Clinical-Heart Block- Brandecker Flashcards
Which bundle conducts over to the left atrium from the right?
Bachman’s bundles
What is arrhythmia?
Any rhythm that is NOT normal sinus rhythm
What are the criteria for normal sinus rhythym?
originates from the sinus node in the right atrium.
Heart rate needs to be in the normal range (60 – 100).
Rate needs to be regular.
Normal upright P waves in lead 2
Which type of arrhythmia is normal in young healthy patients
demonstrates a Slight beat to beat variation
demonstrates heart rate increases on inspiration and slows down during expiration
sinus arrhythmia
As patients get older, they can develop which pathology which results in HR that is innappropriately fast or slow or results in a pause?
Sinus pause/sick sinus syndrome
Sinoatrial exit block is felt to be due to the impulse that in the SA node that is unable to exit the SA node and stimulate the . They basically result in the same process and there is a lack of P and wave. If the pauses is long enough the patient can have a loss of .
originates
atria
QRS
consciousness.
What is the treatment for Sinoatrial exit block?
Treatment will be pacemaker.
If the pause is too long in a sinoatrial exit block, it can result in what?
syncope (loss of consciousness) and is treated with pacemaker
There can be sinus arrest after episodes of atrial fibrillation that can result in .
paroxysmal
syncope
What is the first back up if SA node fails (60 - 100 bpm)?
AV node at 35-60 bpm
What is the next back up if SA and AV node fails or are blocked?
Purkinje cells (25-35 bpm) and Ventricular myocytes 35 bpm or less
What is overdrive suppression?
The fastest pacemaker (normally SA) sets the pace
What could it mean if the P wave maybe inverted, buried(not seen) or after QRS?
escape beats from AV node (AV junctional, junctional) taking over
-atria and ventricles may may be depolarized at same time
If the AV node produces an escape rhythm (35 to 60 bpm), how will the QRS interval appear?
QRS will appear normal since signal is originating in the AV node.
If the AV node produces an escape rhythm (35 to 60 bpm), how will the P wave appear?
The P wave is usually in the opposite direction from the normal P wave and can oftentimes be buried in the QRS complex.
Why can a P wave appear after the QRS complex in juncitonal escape rhythm?
nodal stimulus is frequently conducted back into the atria and a P wave and atrial contraction can occur.
How would you know if you have junctional tachycardia (AV node tachycardia) in an ECG?
no p waves (in lead II) or retrograde p waves in lead III
What is the bpm of a junctional (AV nodal) escape rhythm?
40-60bpm
What bpm is considered an accelerated junctional rhythm?
60-100bpm
What bpm is considered junctional tachycardia?
100+ bpm AV nodal rhythm
Slow rate of 35 beats/min could indicate which type of rhythm?
Can be seen after cardiac arrest
IDIOVENTRICULAR ESCAPE RHYTHM or from cardiac myocytes in ventricles (wide complex originating deep in ventricles)
What could a wide QRS complex indicate?
rhythm origination deep in ventricles
What would an accelerated idioventricular rhythm look like?
faster than 35 bpm, deep QRS complex, can occur after given thrombolytics or after an artery opened in cath lab
Can accelerated ACCELERATED IDIOVENTRICULAR RHYTHM perfuse the heart?
yes
What is the normal QRS duration?
Normal QRS duration equal to or < 120 milliseconds (ms)
What will happen to the normally left leaning vector axis in a right bundle branch block?
depolarization will take longer in the right ventricle and the forces at the end of the depolarization will be directed to the right ventricle.
What happens if there is a delay in ventricular signal due to bundle branch block?
-depolarization takes longer which widens QRS >100 ms and the QRS axis may change and the vector may shifted to last part of ventricles to be depolarized
What is the time frame of QRS complex to indicate a BBB?
BBB QRS complex > 120 ms (3 boxes)