Article history: Received: 17 November, 2015 Revised: 6 December, 2015 Accepted: 19 December, 2015 Published online: 20 December, 2015 Background and Aim: Analysis of heart rate variability (HRV) has recently become the playing field of mathematicians and physicists, losing its relation to physiology and the clinic. To set the record straight, a set of animal experiments is presented here, whic...

We have previously demonstrated that the beneficial effect of cardioselective 13-blockade on exercise-induced ischemia is due entirely to negative chronotropism. Therefore we studied the effect of a new bradycardiac agent (UL-FS 49) in 10 dogs with chronic coronary artery stenosis produced by an ameroid constrictor. Regional myocardial function (sonomicrometers, wall thickness) and blood flow (...

Alcohol has acute and chronic cardiovascular effects. Acutely, it depresses cardiac function and alters regional blood flow. In addition, there is an association between alcohol use and rhythm disturbances, particularly supraventricular tachyarrhythmias even in apparently healthy people. The induction of rhythm disturbances by acute alcohol consumption, especially supraventricular tachyarrhythm...

A 62 year man with tablet-controlled type 2 diabetes was referred by his general practitioner to the emergency medical unit with shortness of breath. He was found to be in atrial fibrillation with a heart rate of 130 beats/min and the patient was commenced on sotalol and warfarin. Thyroid function tests were requested and found to be abnormal, with thyroid-stimulating hormone (TSH) 7.75 mU/l (r...

The autonomic nervous system is crucial for blood pressure and heart rate regulation. Sympathetic efferent fibers elicit vasoconstriction, raise heart rate and cardiac contractility, and promote sodium reabsorption through direct renal tubular actions and renin-angiotensin system activation. Parasympathetic efferent fibers rapidly reduce heart rate. Both autonomic branches are tightly controlle...

Altitude/hypoxic training is nowadays a common practice among swimmers although its benefits are still controversial in scientific literature. Traditional altitude training (“live high-train high”) is still the most frequently used method in swimming, even though from a physiological perspective the “live high-train low” strategy appears to be a more promising alternative. While acute hypoxia d...

To the Editor: excluding any unspecific effect of anaesthesia. This was not the case in the studies cited by Dr. Pagliaro. Therefore, We thank Dr. Pagliaro for his comments. In his letter Dr. we believe that the references cited in our review are Pagliaro focused on two points of the discussion of appropriate and that these investigations have considerable chronotropic effects of endogenous nit...

The cardiovascular beta-adrenergic receptor blocking activities of YB-2 and its optical isomers were investigated in isolated guinea pig atria and anesthetized dogs, and compared with that of propranolol. In isolated guinea pig atria, the positive inotropic and chronotropic responses to isoproterenol were competitively antago nized by these agents, and the order of beta-adrenergic blockade was ...

The effects of phenylephrine and methoxamine were studied on pacemaker activity in the sinoatrial node and on atrial and ventricular contractility in isolated, blood-perfused atrial and ventricular preparations of dogs. Each drug was administered directly into the cannulated sinus node artery of an isolated atrium or the anterior descending branch of the isolated left ventricle over a period of...