Difference between revisions of "Hypertrophic Cardiomyopathy"

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== Introduction ==
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{{cat}}{{dog}}
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*Rare in dogs
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*Common in cats
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[[Image:hypertrophic cardiomyopathy.jpg|right|thumb|125px|<small><center>'''Hypertrophic cardiomyopathy (cat)'''. Courtesy of T. Scase</center></small>]]
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[[Image:hypertrophic cardiomyopathy 2.jpg|right|thumb|125px|<small><center>'''Hypertrophic cardiomyopathy (cat)'''. Courtesy of T. Scase</center></small>]]
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===Signalment===
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Dogs: Rare
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Cats: Pedigrees (e.g. Persians, Maine Coons) & mixed breeds; Occurs in young pedigrees and young to old mixed breeds; Male>Female
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===Description===
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*Left ventricular concentric hypertrophy without an identifiable cause is known as hypertrophic cardiomyopathy. The ventricular myocardium becomes so thick that the lumen is reduced to a size that is not compatible with maintaining the heart's function as a pump.  The left ventricle no longer has the capacity to hold normal volumes of blood during diastole.  As a result, the left atrium dilates from the increased pressure and volume of blood backing up into the lungs.
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===Diagnosis===
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====History & Clinical Signs====
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-Asymptomatic
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-Hindlimb paresis or weakness (saddle thrombus see in cats)
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-Signs of left-sided heart failure
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====Physical Exam:====
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-Systolic murmur
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-Ventricular arrhythmias
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Left ventricular '''concentric hypertrophy''' without an identifiable cause is known as hypertrophic cardiomyopathy. The ventricular myocardium becomes so thick that the lumen is reduced to a size that is not compatible with maintaining the heart's function as a pump. The left ventricle no longer has the capacity to hold normal volumes of blood during diastole. As a result, the left atrium dilates from the increased pressure and volume of blood backing up into the lungs.
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===Radiography===
  
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-Left atrial enlargement
  
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==Signalment==
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-Enlarged heart
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This heart disease is rare in dogs but is the '''most common cardiac disease in cats'''. It more frequently occurs in Persians and Siamese breeds of cat. It is thought to be inherited in Maine Coon cats.
 
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<br>
 
  
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== Clinical Signs ==
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-Pulmonary congestion & edema
  
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The disease can often be present without clinical signs (asymptomatic).
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===Electrocardiography (ECG)====
  
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There may be hindlimb paresis or weakness, if saddle [[Thrombosis|thrombus]] (cats) occurs due to this disease.
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-Tall R wave
  
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There will usually be signs of [[Heart Failure, Left-Sided|left-sided heart failure]]. Tachycardia, [[:Category:Arrhythmia|arrhythmias]] and dyspnoea can also be seen.
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-Wide QRS
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== Diagnosis ==
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-Ventricular arrhythmias
  
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Physical examination and auscultation will reveal a systolic murmur and ventricular arrhythmias.
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-Conduction disturbances
  
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Radiography of the thorax will show a degree of left atrial enlargement, a generally enlarged heart and pulmonary congestion & edema.
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-Sinus tachycardia
  
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On Electrocardiography (ECG), there will often be presence of a '''tall R wave and a wide QRS complex'''. Ventricular arrhythmias, conduction disturbances and sinus tachycardia may also be seen.
 
  
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Upon Echocardiography, left ventricular concentric hypertrophy, left atrial enlargement and mitral valve insufficiency are commonly seen with this condition. The chamber size will appear dramatically reduced.
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====Echocardiography====
  
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-Left ventricular concentric hypertrophy
  
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== Treatment ==
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-Left atrial enlargement
  
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It is necessary to treat the individual symptoms, as there is no treatment for the condition.
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-Mitral valve insufficiency
  
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Drugs with contraindications include arterial vasodilators and positive inotropes.
 
  
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===Treatment===
  
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== Prognosis ==
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-Treat the individual symptoms
  
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Poor for symptomatic cats.
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Contraindications: Arterial Vasodilators; Positive Inotrops
  
  
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{{Learning
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===Prognosis===
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|Vetstream = [https://www.vetstream.com/canis/Content/Disease/dis00924.asp, Hypertrophic cardiomyopathy]
 
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|flashcards = [[Myocardial Pathology Flashcards]]
 
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}}
 
  
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== References ==
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-Poor for symptomatic cats
  
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Ettinger, S.J. and Feldman, E. C. (2000)''' Textbook of Veterinary Internal Medicine Diseases of the Dog and Cat '''Volume 2 (Fifth Edition) ''W.B. Saunders Company''
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==From Pathology==
  
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Ettinger, S.J, Feldman, E.C. (2005) '''Textbook of Veterinary Internal Medicine''' (6th edition, volume 2) ''W.B. Saunders Company''
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[[Image:hypertrophic cardiomyopathy.jpg|right|thumb|125px|<small><center>'''Hypertrophic cardiomyopathy (cat)'''. Courtesy of T. Scase</center></small>]]
  
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Fossum, T. W. et. al. (2007) '''Small Animal Surgery '''(Third Edition) ''Mosby Elsevier ''
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''Incidence:''  
  
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The cat is most commonly affected.
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There is some evidence of inheritance, as in man, and the disease is said to be more common in male cats.  There is a wide age range of 7 months to 24 years.
  
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{{review}}
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Inherited in Maine Coon cats.
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''Clinical signs:''
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Grossly there is disproportionate hypertrophy of the left ventricle and often the interventricular septum.  The chamber size is dramatically reduced. 
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Histologically there is haphazard hypertrophy of the myocardial fibres. 
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The reduction in left ventricular volume and the stiffened ventricular wall results in diastolic dysfunction, the stroke volume is reduced resulting in congestive heart failure and the following clinical signs:
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[[Image:hypertrophic cardiomyopathy 2.jpg|right|thumb|125px|<small><center>'''Hypertrophic cardiomyopathy (cat)'''. Courtesy of T. Scase</center></small>]]
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*Tachycardia.
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*Arrhythmia (abnormal myocardium)
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*Dyspnoea.
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The force of the left ventricular contraction reduces afterload and reduces end-systolic volume to zero in some cases.  This is '''cavity obliteration'''. 
  
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*[[Atrial_Thrombosis|Thromboembolic disease]] is a frequent complication.  The thromboemboli most often impact in the femoral arteries manifesting as an acute hindlimb paralysis.
  
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[[Category:Cardiomyopathy]] [[Category:Cardiac Diseases - Cat]][[Category:Cardiac Diseases - Dog]]
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[[Category:Cardiomyopathy]]
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[[Category:Expert_Review]]
 
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[[Category:Cardiology Section]]
 

Revision as of 14:16, 23 June 2010

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Category:WikiClinical FelineCow
Category:WikiClinical CanineCow
  • Rare in dogs
  • Common in cats
Hypertrophic cardiomyopathy (cat). Courtesy of T. Scase
Hypertrophic cardiomyopathy (cat). Courtesy of T. Scase

Signalment

Dogs: Rare

Cats: Pedigrees (e.g. Persians, Maine Coons) & mixed breeds; Occurs in young pedigrees and young to old mixed breeds; Male>Female


Description

  • Left ventricular concentric hypertrophy without an identifiable cause is known as hypertrophic cardiomyopathy. The ventricular myocardium becomes so thick that the lumen is reduced to a size that is not compatible with maintaining the heart's function as a pump. The left ventricle no longer has the capacity to hold normal volumes of blood during diastole. As a result, the left atrium dilates from the increased pressure and volume of blood backing up into the lungs.


Diagnosis

History & Clinical Signs

-Asymptomatic

-Hindlimb paresis or weakness (saddle thrombus see in cats)

-Signs of left-sided heart failure


Physical Exam:

-Systolic murmur

-Ventricular arrhythmias


Radiography

-Left atrial enlargement

-Enlarged heart

-Pulmonary congestion & edema

Electrocardiography (ECG)=

-Tall R wave

-Wide QRS

-Ventricular arrhythmias

-Conduction disturbances

-Sinus tachycardia


Echocardiography

-Left ventricular concentric hypertrophy

-Left atrial enlargement

-Mitral valve insufficiency


Treatment

-Treat the individual symptoms

Contraindications: Arterial Vasodilators; Positive Inotrops


Prognosis

-Poor for symptomatic cats

From Pathology

Hypertrophic cardiomyopathy (cat). Courtesy of T. Scase

Incidence:

The cat is most commonly affected. There is some evidence of inheritance, as in man, and the disease is said to be more common in male cats. There is a wide age range of 7 months to 24 years.

Inherited in Maine Coon cats.

Clinical signs:

Grossly there is disproportionate hypertrophy of the left ventricle and often the interventricular septum. The chamber size is dramatically reduced.

Histologically there is haphazard hypertrophy of the myocardial fibres.

The reduction in left ventricular volume and the stiffened ventricular wall results in diastolic dysfunction, the stroke volume is reduced resulting in congestive heart failure and the following clinical signs:

Hypertrophic cardiomyopathy (cat). Courtesy of T. Scase
  • Tachycardia.
  • Arrhythmia (abnormal myocardium)
  • Dyspnoea.

The force of the left ventricular contraction reduces afterload and reduces end-systolic volume to zero in some cases. This is cavity obliteration.

  • Thromboembolic disease is a frequent complication. The thromboemboli most often impact in the femoral arteries manifesting as an acute hindlimb paralysis.
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