Arrhythmias

Question 1

Definition of first degree heart block

Answer 1

PR intverval greater than 0.2 (5 small squares). no tx needed

Question 2

mobitz type I heart block definition

Answer 2

progressive PR lengthening until skipped QRS. PR progression, then resets and starts again

Question 3

mobitz type I heart block cuases

Answer 3

intranodal or His bundle conduction defect or as an effect of BBS, CCBs, or digoxin, or vagal tone

Question 4

treatment of mobitz type I heart block

Answer 4

adjust meds (CCBs, BBs, digoxin), no other treatment unless pt has symptomatic bradycardia

Question 5

mobitz type II heart block definition

Answer 5

problem with His bundles or purkinje fibers. patients have randomly skipped QRS without changes in PR interval

Question 6

mobitz type II treatment and complications

Answer 6

tx: pacemaker; can progress to complete heart block

Question 7

complete heart block: definition and tx

Answer 7

absence of conduction between atria and ventricles
patients present with syncope, dizziness, hypotension
Tx: pacemaker, don’t give meds that affect the AV node

Question 8

Paroxysmal supraventricular tachycardia: definition, pt population, cause

Answer 8

definition: tachycardia arising in atria or AV junction
usually seen in young pts with healthy hearts
cause usually reentry anomaly:
-AV nodal reentry: slow and fast conduction pathways (reentrant tachycardia)
-Can also be due to AV reentry as seen in WPW syndrome, which is similar to AV nodal reentry excetp that there is a separate accessory conduction path between the atria and the ventricles. there will be a delta wave on EKG

Question 9

What is the usual hx for paroxysmal supraventricular tachycardia

Answer 9

sudden tachycardia, possible chest pain, SOB, palpitations, syncope

Question 10

What is mutifocal atrial tachycardia?

Answer 10

caused by several ectopic foci in the atria that discharge automatic impulses, causing tachycardia. Will appear as p waves with variable morphology on EKG

Question 11

What is the tx for mutifocal atrial tachycardia?

Answer 11

CCBs or BBs acutely, then catheter ablation or surgery

Question 12

What are the main risk factors for the development of atrial fibrillation?

Answer 12

PIRATES: pulmonary disease, ischemia/CAD, rheumatic heart disease, anemia, hyperthyroid, ethanol, and sepsis
Can also be seen with pericarditis

Question 13

How is afib treated?

Answer 13

anticoagulation, rate control with CCBs or BBs, or digoxin, consider electrical or chemical cardioversion if presening within the first 2 days.
cardioconversion can be performed in delayed presenation if absence of thrombi is confirmed by TEE. If thrombus is seen, anticoagulate and wait 3-4 weeks before cardioversion

Question 14

What are the important complications of afib?

Answer 14

increased risk of MI, heart failure; poor atrial contraction –> blood stasis –> clot/embolization

Question 15

What are the risk factors for atrial flutter?

Answer 15

CAD, CHF, COPD, pericarditis, valvular disease

Question 16

What are causes of PVCs? When are they significant?

Answer 16

become concerning for the development of other ventricular arrhythmias if more frequent than 3x/min
usually benign, but may be due to hypoxia, abnormal electrolytes, hyperthyroidism, caffeine

Question 17

tx for PVCs? possible complications?

Answer 17

none if pt is healthy, consider BB if pt has CAD because they are associated with incr risk of sudden death in pts with CAD

Question 18

VTach

Answer 18

series of 3 or more PVCs with HR 160-240

Question 19

torsades de pointes

Answer 19

VTach with sine wave morphology; poor prognosis and can rapidly convert to vfib; magnesium may be useful in tx

Question 20

How is VTach treated?

Answer 20

electrical cardioversion followed by antiarrhythmic medication. if recurrent, may need internal defibrillator