|
Buyers Guide
Electrify the Heart
Internal and external defibrillators are now far safer and
more efficient than they ever have been, finds out Nancy Singh.
 Using
shock tactics—yes, this is what a defibrillator is known for! Fundamentally
speaking, a defibrillator delivers an electric shock to the heart muscle in
an attempt to reintroduce a normal heart rhythm to someone who has suffered
or is suffering cardiac arrest.
Cardiac arrest or sudden cardiac arrest (SCA) occurs due to 'ventricular fibrillation'.
This is simply a situation in the heart where an electrical 'short-circuit'
occurs, causing the heart muscle to 'fibrillate' or quiver. The short-circuiting
of the heart's electrical system distorts the co-ordinated contractions of the
heart muscle, causing it to fibrillate. This condition means little or no blood
flow in the body, leading to circulatory arrest followed quickly by death. The
brief time span between the onset of cardiac arrest and the death of the victim
is the main reason that currently less than five per cent of people who suffer
SCA do not live through it.
In order to restore a normal heartbeat, an electrical shock must be delivered
to the heart. This is called defibrillation. The defibrillator jolts the heart
back into a normal rhythm so that it can actually pump blood to the body. If
a person is flatline on the heart monitor, then the defibrillator would not
do any good.
The shock itself doesn't switch the heart back to normal—it is not like
flicking a tripped circuit breaker. Instead, defibrillation actually stops the
heart briefly! This gives the pace-making cells a chance to re-establish a normal
heartbeat. "When you apply an electrical shock, the heart muscles are stunned
because of the jolt. So the natural pacemaker cells take over to bring back
the rhythm to normal," explains Dr Ulhas Pandhrangi, Senior Consultant
Cardiologist and Electrophysicist, Madras Medical Mission, Chennai.
Components
 "In
coming years AEDs will come into limelight because of ease of
usability and portability"
- Pankaj Arora
Country Manager
Metrax GmbH
|
It is made up of the main unit and is equipped with a set
of two electrodes. The electrodes are placed directly on or inside the patient.
In the case of an internal implanted defibrillator, the entire device is placed
inside the body, whereas, with an external defibrillator, defibrillation is
carried out by placing the electrodes, or 'pads', at different points on the
chest.
Defibrillators have been around in crude form since the 1940’s. Since the
1980's, the science has been evolving into a very precise and technically efficient
system. Internal and external defibrillators are now far safer and more efficient
than they ever have been.
Basic Types
The defibrillator is broadly divided in two types, Internal and External. External
is of two types i.e. Biphasic Defibrillators and Automated External defibrillators
or AEDs as they are popularly known. Internal defibrillator is of a single type,
i.e. Implantable Cardiovascular Defibrillator (ICD).
Understandbly enough, since it is placed inside the body, ICD classifies as
internal defibrillator. It is also known as an automated implantable cardioverter-defibrillator
(AICD). "It is a device that is implanted under the skin of patients who
are at a risk of sudden cardiac death due to ventricular fibrillation (VF),"
says Dr B Kalmath, Senior Interventional Cardiologist, Bombay Hospital, Mumbai.
The device was designed primarily to deal with ventricular fibrillation. "The
Internal Defibrillators are used in the operation theatre (OT) when the patient's
chest is open and the heart is presentable. Unlike ICDs our internal defibrillator
is just used to give an electric shock to the patient and is not implanted to
the heart," explains R K Narayanan, Cardiac Care & OT Light, Philip
Electronics India Ltd. Its current use has, however, extended to include atrial
and ventricular arrhythmias, as well as it has the ability to perform biventricular
pacing in patients with congestive heart failure and to pace, should there be
any marked bradycardia. The process of implantation of an ICD is similar to
implantation of a pacemaker. Similar to pacemakers, these devices typically
include a wire that runs through the right chambers of the heart, usually ending
in the apex of the right ventricle. ICDs are of two types. "One is single
chamber and other is dual chamber. The dual chamber has two wires that go inside
the heart," explains Dr Hasmukh Rawat, HOD and Senior Cardiologist, Wockhardt
Hospital, Mumbai.
How it Works
 "The
device may sometime give unnecessary shocks"
- Ulhas Pandhurungi
Senior Consultant Cardiologist and Electrophysicist, Madras Medical Mission,
Chennai
|
ICDs constantly monitor the rate and rhythm of the heart and
can deliver therapies when the heart rate goes over a set number of heart rate.
All ICDs are programmed to deliver an electrical shock when the ventricles of
the heart go faster than the set rate. More modern devices can distinguish between
ventricular fibrillation and ventricular tachycardia (VT), and may try to pace
the heart faster than its intrinsic rate in the case of VT, to try to break
the tachycardia before it progresses to ventricular fibrillation. This is known
as fast-pacing, overdrive pacing, or anti-tachycardia pacing (ATP). ATP is only
effective if the underlying rhythm is ventricular tachycardia, and is never
effective if the rhythm is ventricular fibrillation. Many modern ICDs use a
combination of various methods to determine if a fast rhythm is normal, ventricular
tachycardia, or ventricular fibrillation.
The Discriminating Factors: Rate discrimination evaluates
the rate of the lower chambers of the heart (the ventricles) and compares it
to the rate in the upper chambers of the heart (the atria). If the rate in the
atria is faster than or equal to the rate in the ventricles, then the rhythm
is most likely not ventricular in origin, and is usually more benign. If this
is the case, the ICD does not provide any therapy.
Morphology discrimination checks the morphology of every ventricular beat and
compares it to what the ICD believes is a normally conducted ventricular impulse
for the patient. This normal ventricular impulse is often an average of a multiple
of beats of the patient taken in the recent past.
It is also important that ICDs have a good memory function. "ICDs should
be able to differentiate between a normal and abnormal heart rhythm, hence it
is impotant that it has a good memory function," informs Dr Rawat.
Biphasic
Until recently, external defibrillators relied on monophasic shock waves which
essentially means that energy is directed through the heart in one direction.
So, electrical pulses are sent rapidly from one electrode to the other, only
in one direction. There are many types of monophasic waveforms. All monophasic
devices are programmed to deliver increasing levels of energy as required to
achieve conversion of the heart to a normal rhythm. Biphasic defibrillation,
however, alternates the direction of the pulses, completing one cycle in approximately
10 milliseconds. Biphasic technology directs energy through the heart in one
direction and again in the reverse direction.
AEDs
You might have seen medical shows and the way the doctors put the pads on the
chest with the patient's body jumping high on the bed. Today, such a situation
is not limited to the environs of a hospital. This device is becoming sufficiently
'idiot- proof'. In the past, defibrillators were complicated and cumbersome.
Only medical professionals with extensive training in heart rhythm interpretation
could use them. Today, defibrillators are automated, portable and easy to use.
These AEDs read heart rhythms- and determine whether a shock should be delivered.
In addition, AEDs have audio and visual prompts to guide trained operators.
An AED is a portable device that senses your heart's rhythm during cardiac arrest
and, in some cases, delivers an electric shock to get your heart beating again.
AEDs are now even available to the public. They have made their way to the travel
industry and found place in the cockpits of commercial airliners, on cruise
ships, and in other transport related industries. In the West, they are also
available in public gathering places such as theatres, sports stadiums, churches,
etc. The portable defibrillators are now capable of audibly and visually taking
a non-trained individual step-by-step through the entire defibrillation process.
Defibrillators for home use are also becoming more common in homes around the
US, especially used by those who suffer from or have family members who suffer
from, heart related illness. This is an encouraging step forward technologically
and medically. With growing numbers of people having available to them this
life-saving device, the rate at which sudden cardiac arrest claims its victims
may soon be seen to be in decline.
Monophasic Vs Biphasic
In recent years, AEDs began using biphasic waveform technology, the same technology
that is used in implantable defibrillators. Usually, less energy is required
when biphasic waveforms are used. Some devices with biphasic waveforms maintain
a constant energy level for all shocks, others use escalating levels of energy.
Both waveforms are safe and effective and have been approved by the FDA and
meet American Heart Association guidelines for emergency cardiovascular care.
With monophasic waveforms, energy escalates at intervals. This ensures that
ample energy reaches the heart in patients who have high chest impedance. But
in biphasic, in which current travels in one direction and then reverses can
achieve defibrillation, using less energy. Lower energy requirements could lead
to miniaturised devices with smaller capacitors and batteries. To deliver a
360 Jules, monophasic damped sine wave, 5200 volts of electricity is required
compared to only 1,600 to 1,750 volts needed to deliver a 150-Jule biphasic
truncated waveform.
Now-a-days, biphasic defibrillators are in demand. Agrees Pankaj Arora, Country
Manager, Metrax GmbH, "Even the smaller hospitals /nursing homes want to
opt for it. Since biphasic defibrillator delivers less current, nearly half,
for defibrillation as compared to the old monophasic technology which was delivering
very high current, even smaller hospitals prefer biphasic," he explains.
Also, the recovery of the heart is very fast and no post shock repercussions
are there as compared to monophasic.
Rhythm Recognition
Cardiac rhythm recognition has also improved greatly in recent years. "It
is one of the most 'intelligent' devices I have seen," says Dr Pandhrangi.
The first version of the AED used rhythm-recognition protocols that triggered
a shock if the heart rate exceeded 150 beats per minute and the QRS amplitude
rose above 0.15 mm. Current products employ a more sophisticated ECG recognition
system that analyses rate, amplitude, QRS slope, morphology, power spectrum
density, and time away from isoelectric baseline. It then compares this information
with a rhythm strip library. ECG-strip segments of two to three seconds are
recorded and analysed. If, in three consecutive strip segments, the device senses
abnormal QRS complexes at more than twice the frequency of any other QRS complex,
it primes itself to deliver a shock. Rhythms are categorised as shockable, non-shockable,
or indeterminate.
Current devices usually have sensitivity for VF greater than 99 per cent. In
one series of 100 consecutive patients, the detection sensitivity and specificity
were 100 per cent. Most AEDs available in the market take 6 to 12 seconds to
commit to fire. With fully charged batteries, AEDs require 8 to 15 seconds to
reach a level of 360 Joules. Therefore, for most defibrillators, 15 to 30 seconds
between shocks is expected for persistent VF.
Shades of Grey
There is one concern with this smart device. Experts say, that even though it
may be one of the most 'intelligent' devices, still it may give unnecessary
shocks. "Yes," agrees Dr Pandhrangi, "these are so called 'inappropriate
therapies' and I believe in the future defibrillators, the incidences must be
brought down. No doubt, today's devices are much better than the earlier ones
and the incidence of giving unnecessary shocks have reduced up to 20-25 per
cent, still it should be brought down further with better technologies in the
near future." After all, this machine gives high shocks, and in any case,
every shock causes damage to the heart, so with higher incidences of shocks,
there may be irreplaceable damage to the heart.
Market Leaders
The main market players in the Indian scenario for ICDs include St Jude's and
Guidant, whereas for external it is Philips and L&T. "Philips manufactures
and markets defibrillators for use both in external and internal use,"
informs R K Narayanan, Business Development Manager, Philips Electronics India.
The Philips marketed models are Heartstart MRx / Heartstart XL / Heartstart
FR2+ / Heartstart Onsite.
Revenues in the defibrillator market were $737.8 million in 2002 and are projected
to reach $1557.7 million by 2009, reports Frost & Sullivan. Growth in the
use of AEDs will result from a huge increase in public awareness of the importance
of AEDs for treating sudden cardiac arrest. AEDs are being introduced into highly
visible public places and it is this public-access market that holds the further
growth of the defibrillator market. "According to me, in coming years AEDs
will come into limelight because of ease of usability and portability,"
believes Arora.
The Future
The AEDs have already entered into the public arena, and are used outside the
hospital set-up too. And as far as as ICDs go, there is hardly any 'smartness'
which they have not incorporated in itself and that too in the smallest size
possible, but it is still constantly evolving.
Scientists are working on is the battery life as it eventually runs out in.
So every few years, patients need surgery to have the batteries replaced. Now
a company in New York State is planning to tackle the problem by providing patients
with an implantable power source that recharges their implant's batteries using
electricity generated by the patient's own body heat. Necessity as they say,
is the mother of all inventions.
|
ZOLL Defibrillator
|
ZOLL Defibrillator
|
ZOLL Defibrillator
|
ZOLL Defibrillator
|
Metrax GmbH
|
|
|
|
|
|
|
|
M series Mid Range
Portable and light weight.
- Display:
LCD display.
- User friendliness:
Simple and uniform operation, user friendly.
- Biphasic waveform:
Rectilinear biphasic waveform at 200 Joules have greater efficacy
than other biphasic waveform at 360 Joules. As it has a fixed duration
which does not require more energy than 200 Joules.
- Energy selection:
Up to 200 Joules.
- In-built memory:
Inbuilt code summary of more than 100 ECG events.
- Data Mangement system:
PCMCIA card 1-16 MB for data management.
- Non-invasive pacing:
NA.
- 4 to 1 Button for Pacing:
NA.
- Upgradeable to pacemaker and pulse oximetery:
NA.
- With or without AED mode:
Without AED.
- Ac-cum-battery operation:
Can work on mains and battery.
- Battery back-up:
35 discharges or three hours of monitoring.
- Battery location:
Top load, easy to access and change in emergency.
- Wireless connectivity:
NA.
Larsen & Toubro Limited
Medical Equipments & Systems
Marketing Headquarters
Powai Campus
Mumbai - 400072
Tel: 022-67053204 / 3223
Fax: 022-67051267
ebg-med@LNTEBG.com
Website: www.lntmedical .com
|
M Series
Portable and light weight.
- Display:
Electro-luminescent.
- User friendly:
Simple and uniform operation, user friendly.
- Biphasic waveform:
Rectilinear biphasic waveform at 200 Joules have greater efficacy
than other biphasic waveform at 360 Joules. As it has a fixed duration
which does not require more energy than 200 Joules.
- Energy selection:
Up to 200 Joules.
- In-built memory:
Inbuilt code summary of more than 100 ECG events.
- Data Mangement system:
PCMCIA card 1-16 MB for data management.
- Non-invasive pacing:
Patented constant current rectilinear waveform pacing pulse with
40 ms.
- 4 to 1 Button for Pacing:
Yes. Allows the M Series user to check the underlying intrinsic
rhythm.
- Upgradeable to pacemaker and pulse oximetery:
Upgradaeble to Masimo SET pulse oximetry, microstream EtCO2; NIBP.
- With or without AED mode:
AED facility.
- Ac-cum-battery operation:
Can work on mains and battery.
- Battery back-up:
35 discharges or three hours of monitoring.
- Battery location:
Top load, easy to access and change in emergency.
Wireless connectivity:
Blue tooth wireless option.
Larsen & Toubro Limited
Medical Equipments & Systems
Marketing Headquarters
Powai Campus
Mumbai - 400072
Tel: 022-67053204 / 3223
Fax: 022-67051267
ebg-med@LNTEBG.com
Website: www.lntmedical .com
|
M Series CCT
Portable and light weight critical care transport
defibrillator.
- Display:
Colour LCD.
- User friendly:
Simple and uniform operation, user friendly.
- Biphasic aveform:
Rectilinear biphasic waveform at 200 Joules have greater efficacy
than other biphasic waveform at 360 Joules. As it has a fixed duration
which does not require more energy than 200 Joules.
- Energy selection:
Up to 200 Joules.
- In-built memory:
In-built code summary of more than 100 ECG events.
- Data Mangement system:
PCMCIA card 1-16 MB for data management.
- Non-invasive pacing:
Patented constant current rectilinear waveform pacing pulse with
40 ms.
- 4 to 1 Button for Pacing:
Yes. Allows the M Series user to check the underlying intrinsic
rhythm.
- Upgradeable to pacemaker and pulse oximetery:
Upgradaeble to Masimo SET pulse oximetry, Microstream EtCO2; NIBP;
2IBP; Temp; 12 lead (optional).
- With or without AED mode:
AED facility.
- Ac-cum-battery operation:
Can work on mains and battery.
- Battery back-up:
60 defibrillator charges at maximum energy or three hours of continous
monitoring.
- Battery location:
Top load, easy to access and change in emergency.
- Wireless connectivity:
Blue tooth wireless option.
Larsen & Toubro Limited
Medical Equipments & Systems
Marketing Headquarters
Powai Campus
Mumbai - 400072
Tel: 022-67053204 / 3223
Fax: 022-67051267
ebg-med@LNTEBG.com
Website: www.lntmedical .com
|
E Series
Portable and light weight rugged specially designed
for emergency medical services.
- Display:
Trimode display(color/black on white / white on black).
- User friendly:
Simple and uniform operation, user friendly.
- Biphasic waveform:
Rectilinear Biphasic waveform at 200 Joules have greater efficacy
than other biphasic waveform at 360 Joules. As it has a fixed duration
which does not require more energy than 200 Joules.
- Energy selection:
Upto 200 Joules.
- Inbuilt memory:
Inbuilt code summary of more than 100 ECG events.
- Data mangement system:
PCMCIA card 1 - 16 MB for data management.
- Noninvasive pacing:
Patented constant current Rectilinear Waveform pacing pulse with
40 ms.
- 4 to 1 Button for Pacing:
Yes. Allows the E Series user to check the underlying intrinsic
rhythm.
- Upgradeable to pacemaker and pulse oximetery:
Upgradaeble to Masimo SET pulse oximetry, microstream EtCO2;NIBP.
- With or without AED mode:
AED facility.
- Ac cum Battery operation:
Can work on mains and battery.
- Battery back up:
40 defibrillator charges at maximum energy or 3 hours of continous
monitoring
- Battery location:
Easy access battery in emergency.
- Wireless connectivity:
Blue tooth wireless option.
Larsen & Toubro Limited
Medical Equipments & Systems
Marketing Headquarters
Powai Campus
Mumbai - 400072
Tel: 022-67053204 / 3223
Fax: 022-67051267
ebg-med@LNTEBG.com
Website: www.lntmedical .com
|
Primedic-XD series
- Portable and light weight:
4.5 Kg only: The lighter the Defib the better it is since it is
a life saving equipment, it should be easy to carry.
- User friendly:
The energy selections buttons are in front.
- Energy selection:
Energy selection up to 360 Joules. Though uses Biphasic current
control, energy selection is up to 360 Joules which is good for recovery
of obese patient.
- In-built memory:
Pre and post shock events and any other arrythmia can be stored
and can be printed.
- Data management system:
Up to 48 Hours: It means patient Ecg of up to 48 hours can be recorded
and later can be reviewed or can be kept as a data management system.
- Upgradeable to pacemaker and pulse oximetery:
Upgradeable to pacemaker and pulse oximetery.
- With or without AED mode:
With or without AED mode.
- Ac cum battery operation:
Ac cum Battery operation.
- Minimum 50 shocks or five hours of monitoring on battery: During
transport this feature will really help.
- Charging time < one hour.
Head office address :
Metrax GmbH
Rheinwaldstrasse 22
78628 Rottweil
Germany
Metrax GmbH India Office
B-1, Lower Ground Floor
Crwone Plaza Surya
New Friends Colony
New Delhi - 110065
Ph : +91-11-26841741.
Fax :+91-11-26841742.
Mobile: +91 - 9818312002
Email: sales@metraxindia.com
Web: www.metraxindia.com
www.primedic.de
|
|
Philips Electronics India Ltd
|
Philips Electronics India Ltd
|
Philips Electronics India Ltd
|
Philips Electronics India Ltd
|
Meditronics Healthcare & Imaging |
|
|
|
|
|
Out of Hospital
|
In Hospital
|
|
|
HEARTSTART ONSITE
- Data Management:
Data card.
- AC / DC:
DC.
- CPR Measurement & Feedback:
NA.
- Central Monitor Connectivity:
NA.
Philips Electronics India Ltd
A-16, Mohan Coperative Industrial Estate
Mathura Road
New Delhi - 110 044 India
Tel: 0091-11-42095036
Fax:0091-11-26959763 / 26959798
www.medical.philips.com |
HEARTSTART FR2+
- Low energy Biphasic therapy of 200 Joules maximum energy as validated
by American Heart Association under Class II (a):
Yes.
- Therapy validated by peer reviewed studies?
Yes.
- AED Mode / Manual Mode:
AED / Manual Mode.
- Defibrillation?
Through Pads.
- Cardioversion?
No.
- For Adult / Pediatric use?
Yes.
- Pacing?
No.
- Monitoring Parameter:
ECG.
- AC / DC:
DC.
- CPR Measurement & Feedback:
NA.
- Central Monitor Connectivity:
NA.
Philips Electronics India Ltd
A-16, Mohan Coperative Industrial Estate
Mathura Road
New Delhi - 110 044 India
Tel: 0091-11-42095036
Fax:0091-11-26959763 / 26959798
www.medical.philips.com
|
HEARTSTART MRX
Philips Electronics India Ltd
A-16, Mohan Coperative Industrial Estate
Mathura Road
New Delhi - 110 044 India
Tel: 0091-11-42095036
Fax:0091-11-26959763 / 26959798
www.medical.philips.com
|
HEARTSTART XL
- Low energy Biphasic therapy of 200 Joules maximum energy as validated
by American Heart Association under Class II (a):
Yes.
- Therapy validated by peer reviewed studies?
Yes.
- AED Mode / Manual Mode:
AED / Manual Mode.
- Defibrillation?
Through Pads / Paddles.
- Cardioversion?
Yes.
- For Adult / Pediatric use?
Yes.
- Pacing?
Yes.
- Monitoring Parameter:
ECG/SPO2.
Philips Electronics India Ltd
A-16, Mohan Coperative Industrial Estate
Mathura Road
New Delhi - 110 044 India
Tel: 0091-11-42095036
Fax:0091-11-26959763 / 26959798
www.medical.philips.com
|
Cardiomax
- Memory function:
Last 2,5 hours of ECG monitoring( continuous) + events, Drugs administration,
alarms, fails and shock (2 Mb).
- Maximum energy derived : Biphasic delivery up to 360 Joules. For
internal defibrillation 1 to 50 Joules.
- Number of shocks: Upto 140 nos. in 360 Joules or 200 nos. in 200
Joules on battery when fully charged.
- Warranty period: One year.
- Portable light weight:
Trully portable; only 5.5kg (with battery and paddles).
User friendly, easy to operate. Yes.
- Energy selection up to 360 J.: Yes.
- In-built memory:Yes.
- Data Mangement system: Yes.
- Upgradeable to pacemaker and pulse oximetery: Yes.
- AED mode: AED available as optional.
- Ac cum Battery operation: Yes, Minimum 50 shocks or 5 hours of monitoring
on Battery: Yes and more.
- Charging time: 8 hours when fully discharged additional
- Battery back up: 3 to 3.5 hours for ECG monitoring and Shocks upto
140nos. in 360 Joules or 200nos. in 200 Joules on battery when fully
charged.
- Cardioversion: 30 to 35 Ms after QRS peak Upgradeable to Pulseoximetry
& Pacemaker.
- Thermal recorder: available Optional.
- Display: Color TFT display with 6.4 inch screen.
- Waveform: ECG and SPO2.
- Paddles: Multifunction paddles, adult and pediatric.
Meditronics Healthcare & Imaging
101 Shiv Industrial Estate
K B B Marg, Chinchpokli (East), Mumbai - 400012
Tel: 23719143
sales@meditronicsasia.com
Website: www.meditronicsasia.com
|
nancy.singh@expressindia.com
|
