardia and enables interrupting it
• It has the benefit of preventing the traumatic and
painful effect of the shock, which is proven
worsens quality of life, permits prolonging
longevity of the generator, and on the other
hand, preventing the deleterious effect of it in
some given populations of patients
• Numerous studies have consistently shown that
-anti-tachycardia pacing (ATP) effectively ends
with ~85-90% of slow VT (CL<300-320 ms) with
a low risk of acceleration of the VT (1-5%).
Recent studies have shown a high rate of
success and low acceleration in rapid VT (CL
320-240 ms). These observations have
repositioned ICD primarily as an ATP device with
back up defibrillation only if required.
Effective anti-tachycardia pacing
VT (CL 380 ms)
Pacing
Sinus rhythm
Most relevant technological advancements in
cardiac pacing
4) Greater life span of battery. Greater
security of the patient.
Automatic control of ventricular pacing
threshold.
• This system has the function of determining
automatically and periodically the threshold
of atrial and ventricular pacing by making a
threshold test, similar to the one usually
made as a routine control, and adjusting
voltage and pulse width to minimal values
with pre-established security margins
(usually near twice the threshold)
• This function has as benefits the proven
increase of longevity of the pulse
generator, therefore less exchanging–less
interventions and the security-protection of
the patient before the acute or chronic
increase of pacing threshold by different
reasons, e.g. anti-arrhythmic medication,
myocardial infarction, etc.
Capture verification-security patient
Patient A
Patient B
Autocapture algorithm
• Capture is determined by the detection of
the evoked response (ER) of the catheter
tip (produced by the local capture of the
myocardium)
• It seeks ER in each beat
• If ER is not observed, it emits a security
pulse
– 4.5 V and 0.5 ms Pulse Width
Initial Pulse
Loss of Capture
Back up Pulse
Algorithm
Loss of capture, a beat
Initial Pulse
Back-Up Safety Pulse
Detail of automatic control of capture
Most relevant technological advancements in
cardiac pacing
5) Preventing unnecessary pacing and its
deleterious effect. Decrease of pacing
from the right ventricular tip.
• Different published studies in recent years
have shown a deleterious effect of ventricular
pacing from the RV apex in given populations
(1,2,3), for this reason the industry of devices has
developed algorithms to prevent the
unnecessary pacing when this could be
prevented.
(1,2,3) The Mode Selection Trial (MOST) Investigators.. Adverse effect of ventricular pacing on heart failure
and atrial fibrillation among patients with normal baseline QRS duration in a clinical trial of pacemaker
therapy for sinus node dysfunction. Circulation. 2003;107:2932-7. MADIT II Investigators. The clinical
implications of cumulative right ventricular pacing in the multicenter automatic defibrillator trial II. J
Cardiovasc Electrophysiol. 2005 Apr;16(4):359-65. Effect of chronic right ventricular apical pacing on left
ventricular function. Am J Cardiol. 2005;95:771-3.
• The DAVID study “Dual Chamber and VVI
Implantable Defibrillator (DAVID) Trial” (1)
compared CDI -DDD vs. CDI -VVI in 506
patients with conventional indication of
ICD without indication of antibradycardia
pacing with ejection fraction lower or equal
to 40%. Patients with DDD and greater
percentage of RV pacing had a greater
risk of death and/or HF hospitalization.
(1)Dual-chamber pacing or ventricular backup pacing in patients withan implantable defibrillator: the
Dual Chamber and VVI Implantable Defibrillator (DAVID) Trial. JAMA. 2002; 288:3115-23.
The DAVID Trial
.4
Cumulative Probability
P=0.03
.3
DDDR
.2
VVI
.1
0.0
0
6
12
18
Months to death or first hospitalization for CHF
Number at risk:
DDDR
250
VVI
256
159
158
78
90
21
25
Wilkoff BL. JAMA 288: 3115–3123, 2002
% with Primary Endpoint
DAVID subanalysis
50
40
DDDR>40% vs. DDDR<40%
DDDR>40% vs. VVI
p=0.03
p=0.07
DDDR>40%
30
VVI
20
10
DDDR≤40%
0
0
Number at risk:
DDDR>40%
126
VVI
195
DDDR≤40%
59
6
12
18
Months
70
118
35
26
47
16
3
5
4
Sharma AD. Heart Rhythm 2: 830-834, 2005
Gentileza de Medtronic)
Is Dual Chamber Programming Inferior to
Single Chamber Programming in an
Implantable Cardioverter Defibrillator?
INTRINSIC RV Study Results
Brian Olshansky, John D. Day, Stephen Moore, Lawrence
Gering, Murray Rosenbaum,
Maureen McGuire, Scott Brown, Darin R. Lerew.
(Pace 2006,29: 237-243)
Primary end point
Death and Heart Failure Hospitalization
% event-free
1
0.95
0.9
DDDR AVSH
VVI
p<0.001, noninferiority
0.85
0
60
120
180
Days since im plant
240
300
360
Most relevant technological advancements in
cardiac pacing
6) Greater clinico-therapeutic control in
patients with CHF. Measurement of intrathoracic impedance.
• CHF is one of the most frequent causes of
hospitalizations between people older than
60 years old. In spite of therapeutic
advances, most of these patients have
hospitalizations by decompensation of
chronic CHF.
• Most of these hospitalizations are due to
pulmonary liquid accumulation, so that an
early detection of volume enlargement and
pulmonary congestion would allow the timely
adjustment of the treatment, thus preventing
hospitalizations, associated morbi-mortality
and related costs.
• The Medtronic company has added in
cardioverter defibrillators and
resynchronizers, the measurement of
intrathoracic impedance, an efficient
parameter to follow daily changes in the
state of the edema and pulmonary volume.
• Faced with the increase of this
impedance, the device by an audible
signal, alerts the patient to make an
early consultation and to the physician
to establish a more aggressive
treatment.
• Different studies have shown that it
predicts CHF worsening
(1,2)
(1,2 ) Changes in intrathoracic impedance are associated with subsequent risk of hospitalizations for
acute decompensated heart failure: clinical utility of implanted device monitoring without a patient alert.
J Card Fail. August 2009;15(6):475-481.[OFFISER]
Superior performance of intrathoracic impedance-derived fluid index versus daily weight monitoring in
heart failure patients. Results of the Fluid Accumulation Status Trial. Late Breaking Clinical Trials. J
Card Fail. Vol. 15 No. 9 2009, p 813.[FAST]
Most relevant technological advancements in
cardiac pacing
7) Cardiac Resynchronization Therapy.
Electric treatment of heart failure (it will be
dealt with in another presentation of this
symposium)
Conclusions
• Technological advancements in implantable
cardiac devices are very extensive; in this
report, we quote those considered of
greatest clinical impact. We should mention
that there are other types of developments
such as smaller batteries with a longer life
span, evolution of catheters, advancements
in programming, devices with protection for
NMR, telemetric control from a distance, just
to mention a few.