Cardiovascular disorders (34) Flashcards
What is tako tsubo syndrome?
left ventricular enlargement- forms a shape like an octopus pot
- ‘broken heart’
- mimics myocardial infarction
What is the underlying cause of tako tsubo syndrome?
stressful event, mainly affects women
What are the effects of tako tsubo syndrome on cardiac output and life expectancy?
- dec. cardiac output
- ejection fraction around 40%
- 5% mortality
How does tako tsubo syndrome present?
- chest pain
- inc. cardiac biomarkers
- normal blood vessels
- ST segment elevation on ECG
What are the components of a normal ECG?
- P- wave- atrial depolarisation
- PR interval- conduction through AV node (normal= 120-200msec)
- QRS complex- ventricular depolarisation
(N.B. large QRS complex- more muscle mass, wider- slower conduction) - ST segment- plateau phase at baseline
- QT interval- total duration of ventricular depolarisation and repolarisation
- R-R interval- duration between ventricular depolarisations–> so heart beat
- cardiac axis- -30-+90 degrees
What are conduction abnormalities?
disorders that affect bioelectrical transmission along the heart
What is atrial fibrillation?
disorganised electric activity and contraction
What is the underlying cause of atrial fibrillation?
spontaneously active cells throughout the atria (can be associated with pulmonary veins)
What is the effect of atrial fibrillation on cardiac output and life expectancy?
- modest decline in cardiac output
- people die from blood clot formed
- risk of heart failure and stroke
How does atrial fibrillation present?
- palpitations
- chest pain
- absent P-wave on ECG
- ‘irregularly irregular’ rhythm
- fibrillatory waves
What is Wolff Parkinson White?
syndrome causing tachycardia and abnormal cardiac electrical conductance
How does Wolff Parkinson White present?
- palpitations
- chest pain
- pre excitation of QRS complex in ECG
- biphasic T- wave
What is the underlying cause of Wolff Parkinson White?
due to an accessory conduction pathway (bundle of Kent) between atria and ventricles
What is the effect of Wolff Parkinson White on cardiac output and life expectancy?
- cardiac output unchanged
- normal life expectancy
What happens in AV block type 1?
impaired electrical conduction through AV node
What happens in AV block type 2 and 3?
complete block of electrical conduction through AV node
must spontaneously contract itself
What is the underlying cause of AV block?
- heart failure, MI
- fibrosis of the cells or calcification–> damage to AV node cells
What is the effect of AV block on cardiac output?
usually dec. cardiac output
How does AV block present on ECG?
type 1 and type 2: inc. PR interval (>200ms) bc inc. time current stopped at AV node
What is Bundle branch block?
- impaired electrical conduction in the right or left branches or in fascicles on the bundles of His
- LBBB=harmful or RBBB=benign/asymptomatic
How does Bundle branch block present on ECG?
- RBBB and LBBB–> widening QRS complex (>120ms) bc slower depolarisation
- fascicle blockage–> alteration in cardiac axis- left or right axis deviation
What is the underlying cause of LBBB?
ischaemia or heart disease
What is the effect of LBBB on cardiac output?
usually dec. cardiac output
What is hypertension?
clinic BP> 140/90 mmHg
ambulatory BP daytime average > 135/85 mmHg
What is the underlying cause of hypertension?
- primary cause unknown
- various 2y causes (e.g. kidney disease)
What is the effect of hypertension on cardiac output and life expectancy?
- will potentially dec. cardiac output
- inc. likelihood of heart disease or end-organ damage
How does hypertension present?
- asymptomatic
- requires BP monitoring
- no specific ECG findings
What is MI?
acute coronary syndrome resulting in cardiac tissue damage to coronary artery blockage
What is angina?
- pain or discomfort that typically radiates from the chest at rest (unstable-STEMI) or brought on by physical exertion or emotional stress (stable-NSTEMI)
What is STEMI?
‘ST elevated myocardial infarction’
elevation of ST due to complete blockage
What is NSTEMI?
‘non ST elevated myocardial infarction’
partial blockage
What is a cardiomyopathy?
a disorder that affects the cardiomyocytes or cardiac muscle function
What is heart failure?
when the heart is unable to maintain adequate circulation for the metabolic requirements of the body
What is ejection fraction?
percentage of how much blood the left ventricle pumps out with each contraction
What is preserved ejection fraction?
EF> 50%
- diastolic heart failure- heart muscle contracts normally but the ventricles do not relax as they should during ventricular filling
What is reduced ejection fraction?
EF< 40%
- systolic heart failure- muscle of the left ventricle is not pumping as well as normal
What is the underlying cause of heart failure?
- cardiac damage (ischaemia, myopathy)
- hypertension–> inc. after load–> HFpEF
- valve disease
What is the effect of heart failure on cardiac output and life expectancy?
- dec. cardiac output, venous blood accumulation
- poor prognosis: 50% mortality rate < 5yrs
How does heart failure present?
- breathlessness
- fatigue
- fluid retention
- non-specific ECG findings (might get enlarged QRS complex bc inc. muscle mass)
- diagnosis by echocardiography and elevated natriuretic peptide levels
What is the underlying cause of myocardial infarction and angina?
due to formation of an atheroma in a coronary vessel–> myocardial ischaemia/cell death
What is the effect of MI on cardiac output and life expectancy?
- depends on site, but usually dec. cardiac output
- high mortality if untreated
How does MI present on ECG?
ST elevation in specific leads
