QRS wide malformation

Introduction Ventricular tachycardia refers to a tachycardia composed of more than 3-5 wide deformed QRS waves originating from the His bundle bifurcation. QRS complex: represents the potential and time changes of the biventricular depolarization and the earliest repolarization process.

Cause

Can be caused by heart surgery, cardiac catheterization, severe myocarditis, congenital heart disease, infection, hypoxia, electrolyte imbalance and other reasons. However, in many cases, the cause is not easy to determine.

1QRS wave group time: 0.06 to 0.10 seconds for normal adults and 0.04 to 0.08 seconds for children. The chamber wall activation time of the V1 and V2 leads is less than 0.03 seconds, and the chamber wall activation time of V5 and V6 is less than 0.05 seconds. QRS group time or prolongation of ventricular wall activation time is common in ventricular hypertrophy or intraventricular block.

2QRS wave group amplitude: The R wave of the aVL lead in the pressurized monopolar limb leads does not exceed 1.2 mV, and the R wave of the aVF lead does not exceed 2.0 mV. If this value is exceeded, it may be left ventricular hypertrophy. The R wave of the aVR lead should not exceed 0.5 millivolts. Above this value, it may be right ventricular hypertrophy. If the six limbs lead each QRS complex voltage (the arithmetic sum of R+S or Q+R) is less than 0.5 mV or the arithmetic sum of each preamble QRS voltage does not exceed 0.8 mV, called low voltage Found in emphysema, pericardial effusion, systemic edema, mucous edema, myocardial damage, but also seen in a very small number of normal people. The amplitude of the individual lead QRS complex is small and meaningless.

an examination

Related inspection

Blood routine electrocardiogram

(1) Electrocardiogram diagnosis: Although many ECGs are abnormal from the perspective of other electrocardiograms, they may not have clinical cardiac organic changes. At this time, they can directly write their ECG diagnosis, such as ventricular premature contraction, low voltage, Non-specific ST, T changes, etc. So that the clinician can judge whether there is pathological significance in combination with clinical manifestations.

(2) Comply with clinical diagnosis: Some comprehensive ECG changes can be consistent with clinical diagnosis.

(3) Comprehensive clinical diagnosis: ECG diagnosis must be closely combined with clinical data, especially if some ECGs are not specific, they need to be combined with clinical data. In addition, drug and electrolyte disorders must also be combined with clinical data to determine the damage to the myocardium.

(4) Follow-up observation of ECG changes: For example, an electrocardiogram of an acute myocardial infarction must be repeatedly diagnosed by electrocardiogram, and sometimes it is more accurate to refer to the past ECG based on its dynamic evolution.

Differential diagnosis

(1) P wave: The excitation of the heart originates from the sinus node and then reaches the atria. The P wave is produced by the atrial depolarization and is the first wave in each wave group. It reflects the depolarization process of the left and right atrium. The first half represents the right room and the second half represents the left room.

(2) QRS complex: A typical QRS complex consists of three closely connected waves. The first downward wave is called a Q wave. A high-point vertical wave following the Q wave is called an R wave. The backward wave is called the S wave. Because they are closely connected and reflect the process of ventricular electrical activation, they are collectively referred to as QRS complexes. This wave group reflects the depolarization process of the left and right ventricles.

(3) T wave: The T wave is located behind the ST segment and is a relatively low and long-lasting wave, which is produced by the ventricular repolarization.

(4) U wave: U wave is located after T wave, which is relatively low and its mechanism is not completely clear. It is generally considered to be the "excitation potential" of myocardial activation.

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