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26 Cards in this Set
- Front
- Back
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Cardiac Arrhythmias
Definition |
abnormal heart rhythms resulting from alterations in impulse formation and/or conduction
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Cardiac Arrhythmias
Normal Conduction System |
Sinoatrial (SA) node in right atrium initiates impulse
→ stimulation of left atrium and atrioventricular (AV) node → stimulation of left and right bundle branches via bundle of His → stimulation of Purkinje fibers and causes ventricular contraction |
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Cardiac Arrhythmias
are defined by: |
ANATOMIC LOCATION
Supraventricular abnormalities **SA node, atrial tissue, AV node, **Bundle of His Ventricular abnormalities **below the bundle of HIS VENTRICULAR RATE Bradycardia: HR < 60bpm Tachycardia: HR > 100bpm |
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Cardiac Arrhythmias
secondary to disorder of: |
Automaticity (impulse generation)
Latent pacemaker (non SA-node) Triggered automaticity (after-depolarizations) Reentry Impulse conduction Automaticity and impulse conduction |
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Cardiac Arrhythmias
Types |
-----SUPRAVENTRICLAR-----
Bradyarrhythmias ***sinus bradycardia ***atrioventricular (AV) block Tachyarrhythmias ***atrial fibrillation and flutter ***paroxysmal supravantricular tachycardia (PSVT) -----VENRTICULAR----- Ventricular tachycardia (VT) Ventricular fibrillation (VF) |
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Cardiac Arrhythmias
Sinus bradycardia - criteria, causes |
HR < 60bpm, otherwise normal ECG
↓ SA node automaticity Causes: Acute MI, hyprothyroidism, hyperkalemia, drug-induced (BB, digoxin, non-dihydro CCB, clonidine, amiodorone, cholinergics) |
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Cardiac Arrhythmias
Sinus bradycardia - treatment |
intermittant = iv atropine up to 3g
persistent = transvenous or transcutaneous pacemaker |
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Cardiac Arrhythmias
AV block - criteria, causes |
complex diagnostic criteria - skip
prolonged conduction Causes: AV nodal disease, acute MI, myocarditis, increased vagal tone, hyperkalemia, drug - induced (BB, digoxin, non-dihydro CCB, clonidine, amiodorone, cholinergics) |
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Cardiac Arrhythmias
AV block - treatment |
if reversible → temporary pacemaker or intermittent atropine
in chronic → implant permanent pacemaker |
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Cardiac Arrhythmias
Atrial fibrillation and flutter - criteria |
Fibrillation: no p-wave pattern, irregularly, irregular QRS pattern
Flutter: sawtooth P-wave pattern; regular QRS pattern enhanced automaticity and reentrant circuits |
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Cardiac Arrhythmias
Atrial fibrillation and flutter - causes |
Rheumatic heart disease, HF, HTN, ischemic heart disease, pericarditis, cardiomyopathy, mitral valve prolapse, cardiac surgery, infection, ETOH abuse, hyperthyroidism, COPD, PE,
risk increases with age |
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Cardiac Arrhythmias
Atrial fibrillation - 2 treatments |
Rhythm control
--seeks to restore, with cardioversion, the regular heart rhythm and maintain it with drugs --many a/e of antiarrhythmics --reserve for those w/many recurrent symptomatic episodes Rate control --seeks to reduce the heart rate to one that is closer to normal, usually 60 to 100 bpm, without trying to convert to a regular rhythm |
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Cardiac Arrhythmias
Atrial fibrillation - Rate Control |
Control Ventricular Rate (but leave in AF)
+ anticoagulation to prevent thromboembolic stroke |
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Cardiac Arrhythmias
Atrial fibrillation - Rate Control |
Ventricular Rate Control is accomplished with meds that ↑ the degree of block at the level of the AV node ↓ing the number of impulses that reach the ventricles
**digoxin - slow onset **CCBs (non-dihydros) **BBs (esmolol, metroprolol, propranolol) Anticoagulate with warfarin |
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Cardiac Arrhythmias
AF - warfarin INR and doses |
INR 2-3
1 mg (pink) 2 mg (lavender) 2.5 mg (green) 3 mg (tan) 4 mg (blue) 5 mg (peach) 7.5 mg (yellow) 10 mg (white) |
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Cardiac Arrhythmias
AF - warfarin - MOA |
Inhibits manufacturing of Vitamin K
Therefore, inhibits vit K - dependent factors II, VII, IX, X, and proteins C and S Metabolized in liver by P450-2C9 |
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Cardiac Arrhythmias
AF - warfarin - managemnt of ↑ INR |
< 5
lower dose or limit single dose and restart lower dose |
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Cardiac Arrhythmias
AF - warfarin - managemnt of ↑ INR |
between 5 and 9
omit 1-2 doses, resume at lower dose when INR therapeutic or omit dose and give 1-2.5mg vit K orally and restart when INR therapeutic |
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Cardiac Arrhythmias
AF - warfarin - managemnt of ↑ INR |
> 9
hold warfarin, give 5-10 mg vit K orally and restart warfarin when INR therapeutic |
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Cardiac Arrhythmias
AF - warfarin - managemnt of ↑ INR |
serious bleeding at any ↑ INR
--Hold warfarin --give 10 mg vit k IV slow infusion --supplement with fresh frozen plasma or prothrombin complex if necessary |
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Cardiac Arrhythmias
AF - warfarin - managemnt of ↑ INR |
Life-threatening bleeding at any ↑ INR
--Hold warfarin --give prothrombin complex with vit K 10mg via IV slow infusion |
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Cardiac Arrhythmias
Paroxysmal supraventricular tachycardia (PSVT) |
just an fyi that it exists
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Cardiac Arrhythmias
Nonsustained ventricular tachycardia PTs with Heart Dz and Ef > 30% |
PTs with Heart Dz and Ef > 30%
**asymptomatic - no drug tx **symptomatic (palpitations) - BB + other tx to ↓ rist of CV events (eg. ASA, ACEi, statin) |
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Cardiac Arrhythmias
Nonsustained ventricular tachycardia PTs with Heart Dz and Ef < 30% |
PTs with Heart Dz and Ef < 30%
**at ↑ risk for sudden cardiac death **implantable cardioverter defibrillator (ICD) → ↑ survval (amiodarone doesn't) **standard background TX (ASA, ACEis, BBs, statins, Aldosterone Antags) |
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Cardiac Arrhythmias
Torsades de Pointes - causes |
QRS complexes appear to twist around an axis; prolonged QT interval
↓K+, ↓MG, MI, subarachnoid hemorrhage, hypothyroidism, myocarditis or cardiomyopathy, arsenic poisoning |
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Cardiac Arrhythmias
Torsades de Pointes - drug causes |
antiarrhythmics- (amiodarone, quinidine + bunch more)
antipsychotics - old and new antidepressants - TCAs antibiotics - macrolides, fluoroquinolones (spar, gati, moxi), TMP-SMX |
