ABSTRACT
Pediatric cardiology is often the practice of applied cardiovascular physiology. For many, the logical, engineering-like interplay of the predominant forces that influence cardiovascular function become almost intuitive and form the basis for the appeal of cardiology as a clinical practice. We are well aware of the importance of systemic vascular resistance, pulmonary vascular resistance, preload, afterload, and contractility and how they affect cardiac output, chamber remodeling, tissue oxygen delivery, and response to various drugs. The cellular and molecular processes that underlie normal and altered cardiovascular physiology often seem less accessible and more remote from clinical practice. Nevertheless, complex
and highly integrated pathways of signal transduction and protein synthesis underlie the physiology that is so apparent to the clinician. New elements of these processes are constantly being elucidated and indicate the importance of structural elements, contractile proteins, ion channels, and even nonmyocyte cardiac cells as vital components in the process of myocardial adaptation and the clinical syndrome of heart failure. New therapeutic targets are emerging from this research, and advanced understanding of conventional drugs like angiotensin-converting enzyme (ACE) inhibitors and badrenergic agonists, and antagonists is helping to refine their uses. It is thus becoming progressively important for the clinician to understand the multiple mechanisms by which myocardial dysfunction can occur.
