Evaluation of the dopamine β-hydroxylase (DβH) inhibitor nepicastat in participants who meet criteria for cocaine use disorder.

In the present study, we tested the hypothesis that the potent and selective dopamine-β-hydroxylase (DβH) inhibitor nepicastat would have minimal effects on cardiovascular and pharmacokinetic parameters associated with cocaine administration and would reduce the positive subjective effects produced by cocaine. We conducted a double-blind, placebo-controlled, inpatient study of oral nepicastat (0, 80 and 160mg) concurrent with intravenous (IV) cocaine (0, 10, 20 and 40mg) in non-treatment seeking participants who metcriteria for cocaine use disorder. Safety analyses revealed that nepicastat was well-tolerated and there were no differences in adverse events observed after nepicastat plus cocaine vs.

Syncope in adults: systematic review and proposal of a diagnostic and therapeutic algorithm.

This review aims to provide a practical and up-to-date description on the relevance and classification of syncope in adults as well as a guidance on the optimal evaluation, management and treatment of this very common clinical and socioeconomic medical problem. We have summarized recent active research and emphasized the value for physicians to adhere current guidelines. A modern management of syncope should take into account 1) use of risk stratification algorithms and implementation of syncope management units to increase the diagnostic yield and reduce costs; 2) early implantable loop recorders rather than late in the evaluation of unexplained syncope; and 3) isometric physical counter-pressure maneuvers as first-line treatment for patients with neurally-mediated reflex syncope and prodromal symptoms.

Dobutamine stress echocardiography in a patient with Wolff-Parkinson-White syndrome.

We describe the case of a patient with ventricular pre-excitation who underwent dobutamine stress echocardiography to evaluate atypical chest pain. The patient safely underwent the procedure with interesting electrocardiographic findings during pharmacological stress. The risks of dobutamine stress testing, along with possible explanations of this observed event, are discussed.

Modeling left ventricular diastolic dysfunction: classification and key indicators.

Background: Mathematical modeling can be employed to overcome the practical difficulty of isolating the mechanisms responsible for clinical heart failure in the setting of normal left ventricular ejection fraction (HFNEF). In a human cardiovascular respiratory system (H-CRS) model we introduce three cases of left ventricular diastolic dysfunction (LVDD): (1) impaired left ventricular active relaxation (IR-type); (2) increased passive stiffness (restrictive or R-type); and (3) the combination of both (pseudo-normal or PN-type), to produce HFNEF. The effects of increasing systolic contractility are also considered.

Reducing ischaemia/reperfusion injury through delta-opioid-regulated intrinsic cardiac adrenergic cells: adrenopeptidergic co-signalling.

Aims: The purpose of this study was to determine whether intrinsic cardiac adrenergic (ICA) cells release calcitonin gene-related peptide (CGRP), exerting synergistic adrenopeptidergic cardioprotection.

Methods And Results: In situ hybridization coupled with immunostaining demonstrated that ICA cells exclusively expressed CGRP mRNA and co-expressed CGRP and delta-opioid receptor in human and rat left ventricular (LV) myocardium. Radioimmunoassay detected constitutive CGRP release from ICA cells in human and rat hearts.

A human cardiopulmonary model: extension to LV dysfunction.

We update a cardiopulmonary (CP) model previously developed by our group, more convincingly validate the model with additional hemodynamic and echocardiographic data, and demonstrate the utility of the model by extending it to the simulation of left ventricular diastolic dysfunction (LVDD) via a simple parameter change. The model has considerable potential for the characterization of complex cardiopulmonary diseases such as right or left ventricular failure, valve dysfunction, primary pulmonary hypertension, and acute respiratory distress syndrome (ARDS).

Syncope, seizure, or both? An unusual case of complete heart block.

Syncope and epileptic seizures have common presenting features that make it difficult to determine if a patient's collapse is primarily cardiac or neurologic. The distinction is blurred further if epileptic neural activity provokes cardiac arrhythmias known to cause syncope. We present a case of convulsive movements, progressive atrioventricular block, and syncope in a patient known to have epilepsy.

Sudden death prophylaxis in heart failure.

Sudden cardiac death (SCD) is the leading cause of mortality in heart failure (HF). Today the implantable cardioverter-defibrillator (ICD) has become a commonplace therapy around the world for patients with both ischemic and non-ischemic cardiomyopathy and an ejection fraction (EF) < or = 35%. However, EF alone does not discriminate between the modes of death from HF (sudden arrhythmic death vs.

Role of transesophageal echocardiography guided cardioversion in patients with atrial fibrillation, previous left atrial thrombus and effective anticoagulation.

Aims: The value of transesophageal echocardiography (TEE) to prevent cardioversion-related thromboembolic events in patients with atrial fibrillation (AF) and left atrial (LA) thrombus is unclear. We compared the embolic risk associated with a strategy of follow-up TEE-guided direct-current cardioversion (DCCV) with that of blind DCCV in patients with AF, pre-existing LA thrombus and effective anticoagulation.

Methods And Results: We identified 67 subjects with TEE-documented LA appendage thrombi from a total of 520 consecutive patients with symptomatic non-rheumatic AF who were referred to us for elective DCCV.

Medical qualification of a commercial spaceflight participant: not your average astronaut.

Background: Candidates for commercial spaceflight may be older than the typical astronaut and more likely to have medical problems that place them at risk during flight. Since the effects of microgravity on many medical conditions are unknown, physicians have little guidance when evaluating and certifying commercial spaceflight participants. This dynamic new era in space exploration may provide important data for evaluating medical conditions, creating appropriate medical standards, and optimizing treatment alternatives for long-duration spaceflight.

An unusual electrocardiogram artifact: what is its source?

A diabetic female presented with nausea and vomiting. Her electrocardiogram showed sinus rhythm with two artifactual spikes, not synchronized with the cardiac rhythm. The patient had an implanted gastric electrical stimulation system for treating her diabetic gastroparesis.

Benefits, unresolved questions, and technical issues of cardiac resynchronization therapy for heart failure.

This review aims to provide a synthesis of the published evidence regarding the rationale and clinical benefits of cardiac resynchronization therapy (CRT) with implantable atrial-synchronized biventricular pacing (BVP) devices in patients with moderate to advanced heart failure and intra- and interventricular conduction delays. In addition, it addresses clinical and technical issues that have yet to be resolved, such as the selection of the most suitable candidates for CRT; the usefulness of combining BVP with automatic defibrillation backup; the value of CRT in patients with atrial fibrillation; the importance of alternative sites of pacing, such as the atrial septum and the right ventricular (RV) outflow tract; the harmful effects of the long-standing practice of producing an iatrogenic left bundle branch block by conventional RV pacing in patients receiving standard permanent pacemakers; the question of precisely where on the left ventricle optimal pacing is achieved; and the potential applications of CRT in patients with pediatric or congenital heart disease. Considering how major advances have been achieved since the first clinical application of CRT in 1994, one can be optimistic about the future of the electrotherapeutic management of heart failure.

Reperfusion-related polymorphic ventricular tachycardia as a possible mechanism of sudden death in patients with anomalous coronary arteries.

We describe a patient with anomalous origin of the left coronary artery in whom polymorphic ventricular tachycardia developed immediately after an episode of chest pain with ST segment elevation. This is the first report providing direct evidence that reperfusion arrhythmias may be the cause of sudden death in individuals with anomalous coronary arteries.

Electrocardiogram of acute ST-elevation myocardial infarction: the significance of the various "scores".

The Electrocardiogram has extensively been used for evaluation and triage of patients with acute chest pain. The clinician admitting a patient with ST elevation acute myocardial infarction should be able to estimate the size and location of the ischemic area at risk, how much of the ischemic myocardium has already undergone irreversible necrosis by the time of presentation, and the "severity of ischemia" (or what is the rate of progression of necrosis as long as ischemia continues). The electrocardiographic variables that are used to make these estimates are the initial portion of the QRS (Q and R waves), the terminal portion of the QRS (the S waves and the J-point), the ST segment, and the configuration of the T waves.

Pulmonary vein ablation of atrial fibrillation: beyond the traditional.

The present review aims at giving a synthesis on the evolution in the last decade of the catheter-based ablative treatments for atrial fibrillation (AF). We report the rationale of current pulmonary vein (PV) ablation techniques: segmental PV isolation and circumferential PV ablation. The endpoint is the electrical isolation of the PVs from the left atrium, as they house foci triggering AF in 80% to 95% of cases and seem to play a key role in arrhythmia maintenance.

Unusual evolution of ST elevation acute myocardial infarction.

We report a case of acute ST-segment elevation myocardial infarction with an unusual evolution of ST-segment elevation. Several possible explanations of this progression are discussed with supportive evidence for each explaination. The clinical, electrocardiographic, and angiographic features of this case are also illustrated.

Cardiac arrhythmias in cardiothoracic surgery.

Most patients with cardiopulmonary disease are predisposed to develop perioperative arrhythmias with the individual patient risk depending upon the type of operative procedure performed, the risk profile of the patient, and the complexity of the post-operative course. There are several management options that may tend to prevent perioperative arrhythmias that should be considered in certain patient subsets. Most important of these is the use of beta-blocker therapy before and after operation in patients with coronary risks factors undergoing non-cardiac thoracic procedures and in patients having coronary artery bypass grafting.