Buprenorphine as a safe alternative to methadone in a patient with acquired long QT syndrome: a case report.

A 52-year-old man with a medical history of intravenous drug abuse was admitted to our hospital with syncope due to torsades de pointes (TdP). Two days earlier, he had used methadone. The electrocardiogram showed a prolonged corrected QT interval (QTc) of 600 ms. Continuous telemetry observation showed multiple episodes of TdP. The patient was diagnosed with bradyarrhythmia-induced TdP with acquired long QT syndrome resulting from methadone use. The QTc normalised within 2 weeks after discontinuation of the methadone. In this case of a patient with opioid dependency, there is a reasonable risk of repeated methadone use. Therefore, implantable cardioverter defibrillator or pacemaker implantation is justified but risky because of possible infections when using intravenous drugs. Given the high mortality rates seen in untreated illicit opioid users, this patient needs an alternative pharmacological treatment. Buprenorphine is an opiate-receptor agonist associated with less QTc prolongation. The patient was referred to a rehab clinic and treated with an oral combination of buprenorphine and naloxone (Suboxone). During this therapy, his QTc remained normal.

Additional Diagnostic value of Mini Electrodes in an 8-mm Tip in Cavotricuspid Isthmus Ablation.

Background: Eight-mm ablation catheters are widely used in cavotricuspid isthmus ablation (CTI) for treatment of right sided atrial flutter. However a high success rate, these large ablation tips comes with adisadvantage of lower resolution of fractionated signals. Purpose: The aim of this study was to evaluate the additional diagnostic value of the electrograms recordedfrom mini electrodes (MEs) in an 8-mm ablation catheter tip during CTI. Methods: CTI-ablation procedures were compared retrospectively in two groups, namely, group A: the Abbott Safire 8-mm tip with a 3D mapping system (n =37) and group B: the Boston Scientific MiFi IntellaTip XP 8-mm tip without a 3D mapping system (n=13). We analyzedacute procedural success, ablation characteristics and recurrence rate at one-year follow-up. Electrograms from MEs were analyzedright before the onset of the critical ablation application that resulted in acute CTI-block. We determined whether these ME electrograms had additional diagnostic value in addition to of the 8-mm tip derivedelectrogram. Results: At the onset of the critical ablation application, the MEs had an important additional value in 3 out of 13 cases as local signals were sensed on the MEs that were not recorded by the 8-mm tip electrode. In 2cases the ME did not show local electrogramsalthough the ablationwas still effective. Acute procedural and long-term success wereobserved in all patients. No differences were found in time to bidirectional block, procedure time or fluoroscopic exposure. Conclusion: Our data show that signals recorded from the MEs had additional diagnostic value, but only in asmall percentage of the patients. We did not observe, although omitting 3D-mapping in the ME group, any differencebetween groups with regard to procedural or ablation characteristicsduring CTI-ablation.

[A man with FIP1L1/PDGFRA-positive chronic eosinophilic leukemia]. / Een man met FIP1L1-PDGFRA-positieve chronische eosinofiele leukemie.

A 39-year-old man was referred from Surinam to the Onze Lieve Vrouwe Gasthuis, Amsterdam, the Netherlands, for a right ventricular tumour, hypereosinophilia and mild thrombocytopenia. He appeared to have chronic eosinophilic leukaemia that was positive for the 'FIP1-like-1-platelet-derived growth factor receptor alpha' (FIP1L1-PDGFRA) gene. In addition, he had signs of a right ventricular thrombus that had existed for at least 6 months. The patient was treated with oral anticoagulants and the tyrosine kinase inhibitor imatinib. The latter therapy resulted in normalisation of leukocyte count and differential values. After 3 months of therapy, the FIP1L1-PDGFRA fusion transcript was no longer detectable in peripheral blood. After 1 year of follow up, the patient was in complete haematological and molecular remission for chronic eosinophilic leukaemia. The cardiac mass remained unchanged, but caused no haemodynamic problems.

Interference detection in implantable defibrillators induced by therapeutic radiation therapy.

BACKGROUND: Electromagnetic fields and ionising radiation during radiotherapy can influence the functioning of ICDs. Guidelines for radiotherapy treatment were published in 1994, but only based on experience with pacemakers. Data on the influence of radiotherapy on ICDs is limited. OBJECTIVES: We determined the risk to ICDs of interference detection induced by radiotherapy. METHODS: In our study we irradiated 11 ICDs. The irradiation was performed with a 6 megavolt photon beam. In each individual device test, a total of 20 Gray was delivered in a fractionated fashion. During each irradiation the output stimulation rate was monitored and electrogram storage was activated. In case of interference the test was repeated with the ICD outside and the lead(s) inside and outside the irradiation field. RESULTS: With the ICD inside the irradiation field, interference detection was observed in all ICDs. This caused pacing inhibition or rapid ventricular pacing. Ventricular tachycardia (VT) or ventricular fibrillation (VF) detection occurred, which would have caused tachycardia-terminating therapy. If the ICD was placed outside the irradiation field, no interference was observed. CONCLUSION: Interference by ionising radiation on the ICDs is demonstrated both on bradycardia and tachycardia therapy. This can have consequences for patients. Recommendations for radiotherapy are presented in this article.

Fast and slow narrow complex tachycardia in one patient: two of a kind?

A 35-year-old female was referred to our hospital. For more than ten years, she had had complaints of two types of paroxysmal palpitations, both with a sudden onset. The first type was rapid and often accompanied by light-headedness; the second she described as much less rapid, better tolerated, and often terminated by the Valsalva manoeuvre. The incidence and duration of both types of paroxysms were increasing. In the emergency room of the referring hospital, the tachycardia was terminated with intravenous verapamil. The electrophysiological study revealed normal conduction parameters. Premature atrial beats (due to catheter manipulation) or delivered atrial extra stimuli over a wide range easily induced two types of tachycardia. AV node modification by radiofrequency ablation using the posterior approach was performed. With this approach, RF ablation of the caudal extension of the AV node is performed, which modifies the slow pathway, so that the reentrant circuit is interrupted. After this intervention, no tachycardia whatsoever could be induced and during followup (8 months), no recurrent arrhythmia of any kind occurred.