PMT, Johnston - Cardiac Rhythm Disturbances Flashcards
Sinus bradycardia Rate - Rhythm - Axis - Other -
Rate - less than 60
Rhythm - sinus
Axis -
Other -
Tx of sinus bradycardia - when and what
Treat when symptomatic.
Atropine, Epinephrine, Isoprotenerol, Pacemaker
Sinus Arrhythmia Rate - Rhythm - Axis - Other -
Rate -
Rhythm - sinus, identical P waves
Axis -
Other - SAN pacing waxes and wanes with respiration
Sick Sinus Syndrome - caused by, demographic, s/s, rate
Caused by unresponsive Supraventricular automaticity foci.
Demo - elderly who have heart disease
s/s - syncope, dizziness, fatigue, HF
Rate - alternating SSS-tachy-brady
What is automaticity?
Property of a cardiac cell to depol spontaneously during phase4»_space; generation of an impulse.
Atrial arrhythmia
PAC
Seen in absence of significant HD - associated with stress, alcohol, tobacco, caffeine, cOPD, CAD
Paroxysmal Atrial Tachycardia Rate - Rhythm - Axis - Other -
An irritable atrial foci suddenly pacing rapidly. Rate - 150-250 Rhythm - sudden rapid pace Axis - Other -
PAT with AV Block Rate - Rhythm - Axis - Other -
Paroxysmal Atrial Tachycardia - atrial foci.
Rate - rapid
Rhythm - see 2:1 ratio of P:QRS (spiked P)
Axis -
Other -
What should you suspect as the cause of PAT with AV Block?
Digitalis or toxicity
Paroxysmal Junctional Tachycardia (PJT) Rate - Rhythm - Axis - Other -
AVJunction sudden rapid pace Rate - 150-250 Rhythm - sudden rapid pace Axis - Other - Inverted P wave??
AVN Reentry Tachycardia (AVNRT) - what is it and what do you not see?
Continuous reentry circuit develops and rapidly paces atria and ventricles.
No P waves seen.
Paroxysmal Supraventricular Tachy (PSVT). What is it and what does it look like?
When both PAT and PJT originate above the ventricles - (ESW: non-QRS almost looks like Chinaman’s Hat)
QRS less than 0.14.
Paroxysmal Ventricular Tachy (PVT) Rate - Rhythm - Axis - Other -
Rate - 150-250
Rhythm - sudden rapid pace, QRS more than 0.14 sec
Axis - extreme RAD
Other - enormous, consecutive runs of PVC-like complexes. Wide QRS complex. (tall/wide mountains - no QRS/P discernable)
Ventricular Tachycardia (VT) What does VT indicate? Rate - Rhythm - Axis - Other -
Rate -
Rhythm - QRS wider than 0.14sec
Axis - extreme RAD
Other - indicates coronary insufficiency, which causes poor oxygenation of the foci.
How to distinguish “Wide QRS Complex SVT” from VT:
coronary disease, QRS width, AV dissociation, Axis
VT occurs in elderly, indicating diminished coronary blood flow.
QRS: SVT 0.14
Has signs of AV dissociation (irregular rhythm on ECG).
Torsades: RRAO, caused by, tx
Rate - 250-350
Rhythm - twisting
Axis -
Other - Tx is MgSO4, overdrive acing, isoprotenerol
Atrial flutter Rate - Rhythm - Axis - Other -
Rate - 250-350
Rhythm - sawtooth appearance
Axis -
Other - best seen in 2, 3, AVF, 5
Ventricular flutter Rate - Rhythm - Axis - Other -
Rate - 250-350
Rhythm -
Axis - sine waves
Other - leads to vfib
Afib - three things
1) Irregular rhythm, 2) rate is tachycardic (300). 3) NO P WAVES
(ESW: undulating baseline). “Irregularly irregular” Continuously chaotic atrial spikes.
Vfib
Rapid rate discharges, irritable parastolic ventricular foci - erratic rapid switching of ventricles.
Wandering pacemaker Rate - Rhythm - Axis - Other -
Pacemaking activity wanders from SAN to atrial foci.
Rate - LESS than 100
Rhythm - irregular ventricular rhythm
Axis -
Other - P’ wave shape varies. If rate accelerated, it becomes a MAT.
Multifocal Atrial Tachycardia (MAT). Rate - Rhythm - Axis - Other -
Rate - OVER 100
Rhythm -
Axis -
Other - P’ wave shape varies. Three or more consecutive times.
MAT is associated with what disease?
Tx for MAT.
Associated with COPD
Tx - DC theophylline, IV MgSO4, IV verapamil
Types of Premature Atrial Beats
1) PAB with abberant ventricular conduction - wide QRS after the PAB
2) Non-conducted PAC - no QRS after the PAB
3) Atrial bigeminy or trigeminy - two P waves before every 2nd or 3rd QRS
4) PACs - big, peaked P waves, or small inverted p-waves
5) Blocked PACs
Tx of Blocked PACs - when and with what?
Treat if symptomatic with metroprolol, BB.
Premature junctional beat
Premature, INVERTED P’ before the QRS.
Premature Ventricular Beat/Contraction (PVC).
Lost P wave with a giant ventricular complex, followed by a compensatory pause.
What are PVCs caused by?
How many PVCs per minute is considered pathological?
PVC tx?
Caused by MVP.
6+/min
Tx: if unstable, Amiodarone, Lidocaine, Procainamide
What can multifocal PVCs be caused by and why is this dangerous?
Can be caused by severe hypoxia, especially in infarction patients. Greater change of developing a dangerous or deadly arrhythmia.
What is the R on T phenomenon?
When a PVC falls on a T wave.
Particularly with low serum potassium and hypoxic situations. Vulnerable period where dangerous arrhythmias may result.
Hyperkalemia
- Wider QRS
- Tombstone T wave = peaked/huge
- flatter to no P wave
Hypokalemia
- Flat or inverted T
- U wave
Short QT indicative of what 2 possible electrolyte imbalances?
Hypercalcemia
HyperMg
Prolonged QT indicative of what 2 possible electrolyte imbalances?
What can this trigger?
Hypocalcemia or HypoMg
Can trigger torsades
See a “ski slope” ST-segment in V1-3 with ST elevation
Brugada
familial, deadly arrhythmias
See a short PRi with a slurred upstroke (delta) of QRS complex.
PE of palpitations and near fainting spells for several months.
WPW
Accessory bundle of kent - accessory AV conduction pathway that provides ventricular “pre-excitation”.
Hypothermia on ECG
Bradycardia
J-wave (Osborne Wave)
Pulmonary embolus (and acute cor pulmonale)
1) S1 Q3 inverted T3
2) T wave inversion on V1-4
3) RBBB
What is S1 Q3 inverted T3?
Lead 1 = Large S wave
Lead 3 = Large Q wave, T inversion
(Lead 2 = ST depression)
Acute cor pulmonale = low voltage (less than 5mm avg in L1-3)!
Cerebral hemorrhage on ECG
ST-T changes (i.e. deep inversion of T in V2-4)
Hypothyroidism
flattening or inversion of T waves WITHOUT ST-displasement
**Low voltage in limb leads, think what?
High voltage in limb leads, think what?
Low, think COPD, MYXEDEMA/hypothyroid, amyloidosis,
High, think hypertrophy
**If aVR is not downward and L2, L3, aVF are not upright, think what?
Junctional tachycardia
SVT is the most common in what age group?
Young people
How do you treat vtach?
How do you treat third degree block?
Shock.
Pacemaker.
