00:01
So arrhythmia can also be equivalent
to dysrhythmia, whichever one you like.
00:05
I tend to say arrhythmia, but whatever.
00:08
Irregular heartbeat is due to a disorder of
either impulse production, impulse conduction,
or in some instances, can be both.
00:18
So general categories of arrhythmia,
it can be sustained just ongoing.
00:23
So you can have patients who are
in chronic atrial fibrillation.
00:29
It can be intermittent.
00:31
So you can have paroxysmal atrial fibrillation
comes and it goes, depending on
circumstances within the myocardium.
00:40
Okay.
00:41
It can be a supraventricular arrhythmia.
00:44
So things that are originating
from the atrium shown in green.
00:48
It can be a ventricular arrhythmia
originating from ventricular myocardium.
00:56
Among the other general categories
is can it be fast or slow?
So the normal heart rate is somewhere
between 16 and 100 beats per minute,
and it's a regular rhythm.
01:10
Now, you can have bradycardia, a slower
heart rate, less than 60 beats per minute.
01:14
Bump, bump, bump.
01:19
But it's regular.
01:24
You can have tachycardia, a faster heart
rate, greater than 100 beats per minute.
01:29
Again, bump, bump, bump, bump,
bump, bump, bump, bump, bump.
01:33
a regular rhythm, but it's just faster.
01:36
And we have used those terms,
normal bradycardia, tachycardia.
01:46
You can have an irregular rhythm with
a normal ventricular contraction.
01:50
In this case, this is due to atrial fibrillation,
So the atria are quivering for whatever reason,
and it's usually because
the atria has been dilated.
01:58
And so the conduction fibers, those
internodal pathways are stretched,
and we get irregular conduction through
them down to the atriventricular node.
02:06
So the atria are quivering, they're not squeezing.
02:08
They don't make that nice 10 to
15% ejection into the ventricles.
02:13
The signal going through the AV
note intermittently goes through.
02:17
So sometimes it goes through.
02:19
Sometimes we're in a relative refractory
period and it doesn't go through.
02:22
So the rhythm of this can be anything
from bradycardic normal rhythm,
normal kind of intervals between
60 and 100 beats per minute
or can be tachycardic, but it
will be irregularly, irregular.
02:37
So regular beat, bump, bump, bump, bump.
02:40
Atrial fibrillation,
Bump, buh-bump, bump, bump,
buh-buh-buh-buh-bump, bump, bump, bump,
So it's irregularly irregular.
02:56
You can also have ventricular fibrillation.
02:58
This is a lethal arrhythmia.
03:00
Basically, the ventricle is now quivering,
kind of like the atrium did before,
for a variety of reasons.
03:05
The ventricle, when it quivers,
doesn't squeeze blood out at all.
03:09
And now we're not going to be
able to perfuse the brain.
03:11
And within 2 to 3 minutes, the
patient will unfortunately die.
03:16
And then there is no contraction asystole, okay.
03:20
And basically it just means
no systole, no contraction
Signs and symptoms of arrhythmia.
03:29
So patients may be totally asymptomatic.
03:32
Clearly, if they're in ventricular
fibrillation, they're going to be symptomatic.
03:36
But we have patients who are
bradycardic, don't know it.
03:38
Patients who are tachycardic
don't necessarily feel that.
03:41
Patients who are in chronic atrial
fibrillation may be totally unaware of that.
03:46
So it depends on the sensitivity of
the patient and other circumstances,
whether they are aware that they have it.
03:52
It can be symptomatic.
03:54
Patients perceive that there's irregular heartbeat
and if they actually are
measuring their heart rate, they
may sense that it's irregular
or that it's going really, really fast.
04:04
There may be a sensation in the chest
of their heart leaping out of their chest.
04:09
Those are called palpitations.
04:12
depending on the degree of the dysfunction
in terms of the cardiac output,
if you have ventricular fibrillation,
you may not be getting adequate
flow down the coronary arteries, clearly,
which will lead to chest pain or pressure.
04:29
You're having an anginal symptom
as a result of arrhythmias.
04:32
And in some cases of atrial fibrillation
with a rapid ventricular response
where you have AFib that's then getting
conducted through the AV node very quickly,
you can have heart rates of 150 to 180.
04:45
Patients who have coronary atherosclerotic disease,
that may actually get them into a situation
where there is a greater demand than there is a
supply so you can have chest pain or pressure.
04:56
They may be short of breath and again,
this is related to ischemic heart disease,
and then a subsequent left
ventricular dysfunction.
05:05
They may be light headed so if
they're extremely bradycardic
say, for example in the 20s to 30s they
may not be providing adequate perfusion,
especially when they're
standing upright, to their brain.
05:17
They may feel like they're going to pass out
or they may formally lose consciousness,
may have syncope.
05:23
Similarly, if you have atrial fibrillation with
a very high rapid ventricular response rate,
you may be lightheaded, you're just
not, you're beating so quickly with
not much ejection fraction that
you're not perfusing your brain.
05:37
So that can lead to loss of consciousness.
05:40
And clearly in the symptomatic
category of sudden cardiac death where
the QRS complex, the normal electrical
activity, heart ceases altogether.
05:51
Okay, yeah, I'd say that's symptomatic.