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Second hand pacemakers power-up ailing pets |
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You can't take a pacemaker out of one human and replant it in another, for fear of what medical science refers to technically as "cooties."
Dogs, however, are not so particular.
Margie Leja of Dearborn Heights lost her mother-in-law in July. That's not "lost" as in wandered off, but rather lost in the sense that we're not built to last forever, and Genevieve wore out at 90.
Leja adored Genevieve, who bowled and drove until she was 85. "A wonderful mother-in-law," she says, and someone who's missed.
Leja also adores dogs, and those two passions are now connected by something Genevieve donated after her passing:
The little device that occasionally jump-started her heart.
At the request of the family, the funeral home removed her pacemaker and sent it to the veterinary college at Michigan State University. There, if they haven't done so already, surgeons will redeposit it beneath the fur of an ailing animal, most likely one with a waggable tail.
The surgery goes for $2,000 or so, says veterinarian and associate professor Bari Olivier, a deep discount compared to the price at most places that do the work. The pacemaker itself, $7,000 on up at your local Bed, Bath & Surgical Devices, is free.
"It's such a fantastic gift that can be passed on," says Leja, 63, "and nobody knows about it." Or at least, most people didn't. But now more of them will.
Fido stands to benefit
Today's pacemakers are about the size and weight of an Oreo.
At MSU, the vast majority of them go to the dogs, simply because dogs are more likely than other animals to suffer from what's known as third-degree heart block. An experienced surgeon like Olivier can insert one in as little as an hour. Place the device along the neck, slide a wire down the jugular vein, and a poodle with a pulse rate of 20 to 40 beats per minute will be back up to 80-100 before the anesthesia wears off.
Some of them are donated new by manufacturers like Medtronic. Most, however, come gently used, and without them, "we would have a serious problem," Olivier says. MSU performs up to 30 procedures annually, more than twice as many as a few years ago, and the number might well go up if more pacemakers were available.
Removing them from donors is easy and free. They have to be snared by a mortician anyway if there's a cremation, lest they explode or expel unpleasant things like mercury. Just ask, Olivier says, and most funeral homes will gladly ship them to East Lansing.
Can't take it with you
Leja first heard of the program from a funeral director 20 years ago, when her dad died. As someone whose present herd includes a greyhound and two beagles, all rescued, she was immediately intrigued.
About three weeks later, the veterinary school dropped her a note. "They said my father's pacemaker was used for a seeing-eye dog whose family would never have been able to buy one," she says.
That was all she needed to know, and enough to make her want to spread the word. It's the easiest way imaginable to be a buddy to a bulldog or a saint to a St. Bernard.
This article appeared in the Detroit News and was written by
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Pacemaker Implantation in a Boxer |
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Pacemaker Implanatation In A Boxer.
A very interesting document written by renowned animal cardiologist Nicole Van Israel concerning a pacemaker implantation in a 6 year old male boxer called Murdo. The following is the article which is reproduced here courtesy of Dr Van Israel - Please visit Dr Van Israels site Here, and please view all of her incredible papers Here.
A huge thanks from PWP to Dr Van Israel for taking the time to respond to our emails and granting us permission to direct you to her work. Below is an extract from one of her articles which can be downloaded in full, in PDF format HERE.
PRESENTING HISTORY
Murdo is a six-year-old male neutered Boxer presented for investigation of a bradycardia noticed at a pre-anaesthetic check when the intention was to remove an epulis. The dog was completely asymptomatic and there was no previous history of illness.
CLINICAL EXAMINATION
On presentation Murdo was overweight (36 kg; ideal weight 32 kg) but bright, alert and responsive. On clinical examination his mucous membranes were pink and his capillary refill time was less than 2 seconds. He seemed fully hydrated. Multiple epuli were visible in his mouth. No jugular distension was noticed. A strong and regular apex beat was palpable and no precordial thrill was felt. Abdominal palpation, although difficult because of the dog’s obesity, was unremarkable. All lymph nodes were within normal limits.All his extremities were nicely warm. His pulses were strong and without any deficits.
On auscultation a very regular heart rate was audible.The heart rate was 60 BPM. No murmur was audible. The lungs sounded unremarkable. Rectal temperature was 38.5°C.
PROBLEM LIST AND DIFFERENTIAL DIAGNOSIS
Regular bradycardia Sinus bradycardia
Physiological
• in very fit animals
• in animals with increased vagal tone (brachycephalic breeds)
• sleep
Pathological
• hypothermia
• hypothyroidism
• hyperkalaemia
• CNS disease, increased intracranial pressure
• upper airway obstruction
• gastro-intestinal (obstruction)
• urinary (obstruction)
Pharmacological
● tranquilliser, anaesthesia, digoxin, ß-blockers, morphine
Third degree AV-block
• Infiltrative disease (neoplasia, inflammation)
• Idiopathic fibrosis
• Myocardial infarction
• Hyperkalaemia
• Lyme disease
• Bacterial endocarditis
• Associated with congenital defects (aortic stenosis, ventricular septal defect)
DIAGNOSTIC WORK-UP
The dog was admitted to the hospital for electrocardiography, blood work, thoracic radiography and colour flow Doppler echocardiography.
ECG
A 12-lead ECG confirmed the presence of third degree
AV-block with a ventricular escape rhythm of 60 BPM.
The P-wave rate was 120 per minute (Fig. 1).
Fig. 1: Six-lead ECG showing third degree AV-block with an escape rhythm at 60 BPM (50 mm/s; 1 cm=1 mV).
Atropine response test
An atropine response test (atropine 0.02 mg/kg IV; in
normal animals one can expect a 50-100% increase in
heart rate depending on the initial heart rate) increased the
P-wave rate but not the ventricular escape rate.
Lab-work
a. Haematology (Table 1)
Haematology was unremarkable.
b. Biochemistry (Table 2)
The biochemistry showed the presence of a marginally
elevated cholesterol level.T4 levels were within normal
limits. Mildly increased urea and creatinine were
consistent with a mild prerenal azotaemia
The Vertebral Heart Score was 12.5.There was sign of mild R-sided cardiomegaly.The great vessels (aorta, pulmonary artery and caudal vena cava) and the pulmonary vasculature were within normal limits. The pleural space and the lung fields were unremarkable.
Fig. 2: Right lateral thoracic radiograph (expiratory film):
rounding of the cranial border of the cardiac silhouette.The
lung fields are clear.
Colour flow Doppler echocardiography
All chambers measured within normal limits. Posterior wall and interventricular septal wall thickness were within normal limits in diastole. The fractional shortening (FS) as indicator of myocardial contractility was mildly increased (FS53%).
A hyperechoic area was visualised in the lower part of the interatrial septum (Fig. 3). There was no sign of valvular insufficiency.The velocity across the aorta and pulmonary artery were within normal limits.
Fig. 3: Right parasternal long-axis view showing the
hyperechoic area in the interatrial septum (la: left atrium; ra:
right atrium).
FINAL DIAGNOSIS
Idiopathic third degree AV-block.
TREATMENT
The dog was pre-medicated with acepromazine (ACP®, C-Vet; 0.0125 mg/kg) and pethidine (0.5 mg/kg; Martindale) intramuscular. Prophylactic antibiotics (cephalexin, Kefzol®, Lilly; 20 mg/kg IV q 8 hrs) and analgesia (carprofen, Rimadyl®, Pfizer; 4 mg/kg IV) were administered. General anaesthesia was induced with thiopentone IV (Thiovet®, C-Vet; 412 mg) and maintained with isoflurane/O2 (Isoflo®, Mallinckrodt). Under fluoroscopic guidance a bipolar lead (Bipolar Endocardial Lead,Porous tip,Tined;Guidant®, Basingstoke UK; Fig. 4) was implanted in the right ventricle via the left
Fig. 4: Detailed view of the end of a tined pacemaker lead.
jugular vein. The whole procedure was monitored electrocardiographically. The bipolar lead was first connected to an external temporary pacemaker. Once the position of the lead established (pacing threshold less than 1 mA) it was tunnelled subcutaneously and attached to the pacemaker device. The permanent pacing generator (Pacesetter® VVI system) was implanted subcutaneously cranial to the left shoulder.The rate was pre-programmed at 70 BPM. A thoracic radiograph (Fig. 5) was taken for a permanent record of lead placement. The wounds were closed routinely and a protective bandage was applied.
Fig. 5: Right lateral thoracic radiograph showing correct placement of the pacemaker lead in the right ventricle.The lead has an S-bend to allow movement of the neck without putting strain on the lead.
The dog recovered well from anaesthesia, stayed in the Intensive Care Unit for 48 hours and was hospitalised for another three days. After a last technical check at the human hospital, he was discharged with a one-week course of antibiotics (20 mg/kg cephalexin BID PO, Ceporex®;Virbac).
OUTCOME
Three years post-intervention Murdo is still doing very well and the pacemaker seems to be pacing at all times (Fig. 6).
DISCUSSION
Third degree AV-block is an uncommon arrhythmia in the dog. It has been associated with several other conditions (Table 4). In this case no underlying cause could be determined. Dogs with third degree AV-block are usually middle-aged suggesting a degenerative change in the conduction system. Degeneration of the conduction system is common in many breeds. It has been stated that German Shepherd Dogs and Cockers Spaniels are over represented and there is one report where Dobermanns are the most common breed.
The importance of the hyperechoic area in the inter-atrial septum remains unclear. Hyperechogenicity is seen with fatty infiltration and collagen changes. Fibrosis and infiltrative disease are known aetiologies for third degree AV-block. Only a histopathological section might give an explanation.
Although no acetylcholine-esterase receptor antibodies were determined, myasthenia gravis was excluded as a possible aetiology on the basis of the complete absence of clinical signs. Borrelia burgdorfi antibody titres were ignored because Lyme disease is not endemic in the area where the animal lives.
Full bloodwork excluded electrolyte imbalances as a possible reason for the third degree AV-block. The azotaemia was, despite the lack of urinalysis (urine specific gravity), thought to be prerenal secondary to a decreased cardiac output due to the bradycardia.The renal perfusion and renal function parameters (urea, creatinine) should return to normal after pacing but no follow-up data are available in this case regarding this aspect. The mildly increased cholesterol levels could have been suggestive of hypothyroidism but T4 levels in the higher range of normal made this very unlikely.
Most animals with third degree AV-block have exercise intolerance as the main presenting sign. Dogs may also be presented because of syncope or congestive heart failure. In this case the dog was completely asymptomatic. It should be appreciated that third degree AV-block may not cause clinical signs unless there are periods with inadequate escape activity. Most healthy dogs can maintain a normal arterial blood pressure at rest with a heart rate as low as 40¬60 BPM.The ECG confirmed the presence of a relatively stable escape rhythm at 60 BPM. Considering the rate, the escape rhythm was thought to be originating from the subsidiary pacemakers in the bundle of His and the AV-node was the most likely site of the block.
On clinical examination no heart sounds (4th heart sounds) consistent with atrial contraction were noticed, partly due to the broad-chested nature of the dog and his obesity.The bouncy nature of the dog also made prolonged auscultation very difficult.The slow regular rhythm and the absence of a sinus arrhythmia were suggestive of an abnormal rhythm in this dog.The typical cannon A-waves, generated when atrial contraction occurs when the mitral valve is closed, were not observed in this animal’s jugular veins.
The radiographic changes were consistent with breed variation. Boxers have an increased VHS compared to other dogs (normal for Boxers 10.3-12.6v). As well as that bradycardia causes prolonged filling and can cause apparent cardiomegaly (diastolic frame). The echocardiographic changes (increased FS) in this case were typical of a hyperdynamic ventricle (Frank Starling mechanism).
Since the atropine response test was negative (atropine will usually increase the atrial rate without changing the ventricular rate because the ventricles are supplied mainly by sympathetic fibres and have few parasympathetic fibres) and since there was no increase of the heart rate after theophylline treatment a pacemaker implantation was the only alternative.
Fig. 7: Different types of pacemakers available with nomenclature.
Fig. 7 explains the three or five letter abbreviations used for describing the capabilities of the pulse generator.The first letter stands for which chamber is paced (V for ventricle, A for atrium,...), the second letter for which chamber is sensed (ditto), the third letter indicates the mode of response (I for inhibitory, T for triggered,...), the fourth letter shows that the device has multiple parameters that can be programmed and the final letter denotes if an anti¬tachydysrhythmia function is present.
The procedure and the post-operative period passed uneventfully in this case. However, one has to be aware that major (Table 5) and minor complications (Table 6) can occur. Survival analysis in the largest retrospective canine pacemaker study published revealed 1-, 2-, 3- year survival rates of 70, 57 and 45 % respectively.
REFERENCES AND FURTHER READING
TILLEY, L. P. (1992) Third degree AV-block. In: Essentials of canine and feline
electrocardiography, 3d Ed, Lea & Febiger, Philadelphia. Pp 175-178.
KITTLESON, M. D. (1998) Diagnosis and treatment of arrhythmias. In:Small
Animal Cardiovascular Medicine. Eds Kittleson & Kienle, Mosby, Inc, St-Louis.
Pp 489-492
BONAGURA, B. D. (1999) Cardiac pacing. BSAVA Congress synopses,
specialist session.
FOX, SISSON, MOISE (2000) Textbook of canine and feline cardiomyopathy
(W. B. Saunders).
OYAMA, SISSON, LEHMKUHL (2001) Practices and outcome of artificial
cardiac pacing in 154 dogs
(CANPACERS Study). JVIM; 15: 229-239.
© Illustrations Nicole Van Israël.
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Pacemakers for Pooches: A Surprisingly Feasible Option for Older Dogs |
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Putting a pacemaker in a dog may sound high-tech and far-fetched, but the practice is
neither as uncommon nor as costly as you might think. As pacemakers for human beings
have become fairly routine, lower prices and increased availability have made them an
option that can extend some animal's lives for several years.
"Between 100 and 200 pacemakers are implanted into animals--mostly dogs but some cats
and horses--in the United States each year," notes Dr. David Sisson, a veterinary
cardiologist at the University of Illinois College of Veterinary Medicine Teaching Hospital in
Urbana, where the procedure is done 6 to 20 times a year.
Dr. Sisson knows what he's talking about. For the past 5 years, he has served as the
director of a pacemaker registry started in the late 1980s by the Cardiology Specialty of the
American College of Veterinary Internal Medicine, an organization of veterinary medical
specialists who have completed special training and passed a certifying exam. There are
about 70 veterinary cardiologists in the United States.
"Pacemakers can correct the same abnormalities in dogs that they do in people," he
explains. Normally the body sends an electrical charge to stimulate the chambers of the
heart to contract and pump blood through the body. In a condition known as sinus node
dysfunction, or sick sinus syndrome, an abnormality of this electrical charge causes a very
slow heart rate (bradycardia).
Heart block is another condition that may be treated with a pacemaker. It occurs when the
top chambers of the heart, the atria, receive the electrical charge but the impulse doesn't
make it to the lower half of the heart, or ventricles, because of a blockage.
"The main symptom of these disorders is a slow heart rate that cannot be accounted for by
other reasons, such as hypothyroidism or other underlying metabolic problems," says Dr.
Sisson. "Some dogs with a slow heart rate will also exhibit fainting episodes that last 10 to
15 seconds and may occur as often as ten times a day."
Dogs who need pacemakers--like their human counterparts--are typically older. The
average age is 9 years. "The best candidates have hearts in reasonably good shape and
have no systemic illnesses, such as cancer, that would unnecessarily shorten their life span,"
says Dr. Sisson.
"A pacemaker is made up of a pulse generator and wires," he explains. "The pulse
generator, which is about the size of a silver dollar but thicker, contains an energy supply
and a tiny computer that monitors and controls the rhythm of the heart. Wires called leads
transmit electrical impulses between the pulse generator and the heart. When the
pacemaker detects that the heart's electrical activity has failed, it sends an appropriate
stimulus to get the heart going at the correct rate."
Twenty years ago, pacemakers were always implanted surgically. Surgeons cut through the
chest wall to attach the leads to the heart. The leads were brought through the rib spaces
and connected to the pulse generator, which was implanted on the animal's flank. This is still
the standard procedure used with cats.
A less invasive approach was developed in the early 1980s. In this procedure, a lead is
threaded through a vein in the neck until it reaches the heart. A tiny retractable screw built
into the lead attaches it firmly to the heart muscle and keeps it in place until scarring anchors
it there. The pulse generator is inserted under the skin at the back of the dog's neck. This
technique--which may require only one day in the hospital--is less risky for older dogs who
may not withstand major surgery.
The prognosis for dogs with pacemakers depends largely on how healthy the dog is other
than having an abnormal heart rhythm. A pacemaker often extends the life of the dog 3 to 5
years. Young dogs that receive pacemakers because of congenital heart blockage typically
do very well.
For owners, this treatment is not too taxing. "The dog is essentially cured and there are no
pills or injections to administer," Dr. Sisson points out. "All owners have to do is bring the
dog in for a checkup once or twice a year to make sure the pacemaker is functioning
correctly. The cost of the procedure is about the same as the cost of bone plating--surgical
repair of a fractured leg in a dog."
The pacemakers used for dogs are the ones made for people. Manufacturers often donate
unused pacemakers when several months have expired from the shelf-life of the power
source, making it undesirable for use in human beings. Receiving a pacemaker powered for
5 instead of 7 years in not a problem for dogs, since they have much shorter life spans than
people do.
As director of the pacemaker registry, Dr. Sisson contacts manufacturers to request
donations of pacemakers, matches donated pacemakers with needs nationwide, and
collects data from board-certified veterinary cardiologists about the conditions and
outcomes of all pacemaker surgeries. He's currently working on article that will report on 5
years of data from the registry.
Dr. Sisson advises owners considering this procedure in their dog to seek a board-certified
surgeon or cardiologist who is trained to do appropriate programming of the pulse
generator. These specialists can make sure the computer is sensing and pacing the heart
correctly.
If you would like further information, contact your local veterinarian or contact the
American College of Veterinary Internal Medicine, with headquarters in Lakewood, Colo.,
at 800/245-9081 (email:
This e-mail address is being protected from spambots, you need JavaScript enabled to view it
) for a referral.
By Chris Beuoy
Information Specialist
University of Illinois
College of Veterinary Medicine
This originally appeared Here
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Woman donates pacemaker to dog |
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Woman donates pacemaker to dog - extracted from Red & Black dot com.
Sunshine, a 9-year-old German shepherd, will now be able to live another five to six years due to the generosity of an elderly woman who bequeathed her pacemaker to a needy dog or cat.
[Click here to see Sunshine's procedure]
Sunshine's owner, John Wren, of Buford, said he and his wife, Cindy, were walking with Sunshine on Dec. 30, 2001 when they first saw signs that there was a problem with Sunshine's pacemaker, which was installed three years ago.
"I noticed that the leash got tight and, when I turned around, she was laying on her side and it looked like she was having a seizure," Wren said.
A veterinarian informed the Wrens that the ventricular lead of Sunshine's pacemaker had been broken and was causing the problem.
Wren said the lead was replaced at the beginning of the year.
He said during Sunshine's routine checkup Feb. 21, her pacemaker's battery was found to be dead.
The family of Dorothea Edwards donated their mother's pacemaker to the University's College of Veterinary Medicine in hopes that it would help an animal and in accordance with their mother's wish, according to the letter written to the college accompanying the pacemaker.
"Ninety percent of dogs who need pacemakers don't get them because of cost, availability and their location," said Clay Calvert, a cardiologist at the Department of Small Animal Medicine.
He said it is always a struggle to get pacemakers for dogs, although many humans have them.
"Technicians install between 400 and 500 in humans every year," Calvert said.
Pacemakers made for dogs cost between $4,000 and $6,000, said Dot Sparer, public relations coordinator for the College of Veterinary Medicine.
"The average pet owner just can't afford to spend $4,000 to $6,000," Calvert said.
He said the Wrens were being charged $1,000 for the procedure.
"Sunshine is a relatively young dog who could live five to six more years with the pacemaker," Calvert said.
"This is an option and a useful option for animals and is very meaningful for the person donating the pacemaker," Sparer said.
"We put between 10 and 12 pacemakers a year into dogs," Calvert said.
He said the veterinary school occasionally installs pacemakers in cats and horses, but most patients are dogs.
The University's veterinary school has been installing pacemakers in dogs for 25 to 30 years, Calvert said.
The pacemaker Sunshine received is state-of-the-art and relatively new, Calvert said.
The Wrens adopted Sunshine after she was recovered from a drug bust when she was 6 months old, Wren said.
"Her previous owner was the second on the FBI's most wanted list for four months before the arrest," he said.
Sunshine was awake and doing fine as of press time Sunday afternoon, veterinary school officials said. The Wrens said they would be picking Sunshine up from the clinic today. To find out more about Sunshine, visit (www.jcwren.com/sunshine).
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