The pathophysiology of common causes of syncope

An Interesting Case of Recurrent Postprandial Cardiogenic Syncope Caused by Type III Hiatal Hernia

Patients with syncope often present a diagnostic challenge due to the diverse causes of this condition. While a careful assessment can identify the underlying cause in many cases, syncope can arise from a variety of sources, including structural anomalies. Among these, hiatal hernia (HH) is a relatively common yet unusual condition associated with syncope. HH involves the protrusion of abdominal organs into the mediastinum through the diaphragmatic esophageal hiatus, with types III and IV being capable of causing cardiac problems. We report a case of a 92-year-old patient with a known HH history who experienced recurrent syncope episodes triggered by heavy meals. Extensive evaluation ruled out cardiac and neurological causes. Imaging revealed a large HH compressing the left atrium. Despite being an infrequent occurrence, such cases highlight the potential for atrial compression-induced syncope, which can be effectively managed with proton pump inhibitors and lifestyle modifications, as demonstrated by our patient's positive outcome.

Faint of Heart: A Case of Atrial Myxoma Presenting With Atypical Syncope

Syncope is a frequent reason for elderly patients to present to an outpatient office. The underlying cause of syncope can range from benign to serious. Although serious cases of syncope are rare, appropriate workup can help detect and address potentially fatal pathologies. We present a case of a 74-year-old woman who presented with an episode of syncope with associated epigastric cramping. Sudden syncope without significant comorbidities prompted further diagnostic workup, which revealed a rare cardiac myxoma. This case underscores the importance of ruling out potentially fatal causes prior to favoring more conservative diagnoses when investigating syncope in the elderly population.

Intraventricular gradients-When we have to "exercise" our minds: A case report

Increased intraventricular pressure gradients due to dynamic left ventricular outflow tract obstruction during exercise have long been known to cause different symptoms. Exercise stress echocardiography is fundamental in the diagnostic approach of symptoms presenting during exercise. We hypothesize on the possible pathophysiological mechanisms responsible for our patient's syncopal episodes.

Syncope and Cardiac Arrhythmias Caused by a Paratracheal Mass

Background: Syncope is a common complaint in clinical practice. The etiologies and mechanisms can be multiple and complex. Syncope caused by a mediastinal mass compressing the vagus nerve is rare. Case Report: We report the case of a patient who presented to the emergency department experiencing recurrent syncope. Imaging revealed a large, calcified mass in the right paratracheal region. After intracranial lesions, cardiac arrhythmias, and orthostatic hypotension were excluded, we suspected that the syncope was related to vagus nerve compression. The patient underwent surgical resection of a mediastinal mass and had complete resolution of syncopal episodes after surgery. Conclusion: This case outcome suggests that recurrent syncope could be the first symptom of an intrathoracic mass.

Syncope: a complication of chronic cough

Cough syncope is a rare but serious and potentially life-threatening complication of chronic cough. Early identification, comprehensive diagnostic evaluation and appropriate driving advice are fundamental to protect patients and the public. https://bit.ly/3CDAqYa.

Vasovagal reaction among whole blood donors in Hospital Pulau Pinang. A statistical-epidemiological study

CONTEXT

Whole blood donation is generally considered a safe procedure; however, a small percentage of donors could develop vasovagal reactions (VVRs) during or after completion of blood donation.

AIMS

This study was undertaken to establish the prevalence of VVR among whole blood donors in Hospital Pulau Pinang and to investigate factors that lead to its occurrence.

SETTINGS AND DESIGN

A cross-sectional study was conducted involving 27,890 whole blood donations in 2016.

SUBJECTS AND METHODS

For each donation, donor's demographic and blood donation-related information was extracted from the blood bank database.

STATISTICAL ANALYSIS USED

Qualitative data including age group, sex, race, frequency, and location of donation were analyzed using Chi-square tests, while blood pressure was analyzed using t-test.

RESULTS

Overall, 425 cases of VVRs were reported, resulting in a VVR rate of 1.5% (one event in every 65 donations). We found a statistically significant association (P < 0.05) between the occurrence of VVRs with the young age group, female gender, Indian race, first-time donor, lower predonation blood pressure, and donation performed in a mobile donation campaign. The most common vasovagal symptoms are lightheadedness (88%), followed by nausea (5.4%), muscle twitching (3.5%), vomiting (1.4%), loss of consciousness <30 s (1.4%), and paresthesia (0.2%).

CONCLUSIONS

The prevalence of VVRs among whole blood donors in Hospital Pulau Pinang appeared to be low. Our study reaffirms that blood donation is a relatively safe process, and the incidence of VVR can be further reduced by ensuring strict screening procedure before blood donation.

Cerebral Perfusion Monitoring Using Near-Infrared Spectroscopy During Head-Up Tilt Table Test in Patients With Orthostatic Intolerance

The head-up tilt table test (HUT) is one of the primary clinical examinations for evaluating orthostatic intolerance (OI). HUT can be divided into three phases: dynamic tilt phase (supine to tilt up), static tilt phase (remain tilted at 70°), and post tilt phase (tilt down back to supine position). Commonly, blood pressure (BP) and heart rate (HR) are monitored to observe for OI symptoms, but are indirect measurements of cerebral perfusion and can lead to inaccurate HUT evaluation. In this study, we implemented a 108-channel near-infrared spectroscopy (NIRS) probe to characterize HUT performance by monitoring cerebral hemodynamic changes for healthy controls (HCs), OI patients with normal HUT results, and OI patients with positive HUT results: vasovagal syncope (VS), postural orthostatic tachycardia syndrome (POTS), orthostatic hypotension (OH), and orthostatic hypertension (OHT). By the end of the static tilt phase, OI patients typically did not show a complete recovery back to baseline cerebral oxygenation and total blood volume compared to HCs. We characterized the return to cerebral homeostasis by polynomial fitting total blood volume changes and determining the inflection point. The OI patients with normal HUT results, VS, OH, or OHT showed a delay in the return to cerebral homeostasis compared to the HC group during HUT.

Galanin and Adrenomedullin Plasma Responses During Artificial Gravity on a Human Short-Arm Centrifuge

Galanin and adrenomedullin plasma responses to head-up tilt and lower body negative pressure have been studied previously. However, to what extent short-arm human centrifugation (SAHC) affects these responses is not known. In this study, we assessed how the application of variable gradients of accelerations (ΔGz ) via shifting of the rotation axis during centrifugation affects selected hormonal responses. Specifically, we tested the hypothesis, that cardiovascular modulating hormones such as galanin and adrenomedullin will be higher in non-finishers (participants in whom at least one of the pre-defined criteria for presyncope was fulfilled) when compared to finishers (participants who completed the entire protocol in both sessions) during SAHC exposure. Twenty healthy subjects (10 women and 10 men) were exposed to two g-levels [1 Gz and 2.4 Gz at the feet (Gz_Feet)] in two positions (axis of rotation placed above the head and axis of rotation placed at the heart level). Elevated baseline levels of galanin appeared to predict orthostatic tolerance (p = 0.054) and seemed to support good orthostatic tolerance during 1 Gz_Feet SAHC (p = 0.034). In finishers, 2.4 Gz_Feet SAHC was associated with increased galanin levels after centrifugation (p = 0.007). For adrenomedullin, the hypothesized increases were observed after centrifugation at 1 Gz_Feet (p = 0.031), but not at 2.4 Gz_Feet, suggesting that other central mechanisms than local distribution of adrenomedullin predominate when coping with central hypovolemia induced by SAHC (p > 0.14). In conclusion, baseline galanin levels could potentially be used to predict development of presyncope in subjects. Furthermore, galanin levels increase during elevated levels of central hypovolemia and galanin responses appear to be important for coping with such challenges. Adrenomedullin release depends on degree of central hypovolemia induced fluid shifts and a subject's ability to cope with such challenges. Our results suggest that the gradient of acceleration (ΔGz ) is an innovative approach to quantify the grade of central hypovolemia and to assess neurohormonal responses in those that can tolerate (finishers) or not tolerate (non-finishers) artificial gravity (AG). As AG is being considered as a preventing tool for spaceflight induced deconditioning in future missions, understanding effects of AG on hormonal responses in subjects who develop presyncope is important.

Syncope risk factors among military training soldiers; A case-control study

BACKGROUND

Syncope is a transient brief loss of consciousness accompanied with loss of postural tone. Of common places in which people experience syncope, military barracks can be named where training soldiers spend their military courses. The current study aimed to assess etiology and risk factors of syncope among military training soldiers.

METHODS

This was a retrospective case-control study conducted on training soldiers of Army-501 hospital in Tehran, Iran, during the years 2017-2018. Cases were consisted of 50 soldiers who experienced syncope during military training, and controls were 150 soldiers who had not experienced syncope during their military training. Demographic data were recorded for cases and controls.

RESULTS

Members of case and control groups were not statistically different regarding age (P = 0.46) and height (P = 0.70). Logistic regression test was performed and considering crude model, weight [odds ratio (OR): 0.94; 95% of confidence interval (95%CI): 0.90-0.98], body mass index (BMI) (OR: 0.72; 95%CI: 0.61-0.85), standing duration (OR: 1.007; 95%CI: 1.00-1.01), history of syncope (OR: 15.47; 95%CI: 4.15-57.60), positive family history of syncope (OR: 5.94; 95%CI: 1.66-21.25), smoking (OR: 3.5; 95%CI: 1.54-7.91), medical problems (OR: 7.97; 95%CI: 1.98-32.17), anxiety (OR: 2.02; 95%CI: 1.13-4.26), stress (OR: 6.68; 95%CI: 3.28-13.57), and depression (OR: 4.25; 95%CI: 2.15-8.39) were detected as significant predictors of syncope occurrence.

CONCLUSION

Based on the findings of this study, lower BMI, positive history of syncope, smoking, depression, and stress were significant risk factors of syncope occurrence among training soldiers. Higher BMI has protective role in syncope occurrence.

Closed-looped stimulation cardiac pacing for recurrent vasovagal syncope: A systematic review and meta-analysis

BACKGROUND

Vasovagal syncope (VVS) is defined by transient loss of consciousness with spontaneous rapid recovery. Recently, a closed-loop stimulation pacing system (CLS) has shown superior effectiveness to conventional pacing in refractory VVS. However, systematic review and meta-analysis has not been performed. We assessed the impact of CLS implantation and reduction in recurrent VVS events by a systematic review and a meta-analysis.

METHODS

We comprehensively searched the databases of MEDLINE and EMBASE from inception to September 2017. Included studies were published prospective or retrospective cohort, randomized controlled trial, and case-control studies that compared VVS events between recurrent, severe, or refractory cardioinhibitory VVS patient implanted with CLS and conventional pacing. Data from each study were combined using the random-effects, generic inverse variance method of DerSimonian and Laird to calculate odds ratios and 95% confidence intervals.

RESULTS

Six studies from November 2004 to October 2017 were included in this meta-analysis involving 224 recurrent, severe, or refractory cardioinhibitory VVS patients implanted with CLS and 163 recurrent, severe, or refractory VVS patients implanted with conventional pacing. CLS significantly reduced recurrent VVS events compared to conventional pacing (pooled odds ratio = 0.23, 95% confidence interval: 0.13-0.39, P = 0.000, I 2 = 36.5%) as well as subgroup of four randomized controlled trial studies (pooled odds ratio = 0.28, 95% confidence interval: 0.17-0.44, P = 0.000, I 2 = 39.2%).

CONCLUSION

Closed-loop stimulation significantly reduced recurrent VVS events up to 80% when compared to conventional pacing. Our study suggests that CLS is an effective tool for preventing syncope recurrences in patients with recurrent, severe, or refractory cardioinhibitory VVS.

Sudden deaths from positional asphyxia: A case report

RATIONALE

Positional asphyxia is a rare cause of sudden death and a difficult diagnosis, based mostly on the circumstances of the incident, along with particular external and internal findings, frequent in asphyxia (signs of sudden death).

PATIENT CONCERNS

In this report, we are describing one case of adult who was found positioned in a way that led to eventual asphyxiation.

DIAGNOSES

The final diagnosis of positional asphyxia was determined after the autopsy.

INTERVENTIONS

In a head-down position, gravitation and mechanical forces lead to an increased pressure on the diaphragm from the weight of the abdominal organs. Abdominal breathing, and later, chest breathing were hindered by the raised diaphragm and the difference between abdominal and breathing pressures.

OUTCOMES

It is known that death from positional asphyxia can emerge in several ways, such as the external breathing suppression when the victim's torso is compressed or deformed.

LESSONS

Therefore, the current criteria for positional asphyxia are based on the obstruction of normal gas exchange caused by the body position, the impossibility to move to another position, and the exclusion of other causes of death. The forensic medical examination must also be started at the scene of the incident.

Atypical Presentation of Massive Pulmonary Embolism, a Case Report

The lack of pathognomonic signs and symptoms makes the diagnosis of pulmonary embolism (PE) difficult. Here, we report a case of a 42-year-old man presented to the emergency department with worsening epigastric pain, hypotension, frank bradycardia, and final diagnosis of PE. Although previous studies have indicated that abdominal pain was observed in 6.7% of patients with PE, the exact reason for abdominal pain in PE still remains unknown. Tension on the sensory nerve endings, hepatic congestion, and distention of Gilson's capsule are some of the possible mechanisms of abdominal pain in PE. We conclude that emergency physicians should pay more attention to PE, which is an important differential diagnosis of shock state. In this context, rapid ultrasound in shock (RUSH) should be considered as a vital sign that needs to be evaluated when recording the history of patients presented to the emergency department with signs and symptoms of shock.

Hypokalemia-induced abnormal movements: case report

Introduction

A sudden loss of consciousness followed by abnormal movements can be ictal or syncopal in origin. Transient response by the brain to sudden decrease of blood flow may cause sudden loss of consciousness followed by abnormal movements that mimic seizure. Dysrhythmia is one of the important and critical reasons of such events that should be differentiated from seizure.

Case Presentation

In this case report we describe a 55 year-old woman admitted to our emergency department first with the impression of seizure. Eventually, it was realized that she had suffered from brain hypo-perfusion secondary to hypokalemia induced arrhythmia. Her arrhythmia was managed by unsynchronized biphasic shock in acute phase and also potassium replacement. She was then admitted to the CCU (Coronary Care Unit) where she received further care for medical management and drug dose adjustment and was discharged 4 days later.

Conclusions

Syncope from arrhythmia most commonly results from ventricular tachycardia, which accounts for 11% of all cases of syncope. Torsades de point is a unique type of ventricular tachycardia, characterized by QRS complexes of changing amplitude proceeded by prolonged QT intervals and almost often followed by loss of consciousness and also seizure like movements. Prolonged QT interval which is an important provocative factor for torsades de point commonly results from interactions between drug therapy, myocardial ischemia, and electrolyte disturbances such as hypokalemia or hypomagnesaemia. Changes in the extracellular potassium level have predominant and profound influences on the function of the cardiovascular system that may provoke fatal demonstrations such as QT prolongation, ventricular arrhythmia and even cardiac arrest. Electrolyte assessment is particularly important in certain patient populations, such as the elderly in whom a variety of pathological states or conditions like dehydration or renal failure are more common. Early identification and correction of these disturbances are necessary to control either seizures or seizure-like movements and prevent permanent brain damage, as anticonvulsants alone are generally ineffective.