Accelerated idioventricular rhythm as a manifestation of chronic renocardiac syndrome: A case report.

In this case report, we describe a patient who presented with chronic symptoms and signs of uremia and persistent accelerated idioventricular rhythm (AIVR) on electrocardiogram. Findings from blood tests, echocardiography, renal ultrasound, and renal scan were suggestive of heart failure with reduced ejection fraction and chronic kidney disease, and attendance of daily hemodialysis sessions led to the restoration of sinus rhythm. Typically, AIVR has a favorable prognosis and, if necessary, medical intervention focuses on addressing the underlying responsible causes. Accumulation of uremic toxins has the potential to trigger the formation of AIVR and clearance of small solutes through conventional hemodialysis may contribute to sinus rhythm restoration.

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.

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.

Prenatal diagnosis and prognosis of accelerated idioventricular rhythm.

OBJECTIVES: As postnatal identification of accelerated idioventricular rhythm (AIVR) relies on specific electrocardiographic patterns, prenatal diagnosis of this condition is challenging and its true incidence is unknown. The objectives of this study were to evaluate the performance of prenatal ultrasonography in identifying intrauterine cardiocirculatory events linked to specific electrocardiographic signs of postnatal AIVR, including left or right ventricular origin, and to assess the prenatal prognosis of this arrhythmia. METHODS: We reviewed Doppler tracings from the superior vena cava/ascending aorta (SVC/Ao), ductus venosus (DV), ductus arteriosus (DA) and aortic isthmus (AoI), as well as simultaneous M-mode recordings of septal and left ventricular wall motions of fetuses diagnosed with AIVR from January 2004 to December 2014. RESULTS: Three cases of AIVR were identified among 27 912 fetuses. SVC/Ao Doppler flow recordings revealed atrioventricular dissociation (ventricular rates within 20% of atrial rates) in all three fetuses and episodes of isorhythmic atrioventricular dissociation in one, while M-mode confirmed normal left ventricular shortening fraction in all cases. Fusion beats were observed on AoI tracing in one fetus, while simultaneous recordings of AoI and DA revealed signs of right bundle branch block in one case and left bundle branch block in the other two. On DV Doppler recordings, retrograde a-waves in the presence of simultaneous atrial and ventricular contractions were observed in all three fetuses, leading to an increase in central venous pressure in all and hydrops fetalis in two cases without evidence of ventricular dysfunction. CONCLUSIONS: Echocardiographic criteria required for postnatal diagnosis of AIVR can be documented in utero using specific ultrasonographic approaches. During fetal life, AIVR may not be a benign entity. Hydrops fetalis is frequently associated with AIVR because of increase in central venous pressure related to simultaneous atrioventricular contractions; thus, the ultrasonographic investigation protocol of fetuses with unexplained hydrops fetalis should aim at ruling out AIVR and include Doppler flow recordings in SVC/Ao, DV, AoI, DA and umbilical vein. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Implantable cardioverter-defibrillators for treatment of sustained ventricular arrhythmias in patients with Chagas' heart disease: comparison with a control group treated with amiodarone alone.

AIMS: Evidence is inconclusive concerning the benefit of implantable cardioverter-defibrillators (ICDs) for secondary prevention of mortality in patients with Chagas' heart disease (ChHD). The aim of this study was to compare the outcomes of ChHD patients with life-threatening ventricular arrhythmias (VAs), who were treated either with ICD implantation plus amiodarone or with amiodarone alone. METHODS AND RESULTS: The ICD group [76 patients; 48 men; age, 57 ± 11 years; left ventricular ejection fraction (LVEF), 39 ± 12%] and the historical control group treated with amiodarone alone (28 patients; 18 men; age, 54 ± 10 years; LVEF, 41 ± 10%) had comparable baseline characteristics, except for a higher use of beta-blockers in the ICD group (P < 0.0001). Amiodarone was also used in 90% of the ICD group. Therapy with ICD plus amiodarone resulted in a 72% reduced risk of all-cause mortality (P = 0.007) and a 95% reduced risk of sudden death (P = 0.006) compared with amiodarone-only therapy. The survival benefit of ICD was greatest in patients with LVEF < 40% (P = 0.01) and was not significant in those with LVEF ≥ 40% (P = 0.15). Appropriate ICD therapies occurred in 72% of patients and the rates of interventions were similar across patients with LVEF < 40% and ≥40%. CONCLUSION: Compared with amiodarone-only therapy, ICD implantation plus amiodarone reduced the risk of all-cause mortality and sudden death in ChHD patients with life-threatening VAs. Patients with LVEF < 40% derived significantly more survival benefit from ICD therapy. The majority of ICD-treated patients received appropriate therapies regardless of the LV systolic function.

Transient post-reperfusion left bundle branch block and accelerated idioventricular rhythm with paradoxical QRS narrowing.

Accelerated idioventricular rhythm (AIVR) commonly follows coronary reperfusion and has been called a "reperfusion arrhythmia". Transient left bundle branch block (LBBB) is only rarely seen after interventional reperfusion and is usually considered a procedural complication. We report herein electrocardiograms (ECGs) in a case of acute lateral myocardial infarction which demonstrate both post-perfusion AIVR and a simultaneous transient LBBB with fusion complexes causing paradoxical QRS narrowing.

Hyperkalemia-induced accelerated idioventricular rhythm in a patient with acute renal failure.

Electrolyte disorders can alter cardiac ionic currents and depending on the changes can promote proarrhythmic effects. Potassium (K(+)) is the most common intracellular cation related to arrhythmic disorders. Hyperkalemia is mainly seen in the setting of impaired renal function. Severe hyperkalemia may lead to rhythm disorders. Herein, we report a patient with accelerated idioventricular rhythm (AIVR) due to hyperkalemia, which was successfully treated with glucose-insulin (GI) infusion.

Accelerated Idioventricular Rhythm Following Intraoral Local Anesthetic Injection During General Anesthesia.

Some anesthetic agents or adjunct medications administered during general anesthesia can cause an accelerated idioventricular rhythm (AIVR), which is associated with higher vagal tone and lower sympathetic activity. We encountered AIVR induced by vagal response to injection-related pain following local anesthetic infiltration into the oral mucosa during general anesthesia. A 48-year-old woman underwent extraction of a residual tooth root from the left maxillary sinus under general anesthesia. Routine preoperative electrocardiogram (ECG) was otherwise normal. Eight milliliters of 1% lidocaine (80 mg) with 1:100,000 epinephrine (80 µg) was infiltrated around the left maxillary molars over 20 seconds using a 23-gauge needle and firm pressure. Widened QRS complexes consistent with AIVR were observed for ∼60 seconds, followed by an atrioventricular junctional rhythm and the return of normal sinus rhythm. A cardiology consultation and 12-lead ECG in the operating room produced no additional concerns, so the operation continued with no complications. AIVR was presumably caused by activation of the trigeminocardiac reflex triggered by intense pain following rapid local anesthetic infiltration with a large gauge needle and firm pressure. Administration of local anesthetic should be performed cautiously when using a large gauge needle and avoid excessive pressure.

Case Report of Accelerated Idioventricular Rhythm in the Interventional Radiology Suite: A Sticky Situation.

Embolization is a well-established method of treatment of arteriovenous malformations. Most procedures are performed under general anesthesia due to the painful nature of some sclerosing agents, procedure duration, and need for immobilization to allow precise injection. Familiarity with the possible side effects of these agents is important for the anesthesiologist to facilitate timely and successful management of intra- and postprocedural complications. This case report describes an unusual presentation of systemic migration of glue-lipiodol mixture during embolization of a calf arteriovenous malformation in an adolescent that resulted in accelerated idioventricular rhythm and its successful management leading to complete resolution.

Sustained Accelerated Idioventricular Rhythm in a Centrifuge-Simulated Suborbital Spaceflight.

INTRODUCTION: Hypergravitational exposures during human centrifugation are known to provoke dysrhythmias, including sinus dysrhythmias/tachycardias, premature atrial/ventricular contractions, and even atrial fibrillations or flutter patterns. However, events are generally short-lived and resolve rapidly after cessation of acceleration. This case report describes a prolonged ectopic ventricular rhythm in response to high G exposure. CASE REPORT: A previously healthy 30-yr-old man voluntarily participated in centrifuge trials as a part of a larger study, experiencing a total of 7 centrifuge runs over 48 h. Day 1 consisted of two +Gz runs (peak +3.5 Gz, run 2) and two +Gx runs (peak +6.0 Gx, run 4). Day 2 consisted of three runs approximating suborbital spaceflight profiles (combined +Gx and +Gz). Hemodynamic data collected included blood pressure, heart rate, and continuous three-lead electrocardiogram. Following the final acceleration exposure of the last Day 2 run (peak +4.5 Gx and +4.0 Gz combined, resultant +6.0 G), during a period of idle resting centrifuge activity (resultant vector +1.4 G), the subject demonstrated a marked change in his three-lead electrocardiogram from normal sinus rhythm to a wide-complex ectopic ventricular rhythm at a rate of 91-95 bpm, consistent with an accelerated idioventricular rhythm (AIVR). This rhythm was sustained for 2 m, 24 s before reversion to normal sinus. The subject reported no adverse symptoms during this time. DISCUSSION: While prolonged, the dysrhythmia was asymptomatic and self-limited. AIVR is likely a physiological response to acceleration and can be managed conservatively. Vigilance is needed to ensure that AIVR is correctly distinguished from other, malignant rhythms to avoid inappropriate treatment and negative operational impacts.Suresh R, Blue RS, Mathers C, Castleberry TL, Vanderploeg JM. Sustained accelerated idioventricular rhythm in a centrifuge-simulated suborbital spaceflight. Aerosp Med Hum Perform. 2017; 88(8):789-793.

Is accelerated idioventricular rhythm a good marker for reperfusion after streptokinase?

BACKGROUND: Accelerated idioventricular rhythm (AIVR) is a common arrhythmia observed in patients with ST segment elevation myocardial infarction (MI). It is not clear how much value AIVR has in predicting successful reperfusion, since there have been conflicting data regarding this in the past. Streptokinase (STK) even today is the commonest thrombolytic agent used in the public health care set-up in India.(1) Most data for the use of STK are from the 1990s, which had showed that at best it is effective in only 50% of patients in restoring adequate flow.(2) It is probable that with the current dual-antiplatelet loading dose regimen and other newer medications, this figure could be higher. Also, rescue angioplasty for failed thrombolysis is the standard of care now, unlike before. Hence, we need reliable non-invasive markers to judge successful reperfusion in the present era. While ST segment resolution is the standard marker for reperfusion used in thrombolytic trials, in several instances it is not definitive. An additional marker would thus be very useful, especially in such cases. METHODS: This was a prospective observational study carried out at a public teaching hospital. 200 consecutive patients with a diagnosis of acute MI who were given STK within 12h of index pain were included. The STK dose was 1.5 million units, infused over 30min; the ECG was again recorded after 90min of completion of the infusion. Continuous ECG monitoring for the first 24h of ICCU stay was performed and AIVRs during this period were documented. Early AIVR was defined as that occurring within 2h of completing the STK infusion. Echocardiography was performed 24h after presentation. The time course of AIVR was studied vis-a-vis the outcome of thrombolysis. RESULTS: AIVR was seen in 41% of the patients. Though AIVR was found to have low sensitivity (45%) and specificity (64%) as a predictor of successful thrombolysis, early AIVR was a reliable sign of successful thrombolysis (p<0.05). The sensitivity (45%) of early AIVR was low; however, the specificity (94%) and positive predictive value (94%) were very good. CONCLUSION: AIVR is a common arrhythmia in the setting of STEMI receiving thrombolytic therapy. Early AIVR is more common with successful thrombolysis, with an excellent positive predictive value. Thus, early AIVR can be used as an additive criterion to ST segment resolution as a non-invasive marker of successful thrombolysis with STK.

Accelerated Idioventricular Rhythm in a Child With Status Asthmaticus.

Acute asthma exacerbations occur relatively frequently in children. We present the case of a 4-year-old boy who was admitted to our hospital in status asthmaticus and found to have a wide complex rhythm while being treated with inhaled albuterol and intravenous methylprednisolone. This rhythm was diagnosed as accelerated idioventricular rhythm (AIVR), which carries a benign prognosis. It resolved as the medications used to treat his asthma exacerbation were weaned. There was no ventricular ectopy seen on a 24-hour Holter monitor performed 3 months after his hospitalization, suggesting that the AIVR was related to the medications the patient was receiving at the time. This case suggests that albuterol may be a risk factor for the development of AIVR and highlights the importance of recognizing this rhythm to avoid unnecessary and potentially harmful therapies.

Significance of accelerated idioventricular rhythm in idiopathic dilated cardiomyopathy.

Holter monitoring was performed in 202 patients with idiopathic dilated cardiomyopathy, which revealed accelerated idioventricular rhythm in 16 patients (8%) and nonsustained ventricular tachycardia in 70 patients (35%). During 32 +/- 15-month prospective follow-up, no significant difference was observed for major arrhythmic events and transplant-free survival between patients with and without accelerated idioventricular rhythm, whereas patients with nonsustained ventricular tachycardia had a significantly higher incidence of major arrhythmic events and a lower transplant-free survival rate.

Electrocardiographic prediction of the success of coronary reperfusion by intravenous thrombolytic therapy: an experimental study.

The accuracy of electrocardiograms (ECGs) in predicting the success of coronary reperfusion by intravenous (IV) thrombolytic therapy was studied in 49 canine acute myocardial infarctions (MI), induced by occlusive thrombus in the left anterior descending (LAD) coronary artery. Two hours after the onset of MI, urokinase (UK, 3 x 10(4) U/kg) was administered IV and the heart was observed for one further hour. LAD flow and epicardial ECGs were recorded continuously. LAD flow was restored by UK in 26 of 49 animals (Group I); restored LAD flow was stable in 17 of the 26 (Group IA) and unstable with repeated fluctuations in the other 9 (Group IB) during the follow-up period. No coronary reflow was obtained by thrombolysis in 23 of 49 animals (Group II). The best electrocardiographic criterion for predicting coronary reperfusion was reduction of ST elevation by more than 25%, which had a predictive accuracy of 86%. There was a significant correlation between the grade of improvement of coronary blood flow and reduction of ST elevation in Group IA (p less than 0.01), but not in Group IB, indicating that unstable coronary blood flow following thrombolysis due to residual thrombus appears to be one of the major factors preventing accurate prediction of coronary reperfusion with thrombolysis on the basis of changes in ST elevation.

Acute haemodynamic effects of accelerated idioventricular rhythm in primary percutaneous coronary intervention.

AIMS: Accelerated idioventricular rhythm (AIVR) is very frequently observed in primary percutaneous coronary intervention (PCI), however knowledge of the haemodynamic effects is lacking. METHODS AND RESULTS: We studied an ST-segment elevation myocardial infarction cohort of 128 consecutive patients (aged 62±11 years) in whom AIVR occurred following reperfusion during primary PCI. Mean systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate were determined during periods of AIVR and sinus rhythm. We grouped patients according to the infarct-related artery and the site of the coronary occlusion. AIVR caused an immediate reduction in SBP (130±27 vs. 98±22 mmHg, p<0.001) and DBP (80±19 vs. 69±16 mmHg, p<0.001) and a small increase in heart rate (78±12 vs. 83±11 bpm, p<0.001) as compared to sinus rhythm, irrespective of infarct-related artery. Both absolute as well as relative reduction in SBP were more pronounced in distal than proximal left coronary artery (LCA) occlusions (36±16 vs. 27±12 mmHg, p<0.01, respectively 25±9 vs. 20±8%, p<0.05). These haemodynamic differences between proximal and distal occlusion sites were not observed in the right coronary artery. CONCLUSIONS: AIVR following reperfusion is associated with marked reduction in both SBP and DBP, irrespective of infarct-related artery. These haemodynamic effects are accompanied by only a very modest increase in heart rate during AIVR. Patients with a culprit lesion in the proximal LCA showed a smaller reduction in systolic blood pressure than distal LCA lesions.

More pronounced diastolic left ventricular dysfunction in patients with accelerated idioventricular rhythm after reperfusion by primary percutaneous coronary intervention.

OBJECTIVE: Reperfusion-induced accelerated idioventricular rhythm (AIVR) during primary percutaneous coronary intervention (pPCI) may be a sign of left ventricular (LV) dysfunction. We compared LV dynamic effects of reperfusion between patients with and without reperfusion-induced AIVR during pPCI for ST-elevation myocardial infarction (STEMI). METHODS: We studied 15 consecutive patients, who presented with their first acute anterior STEMI within 6 hours after onset of symptoms, and in whom LV pressure-volume (PV) loops were directly obtained during pPCI. Immediate effects of pPCI on LV function were compared between patients with (n = 5) and without (n = 10) occurrence of AIVR after reperfusion, as well as the direct effects of AIVR on LV function compared to sinus rhythm. RESULTS: Patients with reperfusion-induced AIVR showed more pronounced diastolic LV dysfunction before the onset of the arrhythmia, i.e., a delayed active relaxation expressed by Tau (53 ± 15 vs. 39 ± 6 ms; p = 0.03), a worse compliance curve (p = 0.01), and a higher end-diastolic stiffness (p = 0.07). At the end of the procedure, AIVR patients showed less improvement in diastolic LV function, indicated by a downward shift of the compliance curve (-3.1 ± 2.3 vs. -7.5 ± 1.4 mmHg; p = 0.001), a decrease in end-diastolic stiffness (13 ± 18 vs. 34 ± 15%; p = 0.03) and end-diastolic pressure (12 ± 8 vs. 29 ± 19%; p = 0.07). CONCLUSION: STEMI patients with reperfusion-induced AIVR after pPCI showed more pronounced diastolic LV dysfunction before and after AIVR than patients without AIVR, which suggests that diastolic LV dysfunction contributes to the occurrence of AIVR and that AIVR is a sign of diastolic LV dysfunction.