Surgical Treatment of Atrial Fibrillation

The concepts, techniques and evidence relating to surgical ablation of atrial fibrillation are discussed in detail. The historical background to surgical ablation is covered in brief, along with the electrophysiological basis underpinning its effective useage. The epidemiology of surgically treated atrial fibrillation and the current guidelines relating to its use are analysed. Safety aspects and perspectives on its ongoing future use are discussed. Modern surgical technologies and approaches are reviewed, along with the relevant advantages and disadvantages of each. The surgical techniques relating to left atrial appendage intervention are also reviewed, along with the relevant literature and evidence relating to reduction in thromboembolic risk and need for anticoagulation

Valve-in-Valve Transcatheter Aortic Valve Replacement: Challenges for Now and the Future

The recent years have seen a huge expansion in the number of bioprostheses implanted, and this number is likely to increase further in the future. This is likely to lead to a pandemic of patients requiring reoperation/re-intervention for structural deterioration of the valve. Valve-in-valve transcatheter aortic valve replacement (ViV-TAVR) has become a safe and effective alternative to redo aortic valve surgery and has gained approval for use in high-risk patients with prohibitive operative risk. ViV-TAVR is a complex procedure requiring rigorous planning, technical expertise and patient anatomical appreciation. In this chapter, we examine the evidence supporting the use of ViV-TAVR along with the primary technical issues surrounding this procedure such as: elevated postprocedural gradients, coronary obstruction and valve-related thrombosis. TAVR use is also expanding towards an increasingly young patient profile with extended life expectancy, likely to outlive the implanted bioprosthesis. We therefore also examine the huge current challenge of establishing what is the best lifetime strategy for the management of aortic valve disease in younger patients

Continuous in vivo

In this paper, the development of a fully implantable wireless sensor able to provide continuous real-time accurate pressure measurements is presented. Surface Acoustic Wave (SAW) technology was used to deposit resonators on crystalline quartz wafers; the wafers were then assembled to produce a pressure sensitive device. Excitation and reading via a miniature antenna attached to the pressure sensor enables continuous external interrogation. The main advantages of such a configuration are the long term stability of quartz and the low power necessary for the interrogation, which allows 24/7 interrogation by means of a hand-held, battery powered device. Such data are of vital importance to clinicians monitoring and treating the effects of hypertension and heart failure. A prototype was designed and tested using both a bio-phantom test rig and an animal model. The pressure traces for both compare very well with a commercially available catheter tip pressure transducer. The work presented in this paper is the first known wireless pressure data from the left ventricle of the heart of a living swine

Central Cannulation by Seldinger Technique: A Reliable Method in Type A Aortic Dissection Repairs

none11Background: Extensive type A aortic dissections that involve peripheral great vessels can complicate the choice of a cannulation site for cardiopulmonary bypass. We started to employ direct cannulation of the true lumen on the concavity of the aortic arch by Seldinger technique and evaluated the efficacy of this access technique as an alternative arterial inflow target in aortic surgery.Material/Methods: Twenty-four consecutive patients (mean age: 59 +/- 14 years) underwent type A aortic dissection repair using selective antegrade cerebral perfusion. Direct aortic cannulation was used in 14 cases, subclavian access in 6 patients, and femoral entry in 4 patients. Perioperative factors were evaluated to identify the reliability and eventual benefits of direct cannulation method at the aortic arch.Results: There were no operative deaths and cumulative 30-day mortality rate was 25% (6). Permanent neurological deficits were not observed; in 1 patient transient changes occurred (4%). Time to reach circulatory arrest was the shortest in the direct access group, with mean 27 +/- 11 (CI: 20.6-33.3) min vs. 43 +/- 22 (28.0-78.0) min (p=0.058) and 32 +/- 8 (23.6-40.4) min (p=0.34) by femoral cannulation and subclavian entry, respectively. Direct arch cannulation resulted in the best renal function in the first 72 h after surgery and similar characteristics were observed in lactic acid levels.Conclusions: Ultrasound-guided direct cannulation on the concavity of the aortic arch using a Seldinger technique is a reliable method in dissection repairs. Prompt antegrade perfusion provides not only cerebral but also peripheral organ and tissue protection, which is an advantage in this high-risk group of patients.noneGobolos, L; Ugocsai, P; Foltan, M; Philipp, A; Thrum, A; Miskolczi, S; Malvindi, PG; di Gregorio, V; Pousios, D; Navaratnarajah, M; Ohri, SKGobolos, L; Ugocsai, P; Foltan, M; Philipp, A; Thrum, A; Miskolczi, S; Malvindi, Pg; di Gregorio, V; Pousios, D; Navaratnarajah, M; Ohri, S

Effect of Cl, Met and combined MetCl treatment on heart weight (HW) (A) and cardiomyocyte volume measured using confocal microscopy (B) during unloading (MUHF).

<p>Prevention of MU-induced cardiac and cardiomyocyte atrophy is achieved by Met and not Cl, with combined MetCl therapy increasing atrophy. *P<0.05, **P<0.01 and ***P<0.001, (HW and cardiomyocyte volume data acquired from 8 and 4 hearts per group, respectively). Effect of Cl, Met and combined MetCl therapy on heart weight∶body weight ratio (HW∶BW) (C) and cardiomyocyte volume (D). HF-induced cardiac hypertrophy was enhanced by Cl therapy but this effect disappeared during combined MetCl therapy. HF-induced myocyte hypertrophy was partially attenuated by Met, but this effect was lost during combination MetCl therapy (HW and cardiomyocyte volume data acquired from 8 and 4 hearts per group, respectively).</p