Conduction Disorders Flashcards
Sinus tachycardia is a normal sinus rhythm but with a heart rate over ________ bpm
100 bpm
Sinus bradycardia is a normal sinus rhythm with a rate of _________ bpm
< 60 bpm
EKG: no discrete P waves and an irregularly irregular pattern of QRS complexes
Atrial Fibrillation
EKG: Regular, sawtooth pattern (F-waves), narrow QRS complex
Atrial Flutter
EKG: PR interval > .2 seconds
First degree AV block
EKG: Progressive prolongation of the PR interval culminating in a non-conducted P wave
Mobitz I Wenckebach block (longer, longer, drop now you’ve got a Wenckebach)
EKG: Intermittent non-conducted P waves without progressive prolongation of the PR interval
Type II Mobitz block (some get dropped some get through now you’ve got Mobitz 2)
EKG: there is complete absence of AV conduction - none of the supraventricular impulses are conducted to the ventricles
Third degree AV block (P’s and Q’s don’t agree now you’ve got 3rd degree)
EKG: R and R’ (upward bunny ears) in V4-V6
Left bundle branch block
EKG: R and R’ (upward bunny ears) in V1-V3
Right bundle branch block
A faster than normal heart rate beginning above the heart’s two lower chambers in the atria, AV junction or SA node
Supraventricular Tachycardia (SVT)
EKG: Shorter PR Interval, longer QRS complex and a delta wave - slurring slow rise of initial portion of the QRS
Wolff-Parkinson-White Syndrome
EKG: Rapid irregular rhythm > 100 bpm. At least 3 distinct P-wave morphologies
Multifocal Atrial Tachycardia (MAT)
EKG: An abnormal (non-sinus) P wave is followed by a QRS complex
Premature Atrial Complex (PAC)
EKG: Narrow QRS complex, either (1) without a preceding P wave or (2) preceded by an abnormal P wave with a PR interval of < 120 ms
Premature Junctional Complex (PJC)
Broad QRS complex (≥ 120 ms) with abnormal morphology
Premature ventricular contractions (PVC)
Every 3rd beat
trigeminy
Every other beat
bigeminy
EKG: Alternating bradycardia with paroxysmal tachycardia, often supraventricular in origin
Sinus Node Dysfunction (Sick Sinus Syndrome)
Bradycardia - tachycardia syndrome
EKG: Broad complex tachycardia originating in the ventricles
Ventricular Tachycardia (VT)
EKG: Chaotic irregular deflections of varying amplitude
No identifiable P waves, QRS complexes, or T waves
Ventricular Fibrillation
EKG: Polymorphic ventricular tachycardia that appears to be twisting around a baseline
Torsades de Pointes (TdP)
Treatment of Torsades de Pointes (TdP)
IV Magnesium sulfate
EKG: Vertical spikes of short duration, usually 2 ms.
May be difficult to see in all leads
Pacemaker Rhythm with *pacing spikes”
Which antihypertensive medications can cause bradycardia?
Beta blockers
Non-dihydropyridine CCB
Central agents (clonidine)
Which antihypertensive medications can cause AV block?
Non-dihydropyridine CCB Central agents (clonidine)
What is the most likely cause of syncope which occurs in a child during an argument?
Long QT syndrome
Non-cardiac hypoxia (e.g. pneumonia, COPD) commonly causes what arrhythmia?
Atrial fibrillation
What arrhythmia can occur with structural changes such as hypertrophy or dilatation of the ventricle?
Ventricular tachycardia
What two murmurs are most associated with atrial fibrillation?
Mitral stenosis
Mitral regurgitation
What HTN med classes can cause bradycardia?
Beta Blockers
Central agents (clonidine)
Verapamil and Cardizem
What arrhythmia is associated with arterial embolism?
Atrial fibrillation
A 24 year old has a syncopal event. EKG demonstrates a short PR interval with an upswept initial QRS. What underlying condition caused the syncope?
Wolf Parkinson White
A 30 year old male has a syncopal event three days after taking an antibiotic. EKG at the scene reveals ventricular tachycardia. What disease condition do you suspect?
Acquired long QT syndrome due to the antibiotic or medications
Upon auscultation of a patient’s carotid artery they become bradycardic with a three second pause. What is the suspected underlying condition?
Carotid sinus hypersensitivity
A 13 year old boy passes out while having an argument with his principal. His examination findings are normal. What heart conduction condition do you suspect?
Long QT syndrome
Prolonged absence of sinus node activity (absent P waves) > 3 seconds
Sinus arrest
Prolonged absence of sinus node activity (absent P waves) < 3 seconds
Sinus pause
