A 30-year-old female patient has been delivered to a hospital for sudden dyspnea progessing to asthma, sensation of having a "lump in the throat", hand tremor, fear of death. The attack has developed for the first time and is associated with a strong emotion. There is no previous history. Objectvely: respiratory rate - 28/min, Ps - 104/min, rhythmic, AP - 150/85 mm Hg. The patient has rapid superficial vesicular breathing with extended expiration. Percussion findings: heart borders are not changed. Cardiac sounds are loud, rhythmic. What is the most likely diagnosis?