Coronary blood flow reserve in acute aortic regurgitation

Objectives.This study sought to determine the impact of acute aortic regurgitation on coronary blood flow reserve and phasic epicardial coronary blood flow in closed-chest dogs.Background.Hemodynamic changes in acute aortic regurgitation are known to precipitate myocardial ischemia. Coronary blood flow reserve has not been studied in closed-chest experimental preparations with acute aortic regurgitation.Methods.Graded temporary acute aortic regurgitation was produced in 11 mongrel dogs. Phasic coronary blood How velocities were measured using a Doppler guide wire. Coronary flow reserve was defined as the ratio of the time average of spectral peak velocity after administration of papaverine to that of the baseline state.Results.Under control conditions (mean [±SEM]diastolic blood pressure 82.2 ± 4.5 mm Hg), coronary flow reserve was 3.51 ± 0.27 with predominantly diastolic epicardial coronary blood flow. With mild acute aortic regurgitation (diastolic blood pressure 61.8 ± 3.0 mm Hg), coronary flow reserve decreased to 2.38 ± 0.27, with an increase in phasic systolic epicardial coronary blood flow. At the onset of moderate acute aortic regurgitation (diastolic blood pressure 42.1 ± 0.9 mm Hg), coronary flow reserve declined further to 1.46 ± 0.12, and the phasic systolic epicardial coronary blood flow became more prominent. With severe aortic regurgitation (diastolic blood pressure 29.2 ± 2.2 mm Hg), coronary flow reserve reached 1.20 ± 0.05, and the phasic epicardial coronary blood flow pattern was found to be predominantly systolic with retrograde diastolic flow. The ratio of diastolic to systolic pressure-time indexes with severe aortic regurgitation suggested subendocardial underperfusion.Conclusions.This study demonstrates a marked decline in coronary blood flow reserve and documents a progressive change in the phasic epicardial blood flow to a predominantly systolic pattern with increasing degrees of acute aortic regurgitation

ACC/AHA/ACP-ASIM guidelines for the management of patients with chronic stable angina: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients With Chronic Stable Angina)

The ACC/AHA Task Force on Practice Guidelines was formed to make recommendations regarding the diagnosis and treatment of patients with known or suspected cardiovascular disease. Ischemic heart disease is the single leading cause of death in the U.S. The most common manifestation of this disease is chronic stable angina. Recognizing the importance of the management of this common entity and the absence of national clinical practice guidelines in this area, the task force formed the current committee to develop guidelines for the management of patients with stable angina. Because this problem is frequently encountered in the practice of internal medicine, the task force invited the American College of Physicians-American Society of Internal Medicine (ACP-ASIM) to serve as a partner in this effort by naming four general internists to serve on the committee

ACC/AHA Guidelines for Coronary Angiography. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Coronary Angiography)

"The ACC/AHA Task Force on Practice Guidelines herein revises and updates the original “Guidelines for Coronary Angiography,” published in 1987 (1). The frequent and still-growing use of coronary angiography, its relatively high costs, its inherent risks and the ongoing evolution of its indications have given this revision urgency and priority. The expert committee appointed included private practitioners and academicians. Committee members were selected to represent both experts in coronary angiography and senior clinician consultants. Representatives from the family practice and internal medicine professions were also included on the committee. The English-language medical literature was searched for the 10 years preceding development of the guidelines. The searches yielded >1,600 references that the committee reviewed for relevance. Evidence relative to the use of coronary angiography was compiled and evaluated by the committee. Whereas randomized trials are often available for reference in the development of treatment guidelines, randomized trials regarding the use of diagnostic procedures such as coronary angiography are rarely available (2). For development of these guidelines, when coronary angiography was a necessary procedure in describing a clinical subset or in choosing a course of treatment and that therapy was shown to have an advantage for the patient, especially in the context of a randomized trial, then the indication for angiography was given greater consideration than indications cited in less-rigorous evaluations of data.

ACC/AHA guideline update for the management of patients with unstable angina and non-ST-segment elevation myocardial infarction - 2002: Summary article: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on the Management of Patients with Unstable Angina)

The American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for the management of unstable angina and non–ST-segment elevation myocardial infarction (UA/NSTEMI) were published in September 2000.1 Since then, a number of clinical trials and observational studies have been published or presented that, when taken together, alter significantly the recommendations made in that document. Therefore, the ACC/AHA Committee on the Management of Patients With Unstable Angina, with the concurrence of the ACC/AHA Task Force on Practice Guidelines, revised these guidelines. These revisions were prepared in December 2001, reviewed and approved, and then published on the ACC World Wide Web site (www.acc.org) and AHA World Wide Web site (www.americanheart.org) on March 15, 2002. The present article describes these revisions and provides further updates in this rapidly moving field. Minor clarifications in the wording of three recommendations that now appear differently from those that were previously published on the ACC and AHA Web sites are noted in footnotes

ACC/AHA 2002 guideline update for the management of patients with unstable angina and non-ST-segment elevation myocardial infarction - Summary article: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on the Management of Patients with Unstable Angina)

The American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for the management of unstable angina and non–ST-segment elevation myocardial infarction (UA/NSTEMI) were published in September 2000 (1). Since then, a number of clinical trials and observational studies have been published or presented that, when taken together, alter significantly the recommendations made in that document. Therefore, the ACC/AHA Committee on the Management of Patients With Unstable Angina, with the concurrence of the ACC/AHA Task Force on Practice Guidelines, revised these guidelines. These revisions were prepared in December 2001, reviewed and approved, and then published on the ACC World Wide Web site (www.acc.org) and AHA World Wide Web site (www.americanheart.org) on March 15, 2002. The present article describes these revisions and provides further updates in this rapidly moving field. Minor clarifications in the wording of three recommendations that now appear differently from those that were previously published on the ACC and AHA Web sites are noted in footnotes

ACC/AHA/ASE 2003 Guideline Update for the Clinical Application of Echocardiography: Summary Article: A Report of the American College of Cardiology/American HeartAssociation Task Force on Practice Guidelines (ACC/AHA/ASE Committee to Update the 1997 Guidelines for the Clinical Application of Echocardiography)

"The previous guideline for the use of echocardiography was published in March 1997. Since that time, there have been significant advances in the technology of echocardiography and growth in its clinical use and in the scientific evidence leading to recommendations for its proper use. Each section has been reviewed and updated in evidence tables, and where appropriate, changes have been made in recommendations. A new section on the use of intraoperative transesophageal echocardiography (TEE) is being added to update the guidelines published by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists. There are extensive revisions, especially of the sections on ischemic heart disease; congestive heart failure, cardiomyopathy, and assessment of left ventricular (LV) function; and screening and echocardiography in the critically ill. There are new tables of evidence and extensive revisions in the ischemic heart disease evidence tables. Because of space limitations, only those sections and evidence tables with new recommendations will be printed in this summary article. Where there are minimal changes in a recommendation grouping, such as a change from Class IIa to Class I, only that change will be printed, not the entire set of recommendations. Advances for which the clinical applications are still being investigated, such as the use of myocardial contrast agents and three-dimensional echocardiography, will not be discussed.

ACC/AHA guidelines for the management of patients with unstable angina and non-ST-segment elevation myocardial infarction: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on the management of patients with unstable angina)

The ACC/AHA Task Force on Practice Guidelines was formed to make recommendations regarding the diagnosis and treatment of patients with known or suspected cardiovascular disease. Coronary artery disease (CAD) is the leading cause of death in the United States. Unstable angina (UA) and the closely related condition non–ST-segment elevation myocardial infarction (NSTEMI) are very common manifestations of this disease. In recognition of the importance of the management of this common entity and of the rapid advances in the management of this condition, the need to revise guidelines published by the Agency for Health Care Policy and Research (AHCPR) and the National Heart, Lung, and Blood Institute (NHLBI) in 1994 (1) was evident. This Task Force therefore formed the current committee to develop guidelines for the management of UA and NSTEMI, supported by the Agency for Healthcare Research and Quality’s USCF-Stanford Evidence-Based Practice Center. This document should serve as a useful successor to the 1994 AHCPR guideline

ACC/AHA Guidelines for the Management of Patients With Unstable Angina and Non–ST-Segment Elevation Myocardial Infarction: Executive Summary and Recommendations: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on the Management of Patients With Unstable Angina)

The American College of Cardiology (ACC)/American Heart Association (AHA) Task Force on Practice Guidelines was formed to make recommendations regarding the diagnosis and treatment of patients with known or suspected cardiovascular disease. Coronary artery disease (CAD) is the leading cause of death in the United States. Unstable angina (UA) and the closely related condition non–ST-segment elevation myocardial infarction (NSTEMI) are very common manifestations of this disease. These life-threatening disorders are a major cause of emergency medical care and hospitalizations in the United States. In 1996, the National Center for Health Statistics reported 1 433 000 hospitalizations for UA or NSTEMI. In recognition of the importance of the management of this common entity and of the rapid advances in the management of this condition, the need to revise guidelines published by the Agency for Health Care Policy and Research (AHCPR) and the National Heart, Lung and Blood Institute in 1994 was evident. This Task Force therefore formed the current committee to develop guidelines for the management of UA and NSTEMI. The present guidelines supersede the 1994 guidelines