Long-term nocturnal hemodialysis, which uses longer and more frequent sessions than conventional lowers clinic blood pressure left ventricular mass. We tested the hypotheses that short-term hemodialysis would (1) reduce ambulatory pressure; (2) cause peripheral vasodilation; (3) lower plasma norepinephrine concentration; (4) improve arterial response to reactive hyperemia (a marker of endothelium-dependent vasodilation). studied 18 consecutive patients (age, 41+/-2; [mean+/-SEM]) before 1 2...

Background: Effective management and care of diabetes is crucial to reducing associated risks such as heart disease kidney failure. With increasing access use the Internet, online chronic being explored a means providing patients with support necessary tools monitor manage their disease. Objective: The objective our study was evaluate experience providers using an portal for patients. Methods: Participants were recruited from large sample population 887 follow-up questionnaire be completed...

Steady-state responses can be recorded from the human scalp in response to tones that are sinusoidally modulated amplitude at rates between 60 and 120 Hz. For dB SPL 1000-Hz maximum baseline-to-peak of about 0.06 μV occurs for modulation 80 95 The phase does not change with depths greater than 25% saturates 50%. presence or absence a accurately determined by frequency-domain statistics becomes clearly recognizable intensities 16±8 above behavioral thresholds. With increasing intensity...

The cardiovascular benefits of light to moderate red wine consumption often have been attributed its polyphenol constituents. However, the acute dose-related hemodynamic, vasodilator, and sympathetic neural effects ethanol not characterized compared in same individual. We sought test hypotheses that responses one two alcoholic drinks differ with high content elicits a greater effect than alone. Thirteen volunteers (24-47 yr; 7 men, 6 women) drank wine, ethanol, water randomized, single-blind...

Objectives To determine, in sedentary normotensive postmenopausal women, the after-effects of exercise on systemic and regional hemodynamics, whether changes total peripheral conductance after relate to brachial artery flow-mediated vasodilation (FMD). Methods In 13 blood pressure (BP), cardiac output, resistance conductance, calf vascular FMD were measured during baseline rest, again commencing 45 min treadmill exercise. Fourteen premenopausal women completed identical protocol obtain...

Increased repolarization heterogeneity can provide the substrate for reentrant ventricular arrhythmias in animal models of cardiomyopathy. We hypothesized that is also greater patients with cardiomyopathy and arrhythmia vulnerability (inducible tachycardia or positive microvolt T wave alternans, VT/TWA) compared a similar patient population without (no VT/TWA). Endocardial epicardial was measured (n = 12) 10) VT/TWA by using transvenous 26-electrode catheters placed along anteroseptal right...

In healthy subjects a standard drink of either red wine (RW) or ethanol (EtOH) has no effect on muscle sympathetic nerve activity heart rate (HR), whereas two drinks increase both. Using time- and frequency-domain indexes HR variability (HRV), we now tested in 12 (24-47 yr, 6 men) the hypotheses that 1) this reflects concurrent dose-related augmented modulation 2) RW with high-polyphenol content differs from EtOH its acute HRV effects. RW, EtOH, water were provided 3 days, 2 wk apart...

In patients with congestive heart failure, Cheyne-Stokes respiration is accompanied by oscillations in blood pressure and rate at a very low frequency. It not known whether these cardiovascular are primarily related to ventilation or oxyhemoglobin saturation. We hypothesized that abolition of the ventilatory CO2 inhalation would eliminate accompanying but elimination hypoxic dips supplemental O2 not. studied 10 subjects failure during sleep using frequency spectral analysis. During...

Lifestyle behavior modification can reduce the risk of cardiovascular disease, one leading causes death worldwide, by up to 80%. We hypothesized that a dynamic assessment and change tool delivered as mobile app, hosted reputable nonprofit organization, would promote uptake among community members. also predicted be influenced incentives offered for downloading app.The primary objective our study was evaluate engagement levels participants using novel management app. The secondary aim assess...

Many patients with severe obstructive sleep apnea (OSA) do not complain of excessive daytime sleepiness (EDS), possibly due to increased sympathetic nervous activity (SNA) and accompanying heightened alertness. We hypothesized that in OSA, those without subjective EDS (Epworth Sleepiness Scale, ESS score < 11) would have higher very low frequency (VLF) heart rate variability (HRV) during sleep, reflecting greater modulation than an ≥ 11.Patients OSA (AHI 30: 26 65 failure) were divided into...

It is not established whether behavioral interventions add benefit to pharmacological therapy for hypertension. We hypothesized that neurocardiac training (BNT) with heart rate variability biofeedback would reduce blood pressure further by modifying vagal modulation during reactivity and recovery from standardized cognitive tasks ("mental stress"). This randomized, controlled trial enrolled 65 patients uncomplicated hypertension BNT or active control (autogenic relaxation), six 1-hour...

Lower body negative pressure (LBNP; −5 and −15 mmHg) was applied to 14 men (mean age 44 yr) test the hypothesis that reductions in preload without effect on stroke volume or blood increase selectively muscle sympathetic nerve activity (MSNA), but not ratio of low- high-frequency harmonic component spectral power (P L /P H ), a coarse-graining estimate heart rate (HR) modulation. LBNP at mmHg lowered central venous had no (Doppler) systolic reduced vagal HR This latter finding, manifestation...

To determine, in patients with pulmonary arterial hypertension (PAH), whether there is a relationship: (1) between sympathetic nerve firing rate and spectral indices of neural heart modulation; (2) variability (HRV) right atrial pressure, stimulus to sinoatrial node stretch.Characterisation healthy controls.Teaching hospital-based study.9 PAH without elevated capillary wedge pressure nine age-matched control subjects.Heart (HR) muscle activity (MSNA) were recorded during 10 min supine rest...

Steep action potential duration (APD) restitution slopes (&gt;1) and spatial APD heterogeneity provide the substrate for ventricular fibrillation in computational models experimental studies. Their relationship to arrhythmia vulnerability human cardiomyopathy has not been defined. Patients with [left (LV) ejection fraction &lt;40%] no history of arrhythmias underwent risk stratification programmed electrical stimulation or T wave alternans (TWA). Low-risk patients ( n = 10) had inducible...

In patients with end-stage renal disease receiving conventional hemodialysis, both the frequency which brief rises or falls in systolic blood pressure initiate concordant changes pulse interval (arterial baroreflex effectiveness index), and gain of reflex heart rate responses to these stimuli sensitivity) are diminished. chronic failure, low index sensitivity associated increased rates all-cause mortality sudden death, respectively. Conversion home nocturnal hemodialysis augments but its...

Background: Muscle sympathetic nerve firing rate increases as chronic heart failure (CHF) progresses, yet its oscillation, particularly within the frequency range encompassing 0.13Hz, diminishes. The current study tested hypothesis that therapy with lipophilic β-adrenoceptor antagonists augments modulation of muscle activity variability (MSNAV) at this range. Methods and Results: In 21 CHF angiotensin converting enzyme (ACE) inhibitor-treated patients (age: 53±2, ejection fraction: 20±2%),...

Individual differences in heart rate variability (HRV) can be partly attributed to genetic factors that may more pronounced during stress. Using data from the Oman Family Study (OFS), we aimed estimate and quantify relative contribution of genes environment variance HRV at rest stress; calculate overlap environmental influences on under stress using bivariate analyses parameters (HR).Time frequency domain variables average HR were measured beat-to-beat obtained electrocardiogram recordings...

Despite advancements in the development of artificial pancreas, barriers form proprietary data and communication protocols diabetes devices have made integration these components challenging. The Artificial Pancreas Standards Technical Platform Project is an initiative funded by JDRF Canadian Clinical Trial Network with goal developing device standards for interoperability devices. Stakeholders from academia, industry, regulatory agencies, medical patient communities been engaged advancing...