Takykardiat

Takykardiat, or tachycardia, is a condition defined by a heart rate that is faster than normal at rest. In adults, a resting heart rate above about 100 beats per minute is commonly used to define tachycardia. It can result from normal physiological responses, such as exercise or fever, or from medical conditions affecting the heart or the autonomic nervous system.

Two broad categories are sinus tachycardia and tachyarrhythmias. Sinus tachycardia occurs when the sinus node increases the rate but the rhythm remains regular. Tachyarrhythmias are abnormal rhythms that originate from atrial or ventricular tissue and include supraventricular tachycardia, atrial fibrillation with rapid rate, atrial flutter, ventricular tachycardia, and other reentrant or focal arrhythmias.

Common causes include physiological stress (exercise, pain, anxiety), fever, dehydration or anemia, hyperthyroidism, stimulant drugs, alcohol withdrawal, and substances like caffeine or nicotine. Cardiac conditions such as ischemia, heart failure, valvular disease, or electrolyte disturbances can also provoke tachycardia.

Many cases of sinus tachycardia are asymptomatic; symptomatic tachycardia may cause palpitations, lightheadedness, shortness of breath, chest discomfort, or fainting, depending on duration and underlying cause.

Diagnosis relies on electrocardiography showing the heart rate and rhythm. Additional tests may include blood work, thyroid function, imaging, and ambulatory monitoring to assess persistent or intermittent tachycardia and to determine the underlying cause.

Management focuses on treating the underlying cause and controlling heart rate. Acute management for unstable tachycardia may require synchronized cardioversion. Vagal maneuvers and medications such as beta-blockers or calcium channel blockers may be used for stable sinus tachycardia or SVT; antiarrhythmic drugs or electrical cardioversion may be needed for VT or atrial fibrillation with rapid response. In selected cases, catheter ablation is curative. Chronic management includes addressing thyroid disease, electrolyte imbalances, and lifestyle factors.

Prognosis varies; physiologic tachycardia resolves with resolution of the trigger, whereas persistent tachycardias can lead to tachycardia-induced cardiomyopathy and increase risk of complications, especially with certain arrhythmias.