What is supraventricular tachycardia and how does it affect the heart. What are the main symptoms of SVT and when should you seek medical attention. How do doctors diagnose SVT and what treatment options are available for managing this condition.

Understanding Supraventricular Tachycardia (SVT): An Overview

Supraventricular tachycardia (SVT) is a cardiac condition characterized by an abnormally fast heart rhythm originating in the upper chambers of the heart, known as the atria. This umbrella term encompasses several distinct arrhythmias, each with its own unique characteristics and implications for patient health.

To fully grasp the nature of SVT, it’s crucial to understand how a normal heartbeat functions. The heart’s natural pacemaker, the sinoatrial (SA) node, generates electrical impulses that travel through specialized pathways, coordinating the contraction of the atria and ventricles. This intricate system ensures efficient blood pumping throughout the body.

Types of SVT and Their Mechanisms

SVT can arise from three primary mechanisms:

1. Atrial Tachycardia: Abnormal impulse generation in the atria
2. Atrioventricular Nodal Reentrant Tachycardia (AVNRT): A “short circuit” within the AV node
3. Atrioventricular Reentrant Tachycardia (AVRT): An accessory pathway between atria and ventricles

Each type of SVT presents unique challenges in diagnosis and treatment, requiring a nuanced approach from healthcare professionals.

Recognizing SVT Symptoms: When to Be Concerned

Identifying SVT symptoms is crucial for timely diagnosis and intervention. Common manifestations include:

• Palpitations (a fluttering sensation in the chest)
• Shortness of breath
• Awareness of heartbeat in throat or ear
• Reduced exercise tolerance
• Dizziness or lightheadedness

Is SVT a potentially life-threatening condition? While SVT episodes can be alarming, they are generally not dangerous if the heart is structurally normal. However, certain forms of SVT involving accessory pathways may pose a higher risk in rare cases.

Can SVT be mistaken for other conditions? Indeed, some patients with long-standing SVT have been misdiagnosed with panic attacks, highlighting the importance of thorough cardiac evaluation.

Diagnosing SVT: Challenges and Advanced Techniques

The intermittent nature of SVT can make diagnosis challenging. Cardiologists employ various diagnostic tools to capture and analyze abnormal heart rhythms:

Electrocardiogram (ECG)

An ECG provides a snapshot of the heart’s electrical activity. While it’s the primary diagnostic tool, SVT episodes may not always coincide with the test.

Holter and Ambulatory ECG Monitoring

These devices allow for extended heart rhythm monitoring, typically over 24-48 hours or up to a week. Patients wear the monitor during normal activities, enabling correlation between symptoms and cardiac events.

Implantable Loop Recorder

For patients with infrequent episodes, an implantable loop recorder offers long-term monitoring capabilities. This small device, inserted under the skin, can track heart rhythms for up to three years, transmitting data wirelessly to healthcare providers.

Additional Diagnostic Tests

Comprehensive SVT evaluation may include:

• Blood tests to rule out electrolyte imbalances or hormonal issues
• Echocardiogram to assess heart structure and function

Identifying SVT Triggers: Lifestyle Factors and Spontaneous Onset

Understanding potential SVT triggers can aid in management strategies. Common precipitating factors include:

• Caffeine consumption
• Alcohol intake
• Sleep deprivation
• Stress

However, it’s important to note that SVT episodes can also occur spontaneously without any apparent trigger.

SVT Treatment Options: A Personalized Approach

Treatment for SVT is tailored to the individual, considering factors such as the specific type of SVT, frequency of episodes, and impact on quality of life. The main treatment modalities include:

Conservative Measures

For patients with infrequent, mild episodes, lifestyle modifications and simple maneuvers may suffice. These can include:

• Avoiding known triggers
• Learning vagal maneuvers to terminate episodes
• Stress reduction techniques

Medications

Antiarrhythmic drugs can be effective in preventing or terminating SVT episodes. The choice of medication depends on the specific type of SVT and individual patient factors.

Catheter Ablation

This minimally invasive procedure offers a potential cure for many types of SVT. It involves identifying and eliminating the abnormal electrical pathways responsible for the arrhythmia.

Living with SVT: Long-Term Prognosis and Quality of Life

What is the long-term outlook for patients with SVT? With proper management, most individuals with SVT can lead normal, active lives. The prognosis is generally favorable, especially for those who undergo successful catheter ablation.

Can SVT recur after treatment? While catheter ablation has a high success rate, there is a small chance of recurrence. Regular follow-ups with a cardiologist are important for monitoring and addressing any potential issues.

Advancing SVT Research: Future Directions and Emerging Therapies

The field of SVT management continues to evolve, with ongoing research focusing on:

• Improved mapping techniques for more precise ablation procedures
• Novel antiarrhythmic medications with fewer side effects
• Wearable technologies for better rhythm monitoring and early detection
• Genetic studies to understand hereditary factors in SVT development

These advancements promise to enhance our understanding of SVT and improve patient outcomes in the coming years.

SVT in Special Populations: Pregnancy, Athletes, and the Elderly

How does SVT affect different patient groups? The management of SVT requires special considerations in certain populations:

SVT During Pregnancy

Pregnancy can exacerbate SVT symptoms due to hormonal and hemodynamic changes. Treatment options may be limited by potential fetal risks, necessitating close collaboration between cardiologists and obstetricians.

SVT in Athletes

Competitive athletes with SVT face unique challenges. Treatment decisions must balance arrhythmia control with performance considerations and adherence to sports eligibility criteria.

SVT in the Elderly

Older patients may have comorbidities that complicate SVT management. Medication interactions and procedural risks require careful evaluation in this population.

Understanding these nuances is crucial for providing optimal care across diverse patient groups.

Patient Education and Self-Management Strategies for SVT

Empowering patients with knowledge and skills is essential for effective SVT management. Key aspects of patient education include:

• Recognizing symptoms and knowing when to seek medical attention
• Understanding the importance of medication adherence
• Learning and practicing vagal maneuvers
• Maintaining a healthy lifestyle to minimize triggers
• Keeping detailed records of episodes for discussion with healthcare providers

How can patients effectively communicate with their healthcare team? Maintaining open dialogue and providing accurate symptom descriptions can greatly aid in tailoring treatment strategies.

The Role of Electrophysiology Studies in SVT Diagnosis and Treatment

Electrophysiology (EP) studies play a crucial role in the comprehensive management of SVT. These specialized tests offer several benefits:

• Precise diagnosis of SVT mechanism
• Risk stratification for certain types of SVT
• Guidance for catheter ablation procedures
• Evaluation of antiarrhythmic drug efficacy

What can patients expect during an EP study? The procedure involves inserting catheters into blood vessels and advancing them to the heart. Electrical signals are then recorded and analyzed, often with attempts to induce and terminate SVT episodes in a controlled setting.

Psychosocial Aspects of Living with SVT

The impact of SVT extends beyond physical symptoms, affecting various aspects of a patient’s life:

Emotional Well-being

Anxiety and depression are common among SVT patients, often stemming from the unpredictable nature of episodes and fear of recurrence. Addressing these psychological aspects is crucial for comprehensive care.

Social and Occupational Functioning

SVT can disrupt daily activities and work performance. Developing coping strategies and making appropriate accommodations can help patients maintain their quality of life.

Support Systems

Family education and support groups can play a vital role in helping patients navigate the challenges of living with SVT.

How can healthcare providers address the psychosocial needs of SVT patients? A multidisciplinary approach involving cardiologists, psychologists, and social workers can provide comprehensive support.

Emerging Technologies in SVT Management

Advancements in technology are reshaping the landscape of SVT diagnosis and treatment:

Smartphone-based ECG Devices

These portable devices allow patients to record their heart rhythm during symptomatic episodes, facilitating faster diagnosis and treatment adjustments.

Remote Monitoring Systems

Cloud-based platforms enable continuous monitoring of implantable loop recorders, allowing for prompt intervention when abnormalities are detected.

Artificial Intelligence in ECG Interpretation

Machine learning algorithms are being developed to enhance the accuracy and speed of SVT diagnosis from ECG data.

Advanced Mapping Systems for Ablation

High-resolution 3D mapping technologies improve the precision of catheter ablation procedures, potentially increasing success rates and reducing complications.

How will these technologies impact patient care in the future? As these innovations become more widely adopted, they promise to improve diagnostic accuracy, enhance treatment efficacy, and empower patients in managing their condition.

Global Perspectives on SVT Management

The approach to SVT management can vary across different healthcare systems and geographic regions. Factors influencing these variations include:

• Availability of specialized cardiac care
• Access to advanced diagnostic and treatment technologies
• Cultural attitudes towards heart rhythm disorders
• Economic considerations in healthcare delivery

How do international guidelines for SVT management compare? While there is general consensus on many aspects of SVT care, some differences exist in treatment thresholds and preferences for certain interventions.

Understanding these global perspectives can inform efforts to standardize care and improve outcomes for SVT patients worldwide.

The Economic Impact of SVT: Healthcare Costs and Resource Utilization

SVT places a significant burden on healthcare systems and individual patients. Key economic considerations include:

• Direct medical costs (hospitalizations, procedures, medications)
• Indirect costs (lost productivity, disability)
• Long-term economic benefits of curative treatments like catheter ablation

How does the cost-effectiveness of different SVT treatments compare? Studies have shown that catheter ablation, while initially more expensive, can be more cost-effective in the long run compared to ongoing medical management for certain patients.

Understanding these economic factors is crucial for healthcare policy decisions and resource allocation in SVT management.

Integrating SVT Care: The Role of Primary Care Physicians

Primary care physicians play a vital role in the comprehensive management of SVT patients:

• Initial recognition and referral of suspected SVT cases
• Ongoing monitoring and management of stable patients
• Coordination of care with cardiologists and other specialists
• Patient education and support for lifestyle modifications

How can collaboration between primary care and specialist care be optimized for SVT patients? Clear communication channels, shared decision-making protocols, and continuing medical education initiatives can enhance the integration of SVT care across different healthcare settings.

SVT in the Digital Age: Telemedicine and Virtual Care

The COVID-19 pandemic has accelerated the adoption of telemedicine in cardiology, including SVT management. Key aspects of virtual SVT care include:

• Remote consultations for symptom assessment and treatment adjustments
• Virtual education sessions for patients and families
• Telemonitoring of implantable devices and home-based ECG recordings
• Online support groups and resources for SVT patients

What are the benefits and limitations of telemedicine in SVT care? While virtual care offers increased accessibility and convenience, certain aspects of SVT management, such as physical examinations and certain diagnostic procedures, still require in-person visits.

As telemedicine continues to evolve, finding the right balance between virtual and in-person care will be crucial for optimizing SVT management in the digital age.

Prognosis for supraventricular tachycardia | London Heart Clinic

What is SVT?

Supraventricular tachycardia (SVT) is a fast, abnormal heart rhythm that originates from the atria (top chambers of the heart). It is an umbrella term for several different abnormal heart rhythms. Some of these heart rhythms are intermittent, and others are always present. Read on to learn more about SVT, its causes and how we diagnose it. We then discuss SVT treatment in detail so you can make an informed choice about your care.

The normal heartbeat

Our heart is designed to beat efficiently and at the right time through small electric currents that pass through the muscle and tissue of the heart. These small impulses originate from the heart’s “inbuilt pacemaker” – known as the Sino-atrial Node (or SA node). Impulses from the SA node pass down an electrical pathway via a second relay station (AV node) to tell the bottom of the heart to beat. This system ensures that both the atria and the ventricles (bottom chambers) beat at the appropriate time to ensure the blood is pumped efficiently around the body.

Are there different causes of SVT?

An SVT is caused generally in 3 ways:

A part or parts of the atria (not the SA node) gives off impulses which can then pass through the heart, overriding the SA node and causing the heart to beat faster (atrial tachycardia)

An extra bit of wiring exists within the AV node allowing a short circuit and fast heart rhythm (AVNRT)

There is an extra bit of wiring present in the heart between the atria and ventricles or within the atria. This can lead to a short circuit, causing a fast heart rhythm (AVRT) or Wolff-Parkinson-White (WPW) syndrome

What are the symptoms of an SVT?

Most people find that they experience palpitations (feeling a fast fluttering of your heart) or shortness of breath. Some people are aware of their heart beating in their throat or ear. You may notice that you can’t do as much physical activity as you could before. In some cases, it can make you feel dizzy and light-headed. Sometimes patients have symptoms for many years and have been labelled as having panic attacks.

Is an SVT dangerous?

Even though the heart can beat very fast with an SVT, they are usually not dangerous if the heart is structurally normal. However, certain SVTs occur due to an extra pathway between the top and bottom of the heart. Though it is rare, this may be dangerous.

How is an SVT diagnosed?

The unpredictable nature of an SVT can present a diagnostic challenge. It is often difficult to predict how long an episode will last and when it will terminate. We will take a detailed account of your symptoms as an SVT typically starts and stops abruptly. So, your history can be very informative. Generally, we diagnose most SVTs with an ECG (heart rhythm trace). An SVT will interrupt the normal heart rhythm and be visible on an ECG. Then again, the SVT may have stopped by the time we perform an ECG.

ECG

The ECG could provide clues as to the cause but may also be completely normal. Therefore, your cardiologist might perform a longer heart rhythm trace called a Holter or ambulatory ECG monitor. We attach you to an ECG recorder or patch monitor for a prolonged period – usually 24-48 hours, but it can last up to a week. While you wear the monitor, you go about your day as usual, and it records any symptoms you have. We can then match it to what your heart rhythm was doing at that moment.

Implantable loop recorder

In patients with infrequent episodes, we can implant a small device called an implantable loop recorder under the skin (Reveal LinQ monitor). This device can remain in place for up to 3 years. We implant this in the outpatient setting under local anaesthetic, and the procedure only takes several minutes. Wireless technology means we can stay informed of your heart rhythm without you having to make frequent trips to the hospital.

Additional tests

In addition, we will perform blood tests to ensure there is no other reason for your racing heart. For example, your blood salt and hormone levels can affect your heart’s electrical system. We may also perform an ultrasound scan of the heart (an echo) to see if there are any structural abnormalities and obtain an idea of how well the heart is pumping.

Are there any triggers for SVT?

Caffeine, alcohol, sleep deprivation, and stress are common triggers of SVT episodes. However, often there is no particular trigger, and episodes can start spontaneously.

How is an SVT treated?

SVT treatment depends on what is causing the SVT and the impact on your life. I.e. how often it happens and how badly it affects you when it does. Some people find that SVT does not affect them very much, and episodes are infrequent. Essentially there are three types of SVT treatment: conservative measures, medications, and catheter ablation.

Conservative measures

These may include holding your breath in a particular way or using cold water. Whilst effective in some patients for stopping the SVT, they may not work. We call these vagal manoeuvres. Visit our blog to learn more about these and other lifestyle changes to help manage an arrhythmia.

Medications

If symptoms are intrusive or frequent, we may offer you medications which can be used on an ‘as required’ basis and taken when the SVT occurs to settle the heart rhythm back to normal. Alternatively, you can use these medications regularly to try and prevent episodes. However, these medications may not be effective for everyone. They can also cause side effects in some. Also, some patients continue to experience episodes despite being on medications. Commonly used drugs include beta-blockers, verapamil, flecainide and sotalol.

Catheter ablation

Nowadays, the first-line treatment for SVT is Catheter Ablation. This SVT treatment is a minimally invasive procedure (not surgery). We pass fine wires from the vein at the top of your leg to the heart. During catheter ablation, we can do a detailed study of your heart’s electrical activity (an EP study) to identify the exact part of the heart that is causing the abnormal electrical activity.

We do this using electrical signals and sometimes a computer-generated virtual map of your heart. During this procedure, we attempt to trigger your SVT in a controlled environment, which helps us make the correct diagnosis. Once we diagnose you with SVT, we deliver high-frequency energy to the tiny area in the heart causing the problem to destroy or modify the abnormal cells. This prevents them from interfering with the electrical pathway of the heart.

Catheter ablation has a success rate of over 90%. We can perform it under local anaesthetic with sedation or a general anaesthetic, usually as a day case. It is a very safe procedure, and the risks of serious complications are low (1-2%). These include bleeding at the top of the leg, bleeding around the heart, and, rarely, a permanent pacemaker.

Supraventricular Tachycardia – StatPearls – NCBI Bookshelf

Continuing Education Activity

Supraventricular tachycardia (SVT) is a dysrhythmia originating at or above the atrioventricular (AV) node and is defined by a narrow complex (QRS < 120 milliseconds) at a rate > 100 beats per minute (bpm). Atrioventricular nodal reentrant tachycardia (AVNRT), also known as paroxysmal SVT, is defined as intermittent SVT without provoking factors, and typically presents with a ventricular rhythm of 160 bpm. This activity describes the cause, pathophysiology, and presentation of SVT and stresses the importance of an interprofessional team in its management.

Objectives:

• Describe the pathophysiology of SVT.

• Outline the presentation of a patient with SVT.

• Summarize the treatment options for SVT.

• Review the importance of improving care coordination among interprofessional team members to improve outcomes for patients affected by SVT.

Access free multiple choice questions on this topic.

Introduction

Supraventricular tachycardia (SVT) is a dysrhythmia originating at or above the atrioventricular (AV) node and is defined by a narrow complex (QRS < 120 milliseconds) at a rate > 100 beats per minute (bpm).  

Atrioventricular nodal reentrant tachycardia (AVNRT), also known as paroxysmal SVT, is defined as intermittent SVT without provoking factors, and typically presents with a ventricular rhythm of 160 bpm. [1][2][3]

Etiology

The differential diagnosis includes sinus tachycardia, atrial tachycardia, junctional tachycardia, atrial fibrillation, atrial flutter, or multi atrial tachycardia.

In patients susceptible to SVT, medications, caffeine, alcohol, physical or emotional stress, or cigarette smoking can trigger SVT.[4][5]

Epidemiology

The incidence of atrioventricular nodal reentrant tachycardia is 35 per 10,000 person-years or 2.29 per 1000 persons and is the most common non-sinus tachydysrhythmia in young adults. Women have two times higher risk of developing paroxysmal SVT in comparison to men, and older individuals have five times higher compared to a younger person. 

SVT is the most common symptomatic dysrhythmia in infants in children. Children with congenital heart disease are it increased risk for SVT. In children younger than 12 years old, an accessory atrioventricular pathway causing reentry tachycardia is the most common cause of SVT. [6][7]

Pathophysiology

The electrical conduction through the heart starts at the sinoatrial (SA), which then travels to the surrounding atrial tissue to the atrioventricular (AV) node. At the AV node, the electrical signal is delayed for approximately 100 milliseconds. Once through the AV node, the electrical signal travels through the His-Purkinje system, which distributes the electrical signal to the left and right bundles, and ultimately to the myocardium of the ventricles. The pause at the AV node allows the atria to contract and empty before ventricular contraction.

The most common cause of SVT is an orthodromic reentry phenomenon, which occurs when the tachycardia is secondary to normal anterograde electrical conduction from the atria to the AV node to the ventricles, with retrograde conduction via an accessory pathway from the ventricles back to the atrial.

A narrow QRS complex (< 120 milliseconds) indicates the ventricles are being activated superior to the His bundle via the usual pathway through the His-Purkinje system. This implies that the arrhythmia originates from the sinoatrial (SA) node, the atrial myometrium, the AV node, or within the His bundle. 

In the rarer antidromic conduction, conduction passes from the atria to the ventricles via the accessory pathway, then returns retrograde through the AV node to the atria. [8]

History and Physical

Patients typically present with anxiety, palpitations, chest discomfort, lightheadedness, syncope, or dyspnea. In some cases, a patient may present with shock, hypotension, signs of heart failure, lightheadedness, or exercise intolerance. Some may present without symptoms, and the tachycardia is discovered during routine screening, for example, at pharmacies or with fitness trackers. The onset is typically abrupt and can be triggered by stress secondary to physical activity or emotional stress.

Physical exam, aside from tachycardia, is typically normal in a patient with good cardiovascular reserve. Patients beginning to decompensated may show signs of congestive heart failure, (bibasilar crackles, a third heart sound (S3), or jugular venous distention).

Evaluation

The first test to evaluate for SVT is to obtain an ECG.  [9][10][11]

ECG characteristic includes a narrow complex, regular tachycardia with a rate of approximately 180 to 220 beats per minute. P waves are not detectable. If P waves are detectable, consider sinus tachycardia or atrial fibrillation or flutter as a potential etiology.

The remainder of the evaluation is focused on trying to isolate a cause of SVT, for example, electrolyte abnormalities, anemia, or hyperthyroidism. Consider checking a digoxin level of patients using that drug, as SVT can be secondary to supratherapeutic digoxin concentrations.

Treatment / Management

Once an SVT is identified, the next objective is to assess for hemodynamic instability. Signs of hemodynamic instability include hypotension, hypoxia, shortness of breath, chest pain, shock, evidence of poor end-organ perfusion, or altered mental status.[12][13]

If a patient is unstable, consider immediate synchronized cardioversion. It is important that the defibrillator is placed in a sync mode, typically indicated by a marker on the defibrillator screen noting each QRS complex. This mode allows the defibrillator to deliver the shock synchronized with the QRS complex, to prevent the shock from being delivered during the T-wave, while the heart is depolarized. The R on T phenomenon can cause polymorphic ventricular tachycardia. In adults, the starting dose for synchronized cardioversion is 100 joules to 200 joules and can be increased in a stepwise fashion if unsuccessful at lower doses. In children, the first dose for cardioversion is 0.5 J/kg to 1 J/kg and can be doubled to 2 J/kg on subsequent attempts.

In a stable patient, attempted vagal maneuvers while preparing for chemical cardioversion, including the Valsalva maneuver and carotid massage. Both of these act to stimulate the parasympathetic system. This slows impulse formation at the sinus node, slows conduction velocity at the AV node, lengthens the AV node refractory period, and decreases ventricular inotropy.

The Valsalva maneuver is performed expiring against a closed glottis, and needs to be held for 10 seconds to 15 seconds. Patients can achieve this by bearing down as if they are going to have a bowel movement. Younger children can blow out through a syringe or straw. In infants and toddlers, ice packs applied to the face can cause a similar vagal reaction. Although ocular pressure can cause a vagal reaction, it is not recommended as it can lead to a ruptured globe if excessive force is used.

Carotid massage involves placing the patient in a supine position with the neck extended, and applying pressure to one carotid sinus for approximately 10 seconds. Carotid massage is contraindicated in patients with carotid bruit, or who have had a prior transient ischemic attack or cerebral vascular accident in the last three months. Carotid massage is not indicated in children or infants.

The REVERT trial demonstrated that a modified Valsalva maneuver, with the traditional Valsalva maneuver being held for 60 seconds at a 45 degree recumbent position, then being switched to a recumbent position with the legs held at 45 degrees angle for 15 seconds, was more efficacious than the standard Valsalva maneuver. [14]

If vagal maneuvers are ineffective, treat with adenosine. Adenosine is rapidly metabolized in the periphery, and therefore must be given as a rapid push through a large, ideally peripheral, intravenous route. The initial dose is 6 mg intravenously (IV) (pediatric dose 0.1 mg/kg, maximum dose 6 mg). If the initial dose is ineffective, adenosine may be dosed again at 12 mg IVP (pediatric dose 0.2 mg/kg, maximum dose 12 mg). The second dose of adenosine 12 mg IVP may be repeated one additional time if there is no effect. Each dose of adenosine needs to be flushed rapidly with 10 mL to 20 mL normal saline. Often two person administration, with one person administering the adenosine at a proximal IV port, and a second person flushing the IV line via a distal port immediately after adenosine administration, is required to adequate flush in the adenosine.

Consider reducing the adenosine dose to 3 mg IVP if the patient is currently receiving carbamazepine or dipyridamole, is the recipient of a heart transplant, or adenosine is being given through a central line.

In the event of a patient with a misinterpreted rhythm, the administration of adenosine can help slow down the heart rate long enough to determine if the cause of the patient’s tachycardia is due to a different narrow complex tachycardia (e.g., atrial fibrillation or atrial flutter). 

If adenosine fails, second line medications include diltiazem (0.25 mg/kg IV loading dose followed by 5mg/hr to 15 mg/hr infusion), esmolol (0.5 mg/kg IV loading dose, then 0.5 mg/kg/min up to 0.2 mg/kg/min, will need to repeat bolus for every up-titration), or metoprolol (2. 5 mg to 5 mg IV every two to five minutes, not to exceed 15 mg over 10 to 15 minutes). 

These measures still prove ineffective, overdrive pacing, or pacing the heart at a faster rate than its native rhythm, can help discontinue SVT. However, there is an increased risk of ventricular tachycardia or fibrillation, and therefore should be used with caution and with cardioversion immediately available.

Patients with recurrent SVT without a pre-excitation syndrome may require long-term maintenance with oral beta-blockers or calcium to maintain sinus rhythm. They may also require radio-frequency ablation if an accessory pathway is identifiable. Patients should be counseled on how to perform vagal maneuvers on their own for long-term management of recurrent SVT. [2][15]

Differential Diagnosis

Complications

Complications are either related to the medications or radiofrequency ablation. Since the latter is an invasive procedure the following complications may occur:

• Hematoma

• Pseudoaneurysm of the artery

• Bleeding

• Myocardial infarction

• Heart block and the need for a pacemaker

• Stroke

• Death

Pearls and Other Issues

Wolff-Parkinson-White (WPW) syndrome is an example of an accessory pathway syndrome, characterized by a short PR interval (< 120 ms), a prolonged QRS (> 100 ms), and a delta wave (a slurred upstroke to the QRS complex). Patients with WPW can occasionally present with an antidromic reentry tachycardia, in which the accessory pathway is the anterograde limb, and the AV node is the retrograde pathway. These typically present with a wide complex, regular, and extremely rapid tachycardia. In these cases, AV nodal blocking agents like adenosine are contraindicated because they can allow unopposed retrograde conduction through the accessory pathway, leading to ventricular tachycardia or fibrillation. Procainamide (15 mg/kg to 18 mg/kg loading dose, 1 mg/min to 4 mg/min maintenance infusion) is the first-line treatment of this tachydysrhythmia, followed by amiodarone (150 mg over 10 minutes, followed by 360 mg over six hours, then 540 mg over 18 hrs). For ventricular rates greater than 250 bpm, consider synchronized cardioversion at 100 J  to 200 J.

Enhancing Healthcare Team Outcomes

Paroxysmal SVT is usually managed by an interprofessional team of healthcare workers dedicated to cardiac arrhythmias. Since these arrhythmias cannot be prevented, the focus is on treatment. Besides the cardiologist, the role of the nurse and pharmacist is indispensable. The patient should be educated about this arrhythmia and the potential risk of sudden death if left untreated. For patients with SVT managed with medications, the pharmacist should assist the team by educating the patient on potential adverse effects, drug interactions and the need for close follow-up. The patient should also be educated on the option of radiofrequency ablation, which has a much higher success rate compared to medications. [16](Level II)

Outcomes

For the most part, patients with paroxysmal SVT have a good outcome with treatment. However, a small number of patients with WPW do have a tiny risk of sudden death. In patients with SVT arising due to a structural defect in the heart, the prognosis depends on the severity of the defect, but in healthy people with no structural defects, the prognosis is excellent. Pregnant women who develop SVT do have a slightly higher risk of death if there is an unrepaired heart defect. [17][18][19](Level V)

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Figure

Lead II (2) Supraventricular tachycardia SVT. Contributed by Wikimedia Commons, James Heilman, MD (Public Domain-Self)

Figure

A graphical representation of the Electrical conduction system of the heart showing the Sinoatrial node, Atrioventricular node, Bundle of His, Purkinje fibers, and Bachmann’s bundle. Contributed by Wikimedia Commons (Public Domain)

Figure

This is a recording of the termination of a supraventricular tachycardia at about 130/min. which terminates and leaves a pause and then sinus bradycardia. This is a from of “tachy/brady” syndrome where a tachycardia is followed by a bradycardia. Contributed (more…)

References

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Jain D, Nigam P, Indurkar M, Chiramkara R. Clinical Significance of the Forsaken aVR in Evaluation of Tachyarrhythmias: A Reminder. J Clin Diagn Res. 2017 Jun;11(6):OM01-OM04. [PMC free article: PMC5535428] [PubMed: 28764236]

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Chung R, Wazni O, Dresing T, Chung M, Saliba W, Lindsay B, Tchou P. Clinical presentation of ventricular-Hisian and ventricular-nodal accessory pathways. Heart Rhythm. 2019 Mar;16(3):369-377. [PubMed: 30103070]

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Voerman JJ, Hoffe ME, Surka S, Alves PM. In-Flight Management of a Supraventricular Tachycardia Using Telemedicine. Aerosp Med Hum Perform. 2018 Jul 01;89(7):657-660. [PubMed: 29921358]

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Appelboam A, Reuben A, Mann C, Gagg J, Ewings P, Barton A, Lobban T, Dayer M, Vickery J, Benger J., REVERT trial collaborators. Postural modification to the standard Valsalva manoeuvre for emergency treatment of supraventricular tachycardias (REVERT): a randomised controlled trial. Lancet. 2015 Oct 31;386(10005):1747-53. [PubMed: 26314489]

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Mironov NY, Golitsyn SP. [Overwiew of New Clinical Guidelines for the Diagnosis and Treatment of Supraventricular Tachycardias (2015) of the American College of Cardiology/American Heart Association/Society for Heart Rhythm Disturbances (ACC/AHA/HRS)]. Kardiologiia. 2016 Jul;56(7):84-90. [PubMed: 28290912]

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Ordonez RV. Monitoring the patient with supraventricular dysrhythmias. Nurs Clin North Am. 1987 Mar;22(1):49-59. [PubMed: 3644291]

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Balli S, Kucuk M, Orhan Bulut M, Kemal Yucel I, Celebi A. Transcatheter Cryoablation Procedures without Fluoroscopy in Pediatric Patients with Atrioventricular Nodal Reentrant Tachycardia: A Single-Center Experience. Acta Cardiol Sin. 2018 Jul;34(4):337-343. [PMC free article: PMC6066944] [PubMed: 30065572]

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Disclosure: Laryssa Patti declares no relevant financial relationships with ineligible companies.

Disclosure: John Ashurst declares no relevant financial relationships with ineligible companies.

Weather in Novy Svet today, weather forecast Novy Svet for today, Sudak (urban district), Republic of Crimea, Russia

GISMETEO: Weather in Novy Svet today, weather forecast Novy Svet for today, Sudak (urban district), Republic of Crimea, Russia

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Now

9:38

+25 77

Feels +25 77

Sat Jul 15

Today

+2373

+2984

Sun, July 16

Tomorrow

+2272

+2882

Sat, July 15 today

0 ⁰⁰

3 ⁰⁰

9000 2 6 ⁰⁰

9 ⁰⁰

12 ⁰⁰

15 ⁰⁰

18 ⁰⁰

21 ⁰⁰

Air temperature, °CF 3

+2373

+2577

+2882

+2984

+2679

+2475

Feeling temperature, °CF

+2577

+2475

+2475

+2577

+2882

+2984

+2882

+2679

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7561008

7561008

7571009

7581010

7571009

7571009

7581010

7581010

90 174 Relative humidity, %

64

68

74

61

48

52

66

90 002 72

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10

8

4

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Forecast and analysis SWT-method | Forex Blog of independent analysts IAFT

SWT-method. Waiting for the black swan.

Authors: Ph.D. N.I. Skrigan, Ph.D. NN Skrigan

There is a strong subjective feeling of a compressed spring on the world stock markets, which is about to straighten out. Everyone knows that there is a “Black Swan” by N. Taleb, but no one knows when this bird will arrive. However, when analyzing markets using the SWT method, the feeling that it is already close does not leave.

The corrective fall of the American stock market, and not only the American one, which began in the last days of January of the current year, is just flowers. Berries will be ahead. In our analysis, we are guided only by technical factors, in particular, by quantitative analysis of markets based on the SWT method. But the technique in this case is in good agreement with the fundamental.

According to Mikhail Khanov, this weekend is a busy day for hedge fund analysts around the world. Markets on Friday made attempts to go down in search of a new bottom, which then turns out to be a new ceiling, but still these attempts were unsuccessful. They were not crowned with success, but they suggest certain thoughts.

From the point of view of technical analysis, the thoughts are as follows.

Throughout almost the whole of April there were attempts to increase stock indices. At the beginning of the month, there was no complete clarity, whether this was a reversal upwards within the framework of a short-term trend or, nevertheless, a correction. But by the last week of April, it became clear that recovery attempts were fizzling out and the observed rollback upwards in all markets stopped in the zone of local growth targets that define the border of the correctional range of short-term trends. It stopped, and from the zone of these borders, still timidly, the reverse process of a gradual downward slide began with attempts to return to the reached highs of the month and new attempts to go to new lows of the week.

On the last day of the week, the bidders did not make a final decision about what to do. Probably this was prevented by the completion of the weekly trading session. But the five working days of the next trading week give operational scope for the expected bearish revelry.

And a few more words about fundamental factors.

Mikhail Khanov in his Facebook feed also noted the increase in the yield of the US government debt, which, in his opinion, is an incentive to reduce the stock portfolio, and the current values ​​and continued growth in the yield of US government bonds could lead to a fall in the S&P next week by 8-10% . Which means an even more significant correction in the markets of Europe, not to mention India, Brazil and others like them.

Such conclusions do not contradict technical analysis data, which also indicate the completion of corrective growth and a turn down. And if markets don’t go 8-10% down next week, they could go much further over the coming weeks as the downward correction across markets becomes a long-term trend with trend targets beyond the 10% range and much lower. .

An additional stimulus for chaos at the bears’ holiday may be the publication of the Fed’s decision on key interest rates expected on May 2. And it doesn’t matter what decision is made. The mere fact of a meeting is usually an incentive for increased activity and a sharp increase in volatility. And the direction of movement in which the markets can go with the greatest ease and the least resistance is down.

And now briefly about the markets.

S&P500.

April 22

I already know what it was!

I almost broke my brain, thinking about the reasons for the unusual behavior of the equity. The dream of any trader is to create a strategy in which the balance (equity) of a trading account goes in a straight line from the lower left corner of the screen to the right one …

October 31

GOLD. Long-term growth continues with the target at 1575.00

Technical trend analysis and forecast for position trading.

The long-term trend is up.

The medium-term trend is in a downward correction.

The short-term trend is down.

The local trend is in an upward correction.

The daily trend is up.

The intraday trend is in a downward correction.

General description of the situation. The resulting movement along the long-term trend is up with a strength of +92 points, in the medium term – a downward correction with a strength of -23 points, taking place in the form of a short-term downtrend with a strength of -84 points.

Strategic goals remain unchanged – long-term growth with the target at the level of 1575.00 with a possible rollback to the level of 1357 and the continuation of the upward movement to the zone of the historical maximum of 1920.00 and beyond.

October 29

SWT method. Part 1.

Authors: Ph.D. N.I. Skrigan, Ph.D. NN Skrigan CONTENTS 1. Classical technical analysis 2. SWT-method. Theory 3. SWT method. Application practice 4. Principles of trend analysis in the SWT method 5. Trading tactics for positional …

July 29

SWT method. Theory and practice of application

I did not create this world. And he doesn’t have to follow my equations! (c) Quanta. Wall Street Alchemists. Part 1. Principle of decomposition and rules of wave analysis. Authors: Ph.D. N.I. Skrigan, Ph.D. N.N.Skrigan 2017, April, …

May 27

Me and the robot

Me and the robot, or how we have been working together lately. The development of a joint action strategy continues. The robot trades around the clock. Trading mode – local trend with filters for medium-term and …

June 30

Money loves silence…

“Money loves silence”. These words are usually cited by public traders after another public bummer to justify it by some higher powers. There is some rationality in this. Public trading and desire …

November 5

SWT-method: trading robot

On September 23, completely exhausted by aggressive manual trading, I thought: Can I still build a robot?

Nothing is more exhausting than monitoring the market while waiting for the opportunity to open a trade manually.