tachykardii

Tachykardii, commonly referred to as tachycardia, is a condition characterized by an abnormally fast heart rate. In adults, a resting heart rate above 100 beats per minute is generally considered tachycardic. Tachycardia can be a normal response to exercise, stress, fever, or dehydration, or it can reflect an underlying medical condition. When rapid heartbeats occur, the heart may not have enough time to fill properly, reducing cardiac efficiency.

Tachycardia can be categorized as sinus tachycardia, where the sinus node drives the faster rate, or as a tachyarrhythmia arising from electrical circuits or ectopic beats. Common clinically important tachyarrhythmias include atrial fibrillation with rapid ventricular response, atrial flutter, atrial or junctional tachycardias, and ventricular tachycardia. Some tachycardias are paroxysmal, starting and stopping suddenly, while others are persistent.

Causes are broad and include physiological factors (exercise, fever, anxiety, pain, sympathetic stimulation) and pathological conditions such as anemia, hyperthyroidism, heart failure or ischemia, pulmonary disease, electrolyte disturbances, and intoxication with caffeine, alcohol, stimulants, or certain drugs.

Diagnosis relies on clinical assessment and an electrocardiogram (ECG). Additional testing may include blood tests, echocardiography, and ambulatory monitoring (Holter or event recorder) to characterize rhythm, assess heart structure and detect underlying triggers.

Management depends on stability, rhythm type, and underlying cause. In unstable patients, urgent synchronized electrical cardioversion is indicated. For stable tachycardias, vagal maneuvers can be tried, followed by medications such as adenosine for certain atrioventricular nodal reentrant tachycardias, or rate-controlling drugs like beta-blockers or non-dihydropyridine calcium channel blockers. In some cases, antiarrhythmic drugs or catheter ablation may be considered, and treatment of the underlying condition is essential.

Prognosis varies with the cause; tachycardia due to transient physiological factors is usually self-limited, while tachyarrhythmias associated with structural heart disease carry higher risk and may require ongoing management.