Assessment of oesophageal position by direct visualization with luminal contrast compared with segmentation from pre-acquired computed tomography scan-implications for ablation strategy.

AIMS: Atrio-oesophageal fistula is a rare but often fatal complication of catheter ablation for atrial fibrillation (AF). Various strategies are employed to evaluate the oesophageal position in relation to the posterior left atrium (LA). These include segmentation of the oesophagus from a pre-acquired computed tomography (CT) scan and direct, real-time assessment of the oesophageal position using contrast at the time of the procedure. METHODS AND RESULTS: One hundred and fourteen patients with drug-refractory AF underwent CT scanning prior to AF ablation. The LA and oesophagus were segmented from this scan. The oesophagus was deemed midline, ostial if it crossed directly behind any of the pulmonary vein (PV) ostia, or antral if it passed within 5 mm of a PV ostium. Under general anaesthesia at the time of ablation, the same patients were administered contrast via an oro-gastric tube to outline the oesophagus. Catheters were placed at the PV ostia and oesophageal position in relation to the PVs was established radiographically using a postero-anterior view. Oesophageal position assessed by real-time assessment correlated with the CT scan in only 59% of patients. In 34% the oesophagus was more right sided on direct visualization, while in 7% it was more left sided. CONCLUSION: Segmentation of the oesophagus from the CT scan did not correlate the real-time oesophageal position at the time of the procedure in over 40% of patients under general anaesthesia. Reliance on the determination of oesophageal position by previously acquired CT may be misleading at best and provide a false sense of security when ablating in the posterior LA.

Brugada ECG Pattern Unmasked by IV Flecainide in an Individual with Idiopathic Fascicular Ventricular Tachycardia.

A 45-year old man presents with stable monomorphic ventricular tachycardia. He had previously been diagnosed with idiopathic fascicular ventricular tachycardia. Intravenous flecainide results in termination of his tachycardia but unmasks a latent type 1 Brugada ECG pattern not seen on his resting ECG. We discuss his subsequent management and the need to consider an alternative diagnosis in individuals with a Brugada type ECG pattern who present with stable monomorphic ventricular tachycardia.

Vertebral artery dissection secondary to defibrillation threshold testing.

We report a case of vertebral artery dissection presenting 2 days after ICD implantation with defibrillation threshold testing in a 57-year-old man with ischemic cardiomyopathy. The association between vertebral artery dissection and neck trauma and the role of DFT testing in ICD implantation are discussed.

Hyperuricemia and adverse outcomes in cardiovascular disease: potential for therapeutic intervention.

High uric acid levels are associated with increased morbidity and mortality rates in cardiovascular disease. In this article we explore the relationship between cardiovascular disease and xanthine oxidase activity. We look at the evidence that uric acid and its production via the xanthine oxidase pathway, may directly contribute to this increased cardiovascular risk. We examine the relationship between uric acid and other established cardiovascular risk factors and look at the evidence that reducing uric acid production may have a beneficial impact on cardiovascular morbidity and mortality. We conclude that although there is currently insufficient evidence to recommend the routine use of xanthine oxidase inhibitors in those with cardiovascular disease and asymptomatic hyperuricemia, there is sufficient evidence to warrant a large scale morbidity and mortality trial.