2. Cardio Flashcards
What receptors control heart rate?
Beta 1- increase heart rate
Muscarinic- Decrease heart rate
What causes left sided heart failure?
acute myocardial infarction although dysfunction of the valves, mitral valve regurgitation being the most common, can also result in back flow of blood into the pulmonary circulation
How do you work out the rate on an ECG?
Th normal rate of an ECG should be 25mm/sec menaing each small box is 0.04 s and each big box is 0.02 seconds
Therefore 30 big boxes is 6 seconds (30x0.2=6s) and the number of QRS complexes in that time (ventricular contractions) is the heart rate
Where do you place the limb leads in an ECG
Right arm- red
Left arm- amber
Left leg- green
Right leg- black
What is meant by sinus rhythm?
P wave for every Q
What nerves controls heart rate?
Vagus nerve- parasympathetic
Branch of phrenic nerve- sympathetic
Describe the pathway of conduction in the heart?
Sinoatrial node
Atrioventricular node
Bundles of hiss
Perkinje fibres
What hormones control cardiac output?
Epinephirine is released from adrenal medulla constricting arteries
angiotensin is produced in low blood volumes causing arteriolar constriction
vasopressin is an ADH hormone that constricts arterioles
ANP and BNP is produced in response to high blood volume, dilating arteries
Constriction increases BP
What controls short term blood pressure
Carotid and aortic baroreceptors
What controls long term blood pressure
The kidney and there three distinct hormone systems:
Renin-angiotensin-aldosterone system releases angiotensin II increasing MAP
ADH increases MAP when it is low
ANP decreases MAP when it senses it has raised
A patient has a slow rising plateuing pulse. What is this a sign of?
Aortic stenosis
How do you test for endocarditis?
Echocardium and multiple blood cultures
How do you treat infective endocariditis
2 antibiotics for at least 2 weeks IV and then oral
Describe the fate of the aortic arches?
The first and second arches disappear early, a remnant of the 1st arch forms part of the maxillary artery (a branch of external carotid artery)
The third aortic arch constitutes the commencement of the internal carotid artery, and is therefore named the carotid arch
The fourth right arch forms the right subclavian
The fourth left arch becomes the arch of the aorta
The fifth arch disappears on both sides
The sixth arches form the pulmonary arteries
What is the best drug to treat angina?
beta blockers- only one with a negative ionotropic effect. They decrease heart rate, increasing diastole and increasing the time the heart spends in diastole
What other treatments should you consider for angina?
CCB
Aspirin
Statin
Cardiology stenting
(GTN acute)
When should thrombolysis be used for strokes?
only within 4 and a half hours of onset
What are the common types of drug sused in cardio?
Anti hypertensives- CCB, ACE inhibitors, beta blcokers
anti platelets- aspirin and clopidogrel
Anti- coagulants- heparin and warfarin
statins
When do you use digoxin?
Heart failure and AF (not in poor renal function)
Pregnant woman develops red face, breathlessness and a raised JVP?
Mitral stenosis
Could also be JVP but has mitral faces (red face)
What heart valve abnormality is associated with rheumatic heart disease
mitral regurgitation
What are some classic symptoms of marfans
Increased aortic root diameter Apical blebs Mitral regurgitation Tall Ductal ectasia (widening of dural sack)
What genetic mutation causes marfans?
Fibrin mutation
