Antiarrhythmics PDF

HLTENN040 Antiarrhytmics • Administer and monitor medicines and Intravenous Therapy • HLT54121 Christine Prendergast HLT54121 DIPLOMA OF NURSING Acknowledgement of Country We respectfully acknowledge the Wurundjeri People of the Kulin Nation, who are the Traditional Owners of the land on which S...

HLTENN040 Antiarrhytmics • Administer and monitor medicines and Intravenous Therapy • HLT54121 Christine Prendergast HLT54121 DIPLOMA OF NURSING Acknowledgement of Country We respectfully acknowledge the Wurundjeri People of the Kulin Nation, who are the Traditional Owners of the land on which Swinburne’s Australian campuses are located in Melbourne’s east and outer-east, and pay our respect to their Elders past, present and emerging. We are honoured to recognise our connection to Wurundjeri Country, history, culture, and spirituality through these locations, and strive to ensure that we operate in a manner that respects and honours the Elders and Ancestors of these lands. We also respectfully acknowledge Swinburne’s Aboriginal and Torres Strait Islander staff, students, alumni, partners and visitors. We also acknowledge and respect the Traditional Owners of lands across Australia, their Elders, Ancestors, cultures, and heritage, and recognise the continuing sovereignties of all Aboriginal and Torres Strait Islander Nations. HYPERTENSION CCF ARRHYTHMIAS IHD • • • • • • • • • • • Beta blockers ACEI Ca channel blockers Diuretics Diuretics ACEI Beta blockers Digoxin • • • Na channel blockers Beta blockers Potassium channel blockers Ca channel blockers YOU SHOULD KNOW THIS: • Action of each type of drug • Important side effects (not N&V, GI) • Nursing considerations • Example of a drug for each group (generic) HLT54121 DIPLOMA OF NURSING • Nitrates Peripheral vasodilators Thrombolytics Heart Physiology There are three systems that must work together for the heart to beat efficiently 1. 2. 3. Circulatory – network of vessels through which the heart mechanically pumps blood Conduction – electrical wiring (specialised cells) that stimulates the heart to pump Coronary – system of arteries & veins that provide oxygenated blood to meet the metabolic needs of the heart muscle itself HLT54121 DIPLOMA OF NURSING Heart muscle contraction To simplify,  a Sodium ion (Na+) starts the stimulation of the cell (extracellular)  a Calcium ion (Ca2+) extends that stimulation to allow the entire muscle to contract before  Potassium (K+) comes along and tells the muscle cell to relax for a moment and get ready for the next wave. (intracellular) HLT54121 DIPLOMA OF NURSING HLT54121 DIPLOMA OF NURSING Heart Rate • The number of times the heart beats each minute. • Reflects the firing of the SA Node • Normal rate 60 – 100 BPM, regular rhythm • Commonly measured as the pulse HLT54121 DIPLOMA OF NURSING Stroke Volume • The amount of blood pumped by the ventricles per beat. • Average volume is 60-80ml per beat http://www.scottalexander.tv/new-blog/2015/10/16/training-efficiently-and-heart-stroke-volume HLT54121 DIPLOMA OF NURSING 9 10 12 13 14 Key concepts– Dromotropic effect Dromotrope = SPEED Effect on the speed of conduction of the beat through the heart Positive – increase conduction e.g. Adrenaline Negative – decrease conduction e.g. Verapamil HLT54121 DIPLOMA OF NURSING Arrhythmia Any deviation from normal sinus rhythm Due to abnormal spontaneous initiation of an impulse HLT54121 DIPLOMA OF NURSING Sinus Rhythm (SR) HLT54121 DIPLOMA OF NURSING HLT54121 DIPLOMA OF NURSING HLT54121 DIPLOMA OF NURSING HLT54121 DIPLOMA OF NURSING HLT54121 DIPLOMA OF NURSING HLT54121 DIPLOMA OF NURSING HLT54121 DIPLOMA OF NURSING Class II - Beta Blockers block beta-adrenergic receptors and prevent adrenaline (epinephrine) from stimulating these receptors. used to treat abnormal heart rhythms (arrhythmias), prevent abnormally fast heart rate (tachycardia) or irregular rhythms such as premature ventricular beats. 24 https://au.pinterest.co m/explore/beta- / blockers Beta Blockers – general actions Cardiovascular - B1 receptors blocked  heart rate  cardiac output  heart muscle excitability =  blood pressure Respiratory – B2 receptors blocked Causes bronchospasm – beware ASTHMATICS Metabolic – some B blockers prevent the rise in blood glucose which normally follows increased sympathetic activity Central nervous system Believed some B blockers penetrate the CNS Some sedation is fairly common in patients receiving B blockers, sometimes this may be severe 26 β-blockers • ADVERSE DRUG • CONTRAINDICATIONS • Asthma • Peripheral Vascular Disease • Relative contraindication • Raynauds Syndrome REACTIONS • Tiredness /fatigue • Lethargy • Impotence • Heart failure • Bradycardia • Those patients who are dependent on sympathetic drive • Bronchospasm • Bradycardia / Heart block 27 Class III – Potassium channel blockers • Prolongs cardiac ACTION POTENTIAL by increasing the refractory period. Example: amiodarone. • Long half-life Adverse effects • pulmonary toxicity • Bluish discoloration of skin • GI side effects • Liver dysfunction • Thyroid dysfunction 28 Class IV - Calcium channel blockers Block the movement of calcium into heart and blood vessel muscle cells  decrease pumping strength of the heart / relax blood vessels.  muscles relax, lowering blood pressure, slowing the heart rate & decreasing oxygen demands of the heart. • used to treat high blood pressure and angina caused by reduced blood supply to the heart muscle, as well as some arrhythmias. 29 Calcium channel blockers Contraindications • Acute MI • Heart failure, bradycardia Adverse Drug Reactions • Flushing • Headache • Ankle oedema • Indigestion and reflux oesophagitis Rate limiting agents also cause • Bradycardia • Constipation • Amlodipine (Norvasc) • Bepridil (Vascor) • Diltiazem (Cardizem, Cardizem SR) • Nifedipine (Adalat, Procardia) • Verapamil (Isoptin) 31 Verapamil • Blocks calcium channels in the blood vessels and heart = vasodilation • Given for angina, hypertension and dysrhythmias • PO or IV • Adverse effects – constipation, dizziness, h/a, bradycardia, hypotension, edema of ankles and feet 32 Class V - Drugs unclassified in the Vaughan Williams system Adenosine – acts on A1 receptor in AV node. Receptor linked to cardiac K+ channel.  causes hyperpolarisation and slows rate of rise of pacemaker potential.  stops supraventricular tachycardia Extremely short half-life 33 Class V Cardiac glycosides e.g. digoxin. –also increase force of contraction. • Exacerbates AV block (since AV recovery time reduced) • Eventually AV dissociation leads to safer ventricular rate. rhythm contraction Heart rate SLOWS / STRENTHENS / STABILISES 34 Reference List Bullock, S. & Manias, E. (2011). Fundamentals of Pharmacology (6th ed). Frenchs Forest, Australia: Pearson Education Australia. Bryant, B. & Knights, K. (2011). Pharmacology for Health Professionals (3rd ed). Marrickville, Australia: Elsevier. Crisp, J. & Taylor, C. (2012). Potter & Perry’s Fundamentals of Nursing. (8th ed). Marrickville, Australia: Mosby Elsevier. Tiziani, A. (2010). Havard’s Nursing guide to Drugs, (8th ed). Marrickville, Australia: Elsevier. 35