All of cardio Flashcards
Treatment of cardiac tamponade as a complication of an MI
Pericardial aspiration
Surgery
What does the valsalva manoeuvre active
aortic baroreceptors
What is the funny current?
The decreased K+ efflux superimposed upon a Na+ influx
If is mediated by
hyperpolarisation
HCN channels
What does a block of HCN channels cause?
a decrease in the slope of the pacemaker potential, therefore a reduction of heart rate
What is Atropine
a competitive inhibitor of acetylcholine, used in extreme Bradycardia to speed up the heart rate
Invabradine
selective blocker of HCN channels, used to slow down the heart rate in angina
Sacroplasmic recticulum
calcium store
CICR
calcium induced calcium release
Refractory period
a period immediately following stimulation, nerve muscle is unresponsive
What does a long refractory period prevent
tectonic contraction
What are the segments of heart muscle
Actin and myosin
What is the role of calcium in cardiac muscle contraction
Ca2+ is required to bind with troponium, pulling troponium-tropomyosin complex aside
What is bound to actin to prevent muscle contraction
tropomyosin
Define Preload
Pressure exerted on the muscle fibres in the ventricles of the heart at the end of diastole
Frank Starling’s Law of the Heart
SV vs EDV
Afterload
the resistance into which the heart is pumping
Length of diastole
0.5 s
Length of systole
0.3 s
How to calculate the HR from an ECG
300/no. of large square between each R wave
OR
if irregular
Count the number of QRS complexes in 30 large squares, and multiply by 10
How much is a small box and a large box worth on an ECG
- 04 seconds - small box
0. 2 seconds - large box
Anteroseptal MI (STEMI)
ST elevation in chest leads V1-V4
Inferior MI (STEMI)
ST elevation in limb leads II, III, aVF
Anterolateral MI (STEMI)
ST elevation in V4-V6, I, aVL (affects LAD or circumflex)
Lateral MI (STEMI)
ST elevation in I, aVL +/- V5-V6
Posterior MI (STEMI)
Tall R waves, V1-V2
What is the short term regulation of blood volume and MABP?
baroreceptors
What is the long term regulation of blood volume and MABP?
hormones and BV
MABP equation
CO x TPR
What is released in response to significant atrial distension
ANP
ANP
decreasing renin release
What is the parasympathetic relationship with cAMP
decreased cAMP
What is the effect of parasympathetic stimulation opening GIRK channels
opening GIRK channels causes hyperpolarisation
Adrenaline is used for
Cardiac arrest and ALS IV
Anaphylactic shock IM
Dobutamine is used for
Acute, but reversible, heart failure
e.g. following cardiac surgery, cardiogenic/septic shock
What type of drug is propanolol
non selective B-ADR
Examples of B1-selective ADR
atenolol, bisoprolol, metoprolol
Example of a non-selective and partial agonist B-ADR
Alprenolol
What is carvedilol
B-ADR antagonist used to treat mild to moderate heart failure
start low, increase slow
Adverse affects of B-ADR Antagonist
Bronchospasm in asthmatics Aggravation of cardiac patients Bradycardia Hypoglycaemia - diabetics Fatigue Cold extremities
What is the drug used for bradycardia following an MI in incremental doses and what is this dose and what is the alternative medication?
Atropine
300-600 mg
Glycopyronium
Why don’t you ever use B blockers and calcium antagonist
B blockers are decreasing rate
Calcium channel blockers are decreasing force
therefore together they could cause serious heart bradycardia
What is the B-ADR antagonist used primarily for thyrotoxicosis
Propanolol
What is digoxin
a cardiac glycoside that increasing cardiac contractibility
use in Heart failure
Digoxin and dobuatmine are examples of
positive inotropic drugs
Affect of inotropic drugs on ventricular function curve
upward and leftward shift
How does digoxin work
digoxin binds to the alpha subunit of the potassium sodium ATPase, prevent the efflux of calcium
How can affects of digoxin be dangerously enhanced
low plasma potassium
low therapeutic concentration
Indirect effects of digoxin include
increases vagal activity
slows SA node discharge
slows AV node conduction
Digoxin S.E
Heart block
Arrhythmias
Toxicity
Digoxin toxicity
yellow-green blurry vision N/V bradycardia heart block ventricular arrhythmias
What is Levosemendan
calcium sensitiser
What drug binds to tropnium C sensitising it to action of calcium
Levosemendan
When do we use Levosemendan
Acute DECOMPENSATED HF
causes vasodilation - reduces after load - reduces cardiac output
A cardiac drug that inhibits PDE in cardiac and smooth muscle cells
Amrinone
Use and unwanted effects of Amrinone
IV in acute HF
worsens survival in arrhythmias
What is the most important vasodilator that comes from the endothelium
Nitric Oxide
Use of nitric oxides in angina
benefit due to increasing the myocardial oxygen requirement by i) decreasing the preload ii) decreasing the after load and iii) improving perfusion to the ischaemic zone
When do we use Organic nitrates
Angina
Acute Coronary Syndrome (ACS)
Short acting tablet or spray used for rapid effect before exception in ANGINA
Glyceryl trinitrate
Glyceryl trinitrate in ACS
IV infusion (+aspirin)
Longer acting NO used in prophylaxis of angins
Isosorbide mononitrate
S.E. of Nitritic Oxides
Diminished effects
Postural hypotension
Initial headaches
Examples of endothelin antagonists used in pulmonary hypertension
bostentan
ambrisentan
Don’t use ACEI or ARBs in
PREGNANCY
S.E. include dry cough and initial hypotension
ACEI - lisinopril
Calcium antagonists that act on cardiac L-type channels
verapamil
Dihydropyradmines used in patients with heart failure
amlodipine
S.E. of L-type calcium antagonists
excessive vasodilation .. hypotension dizziness ankle oedema flushing
Examples of potassium channel openers
Minoxidil
Nicorandil
Last resort of sever hypertension
minoxidil
Used in untreatable angina
nicorandil
alpha-1 receptor antagonists
pazosin
doxazosin
Thiazide diuretics
mild
acts on distal tubule
BENZOFLUMETHIAZIDE
treats - mild HF, hypertension, resistant oedema
Loop diuretics
stronger
acts on the loop of Henle
FUROSEMIDE
treats - Acute Pulmonary Oedema and Chronic HF
Resistance to blood flow is inversely proportional to the radius of the blood vessel to the power of
4
Bradykinin
vasodilatory adgent
Sympathetic nerve stimulation shift the Frank-Stringling curve to the
left
Where is the needle inserted in pericardial centesis
infrasternal angle, directed superoposteriorly
Anti-hypertensive drugs
Diuretics B-blockers ACEI ARBs Calcium channel antagonists Alpha blockers
Anti-anginal
B-blockers Nitrates Calcium channel antagonists Potassium channel blockers - Nicorandil Ivabradine Ranolazine
Anti-thrombotic
Aspirin
Clopidogrel
Prasugrel
Ticgrelor
Anti-coagulatants
Warfare, heparin, rivaroxaban, dabigatran
Fibrinolitics
Streptokinase, PA
S.E. of diuretics
hypokalaemia arrhythmia hyperglycaemia increased uric acid impotence
ACE S.E.
Cough
renal dysfunction
angioedema
Anti platelet S.E.
Haemorrhage
Peptic ulcer –> haemorrhage
aspirin sensitivity - asthma
Blocks clotting factors 2, 7, 9, 10 and can be reversed by the use of vitamin K
Warfarin
Factor X inhibtor
Rivaroxaban
Factor IIa inhibitor
Dabigatram
Avoid streptokinase in
recent haemorrhage traum bleeding tendencies severe diabetic retinopathy peptic ulcer
Block HMG-CoA reductase
Statins
Statin S.E.
myopathy
renal failure
What group of drugs is bezafibrate from
fibrates