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Aims: Circular irrigated radiofrequency ablation using the nMARQ catheter has recently been introduced for the treatment of atrial fibrillation (AF). The aim of this study is to report the safety and efficacy of catheter ablation using this technology in patients with paroxysmal and persistent AF., Methods and Results: The data of a prospective registry describing the experience of a single operator using this technology on 327 consecutive patients were analysed. The mean procedure time was 69 ± 22 min for paroxysmal AF (n = 228) and 75 ± 23 min for persistent AF (n = 97). Follow-up was available for 206 (63%) patients for 6 ± 5 months (range 1-23, median 3.3). Single procedure success off antiarrhythmic drugs was 75% in paroxysmal AF and 52% in persistent AF. Including the 5% redo cases and those on antiarrhythmic medication, freedom from AF was documented in 90 and 83% of paroxysmal and persistent AF patients, respectively. There were no serious complications in the first 325 patients, but the last two consecutive patients (0.6%) developed atrio-oesophageal fistulas and had a fatal outcome. The catheter has been recalled from market., Conclusion: The nMARQ catheter is a highly effective tool for treatment of paroxysmal and persistent AF. Nevertheless, the occurrence of life-threatening oesophageal fistulas is of major concern and requires further investigation., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)

Aims: We investigated whether myeloid-related protein 8/14 complex (MRP8/14) expressed by infiltrating monocytes and granulocytes may represent a mediator and early biomarker of acute coronary syndromes (ACS)., Methods and Results: Immunohistochemistry of coronary thrombi was done in 41 ACS patients. Subsequently, levels of MRP8/14 were assessed systemically in 75 patients with ACS and culprit lesions, with stable coronary artery disease (CAD), or with normal coronary arteries. In a subset of patients, MRP8/14 was measured systemically and at the site of coronary occlusion. Macrophages and granulocytes, but not platelets stained positive for MRP8/14 in 76% of 41 thrombi patients. In ACS, local MRP8/14 levels [22.0 (16.2-41.5) mg/L] were increased when compared with systemic levels [13.4 (8.1-14.7) mg/L, P = 0.03]. Systemic levels of MRP8/14 were markedly elevated [15.1 (12.1-21.8) mg/L, P = 0.001] in ACS when compared with stable CAD [4.6 (3.5-7.1) mg/L] or normals [4.8 (4.0-6.3) mg/L]. Using a cut-off level of 8 mg/L, MRP8/14 but not myoglobin or troponin, identified ACS presenting within 3 h from symptom onset., Conclusion: In ACS, MRP8/14 is markedly expressed at the site of coronary occlusion by invading phagocytes. The occurrence of elevated MRP8/14 in the systemic circulation prior to markers of myocardial necrosis makes it a prime candidate for the detection of unstable plaques and management of ACS.

Insulin-like growth factor I (IGF-I) enhances myofibrillar development in cardiomyocytes of rats in culture and in vivo. In addition, IGF-I has vasodilatory effects and improves cardiac function in healthy volunteers. This study was conducted to evaluate the acute hemodynamic effects of IGF-I in patients with chronic heart failure Eight patients with chronic heart failure were randomized to receive recombinant human IGF-I (60 micrograms/kg) or placebo, i.v., over 4 h in a cross-over, double blind study on 2 consecutive days. Electrocardiogram as well as systemic hemodynamics were continuously monitored over 7 h by flow-guided thermodilution and radial artery catheters. IGF-I was well tolerated by all patients, and no pathological changes on electrocardiogram were recorded. Compared with placebo, IGF-I increased the cardiac index by 27 +/- 3.7% (+/- SE; P < 0.0005) and the stroke volume index by 21 +/- 5.6% (P < 0.05), and decreased systemic vascular resistance by 28 +/- 4.4% (P < 0.0002), right atrial pressure by 33 +/- 9.0% (P < 0.003), and pulmonary artery wedge pressure by 25 +/- 6.1% (P < 0.03). Mean systemic and pulmonary artery pressure as well as heart rate and pulmonary vascular resistance were not significantly influenced by IGF-I treatment. Insulin and C peptide levels were decreased by IGF-I, whereas glucose and electrolyte levels remained unchanged. Urinary levels of norepinephrine decreased significantly (P < 0.05) during IGF-I infusion. Thus, acute administration of IGF-I in patients with chronic heart failure is safe and improves cardiac performance by afterload reduction and possibly by positive inotropic effects. Further investigations to establish whether the observed acute effects of IGF-I are maintained during chronic therapy appear to be warranted.

The role of aortic diameter on the occurrence of type A dissection was investigated in 73 patients with dilated ascending aorta at the time of pre-operative evaluation. Using transthoracic echocardiography for diagnosis and measurements, 54 patients were identified with type A dissection (group 1) and 19 without dissection (group 2). The true mean aortic diameters were identical (6.0 +/- 1.3 cm in group 1 and 6.4 +/- 1.4 cm in group 2; mean +/- SD; ns) as were the indexed aortic diameters (ratio of diameter/body surface area; 3.2 +/- 0.8 cm.m-2 and 3.4 +/- 0.7 cm.m-2, respectively; ns). However, the individual diameters showed a pronounced scatter in both groups (range from 3.6 +/- 11.0 cm). Of the 73 patients, 66 had surgery (47/54 with and 19/19 without dissection) and seven patients were treated medically. Emergency surgery was performed in 45/66 patients (all with acute type A dissection) and elective repair in 21/66 (19 without and two with chronic type A dissection). In-hospital mortality was 18% in the emergency group, 5% in the elective group and 57% in the medical group. It is concluded that patients with dilated ascending aorta have a substantial incidence of acute dissection. Their clinical course is unpredictable: acute dissection occurs in some, and in others the ascending aorta continues to enlarge without dissection. Because patients with dissection often arrive too late for elective repair and have to be operated on as emergencies with a higher operative risk, we recommend elective surgery before the diameter of the ascending aorta has reached 6 cm.

The occurrence of a left ventricular anterograde flow velocity (maximal: 3.9 m.s-1) is demonstrated in a 32-year-old patient with hypertrophic cardiomyopathy and midventricular obstruction, beginning at early systole and persisting throughout the isovolumic relaxation. Cardiac catheterization with simultaneous dual high fidelity pressure measurements in the apical and basal chambers confirmed the presence of the Doppler maximal instantaneous pressure gradient of 60 mmHg. Contrast left ventricular angiography excluded apical dyskinesia. In the two intracavity compartments, isovolumic relaxation time and the time constant of pressure decay (tau) were abnormal whereby tau was more delayed in the apical than in the basal portion. The presence of an apical high pressure zone during systole with impeded and delayed emptying through the midventricular obstacle and the late onset and prolongation of relaxation are thought to be the cause of the intraventricular flow from apex to base lasting from early systole throughout isovolumic relaxation.