Cardiac conduction blocks Flashcards
What is sick sinus syndrome?
combo of symptoms caused by SA node dysfunction and manifested by marked bradycardia, SA block or sinus arrest. Can have SVT-also called bradycardia/tachycardia syndrome
How do you tx sick sinus syndrome?
Atrial or dual chamber pacemaker
These pts are at high risk of developing PE and should be started on anti-coagulation therapy.
Why are bradydysrhythias pre-operatively a thing to watch for?
Because they can have an unexpected onset as heart block under general anesthesia, mainly in the elderly population
Mobitz type 1-disease of what? treatment:
Disease of AV node, if pt is hemodynamically stable, tx: observation only
Mobitz type 2-disease of what? tx:
Disease of His-Purkinje system, can progress to complete heart block and cause cardiac arrest or sudden death. Tx: pacemaker
Third degree heart block: what are some causes, and what do you do to tx?
3rd degree: no atrial impulses are conducted to ventricles.
Causes; coronary ischemia
congenital: lupus
Tx: dual chamber pacemaker, pharmacologic-continuous infusion of isoproterenol, Pacing-transcutaneous, transvenous
Cause of LBBB:
Activation of left ventricle is delayed. Indicates an underlying cardiac pathology (Dilated or hypertrophic cardiomyopathy, HTN, Aortic valve disease, CAD)
HTN, MI, excessive CAD
Diagnosis of LBBB:
What do you do when you see it?
QRS duration must be >120 msec, QS or RS complex in lead V1
Monophasic R wave in leads 1 and V6
R, R’ in left chest leads V5, V6
Patients require a complete cardiac evaluation, presents with syncope, CHF and prolonged QRS and they require a pacemaker
RBBB: how/why does it happen, what are some causes, and how do you tx it?
RV is normally not directly activated by impulses traveling through RBB. These impulses travel through myocardium of left ventricle and activate right ventricle
Can be caused by central line placement, usually a marker of slow progressive degenerative disease. can be a normal variant in healthy patients. Tx: asymptomatic and does not require tx
RBBB on EKG:
QRS must be >120 msec
R, R’ in leads V1 or V2
if pt has mobitz type 2 and must go back for emergency surgery, what are you going to do?
(postpone if elective)
If emergent, have external pacemaker pads
have defibrillatory in operating room
standard ASA monitoring, begin GA with ETT so pt has airway if she goes into complete heart block
