Buletin USAMV-CN, 61/2005 (340-343)
ISSN 1454-2382
the treatment
of third dEgree atrioventricular
block to dogs. Permanent
cardioacelerator. clinical case
Brăslaşu Daniela Elena, Deutsch Al.*, Brădăţan Cătălina,
Brăslaşu M.C., Istrate V., Radev I., Alexa Ramona
Faculty of Veterinary Medicine
Bucharest
* University Hospital Caritas, Bucharest
Key word: III. Atrioventricular block,
pacemaker, dog.
Abstract. A permanent
pacemaker has been implanted to an 11 – year – old male German Shepherd with
third degree atrioventricular block and with low ventricular frequency (30/40
beats/min).
The endocardial lead was introduced into the right ventricle through the
left jugular vein. The pacemaker was implanted subcutaneously in the cervical /
dorsal region. The pacemaker’s programming was done to 100 beats/min and with a
pulse pressure by 0,4 V.
INTRODUCTION
The third
degree atrioventricular block means the
absence of beat’s transmission from the atriums to the ventricles with an
independent contraction.
The low
ventricular frequency established
clinical signs like: inappetence, sleepiness, syncope, depression. The
implantation of a pacemaker makes the ventricular frequency to increase.
MATERIAL AND
METHOD
Dog German
Shepherd, male 11-year-old.
The
electrocardiograms were made with KENZ 107 electrocardiograph. The ECG’s
parameters were: the limb derivation; 25 mm/sec and 1 mV/10 mm.
The
cardioacceleration was realized with Medthronic SIGMA SS103 pacemaker.
The
endocardial lead was a bipolar MEMBRANEE
EX 1470T type, of 58 cm.
RESULTS
AND DISCUSSIONS
An
11-year-old, male German Shepherd, weighing 35 kg was referred to the Veterinary Hospital
At the
veterinary hospital were made: echocardiogram, electrocardiogram evaluation,
current serum chemistries, thoracic radiography.
Electrocardiographic
was reported an atrial activity independently of ventricles. The atrial rate (P
waves) was 65/min and the ventricular rate was 31,5 / 37,03 / 53,5/min
(arrhythmic)(Fig. 1).
Fig. 1.
Third degree atrioventricular
block. The origin of QRS complex to the Hiss bundle
The dog
received Miofilin for upper limits to the cardiac frequency and Preductal as a
coronary vasodilation.
After a
week the dog was referred to the Veterinary Hospital
The atrial
rate showed an increase from 65 to 125 per min and the ventricular rate from 37
-50 to 50 – 51,72/min. (Fig. 2).
Fig. 2
Third degree atrioventricular
block. The origin of QRS complex to the Purkinje fibers
In view of
these findings, the dog was fitted with a programmable pacemaker.
After 4 –
5 days the dog’s condition was getting worse and a pacemaker implantation was
elected.
After a
premedication with Atropine (1 mg, i.m.) was used a preanesthetic medication,
Combelen and anesthesia was induced with Ketamina (10 cg).
The left
lateral area of the neck was shorn,
raced, disinfected with iodine tincture. Strict aseptic technique is required.
The first
half of the procedure requires isolation of the jugular vein and implanted the
lead, under fluoroscopic guidance into the right ventricle. The lead tip was gently pressed
against the endocardium until a stable position
was obtained. When the lead has been broken through the tricuspid valve,
premature ventricular beats had been showed on ECG (Fig. 3).
Fig. 3
Premature ventricular beats
To the
probe was connected the portable pulse generator with controlled over the heart race.
The
ventricular lead was fixed to the jugular vein using neabsorbable thread.
The
pacemaker was programmed to a rate of 100/min and 4 mV and a pulse width of 0,4
ms.(Fig. 4).
Fig. 4
ECG’s
aspect to a dog with a permanent pacemaker
Into a
subcutaneous loops was fixed the pacemaker and than connected to the extension
lead. The proximal end of the extension lead was attached to the pacemaker
generator via a subcutaneously tunnel.
The
pacemaker generator was positioned into
a pocket formed within the subcutaneous tissue at the dorsal surface of the
neck.
The
patient was monitored before, during and after the surgery. Postoperative were
used antibiotics in order to avoid endocarditis and local infections.
CONCLUSIONS
1.
Total atrioventricular block means the obstruction of migration’s rate from
atriums to ventricles. The atriums contracted in lower limits than the
ventricles. Clinical, more the ventricle rate is lower more the symptoms are
serious: deviation, inappetence, sleepiness, syncope, lipothymy.
2.
If there’s no increasing of ventricle frequency after tachycardia
medication (Atropine, Miofilin); if the ventricle frequency is lower the
implantation of a permanent pacemaker becomes necessary.
3.
The permanent pacemaker was fixed subcutaneously in the dorsal area of
the neck, the lead was advanced through the jugular vein into the right
ventricle. The ventricle frequency was programmed to 100 beats/min and 0,4 mV.
BIBLIOGRAPHY
- Darke P.G.G., Been M., Marks A., 1985 – Use of a programmable,
“physiological” cardiac pacemaker in a dog with total atrioventricular
block (with some comments on complication associated with cardiac
pacemakers). J. small Anim. Parct., 26, 295 – 303.
- Darke P.G.G., McAreavey D., Been M., 1989 – Transvenous cardiac
pacing in 19 dogs and one cat. J. small Anim. Parct., 30, (9), 491 – 499.
- Luca C., 1990 –
Electrostimularea cardiacă. Editura Academiei Române.
- Mark A.O., Sisson D.D., Lehmkuhl Linda B., 2001 – Practices and
outcome of artificial cardiac pacing in 154 dogs. J. Vet. Intern. Med.,
15, 229 – 239.
- Miura N., Fujiki M.,
Setoyama K., Takegawa K., Takahashi T., Miyahara K., Sakamoto H., 2003 – Successful use
an acceleration rate response pacemaker with transvenous steroid/eluting
screw – in lead for third – degree atrioventricular block in a Labrador
retriever. J. Vet. Sci., 65 (10), 1101 – 1105.
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