Nonsustained ventricular tachycardia is usually asymptomatic because of its short duration, but some patients complain about palpitations. It can be recorded at rest in asymptomatic individuals [1] and it can be a part of the “athlete's heart syndrome” [2]. In trained athletes with no structural heart disease, genetic channelopathies and early repolarization, it is considered to be benign, as it disappears during deconditioning periods [3]. However, the physician must inquire about the use of potentially proarrhythmic drugs and personal and familial history of heart disease, syncope and sudden death [4].

Longer arrhythmic episodes can cause lightheadedness and anxiety. Syncope, diaphoresis, pallor, hypotension and dyspnea are not usually encountered with nonsustained ventricular tachycardia episodes, but rather with sustained ones. Physical examination may reveal cannon a-waves if atrial fibrillation or flutter is absent and a variation of the first heart sound’s intensity on auscultation. However, these findings are only present during the acute episode, therefore the physician only finds them if he or she examines the patient during those few seconds, so the patient must have already been admitted to a hospital.

• Camping

  Both exogenous and endogenous catecholamines increase cAMP concentration through the modulation of adenylate cyclise and facilitate tachycardia induction. [escardio.org]

  This model of triggered activity depends on the stimulation of cAMP, which caus- es an increase in intracellular calcium. [link.springer.com]

  Thus, triggered activity secondary to cAMP-mediated delayed after-depolarizations is the most probable mechanism (26). [onlinejacc.org]

• Recurrent Pulmonary Embolism

  Inferior vena cava filters are commonly used to prevent pulmonary embolism in patients who manifest deep vein thrombosis and recurrent pulmonary embolism despite anticoagulation, or in patients with contraindications to anticoagulation. [ncbi.nlm.nih.gov]

• Heart Disease

  Nonsustained ventricular tachycardia (NSVT) may trigger concern, particularly in patients with known congestive heart failure, structural heart disease, or prolonged QT interval. [ncbi.nlm.nih.gov]

  […] with known congestive heart failure, structural heart disease, or prolonged QT interval. [jhu.pure.elsevier.com]

  This poorly reproducible arrhythmia is an overall mortality predictor, especially in patients with structural heart disease. [symptoma.com]

  } } Nonsustained ventricular tachycardia (NSVT) may trigger concern, particularly in patients with known congestive heart failure, structural heart disease, or prolonged QT interval. [semanticscholar.org]

• Left Ventricular Dysfunction

  Nonetheless, noninvasive algorithms that utilize the combination of NSVT with left ventricular dysfunction, abnormal signal-averaged electrocardiogram, and heart rate variability can be used for better risk assessment. [ncbi.nlm.nih.gov]

  Bigger JT, Fleiss JL, Kleiger R et al., and the Multicenter Post - Infarction Research Group: The relationship among ventricular arrhythmias, left ventricular dysfunction, and mortality 2 years after myocardial infarction. [link.springer.com]

  This case report describes the association of LVNC and ventricular arrhythmia and severe left ventricular (LV) dysfunction. [innovationsincrm.com]

  Effect of captopril on mortality and morbidity in patients with left ventricular dysfunction after myocardial infarction: results of the survival and ventricular enlargement trial. ‎ Página 913 - DeWood MA, Spores J, Notske R, et al. [books.google.es]

• Cardiac Signs and Symptoms

  The book and DVD package is designed to provide comprehensive coverage of every aspect of cardiovascular medicine from cardiac signs and symptoms and the full range of cardiac imaging techniques through management of peripheral vascular disease and the [books.google.it]

Nonsustained ventricular tachycardia patients must undergo a thorough cardiac evaluation. The most frequent causes of the disease in middle-aged individuals are myocardial ischemia, valve diseases and cardiomyopathies, whereas younger people may suffer from long QT syndrome, arrhythmogenic right ventricular cardiomyopathy or Brugada syndrome.

Blood workup should include potassium, calcium, magnesium and phosphate evaluation, as well as measurement of serum digoxin and tricyclic antidepressants levels or toxicology screening where appropriate. Cardiac troponins should also be measured when acute myocardial ischemia is suspected.

A simple electrocardiogram is able to pinpoint the approximate location of the ventricular contractions and to describe the tachycardia as monomorphic or polymorphic. The location of the R/S transition may predict the presence of arrhythmogenic right ventricular cardiomyopathy [5], whereas the duration of the cardiac cycle during the episode is an indicator of concomitant polymorphic ventricular tachycardia [6]. Holter monitoring is usually indicated in symptomatic patients and accurately describes arrhythmic episodes [7]. Further information is added by electrophysiology testing. In patients where arrhythmic episodes can be induced, the mortality risk is higher [8].

Some episodes are exercise-induced and may be caused by ventricular outflow arrhythmias [9]. Right ventricular outflow ectopic loci cause a left bundle branch block pattern, whereas those located in the left ventricle outflow tract appear as right bundle branch block complexes. Structural abnormalities of these areas can be demonstrated by magnetic resonance imaging or myocardial biopsy [10] [11].

Echocardiography is another useful tool, as it is able to describe myocardial scars (visualized as akinetic regions), left ventricular hypertrophy (an indicator of long-term hypertension) and the presence and severity of valvulopathies. Cardiomegaly also predicts nonsustained ventricular tachycardia episodes [12]. If the arrhythmia is detected during the recovery period of an exercise test, it indicates cardiovascular mortality during the next decades [13].

• Wide QRS Complex

  Wide QRS Complex Tachycardias. Med Clin North Am. 2001 Mar; 85(2): 245-66. ↑ Gupta AK. Wide QRS Complex Tachycardias. Med Clin North Am. 2001 Mar; 85(2): 245-66. [wikem.org]

  Wide QRS complexes (QRS duration ≥0,12 s). Types of ventricular tachycardia The ECG allows for subclassification of ventricular tachycardia. [ecgwaves.com]

  Andries A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex Circulation, 83 (1991), pp. 1649-1659 [4.] G.F. Van Hare, P. [analesdepediatria.org]

  Depending on the etiology, onset of ventricular tachycardia can be paroxysmal (sudden) or nonparoxysmal, its wide qrs complexes can be uniform or polymorphic, and the ventricular beating may be independent of the atrial beating (av dissociation). [icd10data.com]

  Wide QRS complexes (>120 ms). Presence of AV dissociation. Fusion beats. Retrograde ventriculoatrial conduction may occur, which can generate an ECG complex similar to PSVT with aberrant conduction. [patient.info]

• Early Repolarization

  In trained athletes with no structural heart disease, genetic channelopathies and early repolarization, it is considered to be benign, as it disappears during deconditioning periods. [symptoma.com]

  “Sudden cardiac death associated with early repolarization”. NEJM. vol. 358. 2008. pp. 2016-23. (It is very difficult to determine who will have sudden death as early repolarization is common and often ignored. [thecardiologyadvisor.com]

  repolarization syndromes that usually present with polymorphic episodes. [heartlandcardiology.com]

  NSVT in athletes is considered part of the “athlete's heart syndrome” (12,15) and has no adverse prognostic significance, provided conditions such as hypertrophic cardiomyopathy (HCM), early repolarization syndrome, and other genetic channelopathies are [onlinejacc.org]

• T Wave Alternans

  We examined whether T-wave alternans (TWA) level is correlated with nonsustained ventricular tachycardia (NSVT) incidence in association with PCI in patients with acute ST-segment elevation myocardial infarction (STEMI). [ncbi.nlm.nih.gov]

  Alternans T-wave alternans (TWA) is a test that is thought to reflect dispersion of repolarization and has been shown to predict VT inducibility and future arrhythmic events better than SAECG. 101 In patients similar to those in MADIT II, a microvolt [clinicalgate.com]

  Promising results on the predictive ability of T-wave alternans tests have not been consistent (90–92). [onlinejacc.org]

  Signal-averaged ECG, baroreflex sensitivity, heart rate variability, and T-wave alternans were not helpful for arrhythmia risk stratification. [academic.oup.com]

• Myocardial Fibrosis

  However, chronic, high-intensity exercise sometimes has harmful effects on cardiac health, and pathologic changes, such as myocardial fibrosis, have been observed in endurance athletes. [ncbi.nlm.nih.gov]

  Cardiac MRI revealing delayed contrast enhancement [29, 30] and newly technical innovations like myocardial T1 mapping [31] might be helpful in identifying patients with cardiac fibrosis. [hindawi.com]

  In another report, NSVT, but not myocardial fibrosis, was an independent predictor of arrhythmic events and death (130). [onlinejacc.org]

Assuming NSVT as a potential prognostic marker for sudden death, amiodarone treatment may have exerted a beneficial effect in these patients, but this statement is only a presumption due to the limitations of our study. [ncbi.nlm.nih.gov]

It is important to approach a wide-complex tachycardia in a systematic manner, to ensure correct diagnosis and treatment. [jhu.pure.elsevier.com]

Unclear Valvular Disease Mechanism High incidence in AS, severe MR (25%) Mechanical stress from dysfunctional valvular apparatus Management Beta-blockade if symptomatic Prognosis No evidence that NSVT is an independent predictor of SCD. [ddxof.com]

When NSVT occurs in patients with normal hearts, it usually has a benign prognosis. Therefore, establishing the presence or absence of structural or inherited heart disease is a critical step in each patient's evaluation. [jhu.pure.elsevier.com]

Patients were then stratified by the etiology (ischemic or nonischemic) of cardiomyopathy. [ncbi.nlm.nih.gov]

The etiology of this is likely due to the antiarrhythmic effect of lidocaine initially2 or decrease in sympathetic outflow. However, the effect greatly outlasted the half-life of lidocaine. [journals.lww.com]

Ambulatory* Female Humans Male Middle Aged Prevalence Retrospective Studies Risk Assessment Tachycardia, Ventricular/diagnosis* Tachycardia, Ventricular/epidemiology Tachycardia, Ventricular/etiology Time Factors [ncbi.nlm.nih.gov]

Background Definition[1][2] >3-5 consecutive beats originating below the AV node Rate > 100bpm Duration <30s Patient remains hemodynamically stable Epidemiology Occurs in 0-4% of ambulatory patients Increased frequency in males and with increasing age [wikem.org]

Given the epidemiology of SCD, the normal EF group is an extremely desirable target for intervention. However, in the MERLIN TIMI-36 clinical trial population, even the highest risk group had a SCD rate of only 4.3% at one year. [ahajournals.org]

Cardiovascular Magnetic Resonance and XRay Computed Tomography 245 Choosing Appropriate Imaging Techniques 269 DISORDERS OF RHYTHM AND CONDUCTION 283 Electrophysiology of Cardiac Arrhythmias 285 Treatment of Cardiac Arrhythmias 305 Syncope 329 HEART FAILURE 345 Pathophysiology [books.google.com]

However, indi¬vi¬duals with¬out these recogni¬zed traits and conditions also develop OSA making the etiology and pathophysiology unclear. [umu.se]

Pathophysiology of Heart Disease (3rd ed.). Lippincott Williams & Wilkins. ISBN 978-0-7817-4027-2. ^ G. Morris, Innasimuthu A L, J.P. Fox, R.A. [en.wikipedia.org]

The sympathetic nervous system in heart failure physiology, pathophysiology, and clinical implications. [scielo.br]

These results support the need for ICD implantation for primary prevention, with attention to careful programming of the detection rate to prevent inappropriate therapy. [ncbi.nlm.nih.gov]

A randomized study of the prevention of sudden death in patients with coronary artery disease. Multicenter Unsustained Tachycardia Trial Investigators. N Engl J Med. 1999;341(25):1882–1890. doi:10.1056/NEJM199912163412503. [ddxof.com]

1. Engstrom G, Hedblad B, Janzon L, et al. Ventricular arrhythmias during 24-h ambulatory ECG recording: incidence, risk factors and prognosis in men with and without a history of cardiovascular disease. J Intern Med.1999;246:363–72.
2. Biffi A, Maron BJ, Verdile L, et al. Impact of physical deconditioning on ventricular tachyarrhythmias in trained athletes. J Am Coll Cardiol.2004; 44:1053–8.
3. Biffi A, Maron BJ, Culasso F, et al. Patterns of ventricular tachyarrhythmias associated with training, deconditioning and retraining in elite athletes without cardiovascular abnormalities. Am J Cardiol.2011;107:697–703.
4. Zipes DP, Camm AJ, Borggrefe M, et al. ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death. J Am Coll Cardiol. 2006; 48(5):e247-346.
5. Hoffmayer KS, Machado ON, Marcus GM, et al. Electrocardiographic comparison of ventricular arrhythmias in patients with arrhythmogenic right ventricular cardiomyopathy and right ventricular outflow tract tachycardia. J Am Coll Cardiol. 2011;58:831–8.
6. Shimizu W. Arrhythmias originating from the right ventricular outflow tract: how to distinguish “malignant” from “benign”? Heart Rhythm. 2009; 6:1507–11.
7. Pastor-Pérez FJ, Manzano-Fernández S, Goya-Esteban R, et al. Comparison of detection of arrhythmias in patients with chronic heart failure secondary to non-ischemic versus ischemic cardiomyopathy by 1 versus 7-day Holter monitoring. Am J Cardiol. 2010;106:677–81.
8. Buxton AE, Lee KL, DiCarlo L, et al. Electrophysiologic testing to identify patients with coronary artery disease who are at risk for sudden death: Multicenter Unsustained Tachycardia Trial Investigators. N Engl J Med. 2000;342:1937–45.
9. Kim RJ, Iwai S, Markowitz SM, et al. Clinical and electrophysiological spectrum of idiopathic ventricular outflow tract arrhythmias. J Am Coll Cardiol. 2007;49:2035–43.
10. Carlson MD, White RD, Trohman RG, et al. Right ventricular outflow tract ventricular tachycardia: detection of previously unrecognized anatomic abnormalities using cine magnetic resonance imaging. J Am Coll Cardiol. 1004;24:720–7.
11. Chimenti C, Calabrese F, Thiene G, et al. Inflammatory left ventricular microaneurysms as a cause of apparently idiopathic ventricular tachyarrhythmias. Circulation. 2001;104:168–73.
12. Di Bella G, Passino C, Aquaro GD, et al. Different substrates of non-sustained ventricular tachycardia in post-infarction patients with and without left ventricular dilatation. J Card Fail. 2010;16:61–8.
13. Katritsis DG, Zareba W, Camm AJ.Nonsustained ventricular tachycardia. J Am Coll Cardiol. 2012;60(20):1993-2004.