Charpter 1 Flashcards
Basics
Time of large block
0,2 sec
Time of small block
0,004 sec
Voltage of 1 big block
0,5 mV
P wave
atrial depolarization
QRS complex
ventricular depolarization and contraction
T wave
ventricular repolarization
HR
1) 300/large blocks R-R
2) 1500/small blocks R-R
3) number of QRS over a 6-second interval and multiply by 10
P wave duration
0.06-0.12 seconds (1.5 to 2.75 small boxes)
P wave amplitude
0.05 to 0.25mV (0.5 to 2.5 small boxes)
The PR Interval
the interval from where the P wave begins until the beginning of the QRS complex
The PR interval duration
0.12 to 0.20 seconds (3 to 5 small boxes)
the QRS duration
0.06 to 0.12 seconds (1.5 to 3 boxes)
The QT interval
from the beginning of the QRS complex to the end of the T wave
The QT duration
0.36 to 0.44 seconds (9-11 small boxes)
Standart voltage
10 mm/mV
irregular rhytm
If the rhythm varies by two small boxes or more
Sinus Bradycardia
rate will be less than 60 bpm
sinus tachycardia
rate exceeding 100 bpm
Sinus Dysrhythmia
It is commonly seen in young healthy people and athletes. It is frequently related to breathing and pressure on the vagus nerve. As the patient inhales and the lungs expand, pressure is applied to the vagus nerve which causes a parasympathetic response and a decrease in heart rate.
sinus exit block
The duration of the pause with Sinus Exit Block is in a direct multiple of the R to R interval of the underlying rhythm. Sinus Arrest does not have this specific feature.
Premature Atrial Complex (PAC)
przedwczesne pobudzenie przedsionkowe
- abnormal P wave
- usually followed by a normal QRS complex
- rytm niemiarowy,
- przerwa po PAC krótsza od przerwy wyrownawczej
PAC types
Bigeminy — every other beat is a PAC
Trigeminy — every third beat is a PAC
Quadrigeminy — every fourth beat is a PAC
Couplet – two consecutive PACs
Triplet — three consecutive PACs
Causes of PACs
Anxiety
Sympathomimetics
Beta-agonists
Excess caffeine
Hypokalaemia
Hypomagnesaemia
Digoxin toxicity
Myocardial ischaemia
Wandering Atrial Pacemaker (WAP) -cause
wędrowanie rozrusznika
electrical impulses causing the atrial activity are moving or wandering
WAP - EKG
at least three distinctly different P wave morphologies and a ventricular rate of less than 100 bpm
Multifocal Atrial Tachycardia - cause
A rapid, irregular atrial rhythm arising from multiple ectopic foci within the atria.
Most commonly seen in patients with severe COPD or congestive heart failure.
Multifocal Atrial Tachycardia - EKG
-Heart rate > 100 bpm (usually 100-150 bpm; may be as high as 250 bpm).
-Irregular rhythm
-At least 3 distinct P-wave morphologies in the same lead.
-Isoelectric baseline between P-waves (i.e. no flutter waves).
-Absence of a single dominant atrial pacemaker (i.e. not just sinus rhythm with frequent PACs).
Atrial flutter -EKG
- Narrow complex tachycardia
- Regular atrial activity at ~300 bpm
- Loss of the isoelectric baseline
- “Saw-tooth” pattern of inverted flutter waves in leads II, III, aVF
AF - the ratio of F waves
Atrial Flutter 4:1 (indicates 4 “F” waves to each QRS complex)
Anticlockwise Reentry AF
Commonest form of atrial flutter (90% of cases).