This document summarizes various cardiac arrhythmias and conditions:
- Atrial flutter and fibrillation are described along with treatments like cardioversion, rate control medications, and anticoagulation.
- Other arrhythmias discussed include multifocal atrial tachycardia, supraventricular tachycardia, Wolff-Parkinson-White syndrome, ventricular tachycardia, and ventricular fibrillation.
- The use of temporary and permanent pacemakers is outlined along with indications and ways to identify failures on EKG.
- Automatic implantable cardioverter defibrillators are also summarized.
- Other topics covered include hypertensive emergencies/urgencies,
3. Atrial Fibrillation
⢠Disorganized atrial conduction with irregular conduction to
ventricles
⢠No discernable p- wave with irregular QRS
⢠QRS narrow unless BBB
TX:
⢠Unstable: Synchr Cardioversion (less success if chronic AF or
permanent A-fib)
⢠Stable: Rate control- BB, CCB, Digoxin, Amiodarone,
Anticoagulation-ASA, Heparin, Warfarin based on CHADS2
Score.
4. Multifocal Atrial Tachycardia
⢠Often mistaken for A-fib, but 3 or more discernable p- waves,
Irregular rate, 100-180 BPM.
⢠Narrow QRS, but can be wide QRS with BBB
⢠2/2 lung dz
TX:
⢠Treat underlying lung dz, Rate control with CCB
5. Supraventricular Tachycardia
⢠Reentry Tachycardia
⢠Abrupt onset and termination differentiates from Sinus Tach
⢠Precipitated by PAC or PVC (if AVRT)
⢠Requires 2 different conduction pathways with different refractory
times
⢠Regular rate, p- waves absent, QRS narrow unless BBB
⢠Types:
⢠AVNRT- Conduction pathways within AV node
⢠AVRT- Conduction pathways between Atria and Ventricle
⢠Atrial Reentry Tachycardia- Conduction pathways within atria
TX:
⢠Unstable-Synchr. Cardioversion
⢠Stable- Vagal maneuver, Adenosine, BB, CCB, Procainamide
6. ⢠Preexitation Syndromes- WPW
⢠Men> Women, 10% of Ebstein Anomaly (Tricuspid anomaly- atrialization of RV/ CHD)
⢠Accessory pathway/ Bundle of Kent circumvents AV node, connect. atrium to bundle of His.
⢠Orthodromic SVT/ Narrow QRS (95%):
⢠Antegrade conduction vie AV node/Retrograde via accessory pathway.
TX:
⢠Unstable- Synchr. Cardioversion
⢠Stable- CCB, BB, Adenosine, Procainamide
⢠Antidromic SVT/ Wide QRS and short PR (5%):
⢠Antegrade conduction via accessory pathway, retrograde via AV node.
⢠Wide QRS/ Delta wave. Can be indistinguishable from V-Tach.
TX:
⢠Unstable: Synchr. Cardioversion
⢠Stable: Procainamide, Amiodarone
⢠NO CCB/BB/Dig, Adenosine (blocks AVN, allowing conduction via accessory
pathway)
7. Tachycardia- Wide
Complex
Monomorphic Ventricular Tachycardia
⢠Single ventricular ectopic focus with wide QRS 2/2 depolarization via myocardium (not
as rapid as His- Purkinje fibers).
⢠Absent P- waves, rate >140, QRS> 160 mS
In favor of VT vs SVT w/ aberrancy:
⢠Fusion beats- fusion of wide ectopic beats and normal QRS
⢠Capture beats- Narrow QRS captured between wide QRS
⢠AV dissociation
⢠>50 yrs, cardiac dz
TX:
⢠Unstable: Pulse- Synchronized cardioversion, Pulseless- unsynchronized defibrillation
⢠Stable: Amiodarone, Procainamide, correct underlying etiology
8. Polymorphic Ventricular Tachycardia (Torsade de Pointes)
⢠Wide complex QRS, 180-240, wave like appearance.
⢠Baseline EKG may show long QT
Prolonged QT:
⢠Congenital: Jervell-Lange- Nielson, Romano-Ward
⢠Meds: Antiarrhythmics 1A, IIIA, TCA, Phenothiazine, antipsychotics
⢠Electrolyte: Hypo K, Hypo Mg
⢠ICH
TX:
Unstable: Pulse- Synchr cardioversion, Pulseless- Defibrillation
Stable: Mg, Overdrive pacing or Isoproterenol (incr HR-> Shorter QT)
9. Ventricular Fibrillation
⢠Hyperirritable ventricular myocardium 2/2 Ischemia, scarring,
antiarrhythmics, a-fib, cardioversion.
⢠Disorganized, irregular rapid waveform with no discernable P or QRS.
TX:
⢠ACLS, Defibrillation, or will degenerate in to Asystole.
⢠Epinephrine, Amiodarone, Mg
10. Cardiac
Devices
Ventricular Pacing- Temporary
Indications:
⢠Bradycardia with hemodynamic Instability
⢠Bradycardia with significant escape rhythms
⢠Overdrive pacing
⢠Standby for:
⢠Stable bradycardia
⢠Acute MI with Sinus node dysfunction
⢠Mobitz II or third degree block
⢠Cardiac Ischemia with new LBBB or RBBB
⢠Transcutaneous pacer- pads to ant-post chest. Limited by body habitus.
⢠Transvenous pacer- via Cordis catheter to IJ or SC.
11. Pacemaker- Permanent
Indications:
Third degree block, Sick sinus, Severe CHF
Generator: generates impulse
Lead: deliver impulse
EKG:
⢠Pacer spikes before P and QRS if paced.
⢠Wide QRS/ LBBB pattern.
⢠Demand pacemaker may not have spikes if rhythm is nml
Failure:
⢠Generator- device or battery
⢠Lead- fracture, dislodging, migration of lead
⢠Myocardium- fibrosis, electrolyte imbalance
12. Pacer Failure on EKG
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Rate less than preset= Generator failure
Bradycardia but absent spikes= Failure to pace
Impulses fires inappropriately despite nml rhythm= failure to sense
Impulse/ spike without causing P or QRS= failure to capture
Pacer falsely senses activity of heart therefore and inhibits pacing= Oversensing
Pacer incorrectly misses activity of heart and therefore sends impulses= Undersensing
CXR
⢠Pacer with thin coil to atrium, single ventricle or both ventricles
⢠Defibrillator with thicker shocking coil in atrium and ventricle
Interrogation/ Trouble shooting
⢠Use manufacturer specific magnet held close to Pacemaker.
⢠Most pacers will switch from demand to fixed mode (preset rate for each pacer) with
use of any magnet.
⢠IECD will turn off with magnet.
13. AICD (Automatic Inplantable Cardioverter Defibrillator)
⢠Delivers defibrillatory shock to apex of right ventricle if VF or VT
⢠Almost always combined with pacemaker
Indications:
⢠High risk for dysrhythmia
⢠Sever CHF
⢠Brugada Syndrome
⢠Hypertrophic Cardiomyopathy
Failure:
⢠Generator
⢠Sensing
⢠Lead
⢠Inappropriate discharge: Can turn off AICD with magnet
14. Hypertensive Urgency
Hypertensi
on
⢠Elevation of BP without acute end- organ injury.
⢠Potentially harmful if sustained, usually DBP >130 mmHg.
TX:
⢠Gradual reduction in BP over 24 hrs with Outpatient PO meds:
HCTZ, or BB (CAD), Lisinopril (CHF, RF, DM).
⢠Outpatient evaluation of labs for end- organ damage.
15. Hypertensive Emergency
Hypertension with acute end- organ damage, usually >130 mmHg
⢠Hypertensive encephalopathy, ICH, Ischemic stroke
⢠Renal Failure
⢠ACS, CHF, Pulm edema
⢠Aortic Dissection
⢠Retinal hemorrhage/papilledema
⢠PIH
TX:
⢠Reduce MAP by 20% over next hour with IV meds:
⢠Nicardipine (incr HR), Nitroglycerine (incr HR), Esmolol (short acting,
easily titrated), Labetalol (for PIH, worsen bronchospasm), Sodium
Nitroprusside (poss, cyanide tox, give w/ BB for elev of HR), Enalapril
(avoid in Renal Artery stenosis)
16. Hyperadrenergic Syndromes
⢠Cocaine
⢠Methamphetamine
⢠Pheochromocytoma
TX:
⢠Avoid Beta Blockers- allows unopposed alpha stimulation on blood
vessels-> further elevation of BP.
⢠Caution with cardioversion of dysrhythmia if hyperadrenergic state
since irritable myocardium.
⢠Phentolamine (alpha blocker) for Pheochromocytoma and Cocaine
⢠Benzoâs
17. Aortic Dissection
Aortic
Emergencies
Tear of aortic intima with blood leaking in to media
⢠Abrupt, excruciating pain epigastrum/ chest radiating through to back
⢠If aortic branch vessel occlusion:
⢠Neuro deficits, paraplegia, CHF, ACS, Abdominal pain, flank pain/RF, syncope
⢠Tamponade, HTN, unequal pulses, aortic insufficiency
⢠CXR: wide mediastinum, pleural effusion, apical cap, media separated from calcified
intima, blurred aortic knob.
⢠TEE, CT, CT Aortogram, MRI
Types:
⢠Debakey I: ascending/descending, II: ascending, III: descending
⢠Stanford A: Ascending , B: Descending
TX:
⢠Start IV BB for HR control (Esmolol, Labetalol). Add Vasodilator (Nitroprusside) if needed
to bring BP down to SBP ~100. Analgesia (morphine to reduce sympathetic output.
⢠Surgery for ascending dissection, Medical mgmt. for descending dissection.
18. AAA
⢠True aneurysm, >3cm or incr diameter by 50%. Rupture risk incr @ 5cm.
⢠MC abdominal and infra- renal. Grows 4 mm/yr once over 3cm. Most
commonly asymptomatic until rupture.
⢠White, smoker, hypertensive male with CAD.
⢠If pain, sudden onset in flank, abdomen, chest, back, often pulsatile
mass, hypotensive, unequal pulses.
Imaging: Abd XR, US, CT contrast, angiogram, MRI
TX:
⢠Immediate Surgery consultation/OR
⢠Optimize BP (not to low/ not to high: BP meds/ pressors)
⢠Crossmatch PRBCâs
⢠IVF