Pharmacology II Cardiac

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Pharmacology II Cardiac Vascular

• Kathy Plitnick RN PhD CCRN
• Georgia Baptist College of Nursing

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Physiology of Circulation

• Return of deoxygenated blood to the heart
• Enters the lungs to reoxygenated
• Ejected out of the left ventricle

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Cardiac Glycosides

• Positive Inotropes
• Increase contractility CO
• Improved renal perfusion
• Increased GFR
• Increased urine output
• Slow onset of action

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Digoxin Prototype

• Inhibits Na/K pump
• Calcium remains intracellular longer
• Improves contractility
• Lowers heart rate
• Treatment for At. Fib/Flutter, PSVT
• Digitalization

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Digoxin Prototype

• Side Effects
• Bradycardia
• Heart block
• Toxic Effects
• CNS GI
• Visual disturbances
• Precipitated by low K, Mg, Ca levels
• Antidote Digibind
• Therapeutic Level 0.5-2.0 ng/ml

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Digoxin Prototype

• Nursing
• Assess apical pulse for 60 seconds
• Hold if HR lt 60, Call MD
• Draw blood levels 6-8 hours after dose
• Monitor drug levels, electrolytes
• Teach patient to take own pulse
• Monitor K, Mag Calcium

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Cardiotonics

• Inocor Inamrinone
• Primacor Milrinone
• Both given by continuous IV infusion
• Dosages adjusted to maintain a CI gt 2.0
• Heart Transplant candidates

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Coronary Vasodilators

• Nitrates Nitroglycerin, Isordil
• Relax arterial venous smooth muscle
• Primary effect on veins
• Decrease myocardial work, O2 requirements
• Improves perfusion during ischemia
• Arterial dilatation

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Nitrates

• Routes
• Sublingual
• Oral
• Ointment
• Transdermal
• Parenteral

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Nitrates

• Side Effects
• Headache
• Hypotension
• Dizziness
• Palpitations
• Difficulty breathing
• Chest pain

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Nitrates

• Nursing
• IV infusion frequent VS
• Continuous cardiac monitoring
• Maintain systolic BP gt 90 mmHg
• Sublingual
• 3 tablets q 5 minutes
• Call 911 if no relief
• Continuous cardiac monitoring

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Antidysrhythmic Agents

• Terminate/prevent abnormal cardiac rhythms
• Classified according to primary effect on action
  potential

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Class I Sodium Channel Blockers

• Decrease influx of Na ions through fast channels
  during phase 0
• Prolongs absolute refractory period
• Slow rate of spontaneous depolarization during
  phase 4
• Negative inotrope, chronotrope
• Decrease myocardial O2 demand

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Class IA Quinidine

• Also slows phase 3 repolarization
• Prolong AP duration
• Increases QRS QT
• Depress contractility
• Give with food
• Cardiac monitoring

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Class IB Lidocaine

• Continuous IV for ventricular dysrhythmias
• Weakens phase 4
• Decreases automaticity, AP duration
• Raises V. Fib threshold
• Biphasic half-life
• Topical local anesthetic
• Lidocaine crazies

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Class IC Encainide, Flecainide, Propafenone

• Slow conduction through His-Purkinje
• Increase both PR QRS
• Increased mortality with Encainide Flecainide

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Class II Beta Blockers

• Cardioselective
• Metoprolol
• Atenolol
• Acebutolol
• Non-cardioselective
• Propranolol Prototype
• Nadolol
• Esmolol

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Class III - Amiodarone

• Slow rate of phase 3 repolarization
• Increase effective refractory period
• Treat atrial ventricular dysrhythmias
• Has characteristics of all 4 classes
• Blocks potassium channels
• Vasodilatory action

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Amiodarone

• Major Adverse Effects
• Hypotension, bradycardia, AV block
• Elevation of LFTs
• Proarrhythmic effect
• Torsades
• ARDS
• Pulmonary fibrosis

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Amiodarone

• Nursing
• Baseline pulmonary, LFTs, CXR
• Monitor VS, EKG
• Assess pulse for strength, rate, regularity
• Monitor for side effects
• Nausea, fever, decreased appetite
• Blue-gray discoloration of skin
• Blurred vision

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Amiodarone

• Correct electrolyte imbalances
• Check SaO2/ABGs
• Continuous cardiac monitoring
• Central line for infusion

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Class IV Calcium Channel Blockers

• Inhibit influx of calcium during phase 2
• Primarily in sinus AV nodes, atrial tissue
• Negative inotropic, chronotropic, dromotropic
  effects
• Increases angina threshold

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Verapamil (Calan)

• Depresses sinus AV node
• Terminates SVT caused by AV nodal reentry
• Controls ventricular rate in AFib/Flutter
• Contraindicated in Sick Sinus Syndrome, advanced
  block, cardiogenic shock

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Verapamil

• Nursing
• Administer slow gt 2 minutes
• Continuous EKG monitoring
• Frequency VS
• Avoid concomitant use of Beta Blockers

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Diltiazem (Cardizem)

• Fewer hypotensive side effects
• Control of ventricular rate in atrial
  dysrhythmias
• Rapid conversion of PSVT to NSR
• Treatment of Angina
• Initial bolus followed by continuous IV

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Adenosine

• Treatment of PSVT diagnostic aid
• Slows impulse formation in SA node through AV
  node
• Depresses LV function
• Half-life less than 10 seconds !
• Monitor patient very closely
• Given IV bolus
• Monitor EKG, apical pulse, BP, respirations

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Antihyperlipidemics

• Definition of Hyperlipidemia
• Can lipids be bad?
• 3 Types of Agents Used
• HMG CoA reductase inhibitors - Statins
• Zocor, Mevacor, Pravachol
• Block the synthesis of cholesterol in the liver
• Decrease LDL, increase HDL
• Fibric Acids
• Lopid, Tricor
• Decrease concentration of VLDL
• Increase lipase promotes VLDL catabolism

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Antihyperlipidemics

• Bile Acid Sequestrants
• Questran, Welchol, Colestid
• Lower LDL levels
• Bind bile acids in intestine
• Major Interaction
• Increase effects of anticoagulants
• Do not give with grapefruit juice

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Antihyperlipidemics

• Dietary corrections
• Reduce fats, sugars cholesterol
• High fiber foods
• Obtain baseline levels
• Monitor GI effects
• Increase water intake
• Administer dose in evenings