Cardiology Flashcards
How do you calculate cardiac output?
Heart rate x stroke volume
What three factors influence stroke volume?
Preload (depends on diastolic filling, and fiber stretch)
Contractility
After load (depends on arterial pressure)
What generates S1?
S1 - first heart sound - generated by closure of atrioventricular valves.
Left side - mitral valve (closes first)
Right side - tricuspid valve
What generates S2?
S2 - second heart sound - generated by the closure of the semilunar valves.
Left - aortic valve (first, slightly)
Right - pulmonary valve
What are the 7 stages of the cardiac cycle?
- _____ _____
- Isovolumetric ___
- Rapid ______
- Reduced _____
- Isovolumetric _____
- Rapid ______ _____
- ______
- Atrial systole (sometimes S4)
- Isovolumetric contraction (S1)
- Rapid ejection
- Reduced ejection
- Isovolumetic relaxation (S2)
- Rapid ventricular filling (sometimes S3)
- Diastasis
What type of murmur does aortic stenosis cause?
Ejection systolic murmur (crescendo-decrescendo)
What type of murmur does mitral regurgitation cause?
Pansystolic murmur
What type of murmur does mitral valve prolapse cause?
Late systolic murmur with a midsystolic click
What type of murmur does aortic regurgitation (or pulmonary regurgitation) cause?
Early diastolic murmur
What type of murmur does mitral stenosis cause?
Mid-diastolic murmur, with opening snap
Rearrange these in order from inner lining to outer supporting tissue
Tunica adventitia, tunica intima, tunica media
Tunica intima - inner lining, single layer flattened endothelial cells. Supported by basement membrane and delicate collagenous tissue
Tunica media - intermediate muscular layer
Tunica adventitia - outer supporting tissue
What type of ischemia does ST elevation show on an ECG?
Transmural ischemia (all layers of the heart - endocardium, myocardium, epicardium)
What are the three signs of subendocardial ischemia on ECG?
ST depression - horizontal
ST depression - downsloping
T wave inversion
Where the subendocardial layer of the heart?
What does it contain?
Damage to this layer can result in what?
Between the endocardium and myocardium
Purkinje fibres
Arrhythmias
What are acute coronary syndromes?
MI - STEMI and NSTEMI
Unstable angina
Which are the lateral leads on an ECG?
I, aVL, V5 and V6
Which coronary artery do the lateral leads on an ECG correlate to?
Left circumflex artery
What are the inferior leads on an ECG?
II, III and aVF
What coronary arteries do the inferior leads on an ECG correlate to?
Right coronary artery
Which are the septal leads on an ECG?
Which artery does this correlate to?
V1 and V2
Left anterior descending (LAD)
Which are the anterior leads on an ECG?
Which artery does this correlate to?
V3 and V4
Left anterior descending (LAD)
What does lead I measure on an ECG?
Right arm (-) to left arm (+)
What does ECG lead II measure?
Right arm (-) to left leg (+)
What is the normal cholesterol range?
Which is ‘good’ cholesterol HDL or LDL?
What does HDL cholesterol do?
What does LDL cholesterol do?
Normal range 3.5-6.5 mmol/L
HDLs ‘good cholesterol’ carry cholesterol away from arteries and back to the liver where it can be excreted
LDLs ‘bad cholesterol’ build up in the walls of the arteries, making them more narrow and less flexible
Give four examples of drug classes used to treat hypertension
What drug class is candesartan?
Angiotensin II receptor blocker (ARB)
2nd choice for hypertension behind ACE inhibitors
What type of diuretic is used for heart failure? Give an example.
Loop diuretic - furosemide
What type of diuretic is used for hypertension? Give an example.
Thiazide diuretic - bendroflumethiazide
What type of diuretic is used for heart failure and hypertension together? Give an example
Potassium-sparing : Spironolactone
Give examples of calcium channel blockers.
For which group of people would you prescribe this as first line for hypertension?
Amlodipine, Nifedipine, Verapamil, Diltiazdem
Aged over 55 years or if black/African/Caribbean family origin of any age
Give examples of ACE & ARB
For which group of people would you prescribe this as first line for hypertension?
ACE - Ramipril
ARB - Candesartan
Under 55 years (not black)
What does ECG lead III measure?
Left arm (-) to left leg (+)
On an ECG, If lead I is positive, and lead aVF is negative, what is the axis?
Possible left axis deviation
On an ECG, if lead I is negative and lead aVF is positive, what is the axis?
Right axis deviation
In a normal ECG, most leads are positive, but which are negative?
If lead I is positive, and aVF is positive, what is the axis?
Normally aVR, V1 and V2 are negative.
Normal axis
What class of drugs blocks the conversion of angiotensin I to angiotensin II?
Give an example
ACE inhibitors (angiotensin converting enzyme)
Ramipril, lisinopril, enalapril, captopril,
What type of diuretic is used for treating acute heart failure in the emergency department?
Give an example
Loop diuretic
Furosemide
For a 53 year old Caucasian male with uncomplicated hypertension what are the first line drug choices? Give classes and examples.
ACE inhibitor eg Enalapril
And ARB - eg Losartan
A 74 year old lady has high blood pressure, what drug is first line?
Calcium channel blocker eg Amlodipine, is first line for hypertension in over 55’s. Amlodipine also helps with angina.
Does sympathetic stimulation increase or decrease heart rate?
Sympathetic - increases eg adrenaline
Parasympathetic - decreases eg acetylcholine
Which type of cardiomyopathy causes increased ventricular wall thickness?
Hypertrophic cardiomyopathy
Which type of cardiomyopathy causes increased ventricular cavity size?
And decreased?
Dilated cardiomyopathy - increased
Hypertrophic cardiomyopathy - decreased
Which types of cardiomyopathy cause systolic dysfunction? And which cause diastolic dysfunction?
Systolic dysfunction - dilated CM
Diastolic dysfunction - hypertrophic and restrictive CM
Which cardiomyopathies cause an S3 heart sound and which an S4?
Dilated and restrictive - S3
Hypertrophic - S4
S3 = DCM (three letters)
S4= HOCM (four letters)
How does restrictive cardiomyopathy appear on an ECG?
Low amplitude signals
Short QRS complexes
(Restrictive cardiomyopathy (the least common type) is characterised by rigid ventricles which are unable to stretch appropriately and fill with blood. This causes diastolic dysfunction and normal systolic function. Causes include familial amyloid, hemochromatosis, senile amyloidosis, post radiation myocardial fibrosis, scleroderma)
What drugs can cause drug induced long QT syndrome?
Acronym - ABCDE
Eg. Haloperidol, ondansetron
What does NT-proBNP stand for?
What is it?
What condition does it indicate?
N-terminal pro-B type natriuretic peptide
B type natriuretic peptides are substances made by the myocardial cells in response to wall stress such as in heart failure.
Normally only low levels are found in the bloodstream. High levels mean the heart isn’t pumping as much as the body needs - heart failure.
What is a normal level for NT-proBNP?
What level requires referral to cardiologist (to be seen with in 6weeks) and urgent referral (to be seen within 2 weeks?
Normal = less than 400 pg/ml
Referral = 400-2000
Urgent referral = above 2000
What is this rhythm?
VF = Ventricular fibrillation