My Clinical Notes

• Cardiomyopathy refers to heart disease resulting from a primary abnormality of the myocardium
• Can be divided into;
  • Dilated
  • Hypertrophic
  • Restrictive

 

Dilated cardiomyopathy

• Accounts for 90% of cases
• Characterised by progressive cardiac dilation and systolic dysfunction, usually with concomitant hypertrophy
• Only 25% of patients survive >5 years
• Pathological mechanisms;
  • Genetic defects
    • 25-35% have a familial occurrence, most commonly autosomal dominant inheritance
    • The genetic abnormalities largely affect the cytoskeleton
  • Alcohol toxicity
    • Direct toxicity of alcohol or a metabolite of alcohol on the myocardium
    • May also be associated with thiamine deficiency which is cardiotoxic
  • Peripartum
    • Occurs in pregnancy just before or just after birth
    • Mechanism is unclear but may be due to chronic hypertension, volume overload, nutritional deficiency, metabolic derangement or an immune response
  • Post viral myocarditis

 

Hypertrophic cardiomyopathy

• Heavy, muscular, hypercontractile, poorly compliant heart with poor diastolic relaxation and reduced cardiac output
• Over 50% have an autosomal dominant inheritance
• Mutations are in several genes that encode sarcomeric proteins
• Increased risk of sudden death

 

Restrictive cardiomyopathy

• Rare with multiple aetiologies
• Restrictive ventricular filling leading to reduced cardiac output
• Interstitial myocardial fibrosis is usually present
• Can be idiopathic or be associated with with distinct disease of the myocardium, amyloidosis, sarcoidosis, radiation fibrosis, metastatic tumour
• Specific types of restrictive cardiomyopathy are;

·        Endomyocardial fibrosis

• • Seen in African children and young adults
  • Charcterised by ventricular subendocardial fibrosis

·        Loeffler endocarditis

• • Similar to subendomyocardial fibrosis but with an eosinophilic infiltrate and eosinophilia
• Endocardial fibroelastosis
  • Uncommon disorder associated with a fibroelastic thickening of the endocardium

 

Hypertrophic CM is a disease caused by mutations in the sarcomere whilst dilated CM is associated with abnormalities of the cytoskeleton

This entry was posted on Thursday, February 14th, 2008 at 5:57 am and is filed under Cardiovascular. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.