Cardiac Myopathies & Channelopathies Flashcards
What is a cardiomyopathy?
A problem with heart muscle
What types of congenital heart defects are there?
Structural
Cardiomyopathies
Channelopathies
All cardiomyopathies will present themselves within the first few years of life. True or false?
False!
They can start to develop at any age.
Some people have no abnormalities for many years and suddenly one starts to manifest itself
Who do we screen for congenital heart defects?
People who have affected first degree relatives
Groups at risk of mortality: athletes
List some cardiomyopathies.
Hypertrophic
Dilated
L ventricle non-compaction
Arrhythmogenic
Describe some other non heart specific conditions that can cause CVS diseases.
Palmoplantar keratoderma
Marfan’s syndrome:
Can cause an aortic root aneurysm
Familial Hypercholestrolaemia:
Can’t take up cholesterol from blood due to an LDL receptor fault. Excess blood cholesterol = heart problems
List some Channelopathies.
Long QT
Short QT
Brugada
CPVT
What are the features of hypertrophic cardiomyopathy?
Thick walls, small cavities
When they contract the atria & ventricles contract down to almost nothing
Disorganised arrangement of myocytes
Fibrotic tissue develops: arrhythmias
Why does fibrotic tissue cause arrhythmias?
Fibrotic tissue is an electrical insulator, so it blocks electrical conduction in the heart.
Causes random bursts of ventricular arrhythmias
How do patients with hypertrophic cardiomyopathy present?
Sudden death Angina Dyspnoea Palpitations Syncope Jerky pulse Harsh ejection systolic murmur
What tests can you do to confirm hypertrophic cardiomyopathy?
ECG: shows up the random bursts of ventricular arrhythmia
Echo: shows up the hypertrophic walls
Exercise test with heart monitor
What is the treatment of hypertrophic cardiomyopathy?
Beta blockers or verapamil (a Ca antagonist): to reduce ventricular contractility
Amiodarone: anti-arrhythmic drug
Anti-coagulants: to prevent a clot forming as a result of arrhythmia
Septal myomectomy
Implantable defribrillator
What is septal myomectomy? How is it done?
Removal of a portion of the septum that is obstructing the flow of the blood from the ventricle to the aorta
Can be done surgically or chemically (alcohol ablation)
What is an implantable defibrillator?
A device placed in the heart that senses and corrects any arrhythmias that occur
It corrects them by giving electric shocks to get the heart back into a normal rhythm
Which type of cardiomyopathy causes the most sudden deaths?
Hypertrophic
What are the features of dilated cardiomyopathy?
A dilated, flabby heart
Thin walls
Chambers don’t contract properly
How do patients with dilated cardiomyopathy present?
They present very young with heart failure
Breathless
Fatigue
Fluid retention
Emboli
What are the clinical signs of dilated cardiomyopathy?
Raised pulse Low BP Raised JVP S3 gallop Mitral or tricuspid regurgitation Pleural effusion
What tests can you do to confirm dilated cardiomyopathy?
Bloods:
Look for B-natriuretic peptide which will be raised
U&E: low Ca2+
CXR: cardiomegaly, pulmonary oedema
ECG: tachycardia
Echo: flabby, dilated heart
What is the significance of low Ca2+ in dilated cardiomyopathy?
Low Ca2+ indicates a poor prognosis
What is the treatment of dilated cardiomyopathy?
Bed rest
Diuretics
Digoxin: cardiac stimulant
ACE inhibitors
Anti-coagulants
Transplant
What are the features of left ventricle non-compaction?
The inside of the heart is sponge like during development and is compacted prior to birth to leave chambers
In this condition there’s a fault in the compaction process and the inside of the heart, especially the L ventricle remains spongy and there are excessively prominent trabeculations
This causes poor pumping performance
How do patients with left ventricle non-compaction present?
Heart failure symptoms SOB Oedema Fatigue Exercise intolerance
Tachycardia
Blood clot formation