Inappropriate sinus tachycardia (IST) is a rare type of cardiac arrhythmia within the category of supraventricular tachycardia (SVT). IST may be caused by the sinus node itself having an abnormal structure or function, or it may be part of a problem called dysautonomia, a disturbance and/or failure of the autonomic nervous system. Research into the mechanism and etiology (cause) of inappropriate sinus tachycardia is ongoing. IST is viewed by most to be a benign condition in the long-term. Symptoms of IST, however, may be distracting and warrant treatment. The heart is a strong muscle and typically can sustain the higher-than-normal heart rhythm, though monitoring the condition is generally recommended. The mechanism and primary etiology of inappropriate sinus tachycardia has not been fully elucidated. An autoimmune mechanism has been suggested, as several studies have detected autoantibodies that activate beta adrenoreceptors in some patients. The mechanism of the arrhythmia primarily involves the sinus node and peri-nodal tissue and does not require the AV node for maintenance. Treatments in the form of pharmacological therapy or catheter ablation are available, but the condition is currently difficult to treat successfully. Symptoms
Symptoms reported by patients vary in frequency and severity. They may include:

Frequent or sustained palpitations
Dyspnea (shortness of breath) and palpitations on exertion
Pre-syncope (feeling as if about to faint)
Fatigue
Dizziness
Exercise intolerance
Occasional paresthesia and cramping
Symptoms associated with autonomic nervous system disturbance, including gastrointestinal disturbance

Diagnosis
No formal diagnostic criteria exist.
Kato stated that leaving behind cities and going into rural areas, he could find many traces of animism, fetishism, and phallicism.Kato Genchi stated that the Ten Sacred Treasures were fetishes and the Imperial Regalia of Japan retained the same traits, and pointed out the similarities with the Pusaka of the natives of the East Indies and the Tjurunga of the Central Australians. The Kusanagi no Tsurugi was believed to provide supernatural protection (blessings) through the spiritual experience of the divine sword, and the Kusanagi no Tsurugi was deified and enshrined at Atsuta in Owari Province, which is now the Atsuta Shrine.Akaruhime no Kami, the deity of Hiyurikuso Shrine, was said to be a red ball. In the Kami era, the jewel around Izanagi-no-Mikotos neck was deified and called Mikuratana-kami.William George Aston remarked that the sword at Atsuta Shrine was originally an offering and later became a sacred object, as an example of Fetishism. Sword was one of mitama-shiro (spirit representative, spirit-token), or more commonly known as the shintai (god-body). He observed that people tends to think of the mitama (spirit) of a deity first as the seat of his real presence, and second as the deity itself. Many people do not distinguish between mitama (spirit) and shintai (god-body), and some even confused shintai (god-body) with the gods real body. For example, cooking furnace (kamado) itself was worshipped as god.