Arrythmia Flashcards
LBBB
i. Block in left leads to abnormal depolarization of a larger amount of muscle and thus there are greater differences on EKG leads V1 and V6
ii. Leads V1 and V6 are notched and wide, and do not generally cross the isoelectric line.
RBBB
results in a normal depolarization of the Left Ventricle that is then propagated to the RV.
i. Leads V1 and V6 are notched, but appear somewhat normal in their morphology when compared to LBB
d. AV dissociation
i. There is no communication between AV and SA nodes, but there is an increased rate of the AV node. Appears similar to ventricular tachycardia
Third Degree
i. There is no association between the SA and AV nodes. There is consistent RR and PP intervals but to relationship between the PR interval
ii. Signals absent communication between SA and AV nodes.
iii. Often requires pacing as the AV rate is often too low to provide sufficient oxygen especially under stress.
iv. Treatment is often required, but once again, is based on symptoms not EKG.
Mobitz type 2
- There are drops in beats that are not caused by an increase in the PR interval. There is still SA-AV association and P,QRS association, but there are drops
- May be symptomatic if drops are frequent generally first presenting with syncope. Treat with pacemaker if symptoms are bad
- May progress to third degree heart block because location of lesion is in the His/Perkinje system
Mobitz type 1 (Wekenbach)
- There is an increase in the PR interval until the PR interval is long enough to cause a dropped beat.
- Generally minimally symptomatic with potential syncope.
- Generally does not need to be treated unless there are sever symptoms
First Degree
i. There is an increase in the length of the PR interval over 200 msec.
ii. There are no missed beats
iii. Generally asymptomatic and there is no treatment that is necessary.
A Fib
a. Many uncoordinated contractions
b. High risk of stroke because of blood stasis
i. Warfarin anticoagulation is indicated
ii. CHADS2 score
c. Ablation is generally not successful.
d. Ensure proper function of AV node to prevent V tach
i. Can occur with accessory pathway WPW
AT
a. From Foci that causes an increase in the rate. Can be single or multifocus.
b. Will not respond to adenosine or vagal stimulation because focus is not related to AV node.
c. Often responds favorably to ablation
IX. AVRT
a. Associated with WPW and accessory pathway to ventricles. Generally results in an increased width of QRS.
b. Can be anterograde showing delta waves or can be retrograde that results in a widened QRS appearing like V Tach
c. Generally responds to adenosine or vagal maneuvers
d. Can do ablation
AV nodal Reentry tachychardia (AVNRT)
a. There is a slow and fast conduction pathway that leads to a reentry rhythm generally retrograde down fast and anterograde down slow. This cycles and cuases high heart rates.
b. There is no pathway to ventricles, so generally there are narrow QRS complexes.
c. Generally responds to adenosine or vagal maneuvers. Ablation is also an option.
ICD
a. Given to patients that have survived VF and have not had underlying problem treated
b. Patients with low cardiac function, less than 35%
c. Sustained V tach that is not responsive to other therapies.
Ventricular Fibrilation
a. No functional contraction leading cause of sudden death
b. Must shock immediately
IV. Accelerated Ventricular Rhythm
a. Seen most commonly in the setting of post MI thrombolytic therapy.
long QT
i. Liesch Nielsen is a K channel mutation that is accompanied by sensoneurial hearing loss
ii. Tx of Torsades
1. Usually from electrolyte imbalance
2. Magnesium is common cause and treatment is most successful
3. Can also use K
