Ischemic polymorphic ventricular tachycardia

Introduction to ischemic polymorphic ventricular tachycardia Ischemic polymorphic ventricular tachycardia (IPVT) is a type of QT interval normal polymorphic ventricular tachycardia. When ventricular tachycardia occurs, there may be palpitations, chest tightness, dizziness, and even syncope, A-S syndrome, and sudden death. This type of ventricular tachycardia is unstable. The episode is short-lived and often develops rapidly into ventricular fibrillation, and the incidence of sudden death is high. basic knowledge The proportion of sickness: 0.01% Susceptible people: no specific population Mode of infection: non-infectious Complications: syncope, angina, A-S syndrome, heart failure

Ischemic polymorphic ventricular tachycardia

(1) Causes of the disease

This type of ventricular tachycardia is mostly seen in coronary heart disease, with or without acute myocardial infarction, myocardial damage in coronary heart disease, may or may not have acute myocardial ischemia, may be associated with patients with variant angina, a small number of causes Other causes, such as cardiomyopathy, ventricular hypertrophy, mitral valve prolapse, etc., due to its variable condition, short episodes and high rate of sudden death, clinically rare, therefore, there is little in-depth study of such ventricular tachycardia, The true incidence is also unclear.

(two) pathogenesis

The mechanism of occurrence is still unclear, and stimulation before the procedure can trigger polymorphic ventricular tachycardia. In patients with long QT prolongation syndrome, pre-procedural stimulation rarely induces polymorphic ventricular tachycardia. Overspeed, which is the difference between the two, may be a reentry mechanism, related to local conduction delay, and some patients can also be converted into persistent monomorphic ventricular tachycardia.

Ischemic polymorphic ventricular tachycardia prevention

1. Active treatment of primary diseases is a fundamental measure for the prevention of this type of arrhythmia.

2. Patients with ventricular tachycardia should be promptly controlled for frequent ventricular premature contraction, avoiding the use of drugs known to induce ventricular arrhythmias, while actively correcting certain risk factors such as hypokalemia, hypomagnesemia, and heart failure.

3. Frequent seizures, long duration, and hemodynamically unstable ventricular tachycardia should prevent recurrence.

Ischemic polymorphic ventricular tachycardia complications Complications, syncope, angina, A-S syndrome, heart failure

Common complications of ischemic polymorphic ventricular tachycardia are syncope, angina pectoris, sudden cardiac death, A-S syndrome and heart failure.

Ischemic polymorphic ventricular tachycardia symptoms common symptoms chest pain sudden death syncope chest tightness ventricular fibrillation tachycardia myocardial infarction palpitations angina pectoral dizziness

At the onset of ventricular tachycardia, there may be palpitations, chest tightness, dizziness, and even syncope. A-Syst syndrome, sudden death, unstable ventricular tachycardia, short-lived, often rapidly develop into ventricular fibrillation, syncope The incidence of sudden death is high, and there are still symptoms of the primary disease, such as acute myocardial infarction or variant angina, which may be accompanied by severe chest pain.

Ischemic polymorphic ventricular tachycardia

ECG examination features

(1) ventricular tachycardia is pleomorphic: some can be pointed torsion ventricular tachycardia, QRS wave widened, deformed, time limit > 0.12s.

(2) The ventricular rate is 150 to 300 times/min: the rhythm is not uniform.

(3) It can be repeated: the duration of each episode is uncertain, and the short one can return to normal after 1~2 minutes.

(4) Intermittent QT interval, T wave, U wave are normal: no long-short circumference or very short-term intertemporal ventricular premature contraction induced, but R-on-T ventricular phase can be seen Pre-contraction, no slow heart rhythm occurs.

(5) Pre-procedural stimulation can induce polymorphic ventricular tachycardia.

(6) Electrocardiographic findings that may be associated with myocardial ischemia.

Diagnosis and diagnosis of ischemic polymorphic ventricular tachycardia

diagnosis

1. ECG characteristics

Ventricular tachycardia is pleomorphic, and some can be apical torsion ventricular tachycardia, QRS wave widening, deformity, time limit >0.12s; ventricular rate is 150-300 beats/min, arrhythmia interval QT interval, T wave, U wave are normal, no long-short circumference or extremely short intertemporal ventricular premature contraction induced, but R-on-T ventricular premature contraction, no slowness Heart rhythm can occur with ECG findings of myocardial ischemia.

2. More history of ischemic heart disease.

Differential diagnosis

Ischemic polymorphic ventricular tachycardia and other polymorphic ventricular tachycardia are more difficult to identify, often identified with the following arrhythmias:

1. Need to be differentiated from general ventricular tachycardia or ventricular fibrillation. The general ventricular tachycardia is characterized by a series of broadly fixed wide QRS waves. The ST segment and T wave can be identified, often do not stop by themselves; the general ventricular tachycardia can also be early by RonT room. Induced, but the interval between the early chambers is short, the QRS wave and the ST segment and the T wave cannot be recognized during ventricular fibrillation, the ventricular rate is greater than 300 beats/min, extremely irregular, generally does not terminate by itself, the cardioversion is effective, and ischemic Polymorphic ventricular tachycardia is pleomorphic, and some can be torsades de pointes ventricular tachycardia, QRS wave widens, deformity, time limit >0.12s; ventricular rate is 150-300 beats/min, irregular rhythm Intermittent QT interval, T wave, U wave were normal, no long-short circumference or extremely short intertemporal ventricular premature contraction induced, but R-on-T ventricular premature contraction, There is no slow heart rhythm, which can be accompanied by electrocardiogram manifestations of myocardial ischemia.

2. Need to distinguish from other polymorphic ventricular tachycardia and ventricular fibrillation The following two points are helpful for differential diagnosis:

On the electrocardiogram before or just after the onset of ventricular tachycardia, if there is a prolongation of the QT interval and the presence of U waves, a relatively long interphase interval, or a typical induction sequence (long-short circumference), Then support TDP.

The clinical situation when 2-ventricular tachycardia occurs is helpful for differential diagnosis.

3. The disease should be differentiated from the symptoms of paroxysmal syncope and sudden death, such as intermittently dependent TDP, pre-excitation syndrome with extreme atrial fibrillation, idiopathic ventricular fibrillation, Brugada syndrome, sick sinus syndrome and epilepsy Isotopic identification should exclude the extension of secondary QT interval.

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