Effect of pioglitazone on arterial baroreflex sensitivity and sympathetic nerve activity in patients with acute myocardial infarction and type 2 diabetes mellitus.

Pioglitazone has been shown to reduce the occurrence of fatal and nonfatal myocardial infarction (MI) in type 2 diabetes mellitus (DM). However, the mechanisms of such favorable effects remain speculative. The aim of this study was to investigate the effect of pioglitazone on arterial baroreflex sensitivity (BRS) and muscle sympathetic nerve activity (MSNA) in 30 DM patients with recent MI.

Radiofrequency catheter ablation of posterior paraseptal accessory pathway with atresia of the coronary sinus ostium.

A 42-year-old man was referred to our hospital for an electrophysiologic study because of recurrent episodes of palpitation. On coronary angiogram, an anomalous atresia of the coronary sinus (CS) ostium was discovered. The ablation catheter was inserted from the right femoral artery to the accessory pathway (AP) of posterior paraseptal area.

The effects of clonidine on arterial baroreflex sensitivity and cardiopulmonary baroreflex control of sympathetic nerve activity in patients with left ventricular dysfunction.

Background:   Clonidine is a potent sympatholytic drug with central neural effects. The aim of this study was to evaluate the effects of clonidine on arterial baroreflex sensitivity (BRS) and cardiopulmonary (CP) baroreflex control of muscle sympathetic nerve activity (MSNA) in patients with left ventricular (LV) dysfunction.

Method:   Twenty patients were randomly assigned to either clonidine or placebo groups (10 in each group).

Relationship between arterial baroreflex sensitivity and exercise capacity in patients with acute myocardial infarction.

To investigate the relationship between arterial baroreflex sensitivity (BRS) and exercise capacity, we examined arterial BRS and its relation to exercise capacity during upright bicycle exercise in 40 uncomplicated patients with acute myocardial infarction. Arterial BRS was measured 3 weeks (20 +/- 5 days) after acute myocardial infarction and assessed by calculating the regression line relating phenylephrine-induced increases in systolic blood pressure to the attendant changes in the R-R interval. All patients underwent graded symptom-limited bicycle exercise with direct measurements of hemodynamic and metabolic measurements.

Augmented sympathoinhibitory effect of valsartan when added to angiotensin-converting enzyme inhibitor in patients with left ventricular dysfunction.

Objective: Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) effectively interfere with the sympathetic nerve activity in patients with left ventricular (LV) dysfunction. The aim of this study was to examine the effect of ARBs on sympathetic nerve activity and baroreflex function in patients with LV dysfunction already receiving ACE inhibitors.

Methods: Twenty patients with LV dysfunction already treated with ACE inhibitor (enalapril 5 mg/day) were randomly divided into two groups: treatment with 10 mg/day enalapril (control group) or 5 mg/day enalapril plus 80 mg/day valsartan (combination group).

Resting muscle sympathetic nerve activity, cardiac metaiodobenzylguanidine uptake, and exercise tolerance in patients with left ventricular dysfunction.

Background: Sympathetic nerve overactivity and reduced exercise tolerance are characteristic features of patients with heart failure. However, to what extent sympathetic nerve overactivity contributes to limiting exercise tolerance has not been clearly defined.

Methods: Myocardial iodine 123-metaiodobenzylguanidine (MIBG) scintigraphy, muscle sympathetic nerve activity (MSNA), and cardiopulmonary exercise testing were performed within 3 days in 30 patients with left ventricular dysfunction (LVD).