Cardiomyopathy is a group of diseases that affect the heart muscle and electrical functioning. There are several types including dilated, hypertrophic, restrictive, and arrhythmogenic right ventricular cardiomyopathy. Dilated cardiomyopathy is the most common type in Africa, accounting for 10-17% of cardiac conditions. Risk factors include family history, diabetes, hypertension, infections, and alcoholism. The pathophysiology varies by type, such as dilated cardiomyopathy causing ventricular enlargement and reduced systolic function over time. Clinical features depend on the type, such as fatigue and swelling for dilated cardiomyopathy. Diagnosis involves ECG, echocardiogram, cardiac MRI, and biopsy. Complications include heart failure,

1. CARDIOMYOPATHY
Presenter: Kutemwa Kapata

2. Definition
• A group of diseases of the myocardium often with the electrical and
mechanical dysfunction frequently with a genetic etiology. The walls of the
heart chamber become stretched, thickened or stiff resulting in the
inability of the heart to pump blood well. In some cases, the heart rhythm
is disturbed, resulting in arrhythmias.

3. Classification
• ESC divided cardiomyopathies into clinically-oriented phenotypes: dilated,
hypertrophic, restrictive, arrhythmogenic right ventricular
cardiomyopathy, and unclassified. The cardiomyopathies were then sub
classified into familial and non-familial, where familial is the occurrence in
more than one family member or a phenotype that could be caused the
same genetic mutation. Non-familial is characterized by an absence of
relevant family history and is divided into idiopathic or acquired
cardiomyopathy

4. Epidemiology
• A study conducted in Africa revealed in South Africa and Uganda, DCM
accounts for 10% to 17% of all cardiac conditions encountered at autopsy
and in many parts of Africa and for 17% to 48% of patients who are
hospitalized for heart failure. The incidence and prevalence of DCM in the
United States and elsewhere is reported to be 4 to 8 per 100 000 person-
years and 36.5 per 100 000 individuals, respectively.
• Between 2010 and 2018, prevalence increased for ARVC by 180% and
HCM by 9%. At diagnosis, more patients with CA (66%), DCM (56%) and
RCM (62%) had pre-existing HF compared with ARVC (29%) and HCM
(27%). Among those free of HF at diagnosis of cardiomyopathy, annualised
HF incidence was greatest in CA and DCM.

5. Etiology
Hypertrophic CM : Abnormal calcium kinectics, genetic causes, abnormal
sympathetic stimulation or cardiac structural abnormalities
Dilated CM : heredity, secondary to other cardiovascular diseases, infectious
causes, rheumatologic/connective tissue disorders, nutritional deficiency,
collagen vascular disease, neuromascular disorders, stress-induced or primary
cardiac tumor, myocarditis.
Restrictive CM: can be primary( endomyocardial fibrosis) or secondary
(infiltrative, sarcodiosis, scleroderma, glycogen storage disease,
radiationtreatment induced)
Arrhythmogenic right ventricular CM: inherited disorder. Other cases can
result from viral infections

6. Risk factors
• Dcm is more common in black people than white and is also more
prevalent in men than in women
• Arvcm is more prevalent in the young adults and teenagers.
• The major risk factor for cm is family history cardiomyopathy.
• Other risk factors include :
 Diabetes or other metabolic diseaes
 Long term alcoholism
 Long term high blood pressure
 Viral infections
 Mental stress and physical inactivity

7. Pathophysiology
• Dilated cardiomyopathy
Characterized by ventricular chamber enlargement and systolic dysfunction
with greater left ventricular cavity size. Exposure to a primary injury such as
infection or toxins can cause death of myocytes, the remaining myocytes
hypertrophy to accommodate the increased burden of wall stress. Local and
circulatory factors stimulate deleterious responses that contribute to
progression of the disease even in the absence of further injury. Progressive
dilation can lead to significant mitral and tricuspid regurgitation, which msy
further diminish the cardiac output and increase end systolic volumes and
ventricular wall stress. This leads to further dilation and myocardial
dysfunction

8. Pathophysiology
• Restrictive cardiomyopathy
Patients typically have increased diastolic stiffness and the left ventricle
cannot fill adequately at normal filling pressures, this leads to reduced cardiac
output. As the disease progresses, there is a variable reduction in systolic
function.

9. Pathophysiology
• Hypertrophic cardiomyopathy
The mechanistic events in hcm can be categorized in to four sets of
interlocking mechanisms. The primary defect is mutation, then molecular
changes that occur in response to the change in sarcomere protein structure
and function. The third mechanism is activation of the hypertrophic signaling
pathways which then leads to the manifestation of hcm.

10. Pathophysiology
• Arrhythmogenic right ventricular cardiomyopathy
The structural abnormalities result from genetic abnormalities located on
chromosome 1,2,3,6,7,10 and 12. This leads to progessive rv dilation and
dysfunction resulting from fatty infiltration and fibrosis of the rv myocardium

11. Clinical features
• Dilated CM: fatigue, dyspnea on exertion, shortness of breath, orthopnea,
pnd or increasing weight.
• Restrictive CM: gradual worsening shortness of breath, progressive
exercise intolerance, chest pain (primarily in pts with amyloidosis) or due
to angina, abdominal discomfort or liver tenderness, weight loss.
• Arrhythmogenic right ventricular CM: Most patients are asymptomatic.
Presentation is with symptoms and signs of right heart failure, although
this is more common in the later stages of the disease.
• Hypertrophic cardiomyopathy: dyspnea, syncope, palpitations, dizzines
and sudden cardiac death

12. Investigations
• Ecg
• Echocardiogram/Echocardiography
• Myocardial biopsy
• Cardiac MRI

13. Complications
• Thrombus formation
• Dysarrthymias
• Liver or kidney failure
• Sudden death
• Heart failure