An experimental model of chronic severe mitral regurgitation.

Objective: To develop a minimally invasive, reproducible model of chronic severe mitral regurgitation (MR) that replicates the clinical phenotype of left atrial (LA) and left ventricular dilation and susceptibility to atrial fibrillation. Methods: Under transesophageal echocardiographic guidance, chordae tendinae were avulsed using endovascular forceps until the ratio of regurgitant jet area to LA area was ≥70%. Animals survived for an average of 8.6 ± 1.6 months (standard deviation) and imaged with monthly transthoracic echocardiography (TTE). Animals underwent baseline and preterminal magnetic resonance imaging. Terminal studies included TTE, transesophageal echocardiography, and rapid atrial pacing to test inducibility of atrial tachyarrhythmias. Results: Eight dogs underwent creation of severe MR and interval monitoring. Two were excluded-one died from acute heart failure, and the other had resolution of MR. Six dogs underwent the full experimental protocol; only one required medical management of clinical heart failure. MR remained severe over time, with a mean terminal regurgitant jet area to LA area of 71 ± 14% (standard deviation) and regurgitant fraction of 52 ± 11%. Mean LA volume increased over 130% (TTE: 163 ± 147%, P = .039; magnetic resonance imaging: 132 ± 54%, P = .011). Mean left ventricular end-diastolic volume increased by 38 ± 21% (P = .008). Inducible atrial tachyarrhythmias were seen in 4 of 6 animals at terminal surgery, and none at baseline. Conclusions: Within the 6 dogs that successfully completed the full experimental protocol, this model replicated the clinical phenotype of severe MR, which led to marked structural and electrophysiologic cardiac remodeling. This model allowed for precise measurements at repeated time points and will facilitate future studies to elucidate the mechanisms of atrial and ventricular remodeling secondary to MR and the pathophysiology of valvular atrial fibrillation.

Incidence and prediction of intraoperative and postoperative cardiac arrest requiring cardiopulmonary resuscitation and 30-day mortality in non-cardiac surgical patients.

BACKGROUND: The incidence, prediction and mortality outcomes of intraoperative and postoperative cardiac arrest requiring cardiopulmonary resuscitation (CPR) in surgical patients are under investigated and have not been studied concurrently in a single study. METHODS: A retrospective cohort study was conducted using the American College of Surgeons National Surgical Quality Improvement Program data between 2008 and 2012. Firth's penalized logistic regression was used to study the incidence and identify risk factors for intra- and postoperative CPR and 30-day mortality. simplified prediction model was constructed and internally validated to predict the studied outcomes. RESULTS: Among about 1.86 million non-cardiac operations, the incidence rate of intraoperative CPR was 0.03%, and for postoperative CPR was 0.33%. The 30-day mortality incidence rate was 1.25%. The incidence rate of events decreased overtime between 2008-2012. Of the 29 potential predictors, 14 were significant for intraoperative CPR, 23 for postoperative CPR, and 25 for 30-day mortality. The five strongest predictors (highest odd ratios) of intraoperative CPR were the American Society of Anesthesiologists (ASA) physical status, Systemic Inflammatory Response Syndrome (SIRS)/sepsis, surgery type, urgent/emergency case and anesthesia technique. Intraoperative CPR, ASA, age, functional status and end stage renal disease were the most significant predictors for postoperative CPR. The most significant predictors of 30-day mortality were ASA, age, functional status, SIRS/sepsis, and disseminated cancer. The predictions with the simplified five-factor model performed well and was comparable to the full prediction model. Postoperative cardiac arrest requiring CPR, compared to intraoperative, was associated with much higher mortality. CONCLUSIONS: The incidence of cardiac arrest requiring CPR in surgical patients decreased overtime. Risk factors for intraoperative CPR, postoperative CPR and perioperative mortality are overlapped. We proposed a simplified approach compromised of five-factor model to identify patients at high risk. Postoperative, compare to intraoperative, cardiac arrest requiring CPR was associated with much higher mortality.

Intraoperative Assessment of Hepatic Vein Tracings in Constrictive Pericarditis During Surgical Pericardiectomy.

CONSTRICTIVE PERICARDITIS is characterized by progressive inflammation and fibrosis of the pericardium. It manifests with symptoms of heart failure. The only effective treatment is surgical pericardiectomy. The assessment and diagnosis of constrictive pericarditis with echocardiography is well described with spontaneous ventilation. However, there are limited data on constrictive pericarditis assessment with transesophageal echocardiography with positive pressure ventilation. Also, intraoperative hepatic venous Doppler flow mostly is used intraoperatively to assess the severity of tricuspid regurgitation by focusing on the flow reversal during systole. In this e-challenge, the authors focus on the hepatic vein Doppler tracing as a means to show improvement in diastolic function during positive pressure ventilation in a patient undergoing pericardiectomy. This case demonstrates a severely blunted diastolic flow pattern in the hepatic vein that is reversed after successful pericardiectomy. Also, it shows blunted flow during systole compared to diastole post-pericardiectomy, indicating high right atrial pressure.

Anesthetic Considerations for Transcatheter Tricuspid Valve Repair.

The development of transcatheter approaches for heart valve repair and replacement procedures have revolutionized the field of structural cardiology and cardiac anesthesiology. With the recently reported benefits of transcatheter mitral repair procedures, there has been increasing focus on transcatheter tricuspid repair technologies. Currently, there are multiple transcatheter tricuspid repair devices that are undergoing feasibility testing, and each device has its own unique procedural considerations. This review discusses the anesthetic management of transcatheter tricuspid repair by describing the causes of tricuspid regurgitation, the currently available transcatheter tricuspid repair devices, the procedural considerations relevant to the cardiac anesthesiologist, and pearls for proper intraprocedural image guidance via transesophageal echocardiography.

Anesthetic Considerations for Aortic Arch Stenting.

With advances in modern day imaging techniques for the aorta, there has been an increasing incidence of vascular diseases involving the aortic arch. Historically, the only treatment option for arch disease has been open arch replacement under circulatory arrest conditions with or without selective cerebral perfusion. However, this open procedure has significant morbidity and mortality, especially in elderly patients with multiple comorbidities. To potentially mitigate the risks associated with open replacement, endovascular arch repair has gained momentum as an alternative treatment option. Currently, aortic arch stenting is being trialed in multiple international medical centers across Europe and the United States. The outcomes data available thus far are promising, which suggest that there likely will be an increase in patients being referred for aortic arch stenting procedures in the future. In this emerging technology review, multiple aspects of the aortic arch stenting procedure are discussed including the currently available endovascular arch devices, the unique surgical and anesthetic considerations for arch stent implantation, and the early outcomes data published to date.

Anesthetic Considerations for the Transcatheter Management of Mitral Valve Disease.

The development of transcatheter interventions to provide a minimally invasive alternative to open surgical repair has revolutionized the care of patients with valvular heart disease. Recently, this technology has been expanded to allow for the treatment of pathology of the mitral valve. This review discusses the anesthetic considerations for patients presenting for transcatheter management of mitral valve disease, including transcatheter mitral valve replacement (TMVR) and transcatheter mitral valve repair (TMVRep). The initial focus is on the current literature on transcatheter interventions for mitral valve pathologies as well as current and developing technology for TMVR and TMVRep. The authors' institutional experience with anesthetic management for the TMVR and TMVRep procedures is described, including potential pitfalls and complications, concluding with a discussion of the role of transesophageal echocardiography in the care of this patient population.

Anesthetic Considerations for Transcatheter Pulmonary Valve Replacement.

The introduction of transcatheter therapy for valvular heart disease has revolutionized the care of patients with valvular disorders. Pathologic regurgitation or stenosis of the pulmonary valve, right ventricular outflow tract, or a right ventricle-to-pulmonary artery conduit represent emerging indications for transcatheter therapy. To date, minimal literature exists detailing the anesthetic management of patients undergoing transcatheter pulmonary valve replacement. In this review, the pathophysiology and indications for transcatheter pulmonary valve replacement and possible complications unique to this procedure are reviewed. Anesthetic management, including preoperative assessment, intraoperative considerations, and early postoperative monitoring, are discussed.

Novel use of a noninvasive hemodynamic monitor in a personalized, active learning simulation.

The present study furthered the concept of simulation-based medical education by applying a personalized active learning component. We tested this novel approach utilizing a noninvasive hemodynamic monitor with the capability to measure and display in real time numerous hemodynamic parameters in the exercising participant. Changes in medical knowledge concerning physiology were examined with a pre-and posttest. Simply by observation of one's own hemodynamic variables, the understanding of complex physiological concepts was significantly enhanced.