A scintigraphic study of oropharyngeal swallowing dynamics in Chagas' disease

We studied oropharyngeal function in patients with Chagas' disease and oesophageal disease. Twenty-four patients with Chagas' disease, 17 of them with oesophageal disease, were submitted to scintigraphic oropharyngeal transit. A single swallow of a 10-mL bolus of water labelled with 40 MBq 99m Tc-phytate, followed by image acquisition at 20 images s-1 yielded time-activity curves in which oropharyngeal dynamics was evaluated. Thirteen normal volunteers were used as controls. Oral transit was longer for chagasics with oesophageal disease than for controls (P=0.004) or for chagasics with a normal oesophagus (P=0.028). Oesophageal filling rate, measured by the slope of the ascending aspect of the oesophageal radioactivity curve, was lower for chagasics with oesophageal disease than for controls (P=0.037). Also, maximum oesophageal filling rate was lower (P=0. 021) and occurred later (P=0.003) for chagasics with oesophageal disease than for controls. Pharyngeal clearance was positively correlated with oral transit (r=0.603, P=0.002). We conclude that chagasic oesophageal disease is associated with oral transit delay and a slower oesophageal filling rate.