Chest pain: esophageal, cardiac, or both?

The esophagus may be the origin of chest pain clinically indistinguishable from that of ischemic heart disease. In some patients the esophageal origin of the pain may only be recognized by pharmacological provocation during manometry. We describe nine patients with chest pain which could be explained by disorders of esophageal motility-diffuse spasm in four, high pressure lower esophageal sphincter in three, and "nutcracker esophagus" in two. Methacholine provoked the pain and manometric abnormalities in five patients who had normal baseline tracings. However, seven patients given methacholine developed ischemic changes on the electrocardiogram. In one patient these were typical of Prinzmetal's variant angina. The mannometric and electrocardiographic abnormalities were reversed by intravenous atropine. Ischemic heart disease and esophageal motor disorders may occur concomitantly and pose a dilemma in diagnosis and management. (AU)

A simple method for measuring calorie expenditures during sleep

A simple method for the continuous determination of O2 consumption and CO2 production in sleeping subjects is described. Face masks and mouth pieces have been eliminated and the method has been successful with babies and adults. The apparatus consists of a ventilated hood connected to a vacuum cleaner. The subject sleeps with his head on a pillow inside the hood and fresh air is sucked over his face. Diluted expired air leaves the hood through an outlet in the rear wall and its volume is measured with a gas meter. A side-arm fitted to the outlet enabes continuous samples of diluted expired air to be diverted by an aquarium pump into a sampling bag. Safety circuits are incorporated into the hood. (Summary)