CVS Flashcards
SA node is …
The dominant pacemaker with an intrinsic rate of 60-100 bpm (NORMAL HEART RATE) - the fastest depolarising tissue
ECG paper scale
- Horizontally:
• One small box = 0.04s/40ms
• One large box = 0.20s - Vertically:
• One large box = 0.5mV
Cardiac output equation + unit
(L/min) = Stroke volume (L) x Heart rate (BPM)
Heart sounds
- S1 - mitral and tricuspid valve closure
- S2 - aortic and pulmonary valve closure
- S3 - in early diastole during rapid ventricular filling, normal in children and pregnant women, associated with mitral regurgitation and heart failure
- S4 - ‘Gallop’, in late diastole, produced by blood being forced into a stiff hypertrophic ventricle - associated with left ventricular hypertrophy
ASPIRIN
- used for treating …
- info …
Angina
- Antiplatelet effect (inhibits platelet aggregation) in coronary arteries
thereby avoiding platelet thrombosis - To reduce events
- E.g. salicylate
- COX inhibitor - reduces prostaglandin synthesis including thromboxane A2 resulting in reduced platelet aggregation
- Side effects - gastric ulceration
Angina drug treatment:
Aspirin
Statins
Betablockers - 1st line antianginal:
-Reduce force of contraction of heart
-E.g. Bisoprolol and atenolol
-Act on B1 receptors in the heart as part of the adrenergic sympathetic pathway
-B1activation→Gs→cAMPtoATP→contraction
• Glyceryl Trinitrate (GTN) spray - 1st line antianginal:
- Nitrate that is a venodilator
- Dilates systemic veins thereby reducing venous return to right heart
- Reduces preload
- Thus reduces work of heart and O2 demand
- Also dilates coronary arteries
- Side effect: profuse headache immediately after use
• Ca2+ channel antagonists/blocker:
- Primary arterodilators
- Dilates systemic arteries resulting in BP drop
- Thus reduces afterload on the heart
- Thus less energy required to produce same cardiac output - Thus less work on heart and O2 demand
- E.g. verapamil
ACS (acute coronary syndrome) drug treatment:
Pain relief: GTN spray + IV opioid
Aspirin
P2Y12 inhibitors - E.g. Clopidogrel, Prasugrel & Ticagrelor
Glycoproteins IIIb/IIIa antagonist (IV) - E.g. Abciximab, Tirofiban and Eptifbatide
Beta-blockers (IV & oral) • E.g. Atenolol (IV then oral) or Metoprolol (IV then oral)
Statins • E.g. Simvastatin, Pravastatin and Atorvastin
ACE inhibitors: Ramipril and Lisonopril
ACI (acute myocardial infarction) drug treatment:
Pre-hospital: • Aspirin 300mg chewable • GTN (sublingual) • Morphine Hospital: • IV morphine • Oxygen if their sats are below 95% or are breathless • Beta-blocker - Atenolol • P2Y12 inhibitor - Clopidogrel
Cardiac failure def:
• The inability of the heart to deliver blood and thus O2 at a rate that is commensurate with the requirement of metabolising tissue of the body
Cardia failure drug treatment:
Diuretics:
• Promote sodium and thus water loss thereby reducing ventricular filling pressure (preload) decreasing systemic and pulmonary congestion
• Loop diuretic - furosemide
• Thiazide diuretic - bendroflumethiazide (inhibit sodium reabsorption in the distal convoluted tubule)
• Aldosterone antagonist (thereby inhibiting ADH release resulting in water loss) - spirolactone & epelerone - note with these beware of renal impairment and hyperkalaemia
ACE inhibitors:
• Ramipril, enalipril, captopril
• Side effects: cough (since inhibit ACE and thus the breakdown of substance P and bradykinin which results in cough), hypotension, hyperkalaemia and renal dysfunction
• If cough is a problem then can give angiotensin receptor blockers (not as effective as ACE-inhibitors) e.g. canderstan or valsartan
Beta-blockers:
• Bisoprolol, nebivolol, carvedilol
• Start at low dose and titrate upwards
• DO NOT GIVE TO ASTHMATICS
-Digoxin
-Inotropes
• CLINICAL SCENARIO:
- 84 yr old frail woman of Asian origin with dizziness, low blood pressure and
shortness of breath
- She also has swollen legs (leg oedema) which have become more swollen
over the past few days
• In the context of her shortness of breath and swollen legs, her low BP is
most likely to be indicative of?
- Biventricular failure:
• Shortness of breath due to right ventricular failure
• Leg oedema due to left ventricular failure
Mitral valve disease drug treatment:
- Beta-blockers e.g. Atenolol and digoxin which control heart rate and thus prolong diastole for improved diastolic filling
- Diuretics for fluid overload e.g. Furosemide
Mitral regurgitation drug treatment:
Vasodilators such as ACE-inhibitors e.g. Ramipril or Hydralazine (smooth muscle relaxer)
• Heart rate control for atrial fibrillation with Beta blockers (Atenolol), Calcium channel blockers and digoxin
• Anticoagulation in atrial fibrillation and flutter
• Diuretics for fluid overload e.g. Furosemide
Ineffective endocarditis is caused by:
Staphylococcus aureus (IVDU, diabetes and surgery) - most common cause Pseudomonas aeruginosa Streptococcus viridans (dental problems) - GRAM POSITIVE, alpha haemolytic and optochin resistant (Strep. mutans, strep, sanguis, strep. milleri & strep. oralis)
Ineffective endocarditis drug therapy:
- Antibiotic treatment (which one is decided on organism ascertained from cultures) for 4-6 weeks
- If not staphylococcus then use penicillin ideally Benzylpenicillin & Gentamycin (doesn’t work on own since cannot get through bacterial cell wall)
- If staphylococcus then use Vancomycin & Rifampicin (if MRSA)
Hypertrophic cardiomyopathy (HCM) drug therapy:
Amiodarone - anti-arrythmatic medication, if at high risk of arrhythmia then can place an implantable cardiac defibrillator
• Calcium channel blocker e.g. Verampil
• Beta-blocker e.g. Atenolol
Arrythmogenic right ventricular cardiomyopathy:
• Beta-blockers e.g. Atenolol for patients with non-life-threatening arrhythmias
• Amiodarone for symptomatic arrhythmias
• Occasionally cardiac transplant indicated i.e. in cardiac failure or
devastating arrhythmia
Ventricular septal defects (VSD) drug treatment:
If moderately sized lesion; furosemide, ACE inhibitor e.g. ramipril and digoxin may suffice
Patent ductus arteriosus drug treatment:
Indometacin (prostaglandin inhibitor) can be given to stimulate duct closure
Acute pericarditis def:
Acute inflammation of the pericardium; with or without effusion
Acute pericarditis drug treatment:
NSAID e.g Ibuprofen for two weeks or Aspirin for two weeks
- Colchicine for 3 weeks however is limited by nausea and diarrhoea but does reduce recurrence
• Recurrent or relapsing pericarditis:
- About 20% of cases of acute pericarditis go on to develop idiopathic relapsing pericarditis
- This may occur within 6 weeks during weaning off NSAIDs or intermittently i.e. recurs more than 6 weeks after the initial presentation
- The first line treatment is oral NSAIDs e.g. Ibuprofen
- Colchicine has been proven to be more effective than Aspirin alone
Hypertension:
Normotensive=
Less than 140/90mmHg
Hypertension values -stages …
Stage 1 hypertension:
- More than or equal to 140/90mmHg clinic BP
- Daytime average Ambulatory blood pressure monitoring (ABPM - 24hr BP monitor) or Home blood pressure monitoring (HBPM); greater than or equal to 135/85mmHg
Stage 2 hypertension:
- More than or equal to 160/100mmHg clinic BP
- Daytime average ABPM or HBPM greater than or equal to 150/95mmHg
Severe hypertension:
- Clinic systolic BP greater than or equal to 180mmHg and/or
diastolic BP greater than or equal to 110mmHg
- Start immediate anti-hypertensive drug treatment!
Hypertension treatment
Reach 140/90mmHg
ACD pathway:
A - ACE-inhibitor e.g. Ramipril or Enalapril, or Angiotensin receptor blocker (ARB) (use if ACEi is contraindicated e.g. due to cough) e.g. Candesartan or Losartan
C - Calcium channel blocker (CCB) e.g. Nifedipine or Amlodipine D - Diuretics e.g. Bendroflumethiazide (thiazide, distal tube - less
potent) or Furosemide (loop diuretic, loop of henle - more potent)
NOTE: Beta-blocker e.g. Bisoprolol or Metoprolol (B1 selective) are NOT the FIRST LINE TREATMENT FOR HYPERTENSION but consider in young people especially if they are intolerant of ACEi/ARB
Less than 55 yrs old:
- Ramipril/Candesartan - + Nifedipine
- + Bendroflumethiazide - + Furosemide
Older than 55 yrs/black/African-Caribbean origin:
- Ramipril/Candesartan + Nifedipine - + Bendroflumethiazide
- + Furosemide
Cardiac arrhythmias may cause:
- Sudden death
- Syncope
- Heart failure
- Chest pain
- Dizziness
- Palpitations
- No symptoms at all
AF (atrial fibrillation) drug treatment:
Cardioversion:
- Conversion to sinus rhythm achieved electrically by DC shock e.g. defibrillator - NOTE: give low molecular weight heparin e.g. Enoxaparin or Dalteparin to minimise the risk of thromboembolism associated with cardioversion
- If this fails then achieved medically by IV infusion or anti- arrhythmic drug such as flecainide or amiodarone
Ventricular rate control:
- Achieved by drugs that block AV node:
• Calcium channel blocker e.g. Verapamil • Beta-blocker e.g. Bisoprolol
• Digoxin
• Anti-arrhythmic e.g. Amiodarone
- Long term & stable patient management:
• Two strategies; which to choose should be decided based on individual
patient needs
• Rate control:
- AV nodal slowing agents plus oral anticoagulation
- Beta-blocker e.g. Bisoprolol
- Calcium channel blocker e.g. Verapamil or Diltiazem
- If above fails then try Digoxin and then consider Amiodarone
• Rhythm control:
- Advocated for younger, symptomatic and physically active
patients
- Cardioversion to sinus rhythm and use Beta-blockers e.g.
Bisoprolol to suppress arrhythmia
- Can use pharmacological cardioversion e.g. Flecainide if no structural heart defect or use IV Amiodarone instead if there is structural heart disease
- Appropriate anti-coagulation e.g. Warfarin due to thromboembolism risk with cardioversion
Atrial flutter drug treatment:
Electrical cardioversion but anticoagulate before e.g low molecular weight heparin e.g. Enoxaparin or Dalteparin if acute i.e. atrial flutter started less than 48 hours ago
- Catheter ablation - creating a conduction block to try an restore rhythm and block offending re-entrant wave
- IV Amiodarone to restore sinus rhythm and use a beta-blocker e.g. Bisoprolol to suppress further arrhythmias
Atrioventricular block causes:
First degree AV block:
Second degree …:
Third degree…:
1: • Hypokalaemia
• Myocarditis
• Inferior MI
• Atrioventricular node (AVN) blocking drugs e.g. beta blockers (Bisoprolol), calcium channel blockers (Verapamil) and Digoxin
2: - Atrioventricular node (AVN) blocking drugs e.g. beta blockers
(Bisoprolol), calcium channel blockers (Verapamil) and Digoxin - Inferior MI
Complete AV block
AV block narrow-complex escape rhythm
QRS complex less than 0.12 seconds
Implies block originates in the His bundle and thus the region of block lies
more proximally in the AV node
Recent-onset, narrow-complex AV block that has transient causes may
responses to IV atropine
Chronic narrow-complex AV block requires permanent pacemaker if it is symptomatic
AV block drug treatment:
IV atropine
Right bundle branch block (RBBB) on ECG:
- Looks like maRRow
- maRRow - Right bundle branch block - MarroW:
• M-QRSlookslikeanMinleadV1
• W-QRSlookslikeWinV5&V6
• Causes wide physiological splitting of the SECOND HEART SOUND
Left bundle branch block (LBBB) on ECG:
- Looks like wiLLiam
- wiLLiam - Left bundle branch block
- WilliaM:
• W-QRSlookslikeaWinleadsV1&V2 • M - QRS looks like an M in leads V4-V6
Sinus tachycardia drug treatment:
Beta-blocker like bisoprolol
ATRIOVENTRICULAR RE-ENTRANT TACHYCARDIA (AVRT):
- If stable then vagal manoeuvres:
• Breath-holding
• Carotid massage
• Valsalva manoeuvre - abrupt voluntary increase in intra-abdominal and intrathoracic pressure by straining - several seconds after the release of the strain, the resulting intense vagal effect may terminate the AVNRT or AVRT - If manoeuvres unsuccessful then IV adenosine - causes complete heart block for a fraction of a second and is highly effective at terminating AVNRT and AVRT
Ventricular ECTOPICS OR TACHYCARDIA drug treatment:
- Give beta-blockers e.g. Bisoprolol if symptomatic
SUSTAINED VENTRICULAR TACHYCARDIA
- Haemodynamically unstable (e.g. hypotensive or pulmonary oedema):
97
KP
All information is taken from lectures and textbooks, there may be mistakes!!
• Emergency electrical cardioversion - Stable:
• IV beta-blocker e.g. Esmolol
• IV Amiodarone
Lone QT syndrome drug treatment:
- Treat underlying cause
- If acquired long QT then give IV isoprenaline (contraindicated for congenital
long QT)
Aneurysmal disease
An aneurysm is defined if there is a permanent dilatation of the artery to TWICE the normal diameter
THORACICABDOMINALANEURYSM(TAA) drug treatment:
- Rigorous BP control using beta-blockers e.g. Bisoprolol -
Aortic dissection drug treatment:
- At least 50% are hypertensive and may require urgent antihypertensive medication to reduce blood pressure to less than 120mmHg - give IV beta- blockers e.g. IV metoprolol or vasodilators e.g. IV GTN
- Adequate analgesia e.g. morphine
- Surgery to replace aortic arch
- Endovascular intervention with stents
- PERIPHERAL VASCULAR DISEASE (PVD): Thrombotic disease (more common nowadays):
Symptoms:
Treatment:
- Symptoms: • The 6 P’s: - Pain - Pallor - Perishing cold - Pulseless - Paralysis - Paraesthesia - abnormal tingling or prickling - ‘pins & needles’ - The more P’s present the more sudden and the more complete your ischaemia
• Antiplatelet agent such as P2Y12 inhibitor e.g. Clopidogrel to prevent
progression and minimise risk
SHOCK def
Shock is the term used to describe acute circulatory failure with inadequate or inappropriately distributed tissue perfusion (meaning there is inadequate substrate (glucose & oxygen) for aerobic cellular respiration), resulting in generalised hypoxia and/or an inability of the cells to utilise oxygen
Recognising shock:
- Skin is pale, cold, sweaty and vasoconstricted
- Pulse is weak and rapid
- Pulse pressure reduced - mean arterial pressure (MAP) may be maintained - NOTE; ARTERIAL BP is NOT A GOOD INDICATOR OF SHOCK since it will be maintained until a very large amount of blood loss
- Reduced urine output
- Confusion, weakness, collapse and coma
Effects of shock
Prolonged hypotension which can lead to life threatening organ failure after recovery from the acute event
Causes of shock:
Anaphylactic shock- how?
- Intense allergic
- Massive release of histamine and other vasoactive mediators causing haemodynamic collapse
- Accompanied by breathlessness and wheeze (due to bronchospasm)
Haemorrhagic Shock Classification (Tennis Score):
- Class I: • 15% blood loss • Pulse below 100 bpm • BP normal • Pulse pressure normal • Resp rate; 14-20 • Urine output greater than 30ml/hr • Slightly anxious Class II: • 15-30% blood loss • Pulse greater than 100 bpm (tachycardia - earliest sign) • BP normal due to autonomic response (increased sympathetic activity) • Pulse pressure decreased • Resp rate; 20-30 • Urine output: 20-30ml/hr • Mental status: mildly anxious -Class III: • 30-40% blood loss • Pulse above 120 bpm • BP decreased • Pulse pressure decreased • Resp rate; 30-40 • Urine output: 5-15ml/hr • Mental status: confused
Clinical presentation of cardia shock:
• Increased sympathetic tone
• Tachycardia - narrow pulse pressure and weak pulse • Sweating
• BP may be maintained initially but later hypotension
• Bradycardia
- Cardiogenic shock:
• Signs of myocardial failure
• Raised jugular venous pressure (JVP) • Gallop rhythm
• Basal crackles and pulmonary oedema
Hypertension def
as a clinical BP of 140/90mmHg or higher
Factors controlling BP and thus targets for BP control therapy:
Since; Cardiac output x Peripheral resistance = BP - can target peripheral resistance to alter BP
Hypertension drug treatment:
ANGIOTENSIN CONVERTING ENZYME (ACE) INHIBITORS:
• Indicated for; hypertension, heart failure and diabetic nephropathy • ACE inhibitor end in ‘pril’
• Also REDUCE circulating levels of ALDOSTERONE
• Examples:
- RAMIPRIL
- ENALAPRIL
- PERINDOPRIL
- LISINOPRIL
- TRANDOLAPRIL
ANGIOTENSIN II RECEPTOR BLOCKERS (ARB):
• Indicated for; hypertension, diabetic neuropathy and heart failure (when ACE inhibitor is contraindicated
• ARB’s end in ‘sartan’
• Angiotensin receptor blocker acts on AT-1 receptor (angiotensin receptor)
• Examples:
- CANDESARTAN - LOSARTAN
- VALSARTAN
- IRBESARTAN
- TELMISARTAN
- CALCIUM CHANNEL BLOCKERS (CCB):
Indicated for; hypertension, ischaemic heart disease (IHD) i.e. angina and arrhythmia (tachycardia)
A lot but not all end in ‘pine’ - these are vasodilators Diltiazem & Verapamil have effects on electrical conductivity Examples:
- AMLODIPINE - DILTIAZEM
- VERAPAMIL - NIFEDIPINE
- FELODIPINE - LACIDIPINE
BETA-ADRENOCEPTOR BLOCKERS (BETA-BLOCKERS):
Lower down list in terms of use
Indicated for; ischaemic heart disease (IHD) - angina, heart failure,
arrhythmia and hypertension A lot end in ‘olol’
Examples:
- BISOPROLOL
- CARVEDILOL
- PROPRANOLOL
- METOPROLOL
- ATENOLOL (antagonist at beta-1 adrenoceptor) - NADOLOL
Calcium channel blockers (CCB) Action and adverse effects
- L-type calcium channel blockers (block ion channels and NOT RECEPTORS):
• Dihydropyridines: nifedipine, amlodipine, felodipine, lacidipine: - Preferentially affect vascular smooth muscle
- Peripheral arterial vasodilators
• Phenylalkylamines: verapamil: - Main effect is on heart
- Reduce HR (negatively chronotropic) and force of
contraction of the heart (negatively inotropic)
• Benzothiozepines: diltiazem: - ## Intermediate heart/peripheral vascular effects • Adverse effects:Due to peripheral vasodilation (mainly dihydropyridines e.g. nifedipine and amlodipine):
• Flushing
• Headache
• Oedema - swelling, typically around ankles due to gravity
• Palpitations - due to vasodilation there is decreased BP so body tries to correct by increasing HR (known as reflexive tachycardia)
Due to negatively chronotropic effects (heart rate) mainly verapamil and diltiazem:
• Bradycardia (low HR)
• Atrioventricular block
• POSTURAL HYPOTENSION
Due to negatively inotropic effects (force of contractility) mainly verapamil:
• Worsening of cardiac failure
Verapamil causes constipation - since it affects Ca2+ and thus smooth muscle contraction in the intestines
Diuretics… see flash card
Diuretics
• Indicated for; hypertension and heart failure • Classes & Examples:
-Thiazides (cause Na+ and thus water loss in urine) and related drugs - act on DISTAL TUBE - LESS POTENT, tend to end in ‘thiazide’:
• BENDROFLUMETHIAZIDE • HYDROCHLOROTHIAZIDE • CHLOROTHALIDONE
Loop diuretics (act on LOOP OF HENLE - MORE POTENT): • FUROSEMIDE - blocks NA/K/2Cl (NKCC2) transporter • BUMETANIDE
Potassium-sparing diuretics:
SPIRONOLACTONE EPLERENONE
Note these two have the potential to antagonise aldosterone (anti-aldosterone)
- Aldosterone antagonists • Main adverse effects:
- Hypovolaemia (mainly loop diuretics e.g. furosemide)
- Hypotension (mainly loop diuretics e.g. furosemide)
- Hypokalaemia
- Low serum sodium (hyponatraemia)
- Low serum magnesium (hypomagnesaemia)
- Low serum calcium (hypocalcaemia)
- Raised uric acid (hyperuricaemia - can result in gout (extremely painful)
- Erectile dysfunction (mainly thiazides e.g. bendroflumethiazide)
- Impaired glucose tolerance i.e. diabetes (mainly thiazides e.g.
bendroflumethiazide)
Other antihypertensives
• Alpha-1 adrenoceptor blockers:
- DOXAZOSIN
• Centrally acting (i.e. on brain) anti-hypertensives: - MOXONIDINE
- METHYLDOPA - CAN BE USED IN PREGNANCY • Direct renin inhibitor:
- ALISKIREN
Chronic heart failure drug treatmetn
Basic pharmacology:
- Symptomatic treatment of congestion:
• Diuretics usually loop diuretics e.g. Furosemide
- Disease influencing therapy - neurohumoral blockade:
• Inhibition of renin-angiotensin-aldosterone system e.g. ACE-inhibitors and ARB’s
• Inhibition of the sympathetic nervous system e.g. beta-blockers such as BISOPROLOL which are effective at blocking reflex sympathetic responses which stress the failing heart
- First line treatment:
• ACE inhibitors e.g. Ramipril and beta-blocker e.g. Bisoprolol • Low dose and slow uptitration
- Second line:
• Aldosterone antagonists
• If ACE-inhibitor intolerant then give ARB’s (not as good as ACE-i) e.g. Candesartan
• If ACE-I and ARB intolerant then give Hydralazine/nitrate combination (peripheral vasodilators)
- Consider digoxin or ivabradine (rate-limiting drug)
• CARDIAC NATRIURETIC PEPTIDES:
Explained
Cardiac natriuretic peptides are metabolised by Neutral Endopeptidase (NEP or neprilysin)
NEP inhibition increases levels of natriuretic peptides
Sacubitril - is a neprilysin inhibitor
Valsartan - is a ARB
Entresto - is a combination of sacubitril and valsartan - VERY EFFECTIVE IN HEART FAILURE
NITRATES:
- Arterial and venous dilators
- Reduce preload and afterload
- Lower BP
- Indicated for; ischaemic heart disease (angina) and heart failure - Examples:
• ISOSORBIDE MONONITRATE - long-acting!!
• GTN (GLYCERYL TRINITRATE) SPRAY - sublingual spray, potent vasodilator, commonly give headache
• GTN infusion
- Main adverse effects are headache and GTN spray syncope as well as POTENTIAL TOLERANCE to the drug
• CHRONIC STABLE ANGINA TREATMENT:
Antiplatelet therapy: • ASPIRIN • CLOPIDOGREL (P2Y12 inhibitor) - use if aspirin intolerant 131 KP
All information is taken from lectures and textbooks, there may be mistakes!!
- Lipid-lowering therapy:
• Statins e.g. SIMVASTATIN, ATORVASTATIN, ROSUVASTATIN &
PRAVASTATIN
- Short acting nitrate:
• GTN spray for acute attack - DILATES veins to reduce the preload of the heart
- First line treatment:
• Beta blocker e.g. BISOPROLOL
• Calcium channel blocker e.g. AMLODIPINE
- If intolerant then SWITCH i.e. if using beta-blocker then switch to calcium channel blocker
- If not controlled then COMBINE
- If intolerant and uncontrolled then consider monotherapy or combination
with:
• Long acting nitrates:
- Ivabradine - Nicorandil - Ranolazine
• ACUTE CORONARY SYNDROMES (NSTEMI & STEMI) TREATMENT:
Pain relief:
• GTN spray
• Opiates - DIAMORPHINE (also helps calm patient) Dual antiplatelet therapy:
• Aspirin plus P2Y12 inhibitor (oral) e.g. TICAGRELOR, PRASUGREL or CLOPIDOGREL
Antithrombin therapy:
• Heparin e.g. FONDAPARINUX (injection)
Consider a glycoprotein IIb/IIIa inhibitor (IV) e.g. TIROFIBAN, EPTIFBATIDE or ABCIXIMAB
Background angina therapy:
All information is taken from lectures and textbooks, there may be mistakes!!
• Beta blocker e.g. BISOPROLOL:
- Beta blockers help to relieve pain from angina by:
• Reducing O2 demand by slowing heart rate and reducing myocardial contractility
• Improve O2 distribution by slowing heart rate • Long acting nitrate e.g. IVABRADINE
• Calcium channel blocker e.g. AMLODIPINE - Lipid lowering therapy:
• Statins e.g. SIMVASTATIN
- Therapy for LVSD/heart failure as required:
• ACE-I e.g. RAMIPRIL
• Beta blocker
• Aldosterone antagonist
ANTIARRHYTHMIC DRUGS:
- Vaughan Williams Classification:
• Classes 1 & 3 = Rhythm control • Classes 2 & 4 = Rate control
• Class 1: - Sodium channel blocker e.g. FLECAINIDE • Class 2:
- Beta-adrenoceptor blockers (Beta-blockers):
• Class 3:
Non-selective e.g. PROPRANOLOL, NADOLOL & CARVEDILOL
Selective (B-1) e.g. BISOPROLOL and METOPROLOL
NOTE: PROPRANOLOL is the most useful beta blocker to help control the arrhythmias which occur immediately following a MI since it also BLOCKS SODIUM CHANNELS - Prolong the action potential: • AMIODARONE
• SOTALOL
• Has potential for SIGNIFICANT SIDE EFFECTS - see below • Class 4: - Calcium channel blockers:
• VERAPAMIL (more effective than amlodipine since it DOES
NOT effect the calcium channel at rest)
• DILTIAZEM
• AMLODIPINE - Sympathetic drive e.g. adrenaline worsens arrhythmia - DIGOXIN:
DIGOXIN:
Explained
• Cardiac glycoside
• Inhibits the Na/K pump - found everywhere in body
• Main effect on heart:
- Bradycardia (due to increased vagal (parasympathetic) tone)
- Increased ectopic activity - can trigger extra heartbeats i.e. minor
arrhythmias
- Increased force of contraction (DIRECT POSITIVE INOTROPIC
EFFECT on heart muscle) by increased intracellular Ca2+ - Slowing of AV conduction
• Narrow therapeutic range - need to have precise amount to have desired effects otherwise get side effects:
- Nausea, vomiting, diarrhoea and confusion
• Used in atrial fibrillation to reduce ventricular rate response
• Used in severe heart failure as a positive inotropic (increases heart contractility)
