Ability to induce atrial fibrillation in the peri-operative period is associated with phosphorylation-dependent inhibition of TWIK protein-related acid-sensitive potassium channel 1 (TASK-1).

Peri-operative atrial fibrillation (peri-op AF) is a common complication following thoracic surgery. This arrhythmia is thought to be triggered by an inflammatory response and can be reproduced in various animal models. Previous work has shown that the lipid inflammatory mediator, platelet-activating factor (PAF), synthesized by activated neutrophils, can induce atrial and ventricular arrhythmias as well as repolarization abnormalities in isolated ventricular myocytes. We have previously shown that carbamylated PAF-induced repolarization abnormalities result from the protein kinase C (PKC) ε-dependent phosphorylation of the two-pore domain potassium channel TASK-1. We now demonstrate that canine peri-op AF is associated with the phosphorylation-dependent loss of TASK-1 current. Further studies identified threonine 383 in the C terminus of human and canine TASK-1 as the phosphorylation site required for PAF-dependent inhibition of the channel. Using a novel phosphorylation site-specific antibody targeting the phosphorylated channel, we have determined that peri-op AF is associated with the loss of TASK-1 current and increased phosphorylation of TASK-1 at this site.

An overview of energy sources in clinical use for the ablation of atrial fibrillation.

Recent years have seen many developments in the field of alternative energy sources for arrhythmia surgery. The impetus behind these advances is to replace the traditional, "cut-and-sew" Cox maze III procedure with lesion sets that are simpler, shorter, and safer but just as effective. There is demand for technology to make continuous, linear, transmural ablations reliably with a versatile energy source via an epicardial approach. This would make minimally invasive endoscopic surgical ablation of atrial fibrillation (AF) without cardiopulmonary bypass and with a closed chest feasible. These advances would shorten cardio-pulmonary bypass and improve outcomes in patients having surgical ablation and concomitant cardiac surgery. This review summarizes the technology behind alternative energy sources used to treat AF. Alternative energy sources include hypothermic sources (cryoablation) and hyperthermic sources (radiofrequency, microwave, laser, ultrasound). For each source, the biophysical background, mode of tissue injury, factors affecting lesion size, and advantages and complications are discussed.

Surgery for myocardial salvage in acute myocardial infarction and acute coronary syndromes.

This article addresses the pathophysiology, the treatment options, and their rationale in the setting of life-threatening acute myocardial infarction and acute on chronic ischemia. Although biases may exist between cardiologists and surgeons, with this review, we hope to provide the reader with information that will shed light on the options that best suit the individual patient in a given set of circumstances.

Myocardial Protection and Financial Considerations of Custodiol Cardioplegia in Minimally Invasive and Open Valve Surgery.

OBJECTIVE: Single-dose antegrade crystalloid cardioplegia with Custodiol-HTK (histidine-tryptophan-ketoglutarate) has been used for many years. Its safety and efficacy were established in experimental and clinical studies. It is beneficial in complex valve surgery because it provides a long period of myocardial protection with a single dose. Thus, valve procedures (minimally invasive or open) can be performed with limited interruption. The aim of this study is to compare the use of Custodiol-HTK cardioplegia with traditional blood cardioplegia in patients undergoing minimally invasive and open valve surgery. METHODS: A single-institution, retrospective case-control review was performed on patients who underwent valve surgery in Lee Memorial Health System at either HealthPark Medical Center or Gulf Coast Medical Center from July 1, 2011, through March 7, 2015. A total of 181 valve cases (aortic or mitral) performed using Custodiol-HTK cardioplegia were compared with 181 cases performed with traditional blood cardioplegia. Each group had an equal distribution of minimally invasive and open valve cases. Right chest thoracotomy or partial sternotomy was performed on minimally invasive valve cases. Demographics, perioperative data, clinical outcomes, and financial data were collected and analyzed. RESULTS: Patient outcomes were superior in the Custodiol-HTK cardioplegia group for blood transfusion, stroke, and hospital readmission within 30 days (P < 0.05). No statistical differences were observed in the other outcomes categories. Hospital charges were reduced on average by $3013 per patient when using Custodiol-HTK cardioplegia. CONCLUSIONS: Use of Custodiol-HTK cardioplegia is safe and cost-effective when compared with traditional repetitive blood cardioplegia in patients undergoing minimally invasive and open valve surgery.

Acute type a dissection: impact of antegrade cerebral perfusion under moderate hypothermia.

BACKGROUND: The optimal method of arterial cannulation and circulation management for acute type A aortic dissection (type A) remains debated. Moderate hypothermic circulatory arrest (MHCA) and unilateral selective antegrade cerebral perfusion (uSACP) is effective in the elective setting. In this study, the impact of MHCA and uSACP on outcomes for type A repair was evaluated. METHODS: A retrospective review identified 346 patients who underwent type A repair under circulatory arrest, including 193 patients who had MHCA/uSACP. Measured outcomes included operative mortality, permanent neurologic deficit (PND) and temporary neurologic deficit, renal failure, and tracheostomy. Propensity-adjusted, multivariable logistic regression analysis was used to model adverse outcomes. RESULTS: The mean age of MHCA/uSACP patients was 56 years. The mean temperature during MHCA was 26.9 ± 2.0°C. Operative mortality for MHCA/SACP patients was 9.8% compared with 20.3% for the non-MHCA/SACP group (p < 0.01). Propensity score analysis found that MHCA/uSACP did not represent an adverse risk factor for mortality, temporary neurologic deficit, PND, renal failure, or the need for tracheostomy compared with non-MHCA/uSACP techniques. There was a 2.32-fold higher incidence of PND among patients who underwent cross-clamping of the dissected aorta during cooling before circulatory arrest (p < 0.05). CONCLUSIONS: Emergent type A repair can be accomplished with respectable operative risk using MHCA/uSACP. Cross-clamping the dissected aorta before MHCA increases the incidence of PND. These data suggest that MHCA/uSACP represents an effective circulation management strategy for patients undergoing repair of type A and obviates the need for deep hypothermic circulatory arrest.