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
Symptom of channelopathy
Syncope
How do channelopathies effect ECGs
Long QT
Short QT
Brugada
CPVT
When treating people with channelopathies, why do we have to be aware of QT prolonging drugs
Can kill people with QT syndromes
What is the most common way we can tell a person has cardiomyopathy or channelopathy
Sudden death in young people
Who does SADS (sudden arrhythmia Death Syndrome) tend to effect
Cot death - babies
caused by inherited cardiac conditions
How is familial hyper cholesterolaemia caused
Mutations in genes that regulate cholesterol metabolism
What is Brugada Syndrome
Ventricular fibrillation in people who have no evidence of causative structural cardiac disease
Can aortic aneurysm and dissection be inherited
Inherited
What is coarctation of the aorta
Narrowing of the aorta at insertion of ductus arteriosus - hypertension as renal perfusion decreases
Signs of coarctation
- Asymptomatic early stages
- Headaches (hypertension)
- Nose bleeds (hypertension)
- Cold legs (decreased blood flow)
What is an aortic aneurysm
Dilation of aorta to greater than 1.5 times its normal size - abdominal aorta
Symptoms of aortic aneurysm
None - occasional back pain
What is an aortic dissection
Innermost layer of aorta injury allows blood to flow between layers of aortic wall, forcing layers apart
Name three inheritable aortovascular syndrome
Marfan
Loeys-Dietz
EDS
Are ICCS dominant or recessive
Dominant
