Final answer:
Supraventricular tachycardia (SVT) is an abnormal fast heart rhythm stemming from above the heart's ventricles. It includes conditions like atrial fibrillation, atrial flutter, and paroxysmal supraventricular tachycardia, and can be associated with various systemic conditions. Diagnosis and treatment involve specific medical interventions based on the underlying cause.
Step-by-step explanation:
Supraventricular tachycardia (SVT) is a type of arrhythmia or abnormal heart rhythm. Arrhythmias arise due to problems with the electrical conduction system of the heart. Supraventricular tachycardia can include several conditions such as atrial fibrillation, atrial flutter, and paroxysmal supraventricular tachycardia. While a certain level of increased heart rate is normal during exercise, SVT occurs at rest with heart rates exceeding 100 beats per minute. Conditions that may be associated with SVT include fever, anemia, hypoxia, hyperthyroidism, excess catecholamines, certain cardiomyopathies, valve disorders, and acute radiation exposure. Though not always symptomatic, SVT can present with dizziness, shortness of breath, chest pain, or syncope. Diagnoses typically involve an electrocardiogram (ECG) or a Holter monitor. Treatments may require medications, implantable cardioverter defibrillators, ablation, or surgery, depending on the underlying cause.
Conditions external to the heart such as metabolic, endocrine, electrolyte disturbances, neurological disorders, or drug effects can also cause bradycardia, which differs from tachycardia but is likewise an arrhythmia.