Changes in autonomic nervous activity during endoscopic retrograde cholangiopancreatography: a possible factor in cardiac complications.

BACKGROUND AND AIMS: The changes of autonomic nervous activity during endoscopic retrograde cholangiopancreatography (ERCP) are closely related to the development of cardiovascular complications, such as arrhythmias and acute coronary syndrome. In the present study, the correlation between changes in hemodynamics and autonomic nervous activity during ERCP procedures was evaluated by analyzing heart rate variability and blood catecholamine levels. METHODS: Twenty-three patients who underwent ERCP (ERCP group) and 15 control subjects who were only premedicated (C group) were studied. Ambulant ECG, blood pressure, arterial oxygen saturation, and blood level of catecholamine were measured. Autonomic nervous function was assessed by analyzing the spectral analysis and 1/f fluctuation. The low frequency power (LF power; 0.04-0.15 Hz), high frequency power (HF power; 0.15-0.40 Hz, indicator of parasymapathetic tone), the ratio of LF power to HF power (LF/HF ratio, indicator of sympathetic tone), and 1/f fluctuation (indicator of pleasant mood) were calculated. RESULTS: Blood pressure and heart rate were increased and arterial oxygen saturation was decreased in the ERCP group during the endoscopic procedure. Changes in the parameters of autonomic nervous function (LF power, HF power, LF/HF ratio, and 1/f fluctuation) were significantly greater in the ERCP group than in the C group, especially during cholangiography. Moreover, blood levels of catecholamines were significantly increased during the ERCP procedure. In the C group, however, blood levels of catecholamines did not significantly change except directly after premedication. CONCLUSIONS: Autonomic nervous activity varied greatly during cholangiography, demonstrating that ERCP has more than a little influence on the cardiovascular system. The results of the present study indicated that attention should be focused on changes in hemodynamics in patients with cardiovascular complications by monitoring the aforementioned hemodynamic parameters during ERCP.

Syncope upon swallowing caused by an esophageal hiatal hernia compressing the left atrium: a case report.

We describe a patient with syncope associated with swallowing. This syncope was caused by transient compression of the left atrium (LA) by an esophageal hiatal hernia. Two-dimensional echocardiography demonstrated a hyperechoic mass compressing the LA from the posterior. With air insufflation of the esophagus, compression of the LA by this hernia sac was seen to increase. Pulsed and color Doppler echocardiography revealed greatly decreased velocity of blood flowing into the LA and left ventricle (LV). Thus, marked compression of the LA by an esophageal hiatal hernia can cause syncope by impeding blood flow from the LA to the LV. Echocardiography proved highly useful in diagnosis.