Cardiac ecg indices and transcript
Electrocardiography is a technique for recording and studying electric fields generated by the heart. Electrocardiography is a relatively inexpensive but valuable method of electrophysiological instrumental diagnostics in cardiology. A direct result of electrocardiography is an electrocardiogram (ECG).
To interpret an electrocardiogram is to evaluate the activity of the biopotential of the heart muscle. This allows the doctor to identify a rhythm frequency disorder, ischemia, ventricular hypertrophy, atria and a number of other abnormalities.
The process of ECG decoding (cardiographic pattern data) consists of measuring the length, the size of the segments and the amplitude of the oscillation of the teeth.
The study of the results of a healthy person will help to compare the data, and to identify existing heart problems in case of pathological changes.
Electrocardiography (ECG) is a non-invasive test, which allows you to obtain valuable information about the condition of the heart.
The essence of this method consists in the registration of electrical potentials arising during the work of the heart and in their graphic display on the display or paper.
Interpretation of an ECG of heart
To begin, consider the decryption plan, for this you should install:
- the nature of the heart rate and the determination of the exact value of contractions in the time interval
- cycle of cardiac biopotentials
- excitation source recognition
- conductivity evaluation
- study of the P wave and ventricular interval QRST
- designation of the axis of propagation of signals and the position of the heart relative to its
The work of the heart is determined by the emerging biopotentials.
ECG transcript is a graphical display of the intensity of a given discharge, which helps to determine malfunctions in the work of the heart departments.
The rhythm of the contractions of the heart muscle is determined by the duration of the measurement of RR intervals. If their duration is the same or marked by fluctuations of 10% - this is considered the norm, in other cases it is possible to speak of a rhythm disturbance.
ECG readings and their interpretation
Heart rate (HR)
We list the main ECG indicators that interest us on the cardiogram:
- Teeth - characterize the stages of the cardiac cycle
- 6 leads - parts of the heart, displayed in numbers and letters
- 6 pectoral - fix changes of heart potentials in the horizontal plane
PQ QRS QT Interval Displays Pulse Conductivity
After reviewing the terminology, you can independently try to decipher the results. However, we remind you that only the attending physician can make a 100% objective diagnosis.
We begin to measure the height of the teeth from the isoline — the horizontal line with a ruler, taking into account the location of the positive teeth above the straight line and negative ones — below the axis.
Their shape and size depend on the passage of an electric wave and differ in all leads. According to the automatically specified formula, we calculate the duration of the intervals and segments - we divide the distance between the segments by the tape speed.
The values of the teeth on the cardiogram
The tooth P - is responsible for distribution of an electric signal on auricles. Norm: positive value with height up to 2.5 mm.
For Q wave, pulse placement along the interventricular septum is characteristic. Rate: always negative, and often not recorded by the device due to its small size. Its manifestation is a cause for concern.
R tooth - is considered the biggest. Reflects the activity of the electrical impulse in the ventricular myocardium. His misbehavior indicates myocardial hypertrophy. The interval norm is –0.03 s.
S tooth - shows the completeness of the process of excitation in the ventricles. Standard: negative and does not exceed 20 mm.
PR interval - indicates the rate of distribution of excitation in the atria to the ventricles. Norm: fluctuation 0.12-0.2s. This interval determines the heartbeat.
T wave - reflects the repolarization (recovery) of the biopotential in the heart muscle. Norm: positive, duration - 0.16-0.24 s. Indications are informative for diagnosing ischemic abnormalities.
Interval TR - demonstrates a pause between contractions. Duration - 0.4 s.
The ST segment is characterized by maximum excitation of the ventricles. Norm: a tolerance of 0.5 -1mm downwards or upwards is acceptable.
QRST interval - displays the time period of excitation of the ventricles: from the beginning of the passage of an electrical signal to their final contraction.
Decoding ECG in children
The norms of children's testimony differ markedly from the values of adults. For ECG interpretation in children, the curve should be traced and the digital parameters of the teeth and intervals should be compared.
The norm is:
- deep Q tooth position
- sinus arrhythmia
- ventricular interval QRST susceptible to alternation (reversed polarity of T waves)
- in the atria is the movement of the source of rhythm
- as a child grows up, the number of chest leads with a negative T wave decreases
- large atrial sizes determine the height of the P wave
- The age of the child affects the ECG intervals - they become longer. In small children, the right ventricle prevails.
Sometimes the intensive growth of a baby provokes irregularities in the heart muscle that can be shown by a cardiogram.
What does the sinus rhythm on the cardiogram
ECG decoding shows sinus rhythm? This indicates the absence of pathologies, and is considered normal with a characteristic frequency of strokes from 60 to 80 per minute. with an interval of 0.22 s. Having a doctor's record of sinus rhythm irregularity implies pressure fluctuations, dizziness, chest pain.
The rhythm, marked 110 beats, indicates the presence of sinus tachycardia. The cause of its occurrence may be physical exertion or nervous excitability. This condition may be temporary, and does not imply long treatment.
With anemia, myocardium or fever, persistent tachycardia with palpitations is observed. The ECG transcript in this case determines the unstable sinus rhythm, and indicates an arrhythmia - an increased frequency of contractions of the heart departments.
For children, too, is characterized by a similar symptom, but other sources of origin. This is cardiomyopathy, endocarditis and psychophysical overload.
The rhythm can be disturbed from birth, have no symptoms, and become apparent during electrocardiography.