Week 9- Cardiovascular Disorders Flashcards
What is a cardiomyopathy?
A disorder that affects the cardiomyocytes or cardiac muscle function
What is heart failure?
Inability of the heart to maintain adequate circulation for the metabolic requirements of the body
What happens to ejection fraction during heart failure?
It can be preserved or reduced
What is preserved ejection fraction?
Heart function equal to or below 50% (reduced diastolic function-decreased muscle mass in left ventricle, can pump but can’t relax as well)
What is reduced ejection fraction?
Heart function equal to or below 40% (reduced systolic function-heart hasn’t got enough strength to pump out blood)
What type of ejection fraction causes reduced diastolic function?
Reduced ejection fraction
What type of ejection fraction causes reduced systolic function?
Preserved ejection fraction
What are causes of heart failure?
Secondary to cardiac damage eg ischaemia/myopathy, hypertension, valve disease
What type of ejection fraction does hypertension affect?
Preserved- hypertension causes thickening of the cardiac muscle wall making it harder for the muscle to relax
What happens to cardiac output during heart failure?
It falls
What are general symptoms of heart failure?
Breathlessness, fatigue, fluid retention (caused by cardiac dysfunction)
How is heart failure visible on an ECG?
Enlarged QRS complex (generally taller, can also be wider)
How is heart failure diagnosed?
Echocardiography or elevated natriuretic peptides
What is Tako Tsubo syndrome?
Left ventricular dysfunction where apex balloons and symptoms mimic MI (myocardial infarction)- also known as broken heart syndrome
What is the main cause of Tako Tsubo syndrome?
Stressful event
Who does Tako Tsubo syndrome usually affect?
Women
How does Tako Tsubo syndrome affect cardiac output?
Reduces it to around 40%
How is Tako Tsubo syndrome visible on an ECG?
ST segment elevation
What are some symptoms of Tako Tsubo syndrome?
Chest pain, increased cardiac biomarkers but blood vessels are normal
What are conduction abnormalities?
Disorders that affect bioelectrical transmission along the heart
What is dilated cardiomyopathy?
Cardiomegaly and dilation, systolic dysfunction with
hypo-contraction
What are the causes of dilated cardiomyopathy?
20-50% familial, also secondary to MI
How does dilated cardiomyopathy affect cardiac output?
Reduces it to round 40%
What are some symptoms of dilated cardiomyopathy?
Dyspnoea and fatigue
How is dilated cardiomyopathy visible on an ECG?
No specific changes, similar to LVR (enlarged QRS complex)
What is hypertrophic cardiomyopathy?
Unexplained left ventricular hypertrophy
What area of the heart does hypertrophic cardiomyopathy mainly affect?
Primarily affects the interventricular septum
What does hypertrophic cardiomyopathy do to cardiac output and how does it affect life expectancy?
Reduces cardiac output, can cause sudden death due to cardiac arrest during exercise
What are some symptoms of hypertrophic cardiomyopathy?
Dyspnoea and fatigue
How is hypertrophic cardiomyopathy visible on an ECG?
No specific changes, similar to LVR
What is atrial fibrillation?
Disorganised electrical activity and contraction
What is the cause of atrial fibrillation?
Spontaneously active cells throughout the atria
What effect does atrial fibrillation have on cardiac output and life expectancy?
Reduces output, leads to increased risk of heart failure or stroke
What are some symptoms of atrial fibrillation?
Palpitations and chest pain
How is atrial fibrillation visible on an ECG?
Absence of P wave and fibrillatory waves
What is Wolff Parkinson White?
A syndrome causing tachycardia and abnormal electrical conduction
What is the cause of Wolff Parkinson White?
Due to an accessory conduction pathway (bundle of Kent) between atria and ventricles
What effect does Wolff Parkinson White have on cardiac output and life expectancy?
Cardiac output and life expectancy remain unchanged
What are some symptoms of Wolff Parkinson White?
Palpitations and chest pains
How is Wolff Parkinson White visible on an ECG?
Pre-excitation visible on the QRS complex
Bisphasic or inverted T wave
What is conduction block?
Impaired electrical conduction through the AV node
What are the types of conduction block and how are they different?
Type 1, 2 or 3
Type 1= conduction slows down
Type 2= partial block
Type 3= complete block
What are causes of conduction block?
Fibrosis or calcification of conduction system
What part of the heart does type 1 conduction block affect?
AV node
What part of the heart do type 2 and 3 conduction block affect?
His Purkinje system
How are the different types of conduction block visible on an ECG?
Type I: ↑ P-R interval
Type II: ↑ P-R interval and 1 beat loss of AV conduction
Type III: Complete/persistent loss of conduction from atria to ventricles
What is a bundle branch block?
Impaired electrical conduction in the right or left
branches or fascicles of the bundles of His
Which out of right or left bundle branch block is more dangerous?
Left, right is benign and asymptomatic
How is bundle branch block visible on an ECG?
RBBB and LBBB – Widening QRS complex > 120 msec
Fascicle blockage (hemi-block) – Alterations in cardiac
axis: posterior leads to LAD & anterior leads to RAD
What clinical measurement of blood pressure qualifies as hypertension?
140/90 mmHg
What daytime average measurement of BP qualifies as hypertension?
135/85 mmHg
What does hypertension increase the risk of?
Stroke, heart disease, end organ damage
What are the symptoms of hypertension?
Its asymptomatic
Define myocardial infarction
An acute coronary syndrome resulting in cardiac tissue damage due to coronary artery blockage
Define angina
Pain or discomfort typically radiating from the chest
What are the 2 types of angina and how do they differ?
Stable- when chest pain is severe only after exertion or emotional stress
Unstable- when chest pain is uncontrolled and arises even when at rest
What is visible on an ECG of someone with MI?
ST segment elevation
