Effect of acetylcholinesterase inhibition with pyridostigmine on cardiac parasympathetic function in sedentary adults and trained athletes.

Heart rate variability and postexercise heart rate recovery are used to assess cardiac parasympathetic tone in human studies, but in some cases these indexes appear to yield discordant information. We utilized pyridostigmine, an acetylcholinesterase inhibitor that selectively augments the parasympathetic efferent signal, to further characterize parasympathetic regulation of rest and postexercise heart rate. We measured time- and frequency-domain indexes of resting heart rate variability and postexercise heart rate recovery in 10 sedentary adults and 10 aerobically trained athletes after a single oral dose of pyridostigmine (30 mg) and matching placebo in randomized, double-blind, crossover trial.

Comparison of metabolic vasodilation in response to exercise and ischemia and endothelium-dependent flow-mediated dilation in African-American versus non-African-American patients with chronic heart failure.

Race-related disparities in response to therapy and clinical outcomes have been reported in patients with chronic heart failure (HF). Vascular dysfunction is an important determinant of therapeutic response and clinical outcomes in chronic HF, but race-related differences of vasodilator responses in those with chronic HF have not been previously characterized. We assessed metabolic vasodilation in response to exercise and ischemia and endothelium-dependent flow-mediated dilation in conduit and resistance vessels with strain gauge venous occlusion plethysmography and high-resolution ultrasound imaging in the forearm circulation of 69 African-American and 188 non-African-American patients with chronic HF.

Inhibition of angiotensin-converting enzyme and phosphodiesterase type 5 improves endothelial function in heart failure.

ACE (angiotensin-converting enzyme) inhibitors and PDE5 (phosphodiesterase type 5) inhibitors have each been reported to improve endothelial function in cardiovascular disease patients, but the comparative and combined effects of these two classes have not been studied previously. We sought to characterize the acute effects of ramipril alone, sildenafil alone, or their combination on endothelial function in patients with CHF (chronic heart failure). CHF subjects (n=64) were randomized to receive placebo, 10 mg of ramipril alone, 50 mg of sildenafil alone or a combination of ramipril and sildenafil in a double-blind manner.

Relation of unrecognized hypervolemia in chronic heart failure to clinical status, hemodynamics, and patient outcomes.

Clinically unrecognized intravascular volume overload may contribute to worsening symptoms and disease progression in patients with chronic heart failure (CHF). The present study was undertaken to prospectively compare measured blood volume status (determined by radiolabeled albumin technique) with clinical and hemodynamic characteristics and patient outcomes in 43 nonedematous ambulatory patients with CHF. Blood volume analysis demonstrated that 2 subjects (5%) were hypovolemic (mean deviation from normal values -20 +/- 6%), 13 subjects (30%) were normovolemic (mean deviation from normal values -1 +/- 1%), and 28 subjects (65%) were hypervolemic (mean deviation from normal values +30 +/- 3%).

Treatment of anemia in patients with chronic heart failure.

Anemia occurs frequently in chronic heart failure (CHF) patients and is associated with increased morbidity and mortality risk. Clinical trials with recombinant human erythropoietin in patients with chronic kidney disease and concomitant structural heart disease have demonstrated beneficial effects on ventricular remodeling but variable effects on clinical outcome. Preliminary clinical trials in patients with CHF demonstrate that erythropoietin therapy is well-tolerated and associated with short-term clinical benefits.

Partial reversal of cachexia by beta-adrenergic receptor blocker therapy in patients with chronic heart failure.

Background: Cachexia is a common problem in chronic heart failure (CHF) that may be partly mediated by activation of the sympathetic nervous system. The effects of beta-adrenergic receptor blocker (BB) therapy on body weight in cachectic and noncachectic subjects with CHF has not been previously reported.

Methods And Results: Body weight and plasma norepinephrine, leptin, and insulin levels were measured in 27 subjects with CHF before and after 6 months of beta-adrenergic receptor blockade with carvedilol or long-acting metoprolol.

Comparative effects of carvedilol and metoprolol on regional vascular responses to adrenergic stimuli in normal subjects and patients with chronic heart failure.

Background: Adrenergic receptor blockers used in the treatment of heart failure have distinct receptor affinity profiles. We hypothesized that alpha-adrenergic-blocking effects of carvedilol would limit vasoconstriction in response to adrenergic stimuli when compared with metoprolol.

Methods And Results: Forearm vascular resistance responses to isometric handgrip and cold pressor test were determined by plethysmography before and during adrenergic receptor blockade in prospective randomized trials.

Effect of erythropoietin on exercise capacity in patients with moderate to severe chronic heart failure.

Background: Patients with chronic heart failure (CHF) are frequently anemic. An increase in hemoglobin could enhance exercise performance by increasing oxygen delivery. We investigated the effect of erythropoietin (EPO) on exercise performance in anemic patients with CHF.

Hemodilution is common in patients with advanced heart failure.

Background: Anemia frequently occurs in chronic heart failure (CHF) patients and is associated with a poor prognosis. A low hematocrit may result from an increased plasma volume (hemodilution) or from reduced red blood cell volume (true anemia). The prevalence and clinical outcome of CHF patients with hemodilution is unknown.