Banat`s University of
Agricultural Sciences
and Veterinary Medicine
"King Michael of Romania"
from Timisoara
clinical
research on right heart disease in adult dog
Daniela
Elena Brăslaşu1, Silvia Joiţa1, Simiz Fl.2,
Brăslaşu M.C.1
1. Faculty
of veterinary Medicine Bucharest
2. Faculty
of veterinary Medicine Timişoara
SUMMARY
Right - side heart failure is caused
by right heart disease. The symptoms are
obvious at the splanchnic level: hepatomegaly, hepatic sensitiveness, ascites, jugular
ectasia and only rarely, pleurisy.
Causes
of right heart disease are heartworms, tricuspid valvular disease, right intracardial or extracardial tumors, thrombi, right dilatative cardiomyopathy.
Diagnosis
of right heart disease is performed by clinical examination and is
confirmed by paraclinical methods:
X-rays, electrocardiography and echocardiography. Paraclinical examination play
an important role in establishing the diagnosis and in evaluating the
prognosis.
This
research emphasizes the characteristics of clinical and paraclinical diagnosis
of right-side heart disease.
Key-words: right –side heart failure, heartworms, cardiac tumors, right
dilatative cardiomyopathy.
Right ventricle and
atrium represent the right heart, which is responsible for pulmonary
circulation. Right heart takes over the blood from hepatic and cerebral level
and deliver it to the lungs. As a consequence, right heart disease will have an
impact on liver, CNS and lung.
Right heart disease
also plays an important role as the sinus node is located in the right atrium.
The impairment of sinus node can be the cause of severe cardiac arrhythmia.
Materials
and methods
Patients evaluation
was performed in the Cardiology Department of the Faculty of Veterinary
Medicine Bucharest and in the Internal medicine department of the Faculty of
Veterinary Medicine Timişoara (5 patients)
Two different X-ray
exposures were performed for each animal: right/left lateral exposure
and dorso - ventral exposure.
Electrocardiography parameters were: standard leads, 1mV = 5,10 or
20 mm amplitude and 25 or 50 mm/sec
speed of paper rolling.
Echocardiography was
performed on standing animals, using right and left parasternal windows and 3.5
or 6 MHz transducers.
Cytological
examination for the diagnosis of heartworms and blood serum biochemistry
were also used into the study.
Results and debates
There are not many
symptoms in right heart disease: different degrees of dyspnoea, hepatomegaly
with pain – a differential diagnosis is needed to exclude hepatitis – and ascites.
Jugular veins examination is possible in short hair breed, otherwise the area
has to be clipped.
In most of the
situations , diagnosis of right heart disease has been established when the
heart has been evaluated for the diagnosis of ascites and/or dyspnoea.
Tricuspid degenerative valvulopathy is a disease diagnosed
in most of the cases in small breed dogs. This valvulopathy can evolve alone
(rarely) or together with the
degenerative mitral valve disease. Clinical diagnosis is based on systolic murmur on tricuspid valve
auscultation area. Most of the times, this sound is shielded by the murmur of
mitral valve.
In many situation,
diagnosis of tricuspid valve disease was done by echocardiography, when
diagnosing mixomatous mitral valve disease.
Ultrasound elements
that helped the diagnosis were thickening of mitral valve, tricuspid
regurgitation (Doppler echocardiography) and secondary changes (right atrium
volume increase).
The
valve is thickened, there is valvular regurgitation
and
right atrial dilation (degenerative mitral valve disease it also observed)
Right dilatative cardiomyopathy is an idiopathic
disease often found in large breed dogs. Ultrasound diagnosis is based on right
ventricle dilation and systolic dysfunction. To have an accurate diagnosis, it
is important to make a differential diagnosis from the diseases that can
cause right ventricular dilation (heartworms).
Right
dilatative cardiomyopathy in dog.
Notice
the important dilation of right ventricle
Pulmonary hypertension is a consequence of degenerative
mitral valve disease (very often) or of chronic lung disease (including chronic
heartworms). The disease is often accompanied by dyspnoea, coughing, fatigue,
and eventually by thoracic liquids. To confirm the diagnosis, the arterial
pressure in pulmonary artery has to be measured. Pulmonary hypertension is
considered in advanced condition patients by following the right ventricle
dilation and flattening of interventricular septum (normally, there is a
concave aspect of the septum towards right ventricle).
Pulmonary
hypertension – flattening of interventricular septum
(2D-Eco,
transversal section)
Dirofilariasis is a disease more and more frequently
diagnosed in dogs in our country (Bucharest) . Dirophilariasis is considered in
right heart dilation (not every right heart dilation is a consequence of
dirophilariasis) and diagnosis of larvae is done by cytologic examination –
Parasitology Department. Diagnosis of adults is difficult to establish when
there is a small number of worms. It is also very important to
differentiate the heartworms from the chordae
tendineae, that have a steady position between ventricular walls and tricuspid
valve.
There were 3 cases of Dirophilariosis
diagnosed in Veterinary Cardiology
Department from Bucharest, that were confirmed by hematological examination.
The ultrasound image was comparable with a straw bundle in the right heart; the
worms were floating freely from right atrium
to the right ventricle. Other secondary signs were right ventricular and
atrial dilation and pleurisy.
Heartworms
in dog.
The are
adult worms into right ventricle (transversal section).
There
is also an increase of right heart cavities
Heartworms
in dog.
The
adult worms have the aspect of a straw bundle.
There
is also an increase of right heart cavities
Intracardial echogenic masses can be represented
by tumors or by free clots. In both situations, there was a right
atrioventricular dilation with echogenic intracardiac masses. It is difficult
in many situations to differentiate the
tumors from the clots. The tumors look usually as a steady vascular mass, but
in one case, the aspect of the tumor was that of spherical mass, moving between
right atrium and ventricle. It was the necropsy examination that confirmed the
presence of a pediculate tumor mass.
Tumors
in Right atrium
Even if these
diseases have been diagnosed using echocardiography, electrocardiography also
played an important role. Electrocardiography allowed to see the secondary
effects at the cardiac level: right bundle branch block, cavities increase and
different types of arrhythmia: premature atrial and ventricular beats, atrial
fibrilation et al.
X-rays played an
important role for the confirmation of right atrium and ventricular dilation,
in the diagnosis of chronic lung disease and of lungs tumors et al.
Cytological
examination and complete blood count has often be used to diagnose heartworms
and also to evaluate the general status of the patient (together with serum
biochemistry)
Conclusions
1.
Right-side
heart disease are primary diseases or can be a consequence of a cardial or a
pulmonary disease. Right dilatative cardiomyopathy, tricuspid degenerative
valve disease, pulmonary hypertension, tumors, clots and arrhythmia (right
bundle branch block) are the causes of right cardiopathyes.
2.
These
diseases can cause right heart insufficiency, hepatomegaly, liver sensitiveness, jugular veins
congestion, ascites, fatigue and sometimes pleural effusions .
3.
Diagnosis
is based on complementary investigations. Besides the diagnosis of right heart
dilation, X-ray plays an important role in the diagnosis of lungs disease that
can cause pulmonary hypertension with secondary right heart disease.
4.
Electrocardiography
is the method used to establish the diagnosis of heart arrhythmia: right bundle
branch block, atrial or ventricular premature beats et al.
5.
Echocardiography
is the best method to diagnose right heart disease. There is a right
ventricular dilation and systolic dysfunction in dilatative cardiomyopathy.
Tricuspid valve disease is diagnosed by valve thickening, blood regurgitation (Doppler
ultrasonography) and secondary signs (dilation of right atrium and ventricle).
In dirophilariasis, adult worms can be seen in the right heart. Pulmonary
arterial hypertension could be considered in the situation of interventricular
septum flattening.
6.
Complete
blood count plays an important role in A) confirmation of dirophilariasis
(cytological examination), B) evaluation of general status of the patient and
C) Therapy monitoring
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June A.,
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M.C.
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Book of Abstracts, p. 81
2013, Timisoara, Agroprint
