peptic ulcer is a very common disorder in horse race and foals. in the present research possible relationship between gastric ulcer and the prevalence of cardiac arrhythmia were studied in two different horse race. in this respect, 13 caspian miniature horses and 8 arab horses were studied. gastric ulcers and cardiac arrhythmias were diagnosed in 13 horses (62%) and 12 (57%) out of 211 horses, ...

The precise contribution of the CO2-dependent respiratory rhythm to sinus arrhythmia in eupnea is unclear. The respiratory rhythm and sinus arrhythmia were measured in 12 normal, unanesthetized subjects in normocapnia and hypocapnia during mechanical hyperventilation with positive pressure. In normocapnia (41 +/- 1 mmHg), the respiratory rhythm was always detectable from airway pressure and ins...

An 18 year old girl presented with frequent vasovagal attacks and sinus arrhythmia. The amplitude of respiratory sinus arrhythmia assessed by cosinor analysis was 20%; the predicted value for a normal girl of this age is 4% and the 95% confidence interval is 0-8%. Treatment with propantheline, in a dose sufficient to reduce the amplitude of sinus arrhythmia to normal, abolished her symptoms.

Heart rate increases during inspiration and slows during postinspiration; this respiratory sinus arrhythmia helps match pulmonary blood flow to lung inflation and maintain an appropriate diffusion gradient of oxygen in the lungs. This cardiorespiratory pattern is found in neonatal and adult humans, baboons, dogs, rabbits, and seals. Respiratory sinus arrhythmia occurs mainly due to inhibition o...

Though many consider the magnitude of respiratory sinus arrhythmia as an index of cardiac vagal control, its physiological origins remain unclear. One influential model postulates that the systolic pressure rise within a given beat stimulates the baroreflex arc to adjust the following heart period such that diastolic pressure is "stabilized" and hence displays lesser fluctuation. Accordingly, t...

A substantial portion of sinus arrhythmia in conscious humans appears to be caused by the CO2-dependent central respiratory rhythm. Under some circumstances, therefore, sinus arrhythmia might indicate the presence of the central respiratory rhythm. Humans can voluntarily modify their central respiratory rhythm (e.g., by pacing breathing or by delaying or advancing breaths), but it is not clear ...

Upper airway obstruction during adulthood is associated with cardiovascular morbidity; cardiovascular consequences of childhood upper airway obstruction are less well established. This study aimed at investigating the effect of childhood upper airway obstruction on respiratory sinus arrhythmia as a measure of cardiac vagal modulation during night-time sleep. Overnight polysomnography was conduc...

Cardiac arrhythmias, caused by disorders in the generation and transmission of cardiac impulses, is included among the heart disorders that cause inefficient blood circulation. The most commonly-used method for diagnosing this disorder is electrocardiography. In this study, we aimed to identify and diagnose different types of arrhythmia prevalent among the seemingly-healthy horses of Sanandaj C...