Richard Sutton

Imperial College London | Imperial · Cardiovascular Sciences

There is a perceived need to express concisely the advice of guidelines in the context of consideration of invasive management of highly symptomatic vasovagal syncope. In response to this need the table is presented as a checklist and the text adds explanation and details. It is anticipated that this will prove to be of value for clinicians.

Aims The pathophysiology of orthostatic hypotension (OH), a common clinical condition, associated with adverse outcomes, is incompletely understood. We examined the relationship between OH and circulating endostatin, an endogenous angiogenesis inhibitor with antitumor effects proposed to be involved in blood pressure (BP) regulation. Methods We co...

A reply letter addressing some of the criticism on exercise training in post-COVID POTS.

Cardiovascular autonomic dysfunction (CVAD) is a malfunction of the cardiovascular system caused by deranged autonomic control of circulatory homeostasis. CVAD is an important component of post-COVID-19 syndrome, also termed long COVID, and might affect one-third of highly symptomatic patients with COVID-19. The effects of CVAD can be seen at both...

Objectives Vasospastic angina (VSA) is a complex coronary vasomotor disorder associated with an increased risk of myocardial infarction and sudden death. Despite considerable advances in understanding VSA pathophysiology, the interplay between genetic and environmental factors remains elusive. Accordingly, we aimed to determine the familial VSA ris...

Background/Aims: Postural orthostatic tachycardia syndrome (POTS) is a chronic condition in which patients show a marked increase in heart rate on standing, but also suffer from a range of additional symptoms, which may include fatigue and difficulty in concentration. This study’s aim was to investigate the role of psychological stress, resilience,...

Background Orthostatic hypotension (OH) occurs when blood pressure regulation fails. The underlying molecular mechanism of OH remain largely unexplored. Endostatin is a biologically active molecule cleaved by matrix metalloproteinases, elastases and cathepsins from collagen XVIII in the extracellular matrix and inhibits angiogenesis. Circulating le...

Tilt table testing (TTT) has been used for decades to study short‐term blood pressure (BP) and heart rate regulation during orthostatic challenges. TTT provokes vasovagal reflex in many syncope patients as a background of widespread use. Despite the availability of evidence‐based practice syncope guidelines, proper application and interpretation of...

Tilt testing can help to diagnose unexplained syncope, by precipitating an episode during cardiac monitoring. The Italian protocol, now most widely used, involves giving sublingual nitroglycerine after 15 min, while monitoring beat-to-beat blood pressure (BP) and recording on video. Tilt testing is time-consuming but it is clinically useful and can...

Over the last 25 years, the Europace journal has greatly contributed to dissemination of research and knowledge in the field of syncope. More than 400 manuscripts have been published in the journal. They undoubtedly improved our understanding of syncope. This symptom is now clearly differentiated from other forms of transient loss of consciousness....

Background and aim: Syncope is a common condition with many possible causes, ranging from benign to life-threatening aetiologies. Establishing a diagnosis can be difficult and specialized syncope units, using cardiovascular autonomic tests (CAT) including head-up tilt test can increase the diagnostic yield. However, up to one fifth of examined pat...

This paper aims to improve the diagnosis of syncope and transient loss of consciousness (TLOC) in children. Diagnostic problems stem, first, from some causes spanning various disciplines, e.g. cardiology, neurology and psychiatry, while the most common cause, vasovagal syncope, is not embraced by any specialty. Second, clinical variability is huge...

Background: Postural orthostatic tachycardia syndrome (POTS) is a heterogeneous condition predominantly affecting autonomic control of the cardiovascular system. Its extensive symptom diversity implies multi-organ involvement that interacts in ways still requiring full exploration. Current understanding of POTS pathophysiology suggests alterations...

Background: Pacing for vasovagal syncope is established. Two pacing algorithms are available. The rate-drop-response (RDR-Medtronic) is triggered by falling heart rate acting with modified rate-hysteresis. The closed loop stimulation or system (CLS-Biotronik) is triggered by impedance changes in the right ventricle reflecting falling volume and ri...

Open in new tabDownload slide Evolution of the tilt test protocol for reflex syncope and autonomic dysfunction 1986–2023. The left side represents evolution of the tilt test protocol for reflex syncope leading to the ‘Fast Italian protocol’, and years when changes were introduced. Tilt angles have progressively increased, with 70° now being the no...

Introduction Postural Orthostatic Tachycardia Syndrome (POTS) is a disorder characterized by excessive orthostatic tachycardia and orthostatic intolerance. While traditional inflammatory biomarkers tend to be normal, a subclinical inflammatory process may be present in POTS. Purpose We aimed to analyse novel inflammatory biomarkers in POTS patient...

Open in new tabDownload slide Practical decision pathway for the management of vasovagal syncope. Please see text for details. White circles demonstrate sites of grouping of autonomic ganglia defined as ganglionated plexi (GP). The superior right atrial GP (RSGP) located on the posterosuperior surface of the right atrium adjacent to the junction o...

Background Ambulatory blood pressure (BP) monitoring has long been used to monitor BP in hypertension and lately emerged as a useful tool to detect hypotensive susceptibility in reflex syncope. However, hemodynamic characteristics in reflex syncope have not been sufficiently explored. The present study investigated the differences between ambulator...

Objective: A substantial number of patients with a transient loss of consciousness (T-LOC) are referred to a tertiary syncope unit without a diagnosis. This study investigates the final diagnoses reached in patients who, on referral, were undiagnosed or inaccurately diagnosed in secondary care. Methods: This study is an in-depth analysis of the...

Orthostatic intolerance and other autonomic dysfunction syndromes are emerging as distinct symptom clusters in Long Covid. Often accompanying these are common, multi-system constitutional features such as fatigue, malaise and skin rashes which can signify generalised immune dysregulation. At the same time, multiple autoantibodies are identified in...

Orthostatic intolerance and other autonomic dysfunction syndromes are emerging as distinct symptom clusters in Long Covid. Often accompanying these are common, multi-system constitutional features such as fatigue, malaise and skin rashes which can signify generalized immune dysregulation. At the same time, multiple autoantibodies are identified in...

Background: Complete atrioventricular block (CAVB) is a major reason for implantation of permanent pacemakers, but knowledge of CAVB inheritance is sparse. This nationwide study aimed to determine the occurrence of CAVB in first-, second-, and third-degree relatives (full siblings, half-siblings, and cousins). Methods: The Swedish multigeneratio...

Our recent comment on POTS being a common sequela of COVID-19 in the spectrum of Long COVID variants.

Aims To determine the familial incidence of dilated (DCM) and hypertrophic cardiomyopathy (HCM) in first-, second- and third-degree relatives of affected individuals. Methods and results In this population-based multigenerational cohort study, full-siblings, half-siblings, and cousin pairs born to Swedish parents between 1932 and 2015 were include...

Background Postural orthostatic tachycardia syndrome (POTS) is a common cardiovascular autonomic disorder characterized by excessive heart rate increase on standing and symptoms of orthostatic intolerance, posing significant limitations on functional capacity. No objective tool exists to classify symptom burden in POTS. Methods We conducted a case...

Postural orthostatic tachycardia syndrome (POTS) is a cardiovascular autonomic disorder characterized by excessive heart rate increase on standing, leading to debilitating symptoms with limited therapeutic possibilities. Proteomics is a large-scale study of proteins that enables a systematic unbiased view on disease and health, allowing stratificat...

Technological advances have made diagnosis of heart rhythm disturbances much easier, with a 8 wide variety of options, including single-lead portable devices, smartphones/watches to 9 sophisticated implantable cardiac monitors, allowing accurate data to be collected over different 10 time periods depending on symptoms frequency. 11 This review prov...

Background Diagnostic criteria for ambulatory blood pressure monitoring (ABPM) in patients with suspected reflex syncope are lacking. Purpose We hypothesized that patients with reflex syncope have a higher prevalence of systolic blood pressure (SBP) drops on ABPM than control subjects and we aimed to define the SBP cut-off values that allow identi...

Aims: This study aims to determine the familial incidence of dilated (DCM) and hypertrophic cardiomyopathy (HCM) in first-degree, second-degree, and third-degree relatives of affected individuals. Methods and results: In this population-based multigenerational cohort study, full-siblings, half-siblings, and cousin pairs born to Swedish parents b...

Background: Postural orthostatic tachycardia syndrome (POTS) is a common cardiovascular autonomic disorder characterized by excessive heart rate (HR) increase on standing and symptoms of orthostatic intolerance, posing significant limitations on functional capacity. No objective tool exists to classify symptom burden in POTS. Methods: We conduct...

Open in new tabDownload slide Conduction system pacing in perspective. Abbreviations: RVP = right ventricular pacing; BiV = biventricular pacing; CSP = conduction system pacing; HBP = His bundle pacing; LBBAP = left bundle branch area pacing; CRT = cardiac resynchronization therapy; HOT-CRT = His-optimized CRT; LOT-CRT = left bundle branch optimiz...

This review addresses tilt-testing methodology by searching the literature which reports timing of asystole and loss of consciousness (LOC). Despite the Italian protocol being the most widely adopted, its stipulations are not always followed to the letter of the European Society of Cardiology guidelines. The discrepancies permit reassessment of the...

Recent technological advances have facilitated and diversified the options available for the diagnosis of cardiac arrhythmias. Ranging from simple resting or exercise electrocardiograms to more sophisticated and expensive smartphones and implantable cardiac monitors. These tests and devices may be used for varying periods of time depending on sympt...

Blood pressure regulation is an automatic, moment-by-moment buffering of the blood pressure in response to physiological changes such as orthostasis, exercise and haemorrhage. This finely orchestrated reflex is called the baroreflex. It is a regulated arc of afferent, central and efferent arms. Multiple physiological changes occur with ageing that...

Age-related physiological impairment increases susceptibility to syncope. We tested the hypotheses that cerebral oxygenation during orthostatic provocation, as well as the level at which syncope occurs, differs according to age. Non-invasive hemodynamic monitoring and cerebral oximetry were applied during a head-up tilt test in 139 patients with va...

Background Cardioinhibition may diminish with age, but the changing balance of cardioinhibition and vasodepression with age has not been quantified, leaving the mechanism of vasovagal syncope (VVS) in old age unclear. Objectives This study sought to quantify age-related changes of vasodepression and cardioinhibition in tilt-induced VVS. Methods W...

Aims: Diagnostic criteria for ambulatory blood pressure monitoring (ABPM) in patients with suspected reflex syncope are lacking. The study hypothesis was that patients with reflex syncope have a higher prevalence of systolic blood pressure (SBP) drops on ABPM. Methods and results: ABPM data from reflex syncope patients and controls, matched by a...

Objective: Diagnostic criteria for ambulatory blood pressure monitoring (ABPM) in patients with suspected reflex syncope are lacking. We hypothesized that patients with reflex syncope have a higher prevalence of systolic blood pressure (SBP) drops on ABPM. Design and method: We conducted a retrospective analysis comparing ABPM data from reflex s...

Objective: Implantable cardiac monitors (ILR) have an important role in diagnosing unexplained syncope. However, outcomes of primary vs. delayed ILR implantation after initial syncope evaluation have not been explored. Methods: A total of 1705 patients with unexplained syncope were prospectively enrolled in the SYSTEMA (Syncope Study of Unselect...

Aims: Unexplained syncope is an important clinical challenge. The influence of age at first syncope on the final syncope diagnosis is not well studied. Methods and results: Consecutive head-up tilt patients (n = 1928) evaluated for unexplained syncope were stratified into age groups <30, 30-59, and ≥60 years based on age at first syncope. Clinic...

Introduction: Out-of-hospital cardiac arrest (OHCA) is a big medical problem. Material and methods: The aim of this study was to assess the occurrence of sitting position in victims of OHCA at the arrival of Emergency Medical Services (EMS) and examine whether maintaining a supine position until ambulance arrival impacts the return of spontaneous c...

Syncope is an alarming event carrying the possibility of serious outcomes, including sudden cardiac death (SCD). Therefore, immediate risk stratification should be applied whenever syncope occurs, especially in the Emergency Department, where most dramatic presentations occur. It has long been known that short- and long-term syncope prognosis is af...

Background Syncope is a common clinical problem with a sharp rise in the incidence after 70 years. In older patients, syncope is often a diagnostic challenge. It is unclear whether the age at which patients experience syncope for the first time impacts the results of syncope investigation. Purpose To study the influence of early-onset vs. mature-o...

Syncope is a frequent event in the general population. Approximately 1%-2% of all emergency department admissions are due to syncope and at least one third of all people experience fainting in their life. Although consequences of cardiac syncope are generally feared, non-cardiac syncope is much more common and may be associated with severe injuries...

Aim of this study was to explore whether differences in resting hemodynamic parameters may be associated with tilt test results in unexplained syncope. We analyzed age, gender, systolic (SBP), diastolic blood pressure (DBP) and heart rate (HR) by merging three large databases of patients considered likely to be of vasovagal reflex etiology, compari...

Background Impaired orthostatic blood pressure response and syncope confer a high risk of falls and trauma. The relationship between a history of unexplained syncope and orthostatic hypotension (OH) with subsequent fractures, however, has not been thoroughly examined. In this study, we aimed to investigate the relationship between previous hospital...

n this Specialty Grand Challenge, we outline our vision of the current challenges in the field of Network Physiology (Bashan et al., 2012; Bartsch et al., 2015; Ivanov et al., 2014) as applied to aging and frailty. An expected development in this field for the 21st century is the modelling of the widely used (but still poorly understood) concept of...

Pro Memoriam Dr. Artur Pietrucha

The recent recommendations regarding tilt table testing (TTT) from the European Federation of Autonomic Societies (EFAS) provides a rationale and evidence-base for the use of TTT in conditions that cause transient loss of consciousness (TLOC) and insights into current attitudes regarding TTT.1, 2 Historically, only few neurologists took an interest...

Background Practice guidelines provide clinicians direction for the selection of ambulatory ECG (AECG) monitors in the evaluation of syncope/collapse. However, whether patients’ understand differences among AECG systems is unknown. Methods and Results A survey was conducted of USA (n = 99), United Kingdom (UK)/Germany (D) (n = 75) and Japan (n = 4...

Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Swedish Heart and Lung Foundation, The Swedish Heart and Lung Association, ALF funds, Skåne University Hospital Funds, The Crafoord Foundation. Background There is an increased susceptibility to syncope with aging attributed to age...

Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): The study was funded by The Swedish Heart-Lung Foundation, The Greta and Johan Kock Foundation, and an Agreement for Medical Education and Research (ALF) grant by Swedish Research Council funding for clinical research in medicine. Background Fragility fractures a...

Orthostatic hypotension (OH) is very common in older people and is encountered daily in emergency departments and medical admissions units. It is associated with a higher risk of falls, fractures, dementia and death, so prompt recognition and treatment are essential. In this review article, we describe the physiology of standing (orthostasis) and t...

Postural orthostatic tachycardia syndrome (POTS) is a cardiovascular autonomic disorder with poorly understood etiology and underlying pathophysiology. Since cardiovascular morbidity has been linked to growth hormone (GH), we studied GH levels in patients with POTS. We conducted an age-sex-matched case–control study in patients with POTS (age 31 ±...

Importance Reflex syncope is the major cause of transient loss of consciousness, which affects one-third of the population, but effective treatment for individuals with severe syncope is lacking. Better understanding of reflex syncope predisposition may offer new therapeutic solutions. Objectives To determine the familial risk of syncope in first-...

An expert committee was formed to reach consensus on the use of tilt table testing (TTT) in the diagnosis of disorders that may cause transient loss of consciousness (TLOC) and to outline when other provocative cardiovascular autonomic tests are needed. While TTT adds to history taking, it cannot be a substitute for it. An abnormal TTT result is mo...

This commentary refers to 'Cardiac pacing in severe recurrent reflex syncope and tilt-induced asystole', by M. Brignole et al., doi:10.1093/eurheartj/ehaa936 and the discussion piece 'Effectiveness of Closed Loop Stimulation pacing in patients with cardio-inhibitory vasovagal reflex syncope is questionable', by W. Wieling and D.L. Jardine, doi:10.1...

Swallow (deglutition) syncope is a rare form of neurally mediated cardioinhibitory reflex syncope occurring during swallowing. Patients may present to clinicians across multiple disciplines, so high awareness and careful evaluation are essential. We report 3 such individuals, describing our strategies in diagnosis, investigation and treatment, part...

An expert committee was formed to reach consensus on the use of Tilt Table Testing (TTT) in the diagnosis of disorders that may cause transient loss of consciousness (TLOC) and to outline when other provocative cardiovascular autonomic tests are needed. While TTT adds to history taking, it cannot be a substitute for it. An abnormal TTT result is mo...

Head-up tilt test (TT) has been used for >50 years to study heart rate/blood pressure adaptation to positional changes, to model responses to haemorrhage, to assess orthostatic hypotension, and to evaluate haemodynamic and neuroendocrine responses in congestive heart failure, autonomic dysfunction, and hypertension. During these studies, some subje...

Background: Heart rate control in atrial fibrillation (AF) is typically assessed by 24-hour electrocardiography (ECG). There are scarce data on the use of 24-hour ECG parameters to predict mortality in AF. Aims: We aimed to identify 24-hour ECG parameters that predict mortality in AF. Methods: We enrolled 280 ambulatory patients (mean [SD] age...

Click here to view the Original Article by J. du Fay de Lavallaz et al

Aims Tilt testing (TT) is recognized to be a valuable contribution to the diagnosis and the pathophysiology of vasovagal syncope (VVS). This study aimed to assess the influence of age on TT responses by examination of a large patient cohort. Methods and results Retrospective data from three experienced European Syncope Units were merged to include...

Background: We hypothesized that cardiovascular physiology differs in reflex syncope patients compared with the general population, predisposing such individuals to vasovagal reflex. Methods: In this multicohort cross-sectional study, we compared aggregate data of resting SBP, DBP, pulse pressure (PP) and heart rate (HR), collected from six comm...

Background Electrocardiographic (ECG) characteristics of patients with isolated hypomagnesemia are not well defined. We aimed to investigate these ECG characteristics in order to define clearly the features of isolated hypomagnesemia. Hypothesis Lower serum magnesium could affect ECG parameters after excluding potential confounders. Methods This...

The guidelines of the European Society of Cardiology and the American College of Cardiology provide clinical tips on how to recognize TLOC, its major etiologic groups, and specific syncope forms. The classification of TLOC and syncope applies regardless of age. The differences between adults and children are mostly epidemiological in nature, with a...

BACKGROUND We hypothesized that cardiovascular physiology differs in reflex syncope patients compared with general population, predisposing such subjects to vasovagal reflex. METHODS In this multicohort cross-sectional study, we compared resting systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP) and heart rate (HR),...

The SARS-CoV-2 (COVID-19) pandemic has caused unprecedented morbidity, mortality and global disruption. Following the initial surge of infections, focus shifted to managing the longer-term sequelae of illness in survivors. 'Post-acute COVID' (known colloquially as 'long COVID') is emerging as a prevalent syndrome. It encompasses a plethora of debil...

Background Postural orthostatic tachycardia syndrome (POTS) is a variant of cardiovascular autonomic disorder occurring predominantly in young women. POTS is characterized by an excessive heart rate increase when assuming upright posture accompanied by symptoms of orthostatic intolerance. The pathophysiology of POTS has not been fully established a...

“This volume of Frontiers Cardiovascular Medicine has been generated by the Editors with very close cooperation of many of the leaders in the field of syncope. The aim was to compile a substantial group of papers presenting recent work and contemporary reviews in the field. We felt a need to address a new focus on the genetics of vasovagal syncope...

Editorial on the Research Topic Syncope: Today and Tomorrow This volume of Frontiers Cardiovascular Medicine has been generated by the Editors with very close cooperation of many of the leaders in the field of syncope. The aim was to compile a substantial group of papers presenting recent work and contemporary reviews in the field. We felt a need t...

Background Postural orthostatic tachycardia syndrome (POTS) is characterized by excessive heart rate increase on standing and orthostatic intolerance. Previous data indicate autoimmune involvement. We studied serum activity against G protein–coupled receptors in relation to symptoms in patients with POTS and controls using a commercial cell‐based a...

Aim: Head injury is the most common trauma occurring in syncope. We aimed to assess whether syncope as cause of head-trauma affects short-and long-term prognosis. Methods: From a database retrospective analysis of 97,014 individuals attending Emergency Department (ED), we selected data of patients with traumatic head injury including age, gender, i...

Despite availability of practice Guidelines directing appropriate use of ambulatory electrocardiographic (AECG) monitoring, clinician prescription of AECGs is sometimes less than ideal, and patients are often under-informed concerning the diagnostic monitoring devices available and reasons for their selection. Findings from studies in both the USA...

The most important diagnostic tool available in assessment of dysfunction of the autonomic control of the heart is the clinical history which must be taken in the greatest possible detail including from the patient and witnesses of the syncope/event. Correct history taking will make many diagnoses avoiding need for further testing and guide further...

We disagree with the Perspective by Kulkarni et al 1 who, without offering any convincing data, advocate abolition of head-up tilt testing (HUT) for diagnosing syncope. The method was introduced ≈30 years ago to assess susceptibility to va-sovagal syncope by orthostatic challenge. Recently, expert groups in North America and Europe have independent...

Background: Postural orthostatic tachycardia syndrome (POTS) is a variant of cardiovascular (CV) autonomic disorder of unknown etiology characterized by an excessive heart rate increase on standing and orthostatic intolerance. In this study we sought to identify novel CV biomarkers potentially implicated in POTS pathophysiology. Methods: We cond...

Reflex atrioventricular block is well-recorded although it is considered rare. Recent data suggests that it is less rare than has been supposed. It has been shown to occur in both vasovagal and carotid sinus reflexes. It has to be distinguished from paroxysmal atrioventricular block due to ventricular conduction tissue disease. Low chronic adenosin...

Although diagnostic criteria have been developed characterizing postural orthostatic tachycardia syndrome (POTS), no single set of criteria is universally accepted. Furthermore, there are gaps in the present criteria to identify individuals who have this condition. The reproducibility of the physiological findings, the relationship of symptoms to p...

Background: Orthostatic hypotension (OH) is a major sign of cardiovascular autonomic failure leading to orthostatic intolerance and syncope. Orthostatic hypotension is traditionally divided into classical OH (cOH) and delayed OH (dOH), but the differences between the two variants are not well-studied. We performed a systematic clinical and neuroend...

The role of pacing in vasovagal syncope (VVS) is considered from a physiological basis. Most VVS patients lose consciousness due to hypotension before severe bradycardia/asystole occurs. Patients that benefit from dual-chamber pacing are typically older with highly symptomatic, late-onset, frequent and severe syncope with short/no prodrome and docu...

Background - Upright posture reduces venous return, stroke volume and cardiac output (CO) while causing reflex sinus rate (HR) increase. Yet, in inappropriate sinus tachycardia (IST), postural tachycardia syndrome (POTS), and vasovagal syncope (VVS) symptomatic excessive HR occurs. We hypothesized CO reaches maximum as function of HR in all. Method...

Cerebral autoregulation is crucial for maintaining cerebral blood flow and perfusion. In recent years, the importance of cerebral oxygenation in syncope and orthostatic intolerance (OI) has received increased attention. Cerebral tissue oxygenation can be measured by using near-infrared spectroscopy (NIRS), which determines the ratio of oxygenated h...

Orthostatic hypotension (OH) is a cardinal sign of cardiovascular (CV) autonomic dysfunction as a result of autonomic nervous system failure to control the postural hemodynamic homeostasis. The proportion of individuals with OH increases with aging and chronic conditions, such as neurodegenerative diseases, hypertension, heart failure, diabetes, re...

Introduction: Syncope and orthostatic intolerance in paced patients constitute a common clinical dilemma. We, thus, aimed to determine the aetiology of syncope and/or symptoms of orthostatic intolerance in paced patients. Methods: Among 1705 patients with unexplained syncope and/or orthostatic intolerance that were investigated by cardiovascular au...