From this article you will learn: what is the sinus rhythm of the heart, what can its deviations be, learn how to determine the signs of a normal and pathological sinus rhythm from the ECG.
- The concept and characteristics of sinus rhythm
- What may be the violations of
- How does the sinus rhythm look like in norm and with deviations
By the sinus rhythm of the heart is meant the regular contraction of all parts of the myocardium due to exciting electrical impulses from the sinus node - the most important driverrhythm in the heart. This means that the heart rhythm of every healthy person is sinusoidal.
For a qualified ECG transcript, during which the heart rate is first evaluated, contact a cardiologist.
The concept and characteristics of sinus rhythm
The heart is the central organ of the circulatory system. It shrinks automatically, independently, and as long as it happens - the body maintains vitality. Autonomous activity is possible due to the accumulation of special nerve cells in certain parts of the heart. The largest cluster is called the sinus node. It is located in the upper part of the heart and regularly produces spontaneous strong electrical impulses, which, passing through all parts of the myocardium, cause its consequent contraction. This phenomenon is the basis of regular normal heartbeats.
Sinus rhythm is an indicator of the electrocardiogram( ECG), which says that the heart is contracted by the impulses coming from the sinus node. If this ECG indicator is in order, then it means that the main pacemaker is healthy and has enough strength to suppress other foci of spontaneous electrical activity( small and less active nodes that are in the myocardium).
Description of the main characteristics of normal heartbeats:
- Frequency - in the range from 60 to 90 / minute.
- Regularity - each subsequent heartbeat occurs at regular intervals.
- Sequence - each reduction runs in the same direction, sequentially capturing first the atria and then the ventricles, which is reflected by the peculiarities of the sound of the first and second tones, and also on the ECG.
- Physiological variability - the ability to change the heart rate with stored regularity and consistency in response to external and internal influences( eg, load, sleep, experience, pain, body temperature rise, etc.)
What can be a violation of
Even if ECG signs are registeredsinus rhythm, this does not mean that there can not be any abnormalities in the body. It is possible that impulses occur in the main node, but do not correspond to normal characteristics. The most common violations are listed in the table.
| Nature of change | Possible medical names and illnesses | Too frequent contractions( more than 90 / min) | Sinus tachycardia |
|---|---|---|---|
| Too rare contractions( less than 60 / min) | Sinus bradycardia | ||
| Irregular heartbeats | Arrhythmia - irregular contractions with a normal frequency | ||
| Extrasystole - spontaneousextraordinary pulses between regular contractions | |||
Syndrome of sinus node weakness:
| |||
| Too regular rhythm | Rigidity of heartbeats - no myocardial response to any external influences |
Sinus rhythm disorders can be both a variant of the norm and a signal of a serious pathology!
How does the sinus rhythm look on the ECG in the norm and with the deviations
An electrocardiogram( ECG) is a reflection of the electrical activity of the heart, recorded on paper in the form of a graphic. It is recorded from different parts of the body( limbs) and the region of the heart. In order to determine the sinus rhythm, standard leads are used( indicated by Roman numerals I, II, III - first, second, third).
You need to pay attention to such elements of the ECG:
- tooth P;
- interval P-Q;
- QRS complex;
- intervals Р-Р;
- intervals R-R;
- heart rate.
How does the record of the normal sinus rhythm
appear? Piper P and P-Q interval
- Always pointing upwards( positive P).
- Small in size compared to the largest tooth R.
- Precedes each QRS complex.
- Between each P and QRS there should be a small, but the same interval - the P-Q interval( if not, this may indicate a disease such as Wolff-Parkinson-White syndrome( WPW)).
QRS complexes and R-R-R intervals
- In all QRS complexes, the largest R teeth should be facing upward.
- The distance between the teeth R( intervals R-R-R) should be the same.
Interval RR
The distance between the adjacent teeth P must be the same and the same as the R-R.
How the sinus rhythm pathology looks on the ECG
Sinus tachycardia
Sinus bradycardia
Sinus arrhythmia
In arrhythmia, the heart is shortened by excitation from the sinus node, but irregularly, irregularly with:
- normal frequency;
- acceleration of heart rate;
- slowing down the rhythm.
Sinus extrasystole
If the heart performs an unpredictable extraordinary reduction due to an additional impulse from the main pacemaker, then on the ECG:
- The sinus rhythm is traced, but incorrect - another QRS complex appears prematurely.
- The tooth P must be, but sometimes it may be absent.
- The QRS complex looks unchanged.
- After extrasystoles for a long time there is no next complex - this is called compensatory pause, which is twice the pause between normal complexes.
Syndrome of weakness of the sinus node
ECG is an informative method for assessing the heart rate. To make a final conclusion on an electrocardiogram, only a specialist who knows not only the standard deviations from the norm, but also all possible variants of them!
