2. Arrhythmia
s
Heart rhythm disorders (arrhythmias) are changes in the
normal frequency, regularity and source of cardiac
excitation, as well as disorders of conduction impulse,
communication and/or sequencing disorders between the
activation of the
of the atria and ventricles.
3. Сlassificatio
n
In accordance with the mechanism of arrhythmias, all heart rhythm
disorders can be conditionally subdivided into three types:
1) disorders of automaticity;
2) disorders of excitability;
3)conduction disorders. Such a division in a certain sense
conditional, because in reality it is often encountered
arrhythmias of a combined character.
For example, in ventricular and atrial fibrillation, both
excitability and
conduction disorders may be present.
4. 1. Disorders of
automaticity
sinus
bradycardia
sinus
tachycardia
sinus arrhythmia
Cardiac automaticity disorders are arrhythmias caused by disturbances in
the electrophysiologic activity of the cardiac pacemakers (sinus and sinus
rhythm drivers).
These arrhythmias include:
atrioventricular
tachycardia nodal
rhythm
idioventricular rhythm.
5. Sinus bradycardia is a decrease in heart
rate to 50 beats/min or less while
maintaining a normal rhythm.
The etiologic factors: inc reased vagus
nerve tone, more often - in athletes (does
not require treatment); primary lesion of
the sinus node; increased intracranial
pressure; hypothyroidism; hypothermia;
myocardial infarction of lower
localization; overdose of β-
adrenoblockers or calcium antagonists.
Sinus
bradycardia
6. Sinus tachycardia is an increase in the heart
rate of more than 100 beats per minute while
maintaining a normal rhythm.
Etiological factors: normal reaction to various
stressors (excitement, anxiety, fear, physical
activity); pathological conditions, in particular - fever,
hypotension, thyrotoxicosis, anemia, hypovolemia,
pulmonary embolism, myocardial ischemia, heart
failure, shock, mitral stenosis; taking certain
medications (atropine, catecholamines, thyroid
drugs) or some biologically active substances
(alcohol, nicotine, caffeine).
Sinus
tachycardia
7. Disorders of the excitability of the heart are the basis of such types of
arrhythmias as
extrasystoles,
ventricular tachycardia,
polymorphic ventricular tachycardia,
ventricular and atrial flutter,
ventricular and atrial fibrillation,
2. Disorders of the excitability of
the heart
8. Extrasystoles are additional
heartbeats that occur outside the
physiological heart rhythm and can
cause unpleasant symptoms.
Extrasystoles are also referred to as
skipped heartbeats, “heart hiccups“.
In most cases, the additional
heartbeats can hardly be felt, or only
very faintly. It is the next, regular,
heartbeat, which occurs later and
stronger, that is perceived as the
skipped heartbeat.
Extrasystol
e
9. Ventricular extrasystoles are premature ventricular contractions caused by the presence of a focus
of automatism in the ventricles.
Etiological factors of ventricular extrasystoles: Coronary heart disease, cardiomyopathy, electrolyte
and acid-base balance disorders, hypoxia, thyrotoxicosis, antiarrhythmics
On an ECG: premature QRS complexes that differ from normal complexes with a width of more than
0.12 s, deformation, and the presence of a previous shortened R-R interval. The T wave is enlarged,
STsegment, is discordant, i.e. directed in the other direction. Clinically, ventricular extrasystoles
manifest as a feeling of palpitation or discomfort in the chest, a feeling of heart failure
Ventricular
extrasystole
10. Atrial fibrillation is the absence of coordinated
atrial contractions, which is electrocardiographically
characterized by the isappearance of the P wave.
Atrial fibrillation leads to the cessation of
hemodynamically effective atrial contractions. It is
manifested by irregular small atrial oscillations of
various amplitudes and shapes with a frequency of
350-600 per minute, which cannot be registered on a
conventional electrocardiograph
Etiological factors: atherosclerosis, hypotension,
cardiomyopathy and rheumatic heart disease,
thyrotoxicosis
Atrial
fibrillation
11. Atrial flutter is a violation of the processes of excitation and conduction in the atria, which
electrocardiographic is characterized by the disappearance of the P wave and the
appearance instead of it of frequent low-amplitude oscillations, the so
-called F waves, which got their name from the English word flutter - oscillation. The frequency of
atrial contractions is more than 220 V min, and ventricles - 120-180 in min. QRS complexes are
normal There are tachy-, normo- and bradysystolic forms of atrial flutter.
The etiological factors are the same as in atrial fibrillation.
Atrial
flutter
12. Ventricular fibrillation (and fluttering) is a chaotic asynchronous excitation of
individual muscle fibers or their small groups with cardiac arrest and cessation of
blood circulation. These arrhythmias are the most dangerous, since they can lead
to death in the absence of emergency measures within 3-5 minutes.
On ECG is characterized by the appearance of waves of low amplitude (less than
0.2 mV) and of various shapes with a frequency from 300 to 600 v min .
Ventricular fibrillation occurs in acute coronary insufficiency, myocardial
ischemia, cardiomyopathy.
Ventricular
fibrillation
14. Paroxysmal atrial
tachycardia
Paroxysmal supraventricular tachycardia (PSVT) is a type of atrial arrhythmia. It
happens when there is abnormal electrical activity in the atria. This is caused
by an abnormally irritable area in the atria or by a short circuit in your heart
causing electrical signals to travel around and around in a circular pattern.
This causes the atria to contract quickly over and over again.
Causes
Anemia.
Ingesting drinks and foods that contain
caffeine. Drugs such as nasal decongestants
Heart attac
k
hypertensio
n
16. 3. Disorder of conduction
Conduction disorders
include transverse
heart block,
blockage of the right and/or left legs of the His bundle,
Wolf-Parkinson-White syndrome.
17. Transverse blockade
Transverse blockade is a violation of the excitation in
the area of the atrioventricular node. Transverse
blockade of the heart, in turn, is divided into
blockade I, II, III and IV degrees. The first three
degrees are also called incomplete, and the last one
is called complete transverse heart block.
18. Transverse blockade of the I degree is manifested
by a delay in the conduction of the pulse in the
atrioventricular node. Electrocardiographically, it is
characterized by an elongation of the P-Q
interval.
Transverse blockade of the 1st
degree
19. Grade II transverse blockade is characterized by the fact
that in the structure of each subsequent ECG cycle, the PQ
interval lengthens more and more until one ventricular
complex falls out (Samoilov Wenkebach periods), after which
the duration of the P-Q interval returns to normal, but
immediately begins to lengthen again. Thus, the process is
cyclical
Transverse blockade of the 2
degree
21. Transverse blockade of the III degree is expressed in the fact
that only every second or third pulse passes through the
atrioventricular node from the atria to the ventricles.
The heart rate is significantly reduced, so serious
hemodynamic disorders may occur
Transverse blockade of the 3
degree
23. Wolf-Parkinson-White syndrome . The heart muscle contracts at such a fast
rate that it has very little time to relax and fill with blood inbetween
contractions
There are three main electrocardiographic signs of WPW syndrome:
a) the P-R interval is shortened against the background of a sinus rhythm;
b) the QRS complex is "stretched" beyond the norm with a flat initial part;
c)secondary ST segment changes in which the T wave is discordant (in the
opposite direction) with respect to the QRS complex.
Wolf-Parkinson-White
syndrome
25. Management and
Treatment
Antiarrhythmic drugs that convert the arrhythmia to sinus rhythm (normal
rhythm) or prevent an arrhythmia.
Medicines that control your heart rate.
Anticoagulant or antiplatelet therapy drugs (such as warfarin or aspirin) that
reduce the risk of blood clots forming.
Medications that treat related conditions that may be causing an abnormal
heart rhythm.
