Cardiomyopathy, Myocarditis, and diseases of the pericardium Flashcards
What is cardiomyopathy?
Heart disease resulting from an abnormality in the myocardium.
How is a cardiomyopathy diagnosed?
Traditionally it is a diagnosis of exclusion:
{No major disease or abnormality or coronary arteries
No systemic hypertension or history of hypertension
No disease or abnormality of heart valves
No shunt inside or outside of the heart}
Genetic testing
How is cardiomyopathy classified?
Aetiological:
Primary - heart only
Secondary - Multiple system disorder
Clinico-pathological:
Dilated (DCMP)
Hypertrophic (HCMP)
Restrictive (RCMP)
Arrthmogenic (ARVC)
Extrinsic vs Intrinsic
Extrinsic: Ischaemic HD, Hypertensive HD, alcohol related
Intrinsic: Hypertrophic CM, Dilated CM
What are the types of primary Cardiomyopathy?
Idiopathic (DCMP, HCMP, RCMP)
Familial (DCMP, HCMP)
Eosinophilic endomyocardial disease (RCMP)
Endomyocardial fibrosis (RCMP)
Arrhythmogenic right ventricular CMP (DCMP)
What causes secondary CMP?
Infective (DCMP) Metabolic (DCMP) Familial storage disease Deficiency (DCMP, RCMP) Connective tissue disorders (DCMP) Infiltrations and granulomas (RCMP, DCMP) Neuromuscular (DCMP) Sensitivity and toxic reaction (DCMP) Peripartum heart disease (DCMP)
How is cardiomyopathy diagnosed?
Endomyocardial biopsy
What is dilated in DCMP?
All chambers are hypertrophied and dilated with bowing of the IV septum to the right side
What percentage of cardiomyopathies are DCMP?
90%
What causes DCMP?
Previous myocarditis
Idiopathic
Toxins
Connective tissue disorders
Muscular dystrophies
Peripartum
Can morphologically resemble end stage heart failure from other causes
How is DCMP genetic causes inherited?
Genetically heterogenous:
Autosomal dominant
Autosomal recessive
Mtchondrial inheritence
X-linked transmission also documented
What are the signs of DCMP?
Shortness of breath
Easy fatigability
Poor exertion capacity
Can DCMP be reversed?
Yes with cessation of alcohol abuse, cocaine use, etc
How much larger is the heart than normal in DCMP?
Up to 3x normal
What is the heart structure like with DCMP?
Dilated and flabby heart
Mural thrombi
Patchy fibrous scarring of myocardium and endocardium
Histological abnormalities are non-specific
Hypertrophic myocyes
Endocardial and interstitial fibrosis of variable degree
Subendocardial scars
What age group is DCMP seen in?
20 - 50 years old
How common is hypertrophic cardiomyopathy (HCMP)?
1 in 500 of general population
How does hypertrophic cardiomyopathy occur?
Heart does not fill properly due ti increased thickness of ventricular wall
Single gene mutations
Mutations in any one of the genes that encode sarcomeric proteins
Mostly autosomal dominant
Sporadic
Mutations are found most commonly in beta-myosin heavy chain
What happens to heart of someone with HCMP?
LV capacity is reduced in size
Marked hypertrophy of heart muscle without dilation of ventricle
Disproportionate thickening of ventricular septum (asymmetric septal hypertrophy)
Ventricular cavity has a banana-like configuration due to bulging of septum into the lumen
May have endocardial thickening in outflow tract
What happens to septum in hypertrophic cardiomyopathy?
it grows into the outflow tract.
What are the clinical features of HCPM?
Variable clinical course slowly progressive
Dyspnea
Angina pectoris
Fatigue
Syncope (big warning)
Double or triple apical precordial impulse, harsh systolic murmur, fourth heart sound
Atrial fibrillation with thrombosis and embolism, infective endocarditis on mitral valve, non-responsive heart failure, ventricular arrhythmias and sudden death