lec 4 Flashcards
SINUS RHYTHM means
rhythm is coming from the SA node→ heart rate is regular
Arrhythmia
abnormal rhythm OR abnormal excitation.
SINUS ARRHYTHMIA divide into four main categories
Sinus tachycardia
Sinus bradycardia
Respiratory arrhythmias
Sick sinus syndrome (SSS
Sinus tachycardia
Physiological Responses increase in the heart rate
Sinus bradycardia
Physiological Responses decrease in the heart rate
لفهم
In all sinus arrhythmia, the AP will start normally in
the SA node, with normal ECG, but the rate of
excitation will be abnormal (increased or decreased or blocked)
Respiratory arrhythmias
SINUS ARRHYTHMIA
Physiological Responses
effect of Respiratory arrhythmias on heart rate
increase the heart rate
Respiratory arrhythmias are manifested in
kids or newborn babies. (It is not that clear in the adults).
respiratory arrhythmias occur
after taking a deep inspiration
increase in inspiration
a decrease in expiration
Sick sinus syndrome (SSS)
- problem in the SA node (in the excitation).
- sss give high rate, slow rate or sinus block
- the patient sometimes loses his conscious and falls down.
we have to put an artificial pacemaker in
sinus block → Sick sinus syndrome (SSS)
Atrial arrhythmia types
- Atrial extra systole
- Supraventricular Tachycardia/ atrial tachycardia
- Atrial flutter
- Atrial fibrillation
what happen if extra excitation arrives at the heart
- in the refractory period,
- after the refractory period,
- nothing will happen
2. it will re-stimulate the heart
atrial extra systole.
one extra beat comes before the SA node normal beat, in any point in the atrium (except in the SA node)
extra one beat is called
atrial ectopic / atrial extra systole
patient feels his heart has stopped
atrial extra systole
The patient will feel as if his heart has stopped, why
extra beat comes in the resting period after a
normal beat, the refractory period of the extra beat will cancel the next normal beat coming from the SA node
because a beat is missing and there will be a
pause).
Atrial extra systole شو نوع ال
beat
premature beat \premature atria
after the premature beat there is
pause
Atrial extra systole is called
PAC: premature atrial contraction.
Supraventricular Tachycardia/ atrial tachycardia شو وضع الECG
QRS is normal
atrial tachycardia or SVT (supraventricular tachycardia) شو وضع ال Heart rate
is high, the rate will be 150 to 220 (beat/min).
atrial tachycardia or SVT (supraventricular tachycardia).
T will come closer to the P
T on P
atrial tachycardia or SVT (supraventricular tachycardia).
the patient is watching TV at rest, he feels
tachycardia for few minutes then it’ll stop
atrial tachycardia or SVT (supraventricular tachycardia)
SVT ECGs
Regular (R-R interval are the same, and the ratio between P, QRS and T is 1:1:1) {BUT the rate is high}.
atrial tachycardia or SVT (supraventricular
tachycardia) كم beat / rate
150 to 220 (beat/min)
Atrial flutter ECG
RR interval in between Three excitation in atrium (3 p) + one in ventricle (1 normal QRS)
Repeated P wave in constant frequency (regular). (Here you
can notice 3 P then 1 QRS then 1 T repeatedly).
ECG is abnormal.
QRS is always normal.
P waves more than QRS (and it is more than 220 P/minute).
RR interval is regular.
Atrial fibrillation The heart rate
more than 250 beat/min
Atrial fibrillation ECG
three excitation (3 p) in atrium + one in ventricle
(1 normal QRS); THEN five excitation (5p) in atrium + one in
ventricle (1 normal QRS) {NOT REGULAR OR irregular}.Atrial fibrillation ECG
P is repeated in different frequencies (irregular) {abnormal
ECG} in atrial fibrillation.
QRS is always normal.
In atrial fibrillation, the P wave will be very shallow and
sometime absent, you can see too many P waves, and R-R
interval is irregular. (Note that the R-R interval is regular
in atrial flutter).
MOST common arrhythmia that develops in a normal hearT
Atrial fibrillation
the only type of atrial arrhythmia with irregular R-R
interval is
the atrial fibrillation.
Atrial fibrillation اكتر اشي خطر فيها
the blood in the atria will stay there because there is no time for pumping, leading to a clot.
And after atrial fibrillation is over, this clot will pass in the blood resulting in a cerebrovascular accident {CVA} (leading to paralysis).
anticoagulant give to
atrial fibrillation patients
N.B
الجدزل صفحة 8
the different between atrial flutter and fibrillation
flutter the beats are more than 220 but going in
one pathway (starting and ending at the same point)
2.fibrillation there are so many points that generate
excitation at the same time so some of them cross to the AV
node while other can’t if the AV node is in refractory period
