Nonvitamin K antagonist oral anticoagulants in everyday practice: Stroke prevention in atrial fibrillation and treatment of venous thromboembolism.

Purpose: In recent years, four nonvitamin K antagonist oral anticoagulants (NOACs) were approved to prevent stroke in patients with nonvalvular atrial fibrillation (AF) and to treat venous thromboembolism (VTE). Edoxaban, a direct factor Xa inhibitor, is the latest NOAC to be approved for use by the U.S.

Aging augments renal vasoconstrictor response to orthostatic stress in humans.

The ability of the human body to maintain arterial blood pressure (BP) during orthostatic stress is determined by several reflex neural mechanisms. Renal vasoconstriction progressively increases during graded elevations in lower body negative pressure (LBNP). This sympathetically mediated response redistributes blood flow to the systemic circulation to maintain BP.

Healthy older humans exhibit augmented carotid-cardiac baroreflex sensitivity with aspirin during muscle mechanoreflex and metaboreflex activation.

Low-dose aspirin inhibits thromboxane production and augments the sensitivity of carotid baroreflex (CBR) control of heart rate (HR) during concurrent muscle mechanoreflex and metaboreflex activation in healthy young humans. However, it is unknown how aging affects this response. Therefore, the effect of low-dose aspirin on carotid-cardiac baroreflex sensitivity during muscle mechanoreflex with and without metaboreflex activation in healthy older humans was examined.

Seasonal variation in muscle sympathetic nerve activity.

Epidemiologic data suggest there are seasonal variations in the incidence of severe cardiac events with peak levels being evident in the winter. Whether autonomic indices including muscle sympathetic nerve activity (MSNA) vary with season remains unclear. In this report, we tested the hypothesis that resting MSNA varies with the seasons of the year with peak levels evident in the winter.

Limb suction evoked during arterial occlusion causes systemic sympathetic activity in humans.

Venous saline infusions in an arterially occluded forearm evokes reflex increases in muscle sympathetic nerve activity (MSNA) and blood pressure (BP). We hypothesized that the application of suction to the human limbs would activate this venous distension reflex and raise sympathetic outflow. We placed airtight pressure tanks and applied 100 mmHg negative pressure to an arterially occluded limb (occlusion and suction, O&S) to induce tissue deformation without fluid translocation.

Effect of omega-3 polyunsaturated fatty acid supplementation on central arterial stiffness and arterial wave reflections in young and older healthy adults.

Increased central arterial stiffness and enhanced arterial wave reflections may contribute to increased risk of cardiovascular disease development with advancing age. Omega-3 polyunsaturated fatty acid (n-3) ingestion may reduce cardiovascular risk via favorable effects exerted on arterial structure and function. We determined the effects of n-3 supplementation (4 g/day for 12 weeks) on important measures of central arterial stiffness (carotid-femoral pulse wave velocity; PWV) and arterial wave reflection (central augmentation index) in young (n = 12; 25 ± 1-year-old, mean ± SE) and older (n = 12; 66 ± 2) healthy adults.

Inhibition of cyclooxygenase attenuates the blood pressure response to plantar flexion exercise in peripheral arterial disease.

Prostanoids are produced during skeletal muscle contraction and subsequently stimulate muscle afferent nerves, thereby contributing to the exercise pressor reflex. Humans with peripheral arterial disease (PAD) have an augmented exercise pressor reflex, but the metabolite(s) responsible for this augmented response is not known. We tested the hypothesis that intravenous injection of ketorolac, which blocks the activity of cyclooxygenase, would attenuate the rise in mean arterial blood pressure (MAP) and heart rate (HR) evoked by plantar flexion exercise.

Indications for pacemakers, implantable cardioverter-defibrillator and cardiac resynchronization devices.

Implantable cardiac devices are important management tools for patients with heart rhythm disorders and heart failure. In this article, the current implantable cardiac rhythm devices are described in their evolution. The current indications and contraindications for these cardiac rhythm devices are reviewed.

New oral anticoagulants: their role in stroke prevention in high-risk patients with atrial fibrillation.

Based on efficacy, safety, and ease of use, novel oral anticoagulants will likely replace VKAs for many if not most patients with atrial fibrillation. Novel anticoagulants have a lower rate of intracranial hemorrhage compared with vitamin K antagonists. The incidence of other life-threatening bleeds is similar if not lower.

Ascorbic acid attenuates the pressor response to voluntary apnea in postmenopausal women.

We recently demonstrated that postmenopausal women have an augmented blood pressure response to voluntary apnea compared to premenopausal women. Both obstructive sleep apnea (OSA) and healthy aging are associated with increased oxidative stress, which may impair cardiovascular function. Restoring physiological responses could have clinical relevance since transient surges in blood pressure are thought to be an important stimulus for end-organ damage in aging and disease.

Major complications and mortality within 30 days of an electrophysiological procedure at an academic medical center: implications for developing national standards.

Background: Despite growing attention to performance and quality measures, national standards for reporting of outcomes after all electrophysiology (EP) procedures have not yet been developed. We sought to characterize the incidence and timing of adverse events up to 30 days after EP procedures at a tertiary academic medical center.

Methods And Results: We prospectively followed all patients undergoing EP procedures between January 2010 and September 2012.

Tricuspid valve incompetence following implantation of ventricular leads.

Most cardiovascular implantable electronic devices (CIEDs) require a ventricular lead to be placed across the tricuspid valve. Tricuspid regurgitation (TR) is an understudied clinical complication of right ventricular lead implantation and its clinical significance is unknown. We review the incidence, predictors, and current management of TR as a complication of ventricular lead implantation.

Do peripheral and/or central chemoreflexes influence skin blood flow in humans?

Voluntary apnea activates the central and peripheral chemoreceptors, leading to a rise in sympathetic nerve activity and limb vasoconstriction (i.e., brachial blood flow velocity and forearm cutaneous vascular conductance decrease to a similar extent).

β-Adrenergic receptor blockade impairs coronary exercise hyperemia in young men but not older men.

Patients with coronary artery disease have attenuated coronary vasodilator responses to physiological stress, which is partially attributed to a β-adrenergic receptor (β-AR)-mediated mechanisms. Whether β-ARs contribute to impaired coronary vasodilation seen with healthy aging is unknown. The purpose of this study was to investigate the role of β-ARs in coronary exercise hyperemia in healthy humans.

Ascorbic acid does not enhance hypoxia-induced vasodilation in healthy older men.

In response to hypoxia, a net vasodilation occurs in the limb vasculature in young healthy humans and this is referred to as "hypoxia-induced vasodilation". We performed two separate experiments to determine (1) if hypoxia-induced forearm vasodilation is impaired in older men (n = 8) compared to young men (n = 7) and (2) if acute systemic infusion of ascorbic acid would enhance hypoxia-induced vasodilation in older men (n = 8). Heart rate, mean arterial pressure, oxygen saturation, minute ventilation, forearm vascular conductance (FVC, Doppler ultrasound), and cutaneous vascular conductance (CVC, laser Doppler flowmetry) were recorded continuously while subjects breathed 10% oxygen for 5 min.

Using thermal stress to model aspects of disease states.

Exposure to acute heat or cold stress elicits numerous physiological responses aimed at maintaining body temperatures. Interestingly, many of the physiological responses, mediated by the cardiovascular and autonomic nervous systems, resemble aspects of, or responses to, certain disease states. The purpose of this Perspective is to highlight some of these areas in order to explore how they may help us better understand the pathophysiology underlying aspects of certain disease states.

Coronary responses to cold air inhalation following afferent and efferent blockade.

Cardiac ischemia and angina pectoris are commonly experienced during exertion in a cold environment. In the current study we tested the hypotheses that oropharyngeal afferent blockade (i.e.

Takotsubo's syndrome after mitral valve repair and rescue with extracorporeal membrane oxygenation.

We report a case of Takotsubo's syndrome in a 37-year-old woman after mitral valve repair for severe mitral regurgitation triggered by a severe protamine reaction that was likely associated with immune-mediated coronary hypersensitivity (Kounis' syndrome) and made worse by resuscitation with high doses of catecholamines. The patient recovered fully after a 4-day course of extracorporeal membrane oxygenation therapy (ECMO).