Paroxysmal atrial fibrillation with high vs. low arrhythmia burden: atrial remodelling and ablation outcome.

AIMS: The relation between atrial tachyarrhythmia (ATA) burden in paroxysmal atrial fibrillation (AF), atrial remodelling, and efficacy of catheter ablation (CA) is unknown. We investigated whether high vs. low-burden paroxysmal AF patients have distinct clinical characteristics or electro-mechanical properties of the left atrium (LA) and whether burden impacts outcome of CA. METHODS AND RESULTS: Atrial tachyarrhythmia burden, defined as the percentage of time spent in ATA, was assessed by insertable cardiac monitors in 105 patients before and after CA. Clinical characteristics and electro-mechanical properties of LA were compared between patients with high vs. low ATA burden. Catheter ablation efficacy was assessed by reduction in ATA burden and 1-year freedom from any ATA. Median ATA burden was 2.7% (highest tertile 9.3%). Clinical characteristics and electrical properties of LA (refractoriness, conduction velocity, low voltage) did not differ between high (≥9.3%) vs. low ATA burden (<9.3%) patients. High ATA burden patients had larger LA diameter (46.5 ± 6 vs. 42.5 ± 6mm, P < 0.01), volume (93.8 ± 22 vs. 80.4 ± 21mL, P = 0.01), and lower LA reservoir and contractile strain (19.7 ± 6 vs. 24.7 ± 6%, P < 0.01; 10.3 ± 3 vs. 12.8 ± 4%, P = 0.01). Catheter ablation reduced ATA burden by 100% (100-100) in both groups (P = 1.0). Freedom from ATA after CA was equally high (83% vs. 89%, P = 0.38). CONCLUSION: Paroxysmal AF patients with high ATA burden have altered LA mechanical properties, reflected by larger size and impaired function. Despite mechanical remodelling of the atria, they are excellent responders to CA. Most likely the lack of fibrosis and/or advanced electrical remodelling explain why pulmonary veins remain the dominant trigger for AF in this patient cohort.

Persistent but reversible advanced atrio-ventricular block in a heart transplant man induced by dobutamine stress echocardiography.

Dobutamine when used for stress echocardiography (DSE), it rarely causes transient atrio-ventricular (AV) block. We report a heart transplant patient with high cardiovascular risk who developed symptomatic advanced AV block during DSE which persisted after termination of dobutamine administration, necessitating pacemaker implantation. To our knowledge, this is the first published case of persistent high grade AV block in a heart transplant patient induced by DSE.

A cytologic diagnosis of BRAFV600E Erdheim-Chester disease on pericardial fluid.

We report the case of a 74-year-old woman admitted to the emergency unit for resting dyspnea. Clinical presentation, cardiac MRI and echocardiography were consistent with cardiac tamponade requiring emergency pericardiocentesis. Cytologic examination of the pericardial fluid revealed the presence of CD68pos CD1aneg S100neg foamy histiocytes (Fig. 1). Additional investigations complied with the diagnosis of Erdheim-Chester histiocytosis. Treatment with αIFN was initiated but the patient developed severe neutropenia that contraindicated further administration. The detection of BRAFV600E mutation on histiocytes isolated from the pericardial liquid and CNS involvement (cerebral masses) prompted the administration of vemurafenib, a selective BRAFV600E kinase inhibitor. Four months after the initiation of low-dose vemurafenib, pericarditis almost resolved and cerebral masses decreased by 50% (Fig. 2). To our knowledge, analysis of pericardial fluid allowing the diagnosis of Erdheim-Chester disease and the detection of the BRAFV600E mutation has in fact been rarely described in the literature. This case report and the successful evolution under vemurafenib also support the use of BRAFV600E inhibitors in αIFN-intolerant patients with BRAFV600E mutation, particularly in case of heart and central nervous system involvement.

A case of imported Middle East Respiratory Syndrome coronavirus infection and public health response, Greece, April 2014.

On 18 April 2014, a case of Middle East Respiratory Syndrome coronavirus (MERS-CoV) infection was laboratory confirmed in Athens, Greece in a patient returning from Jeddah, Saudi Arabia. Main symptoms upon initial presentation were protracted fever and diarrhoea, during hospitalisation he developed bilateral pneumonia and his condition worsened. During 14 days prior to onset of illness, he had extensive contact with the healthcare environment in Jeddah. Contact tracing revealed 73 contacts, no secondary cases had occurred by 22 April.

Emergency percutaneous tracheostomy in a severely burned patient with upper airway obstruction and circulatory failure.

Airway inaccessibility is one of the most dreaded situations in emergency medicine. Surgical tracheostomy is not indicated in emergency situations because it takes a long time and can result in death if respiratory support cannot be provided during the procedure. Emergency percutaneous tracheostomy (PCT) was widely regarded as absolutely counterindicated. Recently, however, a number of studies have appeared on the safety and feasibility of PCT in situations regarded as presenting relative contraindications. We describe the life-saving action of Griggs' PCT in a patient with upper airway obstruction resulting from burns, smoke injuries, and unsuccessful tracheal intubation attempts. Emergency PCT using the Griggs technique was immediately performed without aseptic care, and a 9-mm internal diameter tracheostomy tube was successfully inserted in less than one minute. Griggs' PCT is a quick technique that secures an airway when tracheal intubation fails. The feasibility - in selected cases - of using an emergency Griggs' PCT, in experienced hands, rather than cricothyroidotomy or surgical tracheostomy, is recommended.