Borderline ECG. A history of both short and long QT syndromes makes a ventricular origin of the tachycardia likely as well.1012 However, patients with a short QT syndrome and the Brugada syndrome are more likely to present with ventricular fibrillation rather than VT. Infiltrative diseases of the heart such as cardiac amyloidosis or sarcoidosis may also predispose patients to ventricular arrhythmias.13,14 Interestingly enough, VT is also common in patients with Chagas disease.15. Vereckei, A, Duray, G, Szenasi, G. New algorithm using only lead aVR for differential diagnosis of wide QRS complex tachycardia. Of course, such careful evaluation of the patient is only possible when the patient is hemodynamically stable during VT; any hemodynamic instability (such as presyncope, syncope, pulmonary edema, angina) should prompt urgent or emergent cardioversion. ECG results: 79 pbm, Pr interval 152 ms, Qrs duration 100 ms,QT/QTc 352/403 ms, p r t axes 21 20 17. Hanna Ratcovich Unless a defibrillator is used to reset the heart's rhythm, ventricular fibrillation . The hallmark of VT is ventriculoatrial (VA) dissociation (the ventricular rate being faster than the atrial rate), the following examination findings (Table II), when clearly present, clinch the diagnosis of VT. In between, there is a WCT with a relatively narrow QRS complex with an RBBB-like pattern. When a WCT abruptly becomes a narrow QRS rhythm at exactly half the rate of the WCT, atrial flutter with 1:1 AV conduction transitioning to 2:1 AV conduction is very likely (i.e., SVT with aberrancy). A northwest frontal axis during WCT strongly favors VT (since neither RBBB nor LBBB aberrancy results in such an axis). She has missed her last two hemodialysis appointments. One such example would be antidromic atrioventricular reciprocating tachycardia , where the impulse travels anterogradely over an accessory pathway , and then uses the normal His-Purkinje network and AV node for retrograde conduction back up to the atrium. The WCT overtakes the sinus P waves starting at the fourth beat, resulting in apparent PR interval shortening. This pattern is pathognomonic of VT, and represents a form of VA dissociation during VT onset. incomplete right bundle branch block. et al, Antonio Greco Today we will focus only on lead II. Because of this reason, many patients have only ECG telemetry (rhythm) strips available for analysis; however, there is often sufficient information within telemetry strips to make an accurate conclusion about the nature of WCT. The QRS complex is identical to the prior WCT, which was atrial flutter with 2:1 conduction. The normal QRS complex during sinus rhythm is narrow (<120 ms) because of rapid, nearly simultaneous spread of the depolarizing wave front to virtually all parts of the ventricular endocardium, and then radial spread from endocardium to epicardium. The Licensed Content is the property of and copyrighted by DSM. - Case Studies Importantly, the EKGs were not available for additional EKG review, which also . No. These findings would favor SVT. While it may seem odd to call an abnormal heart rhythm a sign of a healthy heart, this is actually the case with sinus arrhythmia. vol. English KM, Gibbs JL,. The PR interval is normal unless a co-existing conduction block exists. 1991. pp. Wide complex tachycardia is defined as a rate of > 100 with QRS > 120ms. Brugada P, Brugada J, Mont L, et al., A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex, Circulation, 1991;83(5):164959. I gave a Kardia and last night I upgraded the Kardia and my first reading was - Answered by a verified Doctor . Toxicity with flecainide, a class Ic antiarrhythmic drug with potent sodium channel blocking capabilities, is a well-known cause of bizarrely wide QRS complexes and low amplitude P waves. Hard exercise, anxiety, certain drugs, or a fever can spark it. Therefore, this tracing represents VT with 3:2 VA conduction (VA Wenckebach); this still counts as VA dissociation. It means the electrical impulse from your sinus node is being properly transmitted. premature ventricular contraction. Irregular rhythms also make it dif cult to Sinus Tachycardia. It also does not mean that you . The apparent narrowness of the QRS may be misleading in a single lead rhythm strip. Each "lead" takes a different look at the heart. In Camm AJ, Lscher TF, Serruys PW, editors. Normal Sinus Rhythm i. Griffith MJ, Garratt CJ, Mounsey P, Camm AJ, Ventricular tachycardia as default diagnosis in broad complex tachycardia, Lancet, 1994;343(8894):3868. The differentiation of wide QRS complex tachycardias presents a challenging diagnostic dilemma to many physicians despite multiple published algorithms and approaches.1 The differential diagnosis includes supraventricular tachycardia conducting over accessory pathways, supraventricular tachycardia with aberrant conduction, antidromic atrio-ventricular reentrant tachycardia, supraventricular tachycardia with QRS complex widening secondary to medication or electrolyte abnormalities, ventricular tachycardia (VT) or electrocardiographic artifacts. The rhythm strip shows sinus tachycardia at the beginning and at the end; each sinus P wave is marked. In cases of respiratory sinus arrhythmia, the P-P interval will often be longer than 0.16 seconds when the person breathes out. The pattern of preexcitation in sinus rhythm (the delta wave) will be exactly reproduced (and exaggerated so called full preexcitation) during antidromic AVRT. The QRS morphology suggests an old inferior wall myocardial infarction, favoring VT. sinus, atrial, junctional or ventricular). Regularity of the rhythm: If the wide QRS tachycardia is sustained and monomorphic, then the rhythm is usually regular (i.e., RR intervals equal); an irregularly-irregular rhythm suggests atrial fibrillation with aberration or with WPW preexcitation. The sensitivity and specificity of this protocol are 96.5 and 95.7 %, respectively, which is similar to the previous alghorithm published by this group.29. If your ECG shows a wide QRS complex, then your ventricles (the bottom chambers of the heart) are contracting more slowly than a normal rhythm. et al, Andre Briosa e Gala Will it go away? Normal Sinus Rhythm . The QRS complexes may look alike in shape and form or they may be multiform (markedly different from beat to beat). And its normal. vol. In the hemodynamically stable patient, obtaining an ECG with specially located surface ECG electrodes can be helpful in recognizing dissociated P waves. The presence of atrioventricular dissociation strongly favors the diagnosis of VT. The timing of engagement of the His-Purkinje network: at some point during propagation of the VT wave front, the His-Purkinje network is engaged, resulting in faster propagation; the earlier this occurs, the narrower the QRS complex. Sinus rhythm is necessary, but not sufficient, for normal electrical activity within the heart.. A normal heartbeat is referred to as normal sinus rhythm (NSR). This initial distinction will guide the rest of the thinking needed to arrive at . And you dont want to, because its a sign of a healthy heart. A Junctional rhythm can happen either due to the sinus node slowing down or the AV node speeding up. SVT, sinus tachycardia, etc. That rhythm changes into a regular wide QRS tachycardia (rate 220 bpm), with QRS characteristics pointing to a ventricular origin (QRS width 180 ms, north-west frontal QRS axis, monophasic R in lead V 1, R/S ratio V 6 <1) 2. However, when in doubt, treat the arrhythmia as if it was VT, as approximately 80 % of wide QRS complex tachycardias are of ventricular origin.30,31, Antonia Sambola American Heart Hospital Journal 2011;9(1):33-6, DOI:https://doi.org/10.15420/ahhj.2011.9.1.33. Looks like youre enjoying our content Youve viewed {{metering-count}} of {{metering-total}} articles this month. It is a somewhat common misconception that patients with ventricular tachycardias are almost always hemodynamically unstable.2 The patients blood pressure cannot be used as a reliable sign for the differentiation of the origin of an arrhythmia. The prognostic value of a wide QRS >120 ms among patients in sinus rhythm is well established. 2008. pp. On a practical matter, telemetry recordings are often erased once the patient leaves that location, and it is important to print out as many examples of the WCT as possible for future review by the cardiology or electrophysiology consultant. Tachycardias are broadly categorized based upon the width of the QRS complex on the electrocardiogram (ECG). WCT tachycardia obtained from a 72-year-old man with a history of remote anteroseptal myocardial infarction and reduced ejection fraction. Tetralogy of Fallot is a common cyanotic congenital lesion.6 Patients with both unrepaired and repaired conditions are at risk of having VT.7,8 Patients with a history of Duchenne muscular dystrophy, Becker muscular dystrophy, myotonic dystrophy, Friedreichs ataxia, and EmeryDreifuss muscular dystrophy are at increased risk of developing cardiomyopathies.9 Thus a diagnosis of VT should be considered in these patients presenting with wide complex tachycardias. The QRS width is useful in determining the origin of each QRS complex (e.g. . Sick sinus syndrome causes slow heartbeats, pauses (long periods between heartbeats) or irregular heartbeats (arrhythmias). Supraventricular tachycardia (SVT) with aberrancy accounts for . Normal sinus rhythm is defined as the rhythm of a healthy heart. Her serum potassium was 7.1 mEq/dl, and with aggressive treatment of hyperkalemia, her ECG normalized. The ESC textbook of Cardiovascular Medicine, Oxford, Blackwell Publishing Ltd, 2006, p950. The normal PR interval is 0.12-0.20 seconds, or 3-5 small boxes on the ECG graph paper. By the fourth wide complex beat, there is 1:1 VA conduction, and now there is VA association with a retrograde P wave (P). What is the reason for the wide QRS in this ECG?While analyzing wide QRS in sinus rhythm, one of my teachers used to put it simply like this: right bundle, l. 2007. pp. You have a healthy heart. Its very common in young, healthy people. Figure 8: WCT tachycardia recorded in a male patient on postoperative day 3 following mitral valve repair. High Grade Second Degree AV Block, All of the following are generally associated with a wide QRS complex EXCEPT: Select one: a. 17,18 An entirely positive QRS complex in lead augmented ventor left (aVR) also supports the diagnosis of VT. 17 When the sinus rhythm with wide QRS becomes narrow with a tachycardia . Sinus rythm with marked sinus arythmia. At first observation, there appears to be clear evidence for VA dissociation, with the atrial rate being slower than the ventricular rate. The width of the QRS complex, both with aberrancy and during VT, can vary from patient to patient. This is called a normal sinus rhythm. Furthermore, there will often be evidence of VA dissociation, with the ventricular rate being faster than the atrial rate, pointing to the correct diagnosis of VT. In EKG results, nonrespiratory sinus arrhythmia can look like respiratory sinus arrhythmia. As expected, the P waves are of low amplitude in hyperkalemia. 83. The QRS complex (ventricular complex): normal and abnormal configurations and intervals. Although this is an excellent protocol, with a sensitivity of 8892 % and specificity of 4473 % for VT, it requires remembering multiple morphologic criteria.25,26, The majority of the protocols use supraventricular tachycardia as a default diagnosis of wide QRS complex tachycardia. A 20-year-old man with recurrent supraventricular tachycardia ( Figure 1) was referred for catheter ablation. The interval from the pacing spike to the captured QRS complex progressively gets longer, before a pacing spike fails to capture altogether; this is consistent with Pacemaker Exit Wenckebach. The QRS duration is 170 ms; the rate is 126 bpm. In most people, theres a slight variation of less than 0.16 seconds. Name: Ventricular Fibrillation- Lethal Rate: N/A Rhythm: chaotic baseline activity which may be coarse or fine P-Waves: none PR-Interval: N/A QRS Complex: none. He had a history of paroxysmal atrial fibrillation. When sinus rhythm exceeds 100 bpm, it is considered sinus tachycardia. One approach to the interpretation of wide QRS complex tachycardias is to divide them into right bundle branch block morphology (QRS complex being predominantly positive in lead V1) and left bundle branch block morphology (QRS complex being predominantly negative in lead V1).20. Drew BJ, Scheinman MM, ECG criteria to distinguish between aberrantly conducted supraventricular tachycardia and ventricular tachycardia: practical aspects for the immediate care setting, PACE, 1995;18:2194208. This is traditionally printed out on a 6-second strip. The presence of antiarrhythmic drugs (especially class Ic or class III antiarrhythmic drugs) or electrolyte abnormalities (such as hyperkalemia) can slow intra-myocardial conduction velocity and widen the QRS complex. Oreto G, Smeets JL, Rodriguez LM, et al., Wide complex tachycardia with atrioventricular dissociation and QRS morphology identical to that of sinus rhythm: a manifestation of bundle branch reentry, Heart, 1996;76(6):5417. Radcliffe Cardiology is part of Radcliffe Medical Media, an independent publisher and the Radcliffe Group Ltd. 578-84. Most importantly, the transition to narrow complex tachycardia is accompanied by an acceleration of the heart rate to about 120 bpm. An abnormally slow heart rate can cause symptoms, especially with exercise. This causes a wide S-wave in V1V2 and broad and clumsy R-wave in V5V6. We recommend using a protocol that one is most familiar and comfortable with and supplementing it with the steps from other protocols to improve the accuracy of the diagnosis. The QRS complex down stroke is slurred in aVR, favoring VT. vol. Wide complex tachycardias with right bundle branch block morphologies are more likely to be of ventricular origin in the presence of the following criteria: Left bundle branch block morphology tachycardias are more likely to be VT if they have the following features: In addition to these criteria, the presence of an R wave of more than 30 ms duration, notching of the downstroke of the S wave, or duration from the onset of the QRS to the nadir of the S wave in leads V1 or V2 of greater than 60 ms and any Q wave in lead V6 favors the ventricular origin of an arrhythmia.23 A protocol for the differentiation of a regular, wide QRS complex tachycardia was published by Brugada et al.24 It consisted of four diagnostic criteria: The presence of any of these criteria supports the diagnosis of VT. Morphologic criteria for right bundle branch block for lead V1 are: the presence of monophasic R wave, QR or RS morphology; for lead V6: Larger S wave than R wave, or the presence of QS or QR complexes. When it happens for no clear reason . For management, see "Management of Wide Complex Tachycardia". The QRS complex duration is wide (>0.12 seconds or 3 small boxes) in every lead. Comparison of the QRS complex to a prior ECG in sinus rhythm is most helpful; a virtually identical (wide) QRS in sinus rhythm favors a supraventricular tachycardia with preexisting aberrancy. Her rhythm strips from the ambulance are shown in Figure 5. Unlike previous protocols, VT was used as a default diagnosis by Griffith et al.27 Only the presence of typical bundle branch criteria assigned the arrhythmias origin to be supraventricular. The ECG shows a normal P wave before every QRS complex. If the QRS duration is normal (<0.12 seconds), the arrhythmia is said to be a narrow complex tachycardia (NCT). The narrow QRS tachycardia shows the typical features of atrial fibrillation (AF). Khairy P, Harris L, Landzberg MJ, et al., Implantable cardioverterdefibrillators in tetralogy of Fallot, Circulation, 2008;117:36370. This is where the experienced electrocardiographer must weigh the conflicting indicators and reach a clinical decision. 2008. pp. Your heart rate increases when you breathe in and slows down when you breathe out. Lau EW, Ng GA, Comparison of the performance of three diagnostic algorithms for regular broad complex tachycardia in practical application, Pacing Clin Electrophysiol, 2002;25(5):8227. Normal sinus rhythm is defined as the rhythm of a . Brugada R, Hong K, Cordeiro JM, Dumaine R, Short QT syndrome, CMAJ, 2005;173(11):134954. Any WCT should be assumed to be VT until proven otherwise. Rhythm: Sinus rhythm is present, all beats are conducted with a normal PR . Normal sinus rhythm is defined as a regular rhythm with an overall rate of 60 to 100 beats/min. Respiratory sinus arrhythmia is actually a sign of a healthy heart. A normal sinus rhythm means your heart rate is within a normal range. The following historical features (Table I) powerfully influence the final diagnosis. Wide complex tachycardia due to bundle branch reentry. Goldberger, ZD, Rho, RW, Page, RL.. Approach to the diagnosis and initial management of the stable adult patient with a wide complex tachycardia. et al, Hassan MH Mohammed