Accelerated idioventricular rhythm in a healthy newborn: frightening but non-threatening.

Accelerated idioventricular rhythm is a rare but benign form of ventricular tachycardia which might be challenging to differentiate from other more worrisome forms. We present the case of a healthy newborn diagnosed with an accelerated idioventricular rhythm which is spontaneously terminated without the need for medical therapy.

Clinical characteristics and therapeutic strategy of frequent accelerated idioventricular rhythm.

BACKGROUND: Accelerated idioventricular rhythm (AIVR) is often transient, considered benign and requires no treatment. This observational study aims to investigate the clinical manifestations, treatment, and prognosis of frequent AIVR. METHODS: Twenty-seven patients (20 male; mean age 32.2 ± 17.0 years) diagnosed with frequent AIVR were enrolled in our study. Inclusion criteria were as follows: (1) at least three recordings of AIVR on 24-h Holter monitoring with an interval of over one month between each recording; and (2) resting ectopic ventricular rate between 50 to 110 bpm on ECG. Electrophysiological study (EPS) and catheter ablation were performed in patients with distinct indications. RESULTS: All 27 patients experienced palpitation or chest discomfort, and two had syncope or presyncope on exertion. Impaired left ventricular ejection fraction (LVEF) was identified in 5 patients, and LVEF was negatively correlated with AIVR burden (P < 0.001). AIVR burden of over 73.8%/day could predict impaired LVEF with a sensitivity of 100% and specificity of 94.1%. Seventeen patients received EPS and ablation, five of whom had decreased LVEF. During a median follow-up of 60 (32, 84) months, LVEF of patients with impaired LV function returned to normal levels 6 months post-discharge, except one with dilated cardiomyopathy (DCM). Two patients died during follow-up. The DCM patient died due to late stage of heart failure, and another patient who refused ablation died of AIVR over-acceleration under fever. CONCLUSIONS: Frequent AIVR has unique clinical manifestations. AIVR patients with burden of over 70%, impaired LVEF, and/or symptoms of syncope or presyncope due to over-response to sympathetic tone should be considered for catheter ablation.

Accelerated idioventricular rhythm resulting in torsades de pointes and cardiac arrest in a child: successfully cryoablated in left'coronary cusp.

Known as a benign arrhythmia and normally requiring no specific treatment, accelerated idioventricular rhythm can rarely degenerate to a life-threatening arrhythmia. Here, we present a child with left coronary cusp-originating accelerated idioventricular rhythm, degenerating into torsades de pointes and resulting in cardiac arrest, which was ablated with a cryocatheter. An 11-year-old boy, followed due to asymptomatic accelerated idioventricular rhythm before, was referred to our department because he had experienced an aborted cardiac arrest during sleep. He had been resuscitated for 5 minutes. Twenty-four-hour Holter-ECG revealed incessant accelerated idioventricular rhythm, consisting up to 90% of the whole record and two torsades de pointes attacks, triggered by accelerated idioventricular rhythm-induced "R on T" phenomenon, and resulting in syncope and cardiac arrest. Transthoracic echocardiography revealed no structural cardiac defect but mild left ventricular systolic dysfunction with an ejection fraction of 45% and shortening fraction 23%. An electrophysiologic study was conducted, and accelerated idioventricular rhythm focus was mapped to left aortic coronary cusp. A cryocatheter with an 8-mm tip was preferred for successful ablation of the accelerated idioventricular rhythm focus, due to close neighbourhood to coronary ostium. The patient was discharged in 3 days without any premature ventricular contractions or accelerated idioventricular rhythm and with normalised cardiac functions. After 9 months on follow-up, he was still asymptomatic, without any premature ventricular contractions or accelerated idioventricular rhythm and with normal cardiac functions. Although the clinical course of accelerated idioventricular rhythm is known as benign, accelerated idioventricular rhythm can rarely degenerate to a life-threatening arrhythmia. In such cases, electrophysiologic study and catheter ablation are a good option in such cases with accelerated idioventricular rhythm for an ultimate cure.

Contribution of Electrocardiographic Accelerated Ventricular Rhythm Alarms to Alarm Fatigue.

BACKGROUND: Excessive electrocardiographic alarms contribute to "alarm fatigue," which can lead to patient harm. In a prior study, one-third of audible electrocardiographic alarms were for accelerated ventricular rhythm (AVR), and most of these alarms were false. It is uncertain whether true AVR alarms are clinically relevant. OBJECTIVES: To determine from bedside electrocardiographic monitoring data (1) how often true AVR alarms are acknowledged by clinicians, (2) whether such alarms are actionable, and (3) whether such alarms are associated with adverse outcomes ("code blue," death). METHODS: Secondary analysis using data from a study conducted in an academic medical center involving 5 adult intensive care units with 77 beds. Electronic health records of 23 patients with 223 true alarms for AVR were examined. RESULTS: The mean age of the patients was 62.9 years, and 61% were white and male. All 223 of the true alarms were configured at the warning level (ie, 2 continuous beeps), and 215 (96.4%) lasted less than 30 seconds. Only 1 alarm was acknowledged in the electronic health record. None of the alarms were clinically actionable or led to a code blue or death. CONCLUSIONS: True AVR alarms may contribute to alarm fatigue. Hospitals should reevaluate the need for close monitoring of AVR and consider configuring this alarm to an inaudible message setting to reduce the risk of patient harm due to alarm fatigue. Prospective studies involving larger patient samples and varied monitors are warranted.

Respuesta al ECG de noviembre de 2018 / Response to ECG, November 2018

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Accelerated idioventricular rhythm degenerating into bidirectional ventricular tachycardia following acute myocardial infarction.

Bidirectional ventricular tachycardia (BVT) is a rare ventricular tachyarrhythmia. It is usually regular, demonstrating a beat-to-beat alternation in the QRS frontal axis that varies between -20° to -30° and +110°. The tachycardia rate is typically between 140 and 180 beats/min and the QRS is relatively narrow, with a duration of 120 to 150 ms. The etiology of published BVT cases is most commonly digitalis toxicity and, rarely, herbal aconitine poisoning, hypokalemic periodic paralysis, catecholaminergic polymorphic ventricular tachycardia (CPVT), myocarditis, and Andersen-Tawil syndrome. We report a case of accelerated idioventricular rhythm (AIVR) degenerating into BVT following acute myocardial infarction, and briefly discuss the proposed mechanisms underlying BVT.

Double ventricular response in dual AV nodal pathways mimicking interpolated premature beat.

Double ventricular response in dual atrioventricular (AV) nodal pathways can result in nonreentrant supraventricular tachycardia. Since this condition was first described in 1979, around 20 cases have been reported. Here, we present the case of a patient with a confirmed diagnosis of double ventricular response in dual AV nodal pathways resembling an interpolated premature beat who underwent successful radiofrequency ablation of the slow pathway.

Ritme idioventricular accelerat transitori en un nounat afectat d’acidèmia metilmalònica / Ritmo idioventricular acelerado en un neonato afecto de acidemia metilmalónica / Transient accelerated idioventricular rhythm in a newborn with methylmalonic academia

Introducció: el ritme accelerat idioventricular (RIVA) és una disrítmia originada a nivell dels feixos de His, de les fibres de Purkinje o dels miòcits ventriculars, molt rara en infants i nadons. Cas clínic: es presenta el cas d'un nounat a terme amb la presència de RIVA els primers dies de vida, sense repercus-sió hemodinàmica, i que s'autolimita als dos mesos d'edat. Posteriorment es va diagnosticar d'acidèmia metilmalònica tipus mut0, i es va iniciar el tractament amb dieta específica, carnitina i vitamina B12, amb bon control metabòlic. En el seguiment presenta extrasístoles ventriculars aïllades i un desenvolupament físic i psicomotor correctes. Comentaris: la identificació d'aquesta disrítmia pot ser difícil i és de gran transcendència, ja que planteja el diagnòstic diferencial principalment amb la taquicàrdia ventricular. El seu pronòstic generalment és benigne i tendeix a la resolució espontània; per tant, els fàrmacs antiarítmics no estan indicats. La coexistència de RIVA i acidèmia metilmalònica en un mateix pacient no ha estat descrita fins al moment

Introducción. El ritmo acelerado idioventricular (RIVA) es una disritmia originada a nivel de los haces de His, de las fibras de Purkinje o de los miocitos ventriculares, muy rara en niños y neonatos. Caso clínico. Se presenta el caso de un recién nacido a término con la presencia de RIVA los primeros días de vida, sin repercusión hemodinámica, y que se autolimita a los dos meses de edad. Posteriormente se diagnosticó de acidemia metilmalónica tipo mut0, y se inició el tratamiento con dieta específica, carnitina y vitamina B12, con buen control metabólico. En el seguimiento presenta extrasístoles ventriculares aisladas y un desarrollo físico y psicomotor correctos. Comentarios. La identificación de esta disritmia puede ser difícil y es de gran trascendencia, puesto que plantea el diagnóstico diferencial principalmente con la taquicardia ventricular. Su pronostico es, generalmente, benigno y tiende a la resolución espontánea; por tanto, los fármacos antiarrítmicos no están indicados. La coexistencia de RIVA y acidemia metilmalónica no ha sido descrita hasta el momento en un mismo paciente (AU)

Introduction. The accelerated idioventricular rhythm (AIVR) is a very rare pediatric dysrhythmia originated in the bundles of His, Purkinje fibers, or ventricular myocytes. Case report. A term newborn presented with AIVR in the first days of life; he was hemodynamically stable, and the arrhythmia resolved by two months of age. The infant was subsequently diagnosed with mut0 methylmalonic acidemia, and was started on specific diet, carnitine, and vitamin B12, with good response. On follow-up, the infant was found to have isolated ventricular extrasystoles and normal physical and psychomotor development. Comments. The identification of this dysrhythmia can be difficult; its prompt recognition is critical due to its differential diagnosis with ventricular tachycardia. The prognosis is usually benign, with spontaneous resolution in most cases; thus, antiarrhythmic agents are not indicated. The coexistence of AIVR and methylmalonic academia has not been previously described (AU)

ECG of the Month: Wide-QRS Tachycardias.

A 61-year-old man came from out of state to attend a football game. He felt well during the game, but when he stood up to leave, he became dizzy and dyspneic. The symptoms lasted 15 to 20 minutes, and when the paramedics arrived, they diagnosed an idioventricular rhythm and brought the patient to the emergency department where a 12-lead electrocardiogram (ECG) was recorded (Figure 1).

Ventricular arrhythmias in children with attention deficit disorder--a symptom of autonomic imbalance?

OBJECTIVES: Potential side effects of stimulants for attention deficit disorder are in the focus of scientific discussions, intensified by the higher number of prescriptions. Children with known arrhythmias or other severe cardiac problems should not receive stimulants because of their sympathomimetic effects. METHODS: This is a retrospective analysis of 24-hour Holter electrocardiograms from 100 consecutive children with attention deficit disorder from January, 2006 to April, 2012. RESULTS: In all, nine children had significant ventricular arrhythmia (mean age 11.4 ± 3.1 years, 77% male, 77% received methylphenidate). All these children had ventricular parasystole - four of them with an accelerated idioventricular rhythm. A significant circadian rhythm of premature ventricular contractions in seven children and the effect of standing and exercise clearly indicate the influence of the autonomic nervous system. In these children, hourly analysis of circadian rhythm within a 24-hour period showed a highly significant correlation between premature ventricular contractions and the vagal tone indicated by the heart rate variability parameter RMSSD (r = -0.83; p < 0.001). Ventricular arrhythmia was unaffected in seven children who received methylphenidate before diagnosis and decreased during metoprolol treatment in two children. CONCLUSION: By Holter electrocardiogram analysis, we observed a remarkably high incidence of ventricular parasystole and accelerated idioventricular rhythm in nine of 100 children with attention deficit disorder, which depends on autonomic imbalance and not on stimulant treatment.