Publicamos, abaixo, a segunda parte do artigo "Cardiac surgery - the infinte quest". Apesar de mais complexo que a anterior, este texto vai além das habilidades técnicas e tem conceitos modernos de como lidar com os sistemas complexos da atual prática da nossa profissão e especialidade.

Heart surgery has much in common with other high technology systems in which performance and outcomes depend on multifaceted interactions of individual, technical and organizational factors. In addition, our specialty often functions as a chaotic/emergent system since the initial circumstances vary in patients with the same medical condition resulting in uncertainty and lack of predictability [1]. Complexity: The American Heritage Dictionary defines complex and complicated as “things whose parts are so interconnected or interwoven as to make the whole perplexing”. If we add rarity and small numbers to complexity, the results is a distinctiveness that explains many aspects of our profession and specialty such as variability with institutional differences in outcomes; inconsistency of results in treating rare diseases and uncertainty on any inference about results of complex rare lesions [2].A system is a set of interdependent elements that are interacting, or working together, to accomplish a common goal. All systems, at the “atomic” level, consist of individuals, activities, connections, and pathways with the following characteristics, qualities or peculiarities in complex systems:• Heterogeneity of the parties (diverse nature and multiple);• Cause-and-effect relationships may be nonlinear and obvious only in retrospect;• Richness of interaction between them (including their contradictory character);• Multidimensional and multi-referential;• Many variables commonly present;• Provide information that by itself reveals the extent of its complexity;• Under an apparent simplicity, they often hide the true dynamics of these processes and interactions between its parts• Vulnerability — Are influenced by factors and surprising circumstances that may affect, cause, or facilitate a change in behavior and expected results, altering all or changed significantly“Complex business generates complex services. Regardless of how much effort and brain power go into designing their complex operations (‘system of work’), it is impossible to do it perfectly and to predict how it will behave under every circumstance” [3]. Complex systems are rich in multiple and interdependent