6.18 - Cardiovascular Disorders Flashcards
(41 cards)
What is the definition of heart failure?
Heart unable to maintain adequate circulation for metabolic requirements of body
What is systolic heart failure?
- reduced ejection fraction (HFrEF) where EF > 40% but reduced systolic function
- left ventricle has weakened heart muscle and muscle is more dilated so less able to pump blood out of it thus reduced EF
What is diastolic heart failure?
- preserved ejection fraction (HFpEF) where EF > 50% and reduced diastolic function
- stiff heart muscle in left ventricle means smaller area for blood in it so less blood fills ventricle - but still get reasonable amount pumped out which is why EF is preserved
- so you get ventricular hypertrophy
What is the main ECG finding of heart failure?
Bigger QRS complex due to increased muscle mass in heart so more electrical current - not always found in heart failure
What are some underlying causes of heart failure?
- secondary to cardiac damage (ischaemia, myopathy)
- hypertension
- valve disease
What are the signs and symptoms of heart failure?
Exertional dyspnoea (i.e. breathlessness during exertion)
What are the tests for heart failure?
- blood test - elevated brain natriuretic peptide (BNP)
- chest X-ray - cardiomegaly
What are the treatment options for heart failure?
Drugs that reduce the exertional pressure on the heart
What is atrial fibrillation? (Electrical transmission disorders - atrial arrhythmias)
- disorganised electric activity and contraction due to pacemaker cells forming in regions outside of SAN and AVN
- prevents smooth transition of electrical current from SAN to AVN
- caused by spontaneously active cells throughout the atria
What are the ECG findings for atrial fibrillation?
Absent P-waves and ‘irregularly irregular’ rhythm
How is atrial fibrillation treated?
Strategies to maintain sinus rhythm (e.g. cardioversion, anti-arrhythmics, catheter ablation)
What is Wolff-Parkinson-White (WPW)? (Electrical transmission disorders - atrial arrhythmias)
- syndrome causing tachycardia and abnormal cardiac electrical conductance
- caused by additional accessory conduction pathway (the bundle of Kent) between the atria and ventricles
What are the ECG findings for Wolff-Parkinson-White?
- QRS pre-excitation
- biphasic/inverted T-wave of ECG - caused by current not being stopped at AVN and another depolarisation starting when ventricles are still repolarising
What are the treatment options for Wolff-Parkinson-White?
Benign - no treatment required
What are the signs and symptoms of atrial fibrillation and Wolff-Parkinson-White? (Atrial arrhythmias - electrical transmission disorders)
Palpitations and chest pain
What is a first-degree block? (Conduction block - electrical transmission disorders)
Slowing down of conduction through AV node (like a traffic jam where current cannot pass through AVN from atria to ventricles as well)
What is the ECG like for a first-degree block?
Increased P-R interval
What is a second-degree block? (Conduction block - electrical transmission disorders)
Reduced transmission of signal from atria to ventricles (types I, II, III)
What is the ECG like for a second-degree block?
Increased P-R interval or ‘missing’ QRS complexes, depending on type of block
What is a third-degree block? (Conduction block - electrical transmission disorders)
- complete block of current from atria to ventricles
- medical emergency - no ventricular depolarisation and muscle contraction
What is the ECG finding for a third-degree block?
P-waves not followed by QRS complexes
What is the underlying cause of conduction block?
Damage (fibrosis, calcification, necrosis) to the conduction system (AV node or His-Purkinje system)
What are the treatment options for conduction block?
- discontinuation of AV-blocking drugs (e.g. beta-blockers, calcium channel blockers)
- pacemaker implantation in severe cases
What is hypertension? (Vasculature disorders)
Clinical BP > 140/90 mmHg & ambulatory BP daytime average > 135/85 mmHg for prolonged period
