Tachyarrhythmia is a type of abnormal cardiac rhythm and is classified based on its site of origin as ventricular (originating below the bundle of His) or supraventricular (above the bundle of His). Ventricular tachyarrhythmias include ventricular tachycardia (VT), ventricular fibrillation (VF), and premature ventricular contraction (PVC). Supraventricular tachycardia (SVT) or paroxysmal supraventricular tachycardia (PSVT) presents a rapid heart rate anywhere between 150-250 beats per minute and is further classified as atrioventricular nodal reentrant tachycardia (AVNRT), atrioventricular reciprocating tachycardia (AVRT), atrial tachycardia (AT), atrial fibrillation and atrial flutter. The clinical presentation of tachyarrhythmias may vary depending on the type of arrhythmia from asymptomatic to chronic and recurrent or highly symptomatic and life threatening. Common symptoms in all tachyarrhythmias include palpitations, chest discomfort, dyspnea, fatigue, lightheadedness, and dizziness. Uncommon symptoms comprise diaphoresis, nausea, presyncope, and syncope.

VT is a tachyarrhythmia of >100 beats per minute which is regular while VF is a more serious type of tachyarrhythmia with an asynchronous discharge of impulses causing the heart to beat erratically, often at a rate > 300 beats per minute. This results in poor perfusion of organs, especially the brain, with possible fatal outcomes. VF is commonly seen in individuals with cardiac disease or a recent history of myocardial infarction. PVCs are a less serious type of tachyarrhythmia with the ventricle contracting prematurely and out of sequence to the normal heart beat. They often start suddenly without a warning and can be stimulated by caffeine, chocolate, and some medicines.

The commonest type of SVT is AVNRT which affects young, healthy women [1], often without structural cardiac disease, though some patients may have pericarditis, previous myocardial infarction, or mitral valve prolapse [2]. AVRT is the second most common type of SVT and is caused by accessory tracts which conduct the abnormal impulses proximally as well as distally creating a reentry circuit [3]. AVRT can occasionally occur with Wolff-Parkinson-White syndrome and may spontaneously degenerate into atrial fibrillation [4]. AT is the third most common type of SVT arising from a focus in the atrium [5]. It is of two types: focal and multifocal AT (MAT). Focal AT originates from a definite focus like the crista terminalis in the right atrium or the ostia of the pulmonary veins in the left atrium [6] [7]. MAT is frequently seen in patients with congestive heart failure or chronic obstructive pulmonary disease [6]. SVT symptoms depend on the patient's age, comorbid medical conditions, and duration of the episodes.

Atrial fibrillation (AF) is a type of SVT and a common cause of stroke and congestive heart failure [8]. Atrial flutter is an irregular SVT originating in the atria which may be asymptomatic in the initial stages or may be associated with palpitations, later degenerating into AF. Wolff-Parkinson-White syndrome is characterized by abnormal accessory conduction pathways (bundle of Kent) between the atria and the ventricle.

• Hypothermia

  Physical examination of svy in pediatrics Following the history, the physical examination should be performed: unexplained hypothermia, with poor perfusion, a picture of sepsis but with negative cultures. [peertechz.com]

  Although this drug is associated with few side effects, maternal hypothermia and fetal bradyarrhythmias have been observed. [escardio.org]

  Causes include: physiological (e.g. during sleep, in athletes) cardiac causes (e.g. atrioventricular block or sinus node disease) non-cardiac causes (e.g. vasovagal, hypothermia, hypothyroidism, hyperkalaemia) drugs (e.g. beta-blockade, diltiazem, digoxin [resus.org.uk]

  Noncardiovascular respiratory causes Pulmonary embolism, pneumonia, lung cancer, and hypothermia have been associated with AF. Drug and alcohol use Stimulants, alcohol, and cocaine can trigger AF. [emedicine.medscape.com]

• Hypoxemia

  Goal should be to identify and rectify this condition (ex. hypoxemia, sepsis, hypovolemia, pharmacology). If the patient had an MI, B-blockers are indicated but B-blockers should not be used in systolic heart failure. [openanesthesia.org]

  Pulmonary Diseases Class I Correction of hypoxemia and acidosis is the recommended primary therapeutic measure for patients who develop AF during an acute pulmonary illness or exacerbation of chronic pulmonary disease. [doi.org]

  Surges of muscle sympathetic nerve activity during obstructive apnea are linked to hypoxemia. J Appl Physiol. 1995 ; 79 :581–588. Crossref Medline Google Scholar 155. [dx.doi.org]

• Acutely Ill Patient

  Acute Noncardiac Illness A number of acute noncardiac conditions are associated with AF (eg, hypertension, postoperative state, pulmonary embolism, viral infections). [doi.org]

• Dyspnea

  Eventually, the fluid enters the air spaces in the lungs, reduces the amount of oxygen that can enter the blood, and causes shortness of breath (dyspnea). [answers.yahoo.com]

  Common symptoms in all tachyarrhythmias include palpitations, chest discomfort, dyspnea, fatigue, lightheadedness, and dizziness. Uncommon symptoms comprise diaphoresis, nausea, presyncope, and syncope. [symptoma.com]

  Also dyspnea in 35% and angina in 20%. Ventricular Tachycardia Any wide complex tachycardia in an ICU patient should be treated as a probably VT (95% of them are). [openanesthesia.org]

  He developed pronounced dyspnea on exertion, and repeated ECGs and another Holter monitor now showed persistent AF. [doi.org]

  Conditions that warrant consideration for referral to an electrophysiologist include symptomatic SVT with debilitating or severe symptoms (e.g., syncope, dyspnea), and intolerance of or resistance to drug therapy. [peertechz.com]

• Tachycardia

  Sub types Fetal tachyarrhythmias can be of many types and includes: fetal sinus tachycardia : some authors classify this under fetal tachyarrythmias although it probably shouldn't as the rhythm is regular fetal supraventricular tachycardia (SVT) most [radiopaedia.org]

  Junctional tachycardia. The origin of the tachycardia is the "junction" between the upper and lower chambers. This is an automatic tachycardia. [cincinnatichildrens.org]

  Five junctional ectopic tachycardia, 2 atrial flutters, 1 paroxysmal supraventricular tachycardia, 1 atrial fibrillation, 1 atrioventricular reciprocating tachycardia with Wolff-Parkinson-White syndrome and 2 excessive sinus tachycardia were treated. [ncbi.nlm.nih.gov]

• Heart Disease

  […] cardiomyopathy) or inherited (CHD or channelopathies) heart disease. [aerjournal.com]

  METHODS: A retrospective analysis was performed on 312 consecutive patients undergoing surgery for congenital heart disease. Twelve patients were treated with landiolol for critical tachyarrhythmia. The mean age of patients was 28.7 ± 10.6 months. [ncbi.nlm.nih.gov]

  The most common causes of AF are coronary heart disease, hypertension, valvular heart disease and hyperthyroidism. [patient.info]

• Hypotension

  DC cardioversion is indicated in the setting of AF in 1) hypotension 2) impaired vital organ function or 3) HR > 150. Always premedicate. [openanesthesia.org]

  After tumor vein ligation, the landiolol was discontinued and her hemodynamics were stable without hypotension. This case demonstrates that landiolol is useful for treating pheochromocytoma-induced tachyarrhythmia safely without hypotension. [journals.lww.com]

  English Some adverse reactions to Herceptin infusion including dyspnoea, hypotension, wheezing, bronchospasm, supraventricular tachyarrythmia, reduced oxygen saturation and respiratory distress can be serious and potentially fatal (see 4.4). [mymemory.translated.net]

  One patient in the landiolol group showed hypotension and bradycardia, without serious consequences. CONCLUSIONS: Landiolol hydrochloride can be effectively and safely used in patients who develop tachyarrhythmia after esophagectomy. [ncbi.nlm.nih.gov]

  Hypotension can occur in a small number of patients (vernakalant 7.6%, placebo 5.1%). [web.archive.org]

• Thrombosis

  Deep vein thrombosis and pulmonary embolism are major causes of morbidity and mortality after ischemic stroke. 48,49 Heparin has a role in the prevention of deep vein thrombosis and pulmonary embolism. 50 In the IST, UHF-allocated patients had fewer pulmonary [dx.doi.org]

  […] surgery is high, but no clear guidelines state how to proceed in those at moderate risk of thrombosis. [ncbi.nlm.nih.gov]

  On July 1, 2011, the FDA approved Xarelto to reduce the risk of blood clots, deep vein thrombosis, and pulmonary embolism following knee or hip replacement surgery. [web.archive.org]

  Transesophageal echocardiography is advised prior to ablation in patients with atrial fibrillation because it can identify the presence of thrombosis. [revespcardiol.org]

• Orthostatic Hypotension

  Postural orthostatic tachycardia syndrome[edit] Usually in women with no heart problems, this syndrome is characterized by normal resting heart rate but exaggerated postural sinus tachycardia with or without orthostatic hypotension. [en.wikipedia.org]

  Care must be taken in these patients because they are often more susceptible to orthostatic hypotension or bradyarrhythmias and when AF is paroxysmal and sinus node dysfunction is more common. Comorbidities should also be considered. [doi.org]

• Sweating

  A 53-day-old female infant was brought to the hospital with sweating, rapid breathing, and rapid heartbeat. She was admitted to the intensive care unit with a suspicion of myocarditis. [go.gale.com]

  He was admitted to our hospital due to spontaneous onset of palpitation and recurrent presyncope with sweating and nausea. [revespcardiol.org]

  Specialty Cardiology Symptoms Palpitations, feeling faint, sweating, shortness of breath, chest pain.[1] Types Atrial fibrillation, paroxysmal supraventricular tachycardia (PSVT), atrial flutter, Wolff-Parkinson-White syndrome[2] Causes Re-entry or increased [en.wikipedia.org]

• Dizziness

  A 31-year-old female presented with atypical chest pain, palpitations, tachycardia, headaches, and dizziness for 2 years. Multiple antiarrhythmics and ultimately cardiac ablation procedure proved to be ineffective. [ncbi.nlm.nih.gov]

  Temporarily discontinue ibrutinib in patients who develop signs or symptoms of ventricular tachyarrhythmia, including, but not limited to, palpitations, chest pain, dyspnoea, dizziness, or fainting. [gov.uk]

  Other times, symptoms such as a rapid heart rate, pounding in the chest, dizziness, lightheadedness, fainting or near fainting can occur. The treatment will vary depending on the type of fast heartbeat and what is making it happen. [heart.emedtv.com]

  Common symptoms in all tachyarrhythmias include palpitations, chest discomfort, dyspnea, fatigue, lightheadedness, and dizziness. Uncommon symptoms comprise diaphoresis, nausea, presyncope, and syncope. [symptoma.com]

  While driving, 2 percent had a syncopal episode, 11 percent had dizziness or palpitations that necessitated stopping the vehicle, 22 percent had dizziness or palpitations that did not necessitate stopping the vehicle, and 8 percent of the 295 patients [nejm.org]

Tachyarrhythmias can be detected by history and physical examination but the diagnosis is confirmed by a 12-lead electrocardiogram (ECG) or a rhythm strip. Often SVT episodes are misdiagnosed as anxiety or panic attacks especially in the presence of a psychiatric disorder [8]. A high index of suspicion is, therefore, important to make a diagnosis [9]. The initial evaluation should determine whether a patient is hemodynamically stable. A brief cardiovascular examination will determine the ventricular rate and its regularity while the nature of the jugular venous pulse waves may also help to detect tachyarrhythmias. In a stable, symptomatic patient, it is important to obtain a 12-lead ECG while a rhythm strip is an initial assessment measure in an unstable patient prior to emergency cardioversion.

The ECG findings are characteristic for each tachyarrhythmia. A supraventricular origin of the tachyarrhythmia is indicated by a narrow QRS complex (< 0.12 sec) while a wide QRS complex (≥ 0.12 sec) indicates a ventricular origin or an SVT conducted by an intraventricular conduction defect or preexcitation in the Wolff-Parkinson-White syndrome. AF features are irregular, continuous, rapid beats at a rate >300 beats/ minute without discrete P waves. If the P waves are discrete and vary with every beat with at least 3 different morphologies then it is suggestive of MAT. Atrial flutter appears as regular, discrete, uniform P waves without intervening isoelectric periods at rates > 250 beats/min while AT features include regular, discrete, uniform, abnormal P waves with intervening isoelectric periods at rates < 250 beats/min. In VF, the rhythm strip will show rapid, irregular heart rate up to 300 beats/ minute. If the QRS complex varies with every beat, then the tachyarrhythmia is called polymorphic VT and the most notorious form of polymorphic VT is torsades de pointes.

Laboratory tests should include serum electrolytes, calcium, phosphate, as well as cardiac troponin level assessment. Echocardiography helps to assess the status of the heart while Holter monitoring is indicated in patients with recurrent tachyarrhythmias. Other tests like stress test may be performed as indicated during the clinical evaluation of the patient.

• Abnormal ECG

  However, an incidental discovery of an abnormal ECG without symptoms or family history may not necessarily imply syndrome phenotype. [bupacromwellhospital.com]

  The performance of ECG itself is not associated with significant harm, although abnormal results may cause anxiety. Misinterpretation of ECG results may lead to misdiagnosis and unnecessary treatment. [doi.org]

Treatment of cardiac arrhythmias during pregnancy - Safety considerations. Drug Safety 1999; 20: 85–94. Crossref | PubMed Tan HL, Lie KI. Treatment of tachyarrhythmias during pregnancy and lactation. Eur Heart J 2001; 22: 458–64. [aerjournal.com]

[…] compared to number of participants with successful treatment. [clinicaltrials.gov]

AIM: The optimal treatment for foetal tachyarrhythmia remains controversial, and this study aimed to fill this gap in the knowledge. [ncbi.nlm.nih.gov]

Early treatment is therefore key to long-term success. [bupacromwellhospital.com]

Secondary effects of fetal circulation can be additionally assessed by: ductus venosus flow assessment umbilical vein flow assessment development of hydrops fetalis Treatment and prognosis Prognosis is somewhat dependent on the presence of hydrops. [radiopaedia.org]

Although cardiac-related causes account for relatively a small proportion of cases of syncope (14%), they should always be excluded due to the worse prognosis (6). [caribbean.scielo.org]

Long-term prognosis, of fetal tachycardia despite severity of illness at time of presentation, is good, especially if conversion or rate control can be attained in utero21 and hydrops is avoided. [uscjournal.com]

Prognosis and outcome A. Maternal and fetal/neonatal outcomes The outcome of pregnancies complicated by fetal tachycardia is related to the underlying cause of the arrhythmia. PACs and PVCs are benign and the prognosis is excellent. [clinicaladvisor.com]

Abstract Observation of major pathological alterations in a young person involves etiological and clinical justifications, in order to properly assess, treat and control these conditions. [ncbi.nlm.nih.gov]

Among the patients with known etiology ischemic heart disease (60%), dilated cardiomyopathy (6%) and arrhythmogenic right ventricular cardiomyopathy (6%) were the most frequent. [ugeskriftet.dk]

All instances of VT must be followed with an etiologic search, including EKG, ABG, chem-12, drug levels. [openanesthesia.org]

Sign in Published on Apr 28, 2014 Mechanisms, etiologies, and EKG characteristics of sinus tachycardia, atrial fibrillation, atrial flutter, multifocal atrial tachycardia, supraventricular tachycardia, and ventricular tachycardia. [youtube.com]

The epidemiological features of AF are described in one of the largest population cohorts ever studied. [dx.doi.org]

Working Group on Epidemiology and Prevention of Cardiovascular Diseases: Meeting of the Working Group of the European Society of Cardiology on Epidemiology and Prevention of Cardiovascular Diseases 9,Suppl.=1 von: Weltgesundheitsorganisation. [zdb-katalog.de]

Soliman Cardiovascular Health Research Unit, Departments of Medicine and Epidemiology, University of Washington, Seattle, WA, USA Nona Sotoodehnia Department of Epidemiology and Internal Medicine, Erasmus University Medical Center Rotterdam, Rotterdam [doi.org]

This review describes the pathophysiology and corresponding electrocardiographic findings of each arrhythmia. In addition, this summary compares the clinical findings, management, and outcomes of these arrhythmias during fetal and postnatal life. [neoreviews.aappublications.org]

Current research on AF support and explore the hypothesis that initiation and maintenance of AF require pathophysiological remodeling of the atria, either specifically as in lone AF or secondary to other heart disease as in heart failure‐associated AF [doi.org]

Pathophysiologic basis of autonomic ganglionated plexus ablation in patients with atrial fibrillation. Heart Rhythm. 2009 ; 6 (12 suppl):S26–S34. Crossref Medline Google Scholar [circ.ahajournals.org]

/atrial flutter, and ventricular tachycardia. [4] The exact cause of ECG changes is yet to be delineated and is linked to myocardial injury occurring following acute cerebrovascular pathology. [5] The increased sympathetic tone is attributed to the pathophysiologic [ruralneuropractice.com]

Our review focuses on the epidemiology and pathophysiology of AF rather than its clinical treatment. Figure 1. [dx.doi.org]

Comparative effectiveness findings for stroke prevention were limited by the direct comparisons between individual direct oral anticoagulants. [doi.org]

Atrial overdrive pacing to prevent atrial fibrillation: insights from ASSERT. Heart Rhythm 9, 1667–1673 (2012). 83. Savelieva, I. & Camm, A. J. [nature.com]

This study found dabigatran is economically dominant versus rivaroxaban for prevention of stroke and systemic embolism among Canadian AF patients. [oadoi.org]

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