Kazakhstan-Russian medical university Independent work Theme: «Tachycardia». Written by: Yusupova D. Checkend by: Abdykadyrova G.I.

Tachycardia is a heart rate that exceeds the normal range Tachycardia is a heart rate that exceeds the normal range. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia. Tachycardia can be caused by various factors that often are benign. However, tachycardia can be dangerous, depending on the speed and type of rhythm. Note that, if it is pathological, a tachycardia is more correctly defined as a tachyarrhythmia.

Symptoms of tachycardia : Dizziness Shortness of breath Lightheadedness Rapid pulse rate Heart palpitations — a racing, uncomfortable or irregular heartbeat or a sensation of "flopping" in the chest Chest pain Fainting (syncope) Some people with tachycardia have no symptoms, and the condition is only discovered during a physical examination or with a heart-monitoring test called an electrocardiogram.

An electrocardiogram (ECG) is used to classify the type of tachycardia An electrocardiogram (ECG) is used to classify the type of tachycardia. They may be classified into narrow and wide complex based on the QRS complex. Presented in the order of most to least common they are: Narrow complex Sinus tachycardia, which originates from the sino-atrial (SA) node, near the base of the superior vena cava. Atrial fibrillation Atrial flutter AV nodal reentrant tachycardia Accessory pathway mediated tachycardia Atrial tachycardia Multifocal atrial tachycardia Junctional tachycardia

Wide complex Ventricular tachycardia, any tachycardia that originates in the ventricles. Any narrow complex tachycardia combined with a problem with the conduction system of the heart, often termed "supraventricular tachycardia with aberrancy." A narrow complex tachycardia with an accessory conduction pathway, often termed "supraventricular tachycardia with pre-excitation" (e.g. Wolff–Parkinson–White syndrome). Pacemaker-tracked or pacemaker-mediated tachycardia.

Heart rate is controlled by electrical signals sent across heart tissues. Tachycardia occurs when an abnormality in the heart produces rapid electrical signals.

In some cases, tachycardia may cause no symptoms or complications In some cases, tachycardia may cause no symptoms or complications. However, tachycardia can seriously disrupt normal heart function, increase the risk of stroke, or cause sudden cardiac arrest or death.

When to see a doctor A number of conditions can cause a rapid heart rate and tachycardia symptoms. It's important to get a prompt, accurate diagnosis and appropriate care. See your doctor if you or your child experiences an tachycardia symptoms. If you faint, have difficulty breathing or have chest pain lasting more than a few minutes, get emergency care, or call 911 or your local emergency number.