In this our final edition as primary authors of this text, we have continued our penchant of focusing on the big picture of how and why the cardiovascular system operates as it does. Our firm belief is that to evaluate the importance and consequences of specific details it is essential to appreciate where they fit in the big picture. The core idea is for students not to get lost in the forest for the trees. The same approach will serve practitioners well throughout their careers as they evaluate new information as it arises.
The cardiovascular system is a circular interconnection of many individual components—each with its own rules of operation that must be followed. But in the intact system, the individual components are forced to interact with each other. A change in the operation of any one component has repercussions throughout the system. Understanding such interactions is essential to developing a big picture of how the intact system behaves. Only then can one fully understand all the consequences of malfunctions in particular components and/or particular clinical interventions.
This ninth edition includes some recent, new findings as well as a newly added emphasis on cardiovascular energetics. The latter is a result of our recent realization that maximizing energy efficiency to limit the workload on the heart is an important part of the overall plan.
As always, we express sincere thanks to our families for their continual support of our efforts, and to our mentors, colleagues, and students for all they have taught us over the years. Also, these authors would like to thank each other for the uncountable but fruitful hours we have spent arguing about how the cardiovascular system operates from our own (and often very different perspectives).