Heart Failure, Part 1. Introduction

There are not so many topics in Pathology, which are easier to explain and learn than heart failure. I have been working in many countries and everywhere students were able to recognize a pitting edema and nutmeg liver. On the other hand, there are not so many topics, which are more difficult than heart failure.

Confusions begin with nomenclature: the condition can be called “heart failure”, “congestive heart failure”, or “cardiac failure”; we can use all these terms as synonyms.

Also there is no complete agreement how to define cardiac failure:

A good definition we can find in Harrison’s Online: “Heart failure (HF) is a clinical syndrome that occurs in patients who, because of an inherited or acquired abnormality of cardiac structure and/or function, develop a constellation of clinical symptoms (dyspnea and fatigue) and signs (edema and rales) that lead to frequent hospitalizations, a poor quality of life, and a shortened life expectancy”. (http://www.accessmedicine.com/ content.aspx?aID=2902063&searchStr=congestive+heart+failure). A pathologist can find this definition purely clinical, which does not disclose the leading pathophysiologic features.

According to Robbins Basic Pathology “Congestive heart failure is a multisystem derangement that occurs when the heart is no longer able to eject the blood delivered to it by venous system”. (7th Ed., P.362). A little bit confusing and, inter alia, incomplete definition, because, so-called compensatory phase of cardiac failure is not mentioned there.

If you open Rubin’s Pathology, you will need to read whole page (431, 5th Ed.) to understand what heart failure is.

The best definition, in my opinion, is given in my favorite text Robbins and Cotran Pathologic Basic of Disease: “In heart failure … the heart is unable to pump blood at the rate commensurate with the requirements of the metabolizing tissues or it can do so only at an elevated filling pressure” (7th Ed. P.560). This definition (pretty similar to that given in your handouts) covers the condition, when the heart is overloaded, but still is to maintain cardiac output.

To be continued tomorrow