Term
Rate and rhythm
Myocardial contraction
Metabolism and blood flow
These are three targets of cardiovascular drugs they correspond to three general conditions? (though there is overlap in treatment) |
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Definition
cardiac dysrhythmias
cardiac failure
coronary insufficiency |
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Term
| Describe the coordinated contraction of the heart with reference to electrical flow? |
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Definition
| SA node impulse arises --> through the atria --> AV node --> Bundle of His --> Purkinje fibres --> ventricles. |
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Term
| Electrophysiological differences of cardiac tissue? |
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Definition
| Pacemaker cells, No fast Na influx rather prolonged gradual Ca influx, influx of Ca for plateau |
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Term
| Dysrhythmias are classified by? |
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Definition
| Site of origin and pace i.e. supraventricular tachcardia |
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Term
| Three most common tachy dysrhythmias? |
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Definition
| Atrial fibrillation (irregular heart beat), SVT (regular rapid), and ectopic beats (either atrial or ventricular) |
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Term
| Most serious dysarryhthmias? |
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Definition
| VT and VF, both are sustained ventricular tachycardias with completely chaotic beats and 0 cardiac output. |
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Term
| Most common brady dysrhythmias? |
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Definition
| Heart block and asystolic arrest. |
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Term
| Cardiac dysrhythmias arise because of 4 reasons? |
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Definition
delayed after-depolarisation --> ectopics
reentry from partial block
ectopic pacemaker activity
heart block |
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Term
| Delayed after depolarisation is caused by? |
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Definition
| Influx of positive ions due to abnormally high levels of intracellular calcium |
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Term
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Definition
| when parts of the myocardium become depolarised |
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Term
| Ectopic pacemaker activity? |
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Definition
| is caused by sympathetic activity |
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Term
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Definition
| results from a diseased conduction system especially at the AV node. |
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Term
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Definition
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Term
| Factors that effect contractility? |
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Definition
| Calcium, oxygen and metabolic energy |
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Term
| During which phase of contract is coronary flow? |
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Definition
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Term
| Parasympathetic vs Sympathetic innervation of the heart? |
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Definition
Para: rate (chronotropic) M2 acetylcholine receptors
Sym: rate and force (inotropic) (b1 adrenoreceptors) i.e. adrenalin |
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Term
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Definition
| atrial natriuretic peptide: released by atrial cells is response to overstretching of atria. Acts of kidneys and vascular system. increase Na and water excretion and relax smooth muscle to decrease blood pressure. And inhibit hormones which do the opposite. increase vascular permeability. |
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Term
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Definition
| The blood supply to the myocardium is insufficient for its needs. |
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Term
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Definition
| stable (preictable on exertion), unstable (pain at rest), variable (prinzmetal, is associated with spasming of the coronary arteries) |
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Term
| Myocardial infarction is? |
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Definition
| when a coronary artery is blocked by a thrombus. Usually caused by venricular failure or other dysrhythmias. |
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Term
| Action of class I antiarrhythmics? |
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Definition
Divided into a, b, and c they block voltage ated sodium channels.
Ia - disopyramide (intermediate dissociation) mid way. may cause anticholinergic symptoms. ventricular dysrhythmias
Ib - lignocaine (fast dissociation) ischemia
Ic - flecainide (slow dissociation) reentry ectopics and ventricular ectopics
These inhibit AP propagation and block high frequency excitation i.e. tachyarrythmias. They are use dependent. |
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Term
| Action of class II antiarhythmics? Propanolol |
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Definition
beta adrenoreceptor antagonists
Propanolol (beta blocker)
Prevention of recurrent SVT post MI |
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Term
| Class III antiarhythmics? Amiodarone |
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Definition
prolongation of cardiac action potential
Amiodarone (potassium channel blocker)
Suppress ectopic beats and reentry tachycardias.
Central vein IV, numerous AEs but used for resus. |
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Term
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Definition
calcium antagonists
Verapamil (calcium channel blocker)
SVT, oral dosing |
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Term
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Definition
| indicated in sinus bradycardia |
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Term
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Definition
| indicated in cardiac arrest |
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Term
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Definition
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Term
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Definition
| indicated in rapid atrial fibrillation |
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Term
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Definition
| indicated in SVT, has replaced Verapamil. shorter half life. blocked by Theophylline. |
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Term
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Definition
| indicated in VT due to hyperkalemia |
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Term
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Definition
| indicated in VF due to digoxin toxicity |
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Term
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Definition
| causes cardiac slowing and reduced rate, increase force of contraction by increasing preload. narrow margin of toxicity. decreased plasma potassium increases activity. to slow rapid AF and to treat heart failure in combination with diuretics and ACEi. |
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Term
| Gylceryl trinitrate (GTN) spray/ Isosorbide mononitrate |
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Definition
| organic nitrates relax the vascular smooth muscle, causing a reduction in central venous pressure (a reduced preload) and venous pooling, and redistribution via collaterals. May cause postural hypotension and dizziness. Isosorbide is longer acting and avoids tolerance. |
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Term
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Definition
| potassium channel activator and vasodilator on arterial and venous. |
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Term
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Definition
| calcium channel blocker. causing relaxtion of smooth muscle. heart specific. negative ionotropes. CI in heart failure. antidysrhythmic |
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Term
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Definition
| calcium channel blocker. causing relaxtion of smooth muscle. artery specific. negative ionotropes. reduce blood pressure, |
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Term
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Definition
| calcium channel blocker. causing relaxtion of smooth muscle. intermediate. negative ionotropes. angina. |
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Term
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Definition
| is a calcium antagonist, it has a much longer half life, given once daily, may cause flushing, headache, ankle swelling. reduce blood pressure |
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Term
| Vasodilators and vasoconstrictors work by? |
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Definition
| decreasing and increasing the concentration of Ca2+ or altering the sensitivity of the machinery. |
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Term
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Definition
| are released from the endothelial cells of micro vessels and are responsible for direct vasodilation, adrenalin antagonism and platelet formation. |
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Term
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Definition
| Nitric oxide is released by resistantance vessels --> vasodilator, inhibits platelet adhesion and aggregation preventing thrombus. |
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Term
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Definition
| The renin angiotensin aldosterone system is responsible for synergistically working with the sympathetic nervous system by increasing adrenalin release, stimulating aldosterone release and controlling the concentration of Na and fluid volume + vascular tone. |
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Term
| Describe briefly the RAAS? |
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Definition
| Renin is released in response to decreased BP, sympathetic response or decrease filtrate Na, it activates angiotensinogen, which is firther activated by ACE, which causes vasoconstriction, vascular growth and salt retention via aldosterone secretion. |
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Term
| Examples of vasoconstrictor drugs and hormones? used in nasal decongestion and coadministered to prolong local anaesthetic |
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Definition
a1 adrenoreceptor agonists, adrenalin reuptake inhibitors
ADH, angiotensin, endothelin |
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Term
| Examples of vasodilator drugs and hormones? Used to treat heart failure, hypertension and angina. |
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Definition
Calcium antagonists, CCB,
ANP
Effect is to reduce preload and afterload and hence cardiac work |
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Term
| Captopril/ Perindopril/ Ramipril |
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Definition
| ACE inhibitors have a power effect on inhibiting the vasoconstrictive action of angiotensin. CI in renal artery stenosis. used in hypertension, cardiac failure, post MI, high risk IHD, diabetic nephropathy and progressive renal insufficiency. AEs dry cough, postural hypotension, hyperkalemia. |
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Term
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Definition
| ARB. Angiotensin receptor blocker, behave clinically similar to ACE apart from the cough. |
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Term
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Definition
| K ATP channel activator for vasodilation. |
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Term
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Definition
| alpha 1 antagonist used for both hypertension and BPH. |
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Term
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Definition
| is an aldosterone antagonist and a K sparing diuretic. Requires K+ monitoring |
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Term
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Definition
| is the antihypertensive of choic during pregnancy |
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Term
| Drugs used in cardiac failure to inhibit Na and water retention? |
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Definition
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Term
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Definition
| Spirinolactone, ACE i, ARB |
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Term
| Antagonise B adrenoreceptors? |
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Definition
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Term
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Definition
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Term
| Relax vascular smooth muscle? |
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Definition
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Term
| Increase force of contraction? |
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Definition
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Term
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Definition
| Shock is a medical emergency due to inadequete perfusion of the internal organs generally due to a dangerously low arterial blood pressure. Treatment is dependent on the cause i.e. infection (antibiotics), hypovolemia (volume replacement), anaphylaxis (adrenalin) |
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Term
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Definition
| Is pain in the legs on walking due to peripheral vascular disease. it i the insufficiency of peripheral vessels: patient is treated for atheromatous disease. i.e. statin, aspirin and ace. |
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Term
| What is the main target to prevent atherogenesis? |
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Definition
| Reduction of LDL- C and increase in HDL in addition to lifestyle changes. i.e. exercise, diet, no smoking. |
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Term
| Simvastatin/Pravastatin/ Atorvastatin |
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Definition
| The statins act by inhibiting HMG CoA reductase, the rate limiting step in cholesterol synthesis. Simvastatin is reversible and short acting. Atorvastatin is longer acting. This increases LDL clearance by upregulating liver receptors. CI pregnancy. AEs common go disturbances and insomnia rare rhabdomyolysis and angioedema. Indicated in secondary prevention of MI due to symptomatic artherosclerosis or primary prevention of arterial disease at high risk elevated cholesterol plasma. |
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Term
| Bezafibrate/ Ciprofibrate |
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Definition
| these are fibrates. marked reduction in circulating VLDL, LDL and increase in HDL, complex MOA. cause rhabdomyolysis if combined with statins with myoglobinurea and acute renal failure. CI in renal impairment. |
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Term
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Definition
| cholesterol absorption inhibitor. adjunct therapy. block in duodenum. distinct from resins. usually well tolerated can cause rash, diarrhea, headache and angioedema. |
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Term
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Definition
| Bile acid binding resin. not absorbed, so no systemic symptoms but gastro symptoms are common. actually raise TAGs but decrease LDLs. Interfere with some drug absorption/ |
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Term
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Definition
| omega 3 fatty acids reduce overall TAGs but increase cholesterol. should be from diet not pills. |
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