Cardio Flashcards
Which of these leads are bipolar and unipolar
I, II, III = biopolar
aVR, aVL, aVF - unipolar
When does a U wave appear on an ECG
After the T wave - typically smaller then the T wave
What polarity (positive of negative) is on each corner of Einthoven’s triangle and what is the resulting direction of the deflection of a wave travelling towards that corner
LA - has negative and positive charge
RA - negative
LL - positive
Depolarisation towards positive = positive deflection
Depolarisations towards negative = negative deflection
What degrees does the heart need to be at to be in left axis deviation
When the QRS axis falls between -30 and -90 degrees
What direction to each of the limb leads travel in
Negative to positive
I : RA > LA
II : RA > LL
III : LA > LL
What is the primary cause of coronary artery disease
Athlerosclerosis
What are three common approaches to treatment of coronary artery disease
1) Lifestyle modifications
2) Medication - antiplatelet agents, statins, beta blockers
3) Revascularisation - stents, bypass grafting
What is the definition of heart failure
Impairment in the hearts ability to pump blood and is insufficient to meet the needs of the body
What are the two primary blood markers in heart failure and what do they each indicate
Troponin - usually found inside the cardiomyocytes, if this is present in the blood we know there is cardiac damage
BPN - this is created when the heart is working hard, so increases during cardiac stress. (>100ph/ml is considered positive and indicative of HF)
What is the difference in mechanism between heart failure with preserved ejection fraction and heart failure with reduced ejection fraction
HF with preserved EF - the heart is contracting normally but the volume of blood is very small. Because the proportion of the blood in and out is the same, the EF is preserved
HF with reduced EF - due to cardiomyocytes death so the heart isn’t contracting properly
What are the different treatment options for people with HF with preserved EF and those with HF with reduced EF
HF preserved EF - no treatment
HF reduced EF - medication, lifestyle changes or pacemakers
What is cardiac resynchronisation therapy
A 3 lead pacemaker is put into the RA, RV and LV to detect irregularities and provide shock if need be
What is restrictive cardiomyopathy and what pathological remodelling is usually associated with it
When the ventricle stiffen and cant fill with blood
Atrial enlargement is common
Infiltration of amyloids, sarcoidosis, too much iron, fibrosis and inherited metabolic disorders are all causes of what disease
Restrictive cardiomyopathy
What 3 blood markers will be present in a patient with restrictive cardiomyopathy
eosinophils, hemochromatosis, BNP
What is Left ventricular non-compaction and what other 2 pathologies can it cause
This occurs when the muscles in the LV don’t compact during development, leaving the muscle of the LV soft and spongy
Atrial enlargement
LBBB
What is Takotsubo Cardiomyopathy and what changes does it cause to the heart
Heart condition developed in response to an intense emotional or physical experience.
Ventricles change shape affecting it’s ability to pump blood
What is Desmoplakin Cardiomyopathy and what causes
This is a rare genetic disorder that is caused by dysfunctional desmosome complex.
Can result in repeated myocardial injury or infiltration of immune cells causing fibrosis
What are the mechanisms of bradycardia and tachycardia in channelopathies
Bradycardia - failure of impulse formation or conduction
Tachycardia - re-entry and mechanism of abnormal automaticity
What does Long QT syndrome effect, what are common symptoms and what is the primary treatment
K+ efflux
fainting, seizures
Medication (usually Na+ channel blockers or beta blockers)
What is the cause of Brugada syndrome
Mutation in voltage gated Na+ channel gene
What causes Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) and what are common treatments for this. What is a common pathological feature associated with CPVT
Inherited mutation of cardiac Ca2+ channels (RyR)
Treatment: beta blockers, antiarrhythmics
Arrythmias are common
What causes Arrhythmogenic cardiomyopathy and what cardiac pathologiy is commonly caused by this disease
Mutation of desmosome proteins
Can lead to HF - lack of desmosomes causes infiltration of fibroses leading to weakening of the heart muscle
1st degree AV block
Delay in the conduction of electrical signal from the atria to the ventricles.
Every impulse from the atria are conducted to the ventricle but at a slower speed