What is inappropriate sinus tachycardia? Cardiology Basics

What is inappropriate sinus tachycardia? Cardiology Basics Inappropriate sinus tachycardia (IST) is sinus tachycardia inappropriate to the situation. It is defined as sinus rates above 100 beats per minute at rest or average sinus rate above 90 beats per minute over 24 hours without an underlying cause. Important secondary causes of sinus tachycardia like the use of caffeine, alcohol, nicotine, drugs of abuse like cocaine, increased function of thyroid gland, fever, anxiety, pain, and other illnesses which can increase the heart rate have to be excluded before considering IST. IST may be either asymptomatic or sometimes associated with palpitation, shortness of breath, near syncope, chest pain, anxiety, or exercise intolerance. In addition to resting sinus tachycardia, an exaggerated response to even minimal exertion or stress are often noted in IST. A condition with similar symptoms is postural orthostatic tachycardia syndrome (POTS). But symptoms of POTS are generally induced only by getting up from lying down or sitting position while those of IST can be induced by any effort and emotional stress. Different types of medications have been used to slow the heart rate in IST. Medications can improve the exercise tolerance of patients with IST significantly. In a study from Mayo Clinic, it was noted that about 90% of their patients with IST were females. The average age of the patients was about 33 years. In a small percentage of patients, a triggering event like pregnancy or ...
Source: Cardiophile MD - Category: Cardiology Authors: Tags: General Cardiology Source Type: blogs