Cardiothoracic surgical critical care certification: A future of distinction.

Cardiothoracic surgical critical care has emerged as a unique area of practice within cardiothoracic surgery. Leaders of multidisciplinary, high-performing teams are uniquely educated, trained, and skilled surgeons. Certification in this specialty by the American Board of Thoracic Surgery is a recognition of their distinction. A foundational framework is proposed toward this goal.

Ebers, DaVinci, and Euler: Calculating the Pulse. Assumptions, Challenges, and Opportunities in Mathematical Modeling of Aortic Flow.

Mathematical modeling of flow in the circulatory system, particularly the arterial system, has long relied on old equations derived from the study of fluid mechanics in rigid tubes, which does not account for the cyclic distension of the vessel or the effects of intraluminal forces on wall components. An understanding of the current scientific evidence and the limitations of such assumptions is essential for adequate computational modeling of the circulatory system. Improved interdisciplinary communication among the basic science, medical, surgical, and biomedical engineering communities should prove to be beneficial in developing safer, more effective, and more reliable tools and devices that are more consistent with physiological processes within the body.

Dissecting the Dissection: Towards More Comprehensive Decision-Making Methodology for Thoracic Aortic Disease.

Aortic dissection remains one of the most devastating diseases. Current practice guidelines provide diagnostic and therapeutic interventions based primarily on the aortic diameter. The level of evidence supporting these recommendations is Level C or "Expert Opinion" Since aortic dissection is a catastrophic structural failure, its investigation along the guidelines of accident investigation may offer a useful alternative, utilizing process mapping and root-cause analysis methodology. Since the objective of practice guidelines is to address the risk of serious events, on the utilization of a probabilistic predictive modeling methodology, using bioinformatics tools, may offer a more comprehensive risk assessment.

Heterogeneity in the Segmental Development of the Aortic Tree: Impact on Management of Genetically Triggered Aortic Aneurysms.

An extensive search of the medical literature examining the development of the thoracic aortic tree reveals that the thoracic aorta does not develop as one unit or in one stage: the oldest part of the thoracic aorta is the descending aorta with the aortic arch being the second oldest, developing under influence from the neural crest cell. Following in chronological order are the proximal ascending aorta and aortic root, which develop from a conotruncal origin. Different areas of the thoracic aorta develop under the influence of different gene sets. These parts develop from different cell lineages: the aortic root (the conotruncus), developing from the mesoderm; the ascending aorta and aortic arch, developing from the neural crest cells; and the descending aorta from the mesoderm. Findings illustrate that the thoracic aorta is not a single entity, in developmental terms. It develops from three or four distinct areas, at different stages of embryonic life, and under different sets of genes and signaling pathways. Genetically triggered thoracic aortic aneurysms are not a monolithic group but rather share a multi-genetic origin. Identification of therapeutic targets should be based on the predilection of certain genes to cause aneurysmal disease in specific aortic segments.

The developing pulmonary veins and left atrium: implications for ablation strategy for atrial fibrillation.

The majority of cases of atrial fibrillation (AF) are the result of triggers originating in the area of the pulmonary veins. The reason for the predilection for that area remains unclear. We sought to examine the different mechanisms responsible for this observation through an extensive search of the medical literature, examining the development of the pulmonary veins, genetics of AF and left to -right cardiac chamber differentiation. Results confirm that the LAA is anatomically and embryologically different from other areas of the atrial walls and develops under distinct genetic and transcriptional pathways. Findings support an ablation strategy whose primary focus should be the creation of a 'box' lesion set, plus additional lines to prevent propagation to the left atrial appendage, the isthmus of the left atrium and the right atrium are likely to be more effective than simple pulmonary vein isolation.

Successful coronary artery bypass in Ehlers-Danlos type IV syndrome case report and review of the literature.

Atherosclerotic coronary artery occlusive disease is very rare in cases of Ehlers-Danlos type IV syndrome. We report what we believe is a unique case of successful coronary artery bypass grafting for atherosclerotic coronary artery disease in a patient with this syndrome and examine the possible implications for the natural progression of the disease through a review of the literature. Nevertheless, we reiterate previous investigators' advice that any invasive procedure on these patients should be approached with extreme caution and that surgery should be performed as a last resort, considering the significantly elevated risks.

Next generation long-term mechanical circulatory support systems: are pulsatile pumps extinct? Challenges, goals, and opportunities.

The therapeutic value of mechanically assisted circulation in the management of end-stage congestive heart failure has been shown. However, the ideal mechanical circulatory support device has not been introduced, especially for long-term or permanent use. Such a device should be durable, completely implantable, autonomous, small in size, and easy to use; it should provide a physiologic perfusion pattern. Current trends have favored non-pulsatile or continuous-flow devices over the older pulsatile devices. There has been no significant innovation in pulsatile devices for over 10 years. There is an ongoing debate about the physiologic impact of non-pulsatile flow. We explore the physiologic impact, biocompatibility issues, challenges in energy management, mechanical efficiency, and implantable power sources that exist in developing new classes of pulsatile devices for long-term mechanical circulatory support.

Left ventricular diverticulum mimicking ventricular pseudoaneurysm in an adult.

True diverticulum of the left ventricle is very rarely seen in adults: the condition typically occurs in children and can be associated with other anatomic defects that involve the thoracoabdominal midline. Left ventricular diverticulum, which is usually asymptomatic and typically discovered incidentally, can pose a substantial challenge to the surgeon.Herein, we report the case of a 46-year-old man who presented with worsening exertional angina and ST-segment elevation in the inferior electrocardiographic leads. After a stent was deployed in the patient's occluded right coronary artery, left ventriculography revealed outward pouching of the left ventricular inferior wall, suggesting an aneurysm or a contained free-wall rupture. Transesophageal echocardiography showed a sizable defect and a possible intracavitary thrombus. The presumptive diagnosis was a postinfarction subacute pseudoaneurysm of the left ventricle. However, during surgery, we saw no clots, intrapericardial blood accumulation, or perforation. A localized area of thinned muscle in the region of the posterior descending coronary artery was consistent with a ventricular diverticulum. The left ventricular epicardial surface was reinforced with a small bovine pericardial patch. The patient's recovery was uneventful. We discuss the forms of congenital left ventricular diverticulum and offer considerations regarding differential diagnosis.

In search of a new therapeutic target for the treatment of genetically triggered thoracic aortic aneurysms and cardiovascular conditions: insights from human and animal lathyrism.

Lathyrism, or the effect of certain plants on connective tissue disruption, particularly involving the vascular and skeletal systems, especially aortic dissection/rupture, has been well documented in animals. Its impact on the pathogenesis of connective tissue diseases in humans is still unclear. An extensive review of the scientific literature from the 1800s until the present time was performed to examine the common pathways between animal and human lathyrism and genetically triggered thoracic aortic aneurysms and cardiovascular conditions in humans, with special focus on the identification of potential therapeutic targets. Search areas covered the following subjects: lathyrism/spontaneous aortic dissection/rupture in animals; beta-aminopropionitrile, semicarbazide and their effects; collagen and elastin synthesis and cross-linking; genetic and molecular biology characteristics of the genetically triggered thoracic aortic conditions. Search results demonstrate Marfan syndrome as a model for the genetically triggered thoracic aortic aneurysms, has been linked to mutations of the fibrillin-1 gene, via transforming growth factor beta-1. Several other conditions do not share this mutation. Inhibition of semicarbazide-sensitive amine oxidase [vascular adhesion protein-1 (VAP-1)] in animals has been shown to result in aortic dilatation due to disruption of elastin cross-linking. Significantly low activity of this enzyme was identified in annulo-aortic ectasia; a condition similar to Marfan syndrome. In conclusion, the precise molecular and genetic pathways responsible for the clinical findings in Marfan syndrome and related conditions remain unclear. Observational and experimental findings relating to the vascular and systemic effects of molecular pathways implicated in the phenomenon of animal and human lathyrism suggest that VAP-1 seems to be involved in the molecular and developmental pathways of the genetically triggered thoracic aortic diseases and thus could be a potential therapeutic target for these conditions.

The artificial ventricle: A conceptual design for a novel mechanical circulatory support system.

We describe a novel design for a new mechanical circulatory support pump which can be utilized for single or biventricular support in a completely internal configuration. The device has a long projected service life, a totally implantable, readily available and off-the-shelf energy source. The proposed device is a pulsatile, positive-displacement blood pump composed of a conically-shaped compliance chamber, constructed of a biocompatible material and attached to two bioprosthetic valves (an inlet valve and an outlet valve), surrounded by radially-arranged contractile elements, made of an electro-active polymer and connected to a common stimulating electrode connected to an implantable permanent pacemaker. The entire assembly is housed in a hermetically sealed biologically inert shell. The energy output from the pacemaker will cause the deformation of the contractile elements and thus compression of the compliance chamber, effecting ejection of the blood through the outlet valve. Based on a design emulating the natural anatomic configuration, the device shall be able to provide clinically significant mechanical assistance and/or replacement of the native heart function and thus a means of supporting the failing ventricle(s) or replacing the failing heart for an extended period of time. The proposed design offers a new pulsatile, positive displacement mechanical circulatory support or replacement for one or both ventricles, is completely implantable, is composed of readily available materials, has minimal energy requirements and an extended service life on internal power supply.

Recovery after resuscitation from cardiac arrest in ST-elevation myocardial infarction: a computer-based medical decision-support tool.

Prediction of outcomes in ST-elevation myocardial infarction with cardiac arrest often presents difficult clinical decision making. Using the observed results from our institution's data, we introduce a customized, computer-based decision support tool to assist in evaluating and predicting outcomes in such situations. We conclude that this tool can be beneficial to clinicians in decision making or triage of this condition.

Calcification of left-sided valvular structures: evidence of a pro-inflammatory milieu.

BACKGROUND AND AIM OF THE STUDY: Calcification of the cardiac valves occurs more frequently on the left side, most commonly involving the aortic and mitral valves. The differences in hemodynamics and blood pressure between the right and left sides have been considered as possible causes. However, the reason for this preferential distribution remains unknown. It is hypothesized that a stronger pro-inflammatory milieu exists in the left side of the heart, and might be responsible for valve calcification occurring most frequently on that side. METHODS: An extensive search of the medical literature using PubMed and Google Internet search engines and online databases, as well as textbooks and journals, was conducted. Search areas included the pathophysiology of normal and dystrophic calcification, and the incidence and distribution of native valve involvement in different diseases. RESULTS: The majority of the disease processes affecting cardiac valves have an increased predilection for the left-sided valves. This was also found to be true in systemic diseases with cardiac involvement. Diseases where the right-sided valves are subjected to higher pressure and comparably forceful hemodynamics were found not to demonstrate a similar increase in the incidence of valve calcification. Pulmonary autografts or homografts in the aortic position appear not to demonstrate the same rate of calcification as their aortic counterparts, despite being subjected to the same hemodynamics. CONCLUSION: The reason for valve calcification occurring more frequently on the left side remains unknown. All available evidence does not support the proposal that a higher pressure and more forceful hemodynamics are causes for this observation. Rather, the data indicate that there is a pronounced pro-inflammatory milieu in the tissues of the left-sided cardiac valves, that may be responsible for such increased valve calcification. Further investigations are required in order to assess, quantitatively, the differences in inflammatory response between right- and left-sided cardiac valves.