Inherited Cardiac Conditions Flashcards
What are cardiomyopathies
Group of diseases of the myocardium that effect the mechanical or electrical activity of the heart
What is Hypertrophic cardiomyopathy
Inherited condition that causes hypertrophy of the myocardium in the absence of an alternative cause (e.g. hypertension)
How is Hypertrophic Cardiomyopathy caused
Mutations in genes coding for sarcomeric proteins
How common is HCM
Affects 1 in 500 people
How does HCM effect the heart
- Hypertrophy that commonly effects the inter ventricular septum
- Left ventricular tract outflow obstruction due to hypertrophy of anterior mitral valve
Symptoms of HCM
- Asymptomatic most cases - usually detected by routine ECG examination
- Chest pain
- Dyspnoea
- Arrhythmia
- Syncope
What is Syncope
Temporary loss of consciousness caused by a drop in BP
Why does Dyspnoea occur in HCM
Impaired relaxation of the heart and LVOT
Clinical features of HCM
- Double apical pulsation (forceful atrial contraction will cause a fourth heart sound)
- Jerky carotid pulse (due to rapid ejection + obstruction to LVOT during systole)
- Ejection systolic murmur (due to LVOTin systole)
How is HCM investigated
- ECG abnormalities (check ST segment)
- Echocardiography (diagnostic)
- CMR
How is HCM treated
Beta-Blockers
Disopyramide tor educe LVOT
What is Dilated Cardiomyopathy
Dilatation of the ventricular heart chambers
How is DCM inherited
Autosomal dominant
How is DCM caused
Cytoskeletal gene mutations
How does DCM usually present
Heart failure symptoms
How is DCM diagnosed
- Echocardiogram (reveals dilatation of left or right ventricles)
How is arrythmogenic cardiomyopathy caused
Mutations in desmosome genes
What is Arrythmogenic cardiomyopathy
Right ventricle - fatty replacement of myocytes leading to dilatation
Symptoms of ACM
Sudden death in early stages
Ventricular arythmies
Clinical feature of ACM
1. Asymptomatic in most patients ARRYTHMIAS 2. Syncope 3. Sudden death 4. Right heart failure (common later stages)
How is ACM diagnosed
- ECG shows inverted t-waves in precordial chest leads
2. CMR (diagnosis) - assess the RV activity and fatty tissue replacement
How are all Cardiomyopathies treated
Beta-blocker
How are channelopathies caused
Ion channel protein gene mutations (K, Na, Ca)
How does channelopathy effect heart structure
No effect
