To the Editor-We would like to thank Drs. Thnish and Downs for their interesting case report, “Vagotonia and Cardiac Arrest during Spinal Anesthesia.”’ These authors discuss the contribution of sympathetic and parasympathetic nervous system imbalance during spinal anesthesia as a mechanism of asystole. They state that in a patient with vasovagal syncope, the combination of cardiac sympathetic b...

Electrical stimulation in medulla oblongata has been carried out in 36 dogs with the purpose of studying the mechanism of cardiovascular and respiratory regulation. By electrocardiographic registration, changes in heart beats were examined, and disturbances of heart rate and rhythm were suggested to be due to direct vagal nucleus stimulation or due to vagal reflex by arterial pressure change. B...

Electroacupuncture (EA) at P5-P6 acupoints overlying the median nerves typically reduces sympathoexcitatory blood pressure (BP) reflex responses in eucapnic rats. Gastric distention in hypercapnic acidotic rats, by activating both vagal and sympathetic afferents, decreases heart rate (HR) and BP through actions in the rostral ventrolateral medulla (rVLM) and nucleus ambiguus (NAmb), leading to ...

The purpose of this study was to investigate the nature of the serotonin-induced coronary chemoreflex in the conscious monkey. Ten chronically prepared and four acute monkeys were used in this study. Five chronically prepared animals had catheters in the left atrium, ascending aorta, descending aorta, and, bilaterally, in the common carotid arteries. In addition, Silastic catheters were placed ...

The effects of exercise training on cardiovascular and autonomic functions were investigated in female rats. After an aerobic exercise training period (treadmill: 5 days/week for 8 weeks), conscious female Wistar (2 to 3 months) sedentary (S, N = 7) or trained rats (T, N = 7) were cannulated for direct arterial pressure (AP) recording in the non-ovulatory phases. Vagal (VT) and sympathetic tonu...

The neurotrophic factor neurturin is required for normal cholinergic innervation of adult mouse heart and bradycardic responses to vagal stimulation. Our goals were to determine effects of neurturin deletion on development of cardiac chronotropic and dromotropic functions, vagal baroreflex response, and cholinergic nerve density in nodal regions of postnatal mice. Experiments were performed on ...

BRINKMAN, CHARLES R. III, GARY H. JOHNSON, AND N. S. ~SSALI. Hemodynamic effects of bradycardia in the fetal lamb. Am. J. Physiol. 223(6) : 1465-1469. 1972.-The hemodynamic impact of induced cardiac deceleration were studied in near-term fetal lamb. Vagal stimulation resulted in rhythmic or arrhythmic bradycardia, each type having somewhat different effects on arterial pressure, stroke volume, ...

Sinus bradycardia can be defined as a sinus rhythm with a resting heart rate of 60 beats per minute or less. While it is assumed that increased autonomic parasympathetic activity is associated with sinus bradycardia, such an association has yet to be proven. The aims of this study were to compute a number of heart rate variability (HRV) parameters in healthy individuals with sinus bradycardia a...

BACKGROUND Cope's sign is the association of bradycardia with symptoms acute cholecystitis, which can occur due to a vagal cardiobiliary reflex. The clinical and electrocardiographic changes or complete heart block mimic presentation coronary syndrome. This report highlights unique possibility that in patients abdominal pain gallstones be this CASE REPORT A 46-year-old obese man hyperlipidemia ...