Increased heart rate with sleep disordered breathing in hypertrophic cardiomyopathy.

Background: Current guidelines recommend medications with rate control properties for symptomatic patients with hypertrophic cardiomyopathy (HCM) based on the rationale that lowering heart rate (HR) improves their symptoms. Whether sleep disordered breathing (SDB) is associated with increased HR in HCM patients is not known.

Method: We diagnosed uncontrolled SDB (oxygen desaturation index ≥5) in consecutive echocardiographically confirmed HCM patients seen at Mayo Clinic, Rochester, and analyzed their HR as recorded by a 24-h Holter monitor.

Association Between Hypoxemia and Mortality in Patients With COVID-19.

Objective: To identify markers associated with in-hospital death in patients with coronavirus disease 2019 (COVID-19)-associated pneumonia.

Patients And Methods: A retrospective cohort study was conducted of 140 patients with moderate to critical COVID-19-associated pneumonia requiring oxygen supplementation admitted to the hospital from January 28, 2020, through February 28, 2020, and followed up through March 13, 2020, in Union Hospital, Wuhan, China. Oxygen saturation (SpO) and other measures were tested as predictors of in-hospital mortality in survival analysis.

Feasibility of directional percutaneous epicardial ablation with a partially insulated catheter.

Purpose: To demonstrate the feasibility of directional percutaneous epicardial ablation using a partially insulated catheter.

Methods: Partially insulated catheter prototypes were tested in 12 (6 canine, 6 porcine) animal studies in two centers. Prototypes had interspersed windows to enable visualization of epicardial structures with ultrasound.

A Novel Defibrillation Tool: Percutaneously Delivered, Partially Insulated Epicardial Defibrillation.

Introduction: Epicardial defibrillation systems currently require surgical access. We aimed to develop a percutaneous defibrillation system with partially-insulated epicardial coils to focus electrical energy on the myocardium and prevent or minimize extra-cardiac stimulation.

Methods: We tested 2 prototypes created for percutaneous introduction into the pericardial space via a steerable sheath.

Differential likelihood of NSTEMI vs STEMI in patients with sleep apnea.

Background: Sleep apnea (SA) is associated with intermittent hypoxemia that may lead to ischemic preconditioning in the myocardium. This potential cardioprotective effect of SA may play a role in the development of non-ST-elevation myocardial infarction (NSTEMI) versus ST-elevation myocardial infarction (STEMI) during acute ischemia. However, there is limited evidence about the relative prevalence of NSTEMI versus STEMI in SA patients.

Percutaneous Epicardial Pacing using a Novel Insulated Multi-electrode Lead.

Introduction: Epicardial cardiac resynchronization therapy (CRT) permits unrestricted electrode positioning. However, this requires surgical placement of device leads and the risk of unwanted phrenic nerve stimulation. We hypothesized that shielded electrodes can capture myocardium without extracardiac stimulation.

Novel Techniques in Epilepsy Management: Venous Pacing and Capture of Electrical Activity in the Primate Cortex.

Objective: Pharmacotherapy for epilepsy is limited with 30% of patients refractory to this approach of suppressing seizures. Current surgical options are invasive and carry significant morbidities including infection, bleeding, and the potential for deleterious neurocognitive effects. As a result, there is a burgeoning need for innovation to develop safer and efficacious interventions.

Sleep, sleep deprivation, autonomic nervous system and cardiovascular diseases.

Sleep deprivation (SD) has become a relevant health problem in modern societies. We can be sleep deprived due to lifestyle habits or due to sleep disorders, such as insomnia, obstructive sleep apnea (OSA) and neurological disorders. One of the common element of sleep disorders is the condition of chronic SD, which has complex biological consequences.

Current Status of Left Ventricular Assist Device Therapy.

Congestive heart failure (HF) remains a serious burden in the Western World. Despite advances in pharmacotherapy and resynchronization, many patients have progression to end-stage HF. These patients may be candidates for heart transplant or left ventricular assist device (LVAD) therapy.

Longitudinal tracking of muscle sympathetic nerve activity and its relationship with blood pressure in subjects with prehypertension.

Prehypertension is associated with increased cardiovascular events. While the "tracking phenomenon" is an important longitudinal characteristic of blood pressure (BP), changes in muscle sympathetic nerve activity (MSNA) over time remain unclear. This study tested the hypothesis that MSNA tracking contributes to BP trends in prehypertension.

Primary PCI is associated with different cardiac autonomic patterns in relation to the site of myocardial infarction.

Aim: Reflex alterations of cardiac autonomic modulation have been described after acute myocardial infarction (AMI). The non-homogeneous autonomic innervation of the heart gives reason of different patterns of autonomic modulation depending upon the site of AMI. Conflicting data are available on cardiac autonomic modifications after primary percutaneous coronary intervention (pPCI).

Effect of beta-blocker therapy on heart rate response in patients with hypertension and newly diagnosed untreated obstructive sleep apnea syndrome.

Background: Beta1-receptor antagonists (BBs) are commonly administered in the treatment of cardiovascular disease (CVD). The reported benefits of BB use in CVD patients with concomitant obstructive sleep apnea (OSA) may be limited by their impact on apnea-induced bradycardias. Therefore the aim of the study was to test the influence of BBs on periapneic heart rate (HR) fluctuations in hypertensive patients with newly-detected and untreated OSA.

Effects of Atorvastatin (80 mg) Therapy on Quantity of Epicardial Adipose Tissue in Patients Undergoing Pulmonary Vein Isolation for Atrial Fibrillation.

Epicardial adipose tissue (EAT) has been recognized as a sensitive marker of cardiometabolic risk. Recent evidence suggests efficacy of long-term statin therapy in reducing EAT in patients with coronary artery disease. Whether short-term statin therapy is associated with changes in the volume of EAT is currently unknown.

Comparison of sublingual isosorbide dinitrate and Valsalva maneuver for detection of obstruction in hypertrophic cardiomyopathy.

Introduction: A left ventricular outflow tract (LVOT) obstruction assessment with a provoking test should be a routine part of the evaluation of patients with hypertrophic cardiomyopathy (HCM). The aim of this study was to compare the utility of the Valsalva maneuver (VM) and sublingual spray application of isosorbide dinitrate (ISDN) for detection of an obstruction.

Material And Methods: We prospectively evaluated 81 consecutive HCM patients without severe rest LVOT obstruction (defined as peak rest pressure gradient (PG) ≥ 50 mm Hg).

Effects of the Mueller maneuver on functional mitral regurgitation and implications for obstructive sleep apnea.

Obstructive sleep apnea is prevalent and adversely affects cardiovascular health. However, little is known of the acute effects of an obstructive apnea on cardiovascular physiology. We hypothesized that pre-existing functional mitral regurgitation (MR) would worsen during performance of a Mueller maneuver (MM) used to simulate an obstructive apnea; 15 subjects with an ejection fraction ≤35% and pre-existing functional MR were studied with Doppler echocardiography.

Decreased exercise capacity and sleep-disordered breathing in patients with hypertrophic cardiomyopathy.

Background: Mechanisms of decreased exercise capacity in patients with hypertrophic cardiomyopathy (HCM) are not well understood. Sleep-disordered breathing (SDB) is a highly prevalent but treatable disorder in patients with HCM. The role of comorbid SDB in the attenuated exercise capacity in HCM has not been studied previously.

Cardiac transplantation for radiation-induced cardiomyopathy: the Mayo Clinic experience.

Background: High-dose radiotherapy to the mediastinum for the treatment of malignancies causes injury to the intrathoracic organs. Coronary artery disease, valvular dysfunction, cardiomyopathy, and chronic constrictive pericarditis are common cardiovascular sequelae during long-term follow-up. Cardiac transplantation is indicated for the surgical treatment of heart failure due to radiation-induced end-stage cardiac disease.

Chemoreflexes, sleep apnea, and sympathetic dysregulation.

Obstructive sleep apnea (OSA) and hypertension are closely linked conditions. Disordered breathing events in OSA are characterized by increasing efforts against an occluded airway while asleep, resulting in a marked sympathetic response. This is predominantly due to hypoxemia activating the chemoreflexes, resulting in reflex increases in sympathetic neural outflow.

Sleep apnea prevalence in acute myocardial infarction--the Sleep Apnea in Post-acute Myocardial Infarction Patients (SAPAMI) Study.

Background: While sleep apnea (SA) might be a modifiable cardiovascular risk factor, recent data suggest that SA is severely underdiagnosed in patients after acute myocardial infarction (MI). There is limited evidence about day-night variation of onset of MI on dependence of having SA. We therefore investigated the prevalence of SA and examined the day-night variation of onset of MI in acute MI patients.

MicroRNAs involved in the lipid metabolism and their possible implications for atherosclerosis development and treatment.

Hyperlipidemia is a well-accepted risk factor in the development of atherosclerosis. MicroRNAs (miRNAs), a novel class of posttranscriptional regulators of gene expression, are involved in a variety of biological and pathological processes, including the regulation of the lipid metabolism and atherosclerosis. As our knowledge of miRNAs expands, a new class of "circulating miRNAs" has recently been described.

Advances in radiofrequency ablation of the cerebral cortex in primates using the venous system: Improvements for treating epilepsy with catheter ablation technology.

Background: Pharmacology frequently fails for the treatment of epilepsy. Although surgical techniques are effective, these procedures are highly invasive. We describe feasibility and efficacy of minimally invasive mapping and ablation for the treatment of epilepsy.