[Cardiogenic oscillation--utility of classifying types of sleep apnea].

Cardiogenic pulse waves that travel along the airway wall are captured as airflow variations synchronized with the electrocardiogram at the airway exit. We have used airflow variations caused by cardiogenic pulse waves (hereinafter referred to as cardiogenic oscillation) to classify types of sleep apnea. Pulse waves do not travel downstream if there is an airway obstruction or choke point (wave speed theory). Thus, cardiogenic oscillation was detectable in central apnea or hypopnea, but not in obstructive apnea. In mixed-type sleep apnea, cardiogenic oscillation disappeared, and thus airway obstruction was judged to have occurred, during central sleep apnea. It was thought that obstructive sleep apnea followed central sleep apnea because there was an airway obstruction, although respiratory effort resumed after the end of central sleep apnea. The pattern of mixed-type sleep apnea was understood from the observation of cardiogenic oscillation. Cardiogenic oscillation is useful for not only classifying types of sleep apnea but also for detecting an airway obstruction.

[A case of tomato juice-induced oral allergy syndrome in which dyspnea onset occurred during the season of Japanese cedar pollen dispersion].

A 42-year-old-man with a history of Japanese cedar pollinosis repeatedly visited the emergency clinic due to dyspnea during the season of Japanese cedar pollen dispersion. Before each onset of this symptom, he had always drunk tomato juice. Swelling of the oral and nasal mucosa, and congestion of the bulbar conjuctiva was observed. No audible wheezing was present. His pulmonary function test results were normal (FEV 1.0 = 4.02 L, %FEV 1.0-124%, negative reversible test). The CAP RAST scores were 4 for tomatoes and 3 for Japanese cedar pollen. A result was obtained in a challenge test using tomato juice. Since tomato juice was involved in the development of the symptoms, a diagnosis of oral allergy syndrome induced by tomato juice was made. When tomato juice consumption was avoided, no symptoms developed. A common antigenicity was found between tomatoes and Japanese cedar pollen. This may be associated with the development of this allergy during the dispersion season of Japanese cedar pollen. The dyspnea may have reflected a feeling of pharyngeal narrowing which is a symptom of oral allergy syndrome. The possibility of oral allergy syndrome as the chief complaint should be considered also in patients with dyspnea. This is the first reported case of oral allergy syndrome induced by tomato juice.