Sinus Tachycardia. Help us improve our data based on your experience.
Specialty scores for Sinus Tachycardia
Sinus tachycardia is a sinus rhythm with an elevated rate of cardiac impulses, defined as a rate more than 100 beats per minutes in an average adult. Also known as fast heartbeat, sinus tachycardia occurs because of rapid firing by the sinoatrial node (SA node). Sinus tachycardia is a rapid contraction of heart in response to a myriad of conditions, physiological and pathological.
Sinus tachycardia is generally a normal response to normal physiological situations, such as physical exercise and increased catecholamine release in the conditions of stress, fright, nervousness, flight, anger and anxiety. Other causes of sinus tachycardia include pain, fever, dehydration, malignant hypothermia, hypovolemia, hypotension, shock, anemia, heart failure, hyperthyroidism, mercury poisoning, acute coronary ischemia, myocardial infarction, kawasaki disease (inflammation in the walls of some blood vessels), pheochromocytoma (neuroendocrine tumor of the medulla of the adrenal glands), sepsis, pulmonary embolism, chronic obstructive pulmonary disease, cardiomyopathy, myocarditis, hypoxia, intake of stimulants such as caffeine, nicotine, cocaine, or amphetamines, hyperdynamic circulation, electric shock, withdrawal of certain drugs, porphyria, acute inflammatory demyelinating polyradiculoneuropathy (autoimmune process characterized by progressive areflexic weakness and sensory changes), various cancers, leukemia, and postural orthostatic tachycardia syndrome.
Signs and symptoms:
Sinus tachycardia is associated with an array of signs and symptoms, such as shortness of breath, lightheadedness, rapid pulse rate, racing, uncomfortable or irregular heartbeat or a sensation of flopping in the chest, chest pain & fainting episode.
Sinus tachycardia is usually apparent on the ECG, but if heart rate goes above 140 beats per minute the P wave may be difficult to distinguish from the previous T wave. ECG characteristics include heart rate greater than or equal to 100 per minute, regular rhythm, upright P waves, PR interval between 0.12-0.20 seconds which shortens with increasing heart rate & QRS complex less than 0.12 seconds and normal in morphology.
No treatment is required for physiologic sinus tachycardia. Management includes treatment of underlying causes if present. Sinus tachycardia secondary to cardiac ischemia may be treated with beta blockers unless specifically contraindicated. Beta blockers are useful if sinus tachycardia is due to sympathetic overactivity. If sinus tachycardia is due to decreased vagal activity, it may require radiofrequency catheter ablation.