OBJECTIVE To evaluate the ability of different parameters of exercise treadmill test to detect autonomic dysfunction in hemodialysis patients. METHODS Cross-sectional study involving hemodialysis patients and a control group. Clinical examination, blood sampling, echocardiogram, 24-hour Holter, and exercise treadmill test were performed. A ramp treadmill protocol symptom-limited with active r...

The chronotropic responses of isolated sinoatrial node and ventricular muscle cells to neurotransmitters were compared in vitro with and without selective adrenergic and cholinergic innervation. Explants of either thoracolumbar sympathetic ganglion or sacrococcygeal spinal cord were added to cultures of newborn rat sinus node regions or ventricular apexes harvested before the onset of autonomic...

We have previously shown that oxytocin receptors are present in the heart and that perfusion of isolated rat hearts with oxytocin results in decreased cardiac flow rate and bradycardia. The mechanisms involved in the negative inotropic and chronotropic effects of oxytocin were investigated in isolated dog right atria in the absence of central mechanisms. Perfusion of atria through the sinus nod...

For practical purpose, most studies define CI as the incapacity to reach 80% of heart rate (HR) reserve according to the formula: HR reserve = (peak HR – resting HR) / (maximum HR – resting HR) x 100. It has been suggested that the definition of CI should be assessed when the diagnostic method uses positive inotropic drugs to induce HR increase. It is necessary to better understand which practi...

OBJECTIVE To evaluate the chronotropic response to exercise during immediate and late postoperative period after atrial fibrillation and mitral valve surgical treatment by different techniques. METHODS Prospective controlled clinical study of 42 patients presenting chronic AF associated mitral valve disease, who underwent surgery by the techniques of pulmonary veins isolation (n=16), Modified...

Exercise capacity in cardiac transplanted patients has been reported to remain decreased in some studies; however, functional results after transplantation may vary, ranging from modest to spectacular improvement. The aim of the study was to quantify exercise capacity in a large series of transplanted patients and to search for factor predictive of a good functional result. Eighty-five patients...

Calcitonin gene-related peptide (CGRP) is present in sensory nerve fibers in the heart and around peripheral arteries. On interaction with specific CGRP binding sites and activation of adenylate cyclase, CGRP causes vasodilation and has positive inotropic and chronotropic effects on the heart. In the present study, human CGRP I and II exerted positive inotropic effects on isolated human right a...