Cardiopharma

• Bradycardia


  Slow heart rate
• Medications for bradycardia


  • Atropine
  • Epinephrine
  • Dopamine
• Objective of bradycardia treatment


  Identify and treat the cause of the problem
• Medications indicated for bradycardia

  If symptomatic bradycardia cannot be corrected by treating an underlying cause or if the cause cannot be determined
• Atropine

  1 mg for the first dose and then repeat every 3-5 minutes max: 3 mg (3 doses)
• Dopamine

  400 mg is mixed with 250 ml NS infusion rate of 5-20 mcg/kg/min
• Epinephrine


  1mg epinephrine is mixed with 500ml of NS or D5W- infusion rate of 2-10 mcg/min
• Atropine


  • Causes an increase in heart rate
  • Blocks the effects of the vagus nerve on the heart
• Atropine


  When the vagus nerve is blocked, the SA node increases its rate of electrical discharge and results in the increased HR
• Atropine


  • First line drug for symptomatic bradycardia
  • Organophosphate poisoning: requires larger doses (2 – 4 mg or more)
  • Parasympatholytic
  • (+) chronotropic effect, (+) dromotropic effect, relaxes bronchial smooth muscles and decreases secretions, decreases GI motility, decreased sweat production and causes pupil dilation

  
• Atropine


  • Onset: increases heart rate in 1 minute and decreases secretions in 30 minutes
  • Duration: 2 hours
• Epinephrine


  • Stimulates the entire myocardium (atria, SA node, AV node, and ventricles)
  • May be effective in a broader range of bradycardias compared to atropine

  
• Epinephrine


  • Sympathomimetic
  • Alpha Adrenergic: constriction of BV
  • Beta 1 agonist: (+) inotropic, (+)chronotropic
  • Beta 2 agonist: relaxation of bronchial muscles
• Epinephrine


  • Precautions: Increases cardiac oxygen demand
  • Onset: 1 – 2 minutes
• Epinephrine for cardiac arrest

  • IV/IO: 1mg (10ml of 1:10000 sol'n) administered every 3 – 5 minutes during resuscitation. Flush with 20cc of NS and elevate arm to 20 seconds
  • Continuous infusion: initial rate: 0.1 to 0.5 mcg/kg per minute and titrate to patient's response
  • Endotracheal tube: 2 – 2.5 mg diluted in 10 ml NS

  
• Indications for epinephrine


  • Cardiac arrest: VF, PVT, asystole and PEA
  • Symptomatic bradycardia: after admin of atropine as an alternative to dopamine
  • Severe hypotension: if atropine doesn't work, hypotension is accompanied with bradycardia or with phosphodiesterase enzyme inhibitor
  • Anaphylaxis: combined with large fluid volume, corticosteroids and antihistamine

  
• Dopamine


  Stimulates cardiac muscle contraction and increases the heart rate, which results in improved cardiac output. Its vasodilatory effects improve blood flow to vital organs such as the kidneys, enhancing their function.
• Dopamine dose ranges


  • Low dose: dopaminergic effect (0.5 – 2mcg)
  • Medium dose: (beta effects (2 – 10 mcg)
  • High dose: pressor dose (10 – 20mcg)
• Dopamine


  Onset: 2 – 5 minutes . Do not combine with NaHCO3
• Dopamine for shock/CHF


  • Responsibilities: Titrate to desired blood pressure
  • Fluid resuscitation in shock done first
  • Cardiac and BP monitoring

  
• Bradycardia treatment


  • Atropine: Initial 1mg, subsequent 1mg every 3-5 min, max 3mg
  • Dopamine drip: Initial 5 mcg/kg/min, titrate to response (5-20 mcg/kg/min)
  • Epinephrine infusion: Initial 2-10 mcg/min, titrate to response
• Tachycardia treatment


  • NCT SVT: Adenosine
  • WCT VTach with pulse: Amiodarone
  • Pulseless VTach: Epinephrine, Amiodarone
• Adenosine


  • IV bolus 6 mg then 12 mg (1-2 minutes)
  • Produces transient atrioventricular nodal block when injected as an intravenous bolus
  • Therapeutic value in the conversion to sinus rhythm of the majority of paroxysmal supraventricular tachycardias
  • Remarkable for its rapid metabolism and brevity of action, with a half-life of a few seconds
• Adenosine


  • First drug in treating re-entry phenomena involving AV node or SA node
  • Does NOT CONVERT atrial fibrillation, atrial flutter or ventricular tachycardia
  • Contraindicated in poisoning and drug induced tachycardia, may be less effective if patient is taking theophylline or caffeine
  • Safe for pregnant women

  
• Adenosine injection technique


  1. Record rhythm strip during medication administration

  2. Draw up medication dose in two separate syringes

  3. Attach syringes in two injection ports closest to the patient

  4. Clamp intravenous tubing above injection port

  5. Push drug as quickly as possible (1 – 3 seconds)

  6. Push NS rapidly as possible after adenosine admin without releasing pressure on the adenosine plunger

  7. Unclamp IV tubing
• Adenosine


  • Endogenous nucleoside(natural antiarrhythmic)
  • Slows Sinus rate, slows conduction time through AV node, interrupts re entry pathways through the AV node
  • Given IV push in 1 – 3 seconds
  • Precautions: may result to heart blocks because of AV blocking but may be self limiting
• Amiodarone


  • Rapid infusion or >2.2 g in 24 hours may cause HYPOTENSION
  • Do not administer with procainamide
  • Terminal elimination is extremely long (lasts 40 days)
  • May cause TOXICITY thus monitor patient very closely when administered
  • May be given to patients with: WCT (VT with pulse), Ventricular fibrillation, Pulseless Ventricular Tachycardia, unresponsive to CPR, Shocks and Vasopressors
• Amiodarone


  • Class I (blocks sodium channels)
  • Class II (blocks sympathetic stimulation)
  • Class III (blocks potassium channels)
  • Class IV (blocks calcium channels)
  • If ROSC occurs: continuous administration through IV infusion (1mg/minute for 6 hrs then 0.5mg/min infusion for the next 18 hrs)
  • Precautions: may cause severe bradycardia and hypotension
• Ventricular fibrillation & pulseless ventricular tachycardia treatment

  • Epinephrine: Initial 1mg, subsequent 1mg every 3-5 min, no max
  • Amiodarone: Initial 300mg, subsequent 150mg every 10 min, max 2.2g in 24 hrs
• Asystole and pulseless electrical activity treatment

  • Epinephrine: Initial 1mg, subsequent 1mg every 3-5 min, no max

  
• Procainamide


  • Decreases atrial conduction, exerts a peripheral vasodilatory effect, decreases automaticity in the HIS-PURKINJE system
  • Must attach patient to ECG monitor and if BP drops 15mmHg, administration is temporarily stopped
  • Stop if dysrrhythmia resolves, hypotension happens and total dose of 17mg/kg is administered
  • Effects may be increased if given with Amiodarone
• Sotalol


  • Antiarrhythmic treatment of supraventricular and ventricular arrhythmias in patients without structural disease. Should be avoided in poor perfusion because of significant inotropic effects.
  • Adverse reactions include bradycardia, hypotension and torsades de pointes.
  • IV dose 100 mg over 5 minutes.
  • Avoid if with prolonged QT.
• Magnesium sulfate


  • Given only if Torsades de Pointes or hypomagnesemia is suspected
  • Watch out for occasional falling of the blood pressure with rapid administration
  • Watch with caution if renal failure is present
  • Cardiac arrest due to hypomagnesemia or Torsades de Pointes: 1 – 2 g (2-4ml of a 50% solution) diluted in 10ml of D5W IV/IO
• Vasopressin


  • Can be given via endotracheal tube
  • Used as an alternative pressor to epinephrine in treatment of adult cardiogenic shock, asystole, PEA
  • May be useful in vasodilatory shock as in septic shock
  • Potent peripheral vasoconstrictor
  • Increase peripheral vascular resistance which may provoke myocardial ischemia and angina
  • IV Administration: Cardiac arrest: one dose 40U IV/IO push may replace either first or second dose of epinephrine
  • Vasodilatory shock: continuous infusion of 0.02 to 0.04 units per minute
• Ventricular tachycardia with pulse treatment

  • Adenosine: Initial 6mg, subsequent 12mg every 2 min, max 3rd dose
  • Amiodarone: Initial 150mg, subsequent 150mg every 10 min, max 2.2g in 24 hrs
  • Lidocaine: Initial 1-1.5 mg/kg, subsequent 0.5-0.75 mg/kg every 5-10 min, max 3mg/kg
  • Procainamide drip: 20mg/min, titrate to response, max 17mg/kg
• Lidocaine


  • Inhibits influx of sodium, decreases conduction in the ischemic heart tissue
  • Maintenance infusion is 4mg/min and is reduced to 1 – 2mg/min in the next 24 hours
  • Onset: 45 to 90 seconds
  • Duration: 10 – 20 minutes
• Atrial fibrillation and atrial flutter treatment

  • Verapamil: Initial 2.5-5mg, subsequent 5-10mg every 15-30 min, max 20mg
  • Inderal: Initial 0.1mg/kg divided in 3 doses, subsequent 2nd and 3rd dose
  • Diltiazem: Initial 15-20mg, subsequent 20-25mg every 15-30 min, IV infusion 5-15mg/hr
• Verapamil


  • Ca channel blocker
  • Relaxation of vascular muscles, decreases SA and AV conduction, dilation of large and small coronary arteries
  • Monitor closely for AV blocks and hypotension
  • Onset: 2 – 5 minutes
• Inderal


  • Slows sinus rate, decreases AV conduction, decreases BP and decreases myocardial oxygen consumption
  • Do not give if HR is below 60 and if patient is hypotensive
• ACS treatment


  • Morphine Sulfate
  • Oxygen
  • Nitroglycerin
  • Aspirin