This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Carabello, B. A. Search for Related Content PubMed PubMed Citation Articles by Carabello, B. A. Related Collections Other Treatment

(Circulation. 2006;113:1721-1722.)
© 2006 American Heart Association, Inc.

Editorial

Understanding Coronary Blood Flow

The Wave of the Future

Blase A. Carabello, MD

From the Department of Medicine, The W.A. "Tex" and Deborah Moncrief Jr, Baylor College of Medicine, and Veterans Affairs Medical Center, Houston, Tex.

Correspondence to Dr Blase A. Carabello, Baylor College of Medicine, Department of Medicine, and the Veterans Affairs Medical Center, One Baylor Plaza, Houston, TX 77030.

Key Words: Editorials • blood flow • hypertrophy

An extract of the first 250 words of the full text is provided, because this article has no abstract.

	Introduction

 
Fick’s principle states that oxygen consumption of an organ or organism is equal to the product of blood flow and oxygen extraction from the blood. Among all organs, the heart is unique in that oxygen extraction is constantly close to maximal. Thus, the only way that this metabolically demanding organ can increase oxygen consumption is by increasing coronary blood flow. In this aspect of oxygen delivery, the heart also is unique because most flow occurs in diastole instead of in systole. In other organs, blood flows down a pressure gradient from its arterial source through the resistance of the arterioles into the capillary bed and thence venous return. In the heart, the compression of the vasculature by its surrounding muscle during systole impedes flow so that while the pressure head for flow is maximum in systole, flow is maximum in diastole. Thus, a simple "vascular waterfall" model in which flow moves from highest to lowest pressure does not fully explain observed myocardial flow phenomena.

Article p 1768

In this week’s Circulation, Davies et al¹ used computer analysis of recordings of blood flow and pressure to detect and quantify intracoronary waves and to study coronary flow events in normal subjects and those with left ventricular hypertrophy (LVH). Waves were generated from both ends of the coronary tree. Proximal waves moved forward; distal waves moved backward. In this schema, proximal "pushing" waves and distal suction waves accelerate forward blood flow, while proximal suction waves and distal pushing waves do the opposite. . . . [Full Text of this Article]