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Young Male With Incessantly Alternating Tachyarrhythmias

2020; Lippincott Williams & Wilkins; Volume: 142; Issue: 8 Linguagem: Inglês

10.1161/circulationaha.120.047924

1524-4539

Ping‐Huang Tsai, Yuan Hung, Pauling Chu,

Atrial Fibrillation Management and Outcomes

HomeCirculationVol. 142, No. 8Young Male With Incessantly Alternating Tachyarrhythmias Free AccessCase ReportPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyRedditDiggEmail Jump toFree AccessCase ReportPDF/EPUBYoung Male With Incessantly Alternating Tachyarrhythmias Ping-Huang Tsai, MD Yuan Hung, MD Pauling ChuMD, PhD Ping-Huang TsaiPing-Huang Tsai Division of Nephrology (P.-H.T., P.C.), Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan. , Yuan HungYuan Hung Division of Cardiology (Y.H.), Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan. , Pauling ChuPauling Chu Pauling Chu, MD, PhD, 325 Section 2, Cheng-Kung Road, Neihu District 114, Taipei, Taiwan. Email E-mail Address: [email protected] https://orcid.org/0000-0002-4221-5152 Division of Nephrology (P.-H.T., P.C.), Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan. Originally published24 Aug 2020https://doi.org/10.1161/CIRCULATIONAHA.120.047924Circulation. 2020;142:810–813ECG ChallengeA 19-year-old male patient with history of depression presented to the emergency department with unconsciousness and seizure-like activity after a suicide attempt involving ingestion of 40 g anhydrous caffeine powder. He did not have arrhythmia, syncope, epilepsy-like symptoms, aborted cardiac arrest, or sudden cardiac death before this event. None of his relatives had syncope or sudden cardiac death. Physical examination at presentation revealed extreme tachycardia of 193 beats per minute, blood pressure of 152/72 mm Hg, temperature of 35.8°C (96.44°F), and respiration of 35 breaths per minute. Laboratory testing revealed a serum potassium level of 2.3 mmol/L, creatine kinase level of 1655 U/L, serum lactate level of 7.2 mmol/L, and a serum pH of 7.182. Serum free calcium and magnesium levels were normal. No pericardial effusion or collapse of the left and right atria in end diastole was revealed by transthoracic echocardiography. A 12-lead ECG was recorded (Figure 1). What is the arrhythmia displayed in Figure 1, and how should the patient be managed?Download figureDownload PowerPointFigure 1. Twelve-lead ECG of the presenting arrhythmias.Please turn the page to read the diagnosis.Response to ECG ChallengeTwelve-lead ECG revealed a narrow QRS complex tachycardia with alternating QRS morphologies and frontal axis deviation between +40° and +150° in every lead. Right bundle-branch block morphology was seen in every other beat and QRS transition alternating from lead V1 to V6. Retrograde P waves were recognized in leads I and V3. A cautious analysis of the association between 2 QRS morphologies (namely, X and Y) shows that the X–X interval is 600 ms and the Y–Y interval is 600 ms, resulting in a tachycardia rate of 200 beats per minute (tachycardia cycle length of 300 ms). The relationship of X to Y interval is constant at 320 ms, and Y to X interval is constant at 280 ms, which is continuous throughout the tachycardia (Figure 2). It represents 2 different foci producing a bidirectional pattern because of the alternating morphology and regular time interval. Synchronized direct-current cardioversion of 100 J was performed and tachycardia was transiently terminated and reinitiated soon after cardioversion (Figure 3A). After infusion of amiodarone (150 mg), the tachyarrhythmia persisted but the QRS morphology changed from wide to narrow QRS complex, presenting with alternating positive and negative deflection (Figure 3B). These findings were highly suggestive of bidirectional ventricular tachycardia (BVT) originating from the His-Purkinje system with 1:1 ventriculoatrial conduction.Download figureDownload PowerPointFigure 2. Annotated original 12-lead ECG.Alternating morphologies of QRS complex (namely, X and Y) with X to X interval being 600 ms and Y to Y interval being 600 ms, building up the tachycardia of 200 beats per min. The relationship of X to Y interval is constant at 320 ms and Y to X interval is constant at 280 ms. Retrograde P waves can be discerned in leads I and V3 (arrowheads)Download figureDownload PowerPointFigure 3. ECG tracing strips (lead II).A, After DC cardioversion with 100 J, polymorphic ventricular tachycardia was noted, and it transited into a narrow QRS complex tachycardia. B, After amiodarone infusion, ECG tracing in lead II revealed a transition from wide QRS complex tachycardia to narrow QRS complex tachycardia and then bidirectional ventricular tachycardia with superior and inferior axes alternately.BVT is a rare tachyarrhythmia occurring in the setting of catecholaminergic polymorphic ventricular tachycardia, digitalis intoxication, aconite poisoning, myocarditis, and conditions that predispose cardiac myocytes to delay after depolarization and triggered activity.1,2 The typical ECG finding of catecholaminergic polymorphic ventricular tachycardia is the presence of BVT, characterized by beat-to-beat 180° alternating QRS axis, and relative bradycardia after resumption of sinus rhythm. Several hypotheses have been suggested to clarify the mechanism behind BVT. Baher et al2 reported a ping-pong mechanism caused by the reciprocated triggering of delayed afterdepolarizations from elevated intracellular calcium at 2 distinct ventricular foci. The alternating morphologies with different axes, width, or bundle-branch block–like morphology could result from trigger activities from different foci in the His-Purkinje system. Ventricular bigeminy is driven by the first site of delayed afterdepolarization–triggered ectopy subsequent of each natively conducted beat when the heart rate surpassed the threshold for bigeminy occurrence at the first site, whereas BVT develops because of a second ventricular site activating the first reciprocally.Caffeine intoxication–induced BVT is an unusual presentation. Caffeine acts as a phosphodiesterase inhibitor and increases myocardial intracellular calcium level through calcium release from the sarcoplasmic reticulum, which is an important generator for delayed afterdepolarization.3 Conventional hemodialysis can easily remove this agent because of its chemical characteristics such as small molecular weight (194 g/mol), low protein binding (10% to 35%), and low volume of distribution (0.6–0.8 L/kg). The patient received renal replacement therapy considering severe acidosis and caffeine intoxication, and caffeine level decreased from 906.4 to 564.4 µmol/L after 3 hours of hemodialysis. After emergent hemodialysis, he did not experience palpitation and had very few ventricular ectopic beats recorded in the following continuous ECG recordings, and neither ventricular premature beats nor ventricular tachycardia were noted during stress test. Repeat ECG revealed sinus rhythm without arrhythmia recurrence (Figure 4).Download figureDownload PowerPointFigure 4. Twelve-lead ECG after hemodialysis.ECG reveals sinus rhythm after renal replacement therapy.DisclosuresNone.Footnotes*Drs Hung and Chu are joint senior authors.Pauling Chu, MD, PhD, 325 Section 2, Cheng-Kung Road, Neihu District 114, Taipei, Taiwan. Email pauling.[email protected]comReferences1. Sato D, Xie LH, Sovari AA, Tran DX, Morita N, Xie F, Karagueuzian H, Garfinkel A, Weiss JN, Qu Z. Synchronization of chaotic early afterdepolarizations in the genesis of cardiac arrhythmias.Proc Natl Acad Sci U S A. 2009; 106:2983–2988. doi: 10.1073/pnas.0809148106CrossrefMedlineGoogle Scholar2. Baher AA, Uy M, Xie F, Garfinkel A, Qu Z, Weiss JN. Bidirectional ventricular tachycardia: ping pong in the His-Purkinje system.Heart Rhythm. 2011; 8:599–605. doi: 10.1016/j.hrthm.2010.11.038CrossrefMedlineGoogle Scholar3. Voskoboinik A, Kalman JM, Kistler PM. Caffeine and arrhythmias: time to grind the data.JACC Clin Electrophysiol. 2018; 4:425–432. doi: 10.1016/j.jacep.2018.01.012.CrossrefMedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetails August 25, 2020Vol 142, Issue 8Article InformationMetrics Download: 660 © 2020 American Heart Association, Inc.https://doi.org/10.1161/CIRCULATIONAHA.120.047924PMID: 32833522 Originally publishedAugust 24, 2020 PDF download SubjectsArrhythmiasElectrocardiology (ECG)Nephrology and Kidney