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.

• Acutely Ill Patient

  However, during acute illness, patients may require rate control with cardioversion, AV nodal blockers, and/or antiarrhythmic drugs if AF is poorly tolerated or rate control is not feasible. [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]

  Cardiac arrest If the patient displays one or more of the first three symptoms (palpitations, dyspnea, chest discomfort) it is considered safe to take time to judge the ECG and additional information. [ecgwaves.com]

  syncope, dyspnea), and intolerance of or resistance to drug therapy. [peertechz.com]

• Tachycardia

  […] due to the accessory pathway, atrial ectopic tachycardia and permanent junctional reciprocal tachycardia). [ncbi.nlm.nih.gov]

• Heart Disease

  KEYWORDS: Amiodarone; Anti-arrhythmic drug; Congenital heart disease; Tachyarrhythmia [ncbi.nlm.nih.gov]

  We will discuss the following ventricular tachyarrhythmias in more depth: Ventricular Tachycardia (VT) in patients with structural heart disease, Ventricular Tachycardia (VT) in patients without structural heart disease, and Ventricular Fibrillation [washingtonhra.com]

• 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]

  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]

  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]

  Adenosine must not be administered during ventricular tachycardia because it may accelerate the ventricular tachcyardia and cause hypotension. [ecgwaves.com]

• Cardiac Signs and Symptoms

  Conclusion Cardiac tumours are rare in childhood and should be considered as part of the differential diagnosis in a child presenting with cardiac signs and symptoms and treatment should be individualised for each patient. [ncbi.nlm.nih.gov]

  Cardiac tumours are rare in childhood and should be considered as part of the differential diagnosis in a child presenting with cardiac signs and symptoms and treatment should be individualised for each patient. [um.edu.mt]

• Hepatojugular Reflux

  These clinical and paraclinical aspects were: stasis hepatomegaly with hepatojugular reflux, pulmonary congestion with stasis rales, peripheral edema, transudative polyserositis - pericarditis, hydrothorax, ascites, dilatation of inferior vena cava and [ncbi.nlm.nih.gov]

• Sweating

  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. Classification D ICD-10: I47.1 ICD-9-CM: 427.89, 427.0 MeSH: D013617 Cardiac Disorders – Open Directory Project [en.wikipedia.org]

  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]

• 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]

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

  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]

  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.

• Complete Left Bundle Branch Block

  This disturbance is much more common than the development of complete left bundle branch block (LBBB). [ncbi.nlm.nih.gov]

  Cumulative effect of complete left bundle-branch block and chronic atrial fibrillation on 1-year mortality and hospitalization in patients with congestive heart failure. [doi.org]

• Abnormal ECG

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

  At the same time, the harms of diagnostic follow-up and treatment prompted by abnormal ECG results are well established and include misdiagnosis and invasive testing. [doi.org]

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