Exercise induced bradycardia

BACKGROUND: Right-sided vagus nerve stimulation (RS-VNS) is indicated when the procedure was deemed not technically feasible or too risky on the indicated left side. OBJECTIVE: The present study aims to systematically review the literature on RS-VNS, assessing its effectiveness and safety. METHODS: A systematic review following PRISMA guidelines was conducted: Pubmed/MEDLINE, The Cochrane Library, Scopus, Embase and Web of science databases were searched from inception to August 13th,2023...

BACKGROUND: Primary autonomic failure (PAF) or Bradbury Eggleston syndrome is a neurodegenerative disorder of the autonomic nervous system characterized by orthostatic hypotension. CASE SUMMARY: We report the case of a 76-year-old patient with a history of hypertension, who presented with exercise-induced fatigue. He exhibited systolic hypertension and resting bradycardia in the supine position, with orthostatic hypotension without reactive tachycardia, suggesting dysautonomia...

BACKGROUND: Myocardial abnormalities are sometimes overlooked in congenital heart disease (CHD). The co-existence of hypertrophic cardiomyopathy is so uncommon that it is assumed to be a coincidence rather than an association. CASE SUMMARY: A 24-year-old gentleman, who was previously clinically well following a staged Fontan palliation for single-ventricle CHD, was transferred to our centre following an out-of-hospital cardiac arrest. He had return of spontaneous circulation after a period of cardiopulmonary resuscitation...

Arrhythmogenic cardiomyopathy (AC) is an inherited disorder characterized by progressive loss of the ventricular myocardium causing life-threatening ventricular arrhythmias, syncope and sudden cardiac death in young and athletes. About 40% of AC cases carry one or more mutations in genes encoding for desmosomal proteins, including Desmoplakin (Dsp). We present here the first stable Dsp knock-out (KO) zebrafish line able to model cardiac alterations and cell signalling dysregulation, characteristic of the AC disease, on which environmental factors and candidate drugs can be tested...

Six months ago, a middle-aged African American male visited the cardiology clinic for a follow-up on acute coronary syndrome along with atrial fibrillation. The patient was initially diagnosed with unstable angina with palpitation and underwent cardiac catheterization. During the visit, the patient complained of unspecific chest discomfort, palpitation, and reduced exercise tolerance after the use of cocaine for several months. ECG showed the absence of atrial fibrillation but instead showed atrial flutter with bradycardia...

The existence of a tetrafascicular intraventricular conduction system is widely accepted by researchers. In this review, we have updated the criteria for left septal fascicular block (LSFB) and the differential diagnosis of prominent anterior QRS forces. More and more evidence points to the fact that the main cause of LSFB is critical proximal stenosis of the left anterior descending coronary artery before its first septal perforator branch. The most important characteristic of LSFB that has been incorporated in the corresponding diagnostic electrocardiographic criteria is its transient/intermittent nature mostly observed in clinical scenarios of acute (ie, acute coronary syndrome including vasospastic angina) or chronic (ie, exercise-induced ischemia) ischemic coronary artery disease...

Hypertension augments while exercise training corrects the increased vesicle trafficking (transcytosis) across the blood-brain barrier (BBB) within preautonomic areas and the autonomic imbalance. There is no information on possible mechanism(s) conditioning these effects. Knowing that Mfsd2a is the major transporter of docosahexaenoic acid (DHA) and that Mfsd2a knockout mice exhibited leaky BBB, we sought to identify its possible involvement in hypertension- and exercise-induced transcytosis across the BBB...

Introduction: Chronic hypertension is accompanied by either blood-brain barrier (BBB) leakage and autonomic dysfunction. There is no consensus on the mechanism determining increased BBB permeability within autonomic areas. While some reports suggested tight junction's breakdown, others indicated the involvement of transcytosis rather than paracellular transport changes. Interestingly, exercise training was able to restore both BBB permeability and autonomic control of the circulation. We sought now to clarify the mechanism(s) governing hypertension- and exercise-induced BBB permeability...

Despite consensus on the benefits of food readjustment and/or moderate-intensity continuous exercise in the treatment of cardiometabolic risk factors, there is little evidence of the association between these two cardiovascular risk management strategies after menopause. Thus, the objective of this study was to evaluate the effects of food readjustment and/or exercise training on metabolic, hemodynamic, autonomic, and inflammatory parameters in a model of loss of ovarian function with diet-induced obesity. Forty C57BL/6J ovariectomized mice were divided into the following groups: high-fat diet-fed - 60% lipids throughout the protocol (HF), food readjustment - 60% lipids for 5 weeks, readjusted to 10% for the next 5 weeks (FR), high-fat diet-fed undergoing moderate-intensity exercise training (HFT), and food readjustment associated with moderate-intensity exercise training (FRT)...

The dive response allows marine mammals to perform prolonged breath-hold dives to access rich marine prey resources. Via dynamic adjustments of peripheral vasoconstriction and bradycardia, oxygen consumption can be tailored to breath-hold duration, depth, exercise, and even expectations during dives. By investigating the heart rate of a trained harbor porpoise during a two-alternative forced choice task, where the animal is either acoustically masked or blindfolded, we test the hypothesis that sensory deprivation will lead to a stronger dive response to conserve oxygen when facing a more uncertain and smaller sensory umwelt...

Physiological and environmental stressors can cause osmotic stress in fish hearts, leading to a reduction in intracellular taurine concentration. Taurine is a beta amino acid known to regulate cardiac function in other animal models but its role in fish has not been well characterized. We generated a model of cardiac taurine-deficiency (TD) by feeding brook char (Salvelinus fontinalis) a diet enriched in β-alanine, which inhibits cardiomyocyte taurine uptake. Cardiac taurine levels were reduced by 21% and stress-induced changes in normal taurine handling were observed in TD brook char...

BACKGROUND: A preclinical model standardized at different remodeling stages after AV block induction in awake state is suitable for the evaluation of improved cardiac devices. We studied exercise-induced cardiorespiratory parameters at three different timepoints after inducing AV block in dogs. METHODS: Mongrel dogs (n = 12) were placed on a treadmill with a 10% incline and performed a moderate exercise protocol (10-minute run at 6 km/h). Dogs ran at sinus rhythm (SR), at two days (AVB2d, initiation of remodeling), three weeks (CAVB3) and six weeks (CAVB6, completed remodeling) after AV block...

Aureobasidium melanogenum is a saprophytic, dematiaceous, yeast-like fungus rarely implicated in human infections. Here, we report the first case of A. melanogenum fungemia in a 30-week-old preterm, very low birth weight neonate born to a primigravida with history of gestational diabetes, pregnancy induced hypertension and oligohydramnios. The baby developed respiratory distress, hypotension, bradycardia, coagulopathy and septic shock shortly after birth, and eventually succumbed to multiple organ dysfunction syndrome on day 9 of life...

Prolongation of the PR interval is common among competitive athletes. However, further investigations should be performed when the PR interval is markedly prolonged. We report the case of a young male athlete with an autoimmune-mediated atrioventricular block due to circulating anti-Ro/SSA-antibodies in the mother (late progressive congenital form). ( Level of Difficulty: Advanced. ).

Introduction: Cold water exposure poses a unique physiological challenge to the human body. Normally, water submersion increases activation of parasympathetic tone to induce bradycardia in order to compensate for hemodynamic shifts and reduce oxygen consumption by peripheral tissues. However, elevated stress, such as that which may occur due to prolonged cold exposure, may shift the sympatho-vagal balance towards sympathetic activation which may potentially negate the dive reflex and impact thermoregulation...

Besides the health benefits of regular exercise, high-level training - above an optimal level -may have adverse effects. In this study, we investigated the effects of long-term vigorous training and its potentially detrimental structural-functional changes in a small animal athlete's heart model. Thirty-eight 4-month-old male guinea pigs were randomised into sedentary and exercised groups. The latter underwent a 15-week-long endurance-training program. To investigate the effects of the intense long-term exercise, in vivo (echocardiography, electrocardiography), ex vivo and in vitro (histopathology, patch-clamp) measurements were performed...

This case study provides an example of bradycardia associated with an increase in exercise training in a recreational athlete. Although recognised among high-level endurance athletes, this case demonstrates the potential negative effects of exercise on the heart in a patient participating in the levels of exercise recommended by Public Health England. It adds weight to the ongoing discussion of the incomplete understanding of the level of exercise needed to induce pathological changes in cardiac physiology...

BACKGROUND: The purpose of the present study was to investigate the effects of bradycardia induced by pre-exercise acupuncture on heart rate responses during short-duration exercise. METHODS: A total of 29 healthy subjects underwent two protocols: protocol 1 assessed the effects of manual acupuncture on heart rate response during rest, and protocol 2 tested the hypothesis that the bradycardic effects induced by pre-exercise acupuncture continue during low- and high-intensity exercise...

Although hypertension disrupts the blood-brain barrier (BBB) integrity within the paraventricular nucleus of hypothalamus (PVN) and increases the leakage into the brain parenchyma, exercise training (T) was shown to correct it. Since there is scarce and contradictory information on the mechanism(s) determining hypertension-induced BBB deficit and nothing is known about T-induced improvement, we sought to evaluate the paracellular and transcellular transport across the BBB within the PVN in both conditions. Spontaneously hypertensive rats (SHR) and WKY submitted to 4-wk aerobic T or sedentary (S) protocol were chronically catheterized for hemodynamic recordings at rest and intra-arterial administration of dyes (Rhodamine-dextran 70 kDa + FITC-dextran 10 kDa)...

Introduction: Acute apnea evokes bradycardia and peripheral vasoconstriction in order to conserve oxygen, which is more pronounced with face immersion. This response is contrary to the tachycardia and increased blood flow to muscle tissue related to the higher oxygen consumption during exercise. The aim of this study was to investigate cardiovascular and metabolic responses of dynamic dry apnea (DRA) and face immersed apnea (FIA). Methods: Ten female volunteers (17.1 ± 0.6 years old) naive to breath-hold-related sports, performed a series of seven dynamic 30 s breath-holds while cycling at 25% of their peak power output...