A new tool for benchmarking cardiovascular fluoroscopes.

This article reports the status of a new cardiovascular fluoroscopy benchmarking phantom. A joint working group of the Society for Cardiac Angiography and Interventions (SCA&I) and the National Electrical Manufacturers Association (NEMA) developed the phantom. The device was adopted as NEMA standard XR 21-2000, "Characteristics of and Test Procedures for a Phantom to Benchmark Cardiac Fluoroscopic and Photographic Performance," in August 2000. The test ensemble includes imaging field geometry, spatial resolution, low-contrast iodine detectability, working thickness range, visibility of moving targets, and phantom entrance dose. The phantom tests systems under conditions simulating normal clinical use for fluoroscopically guided invasive and interventional procedures. Test procedures rely on trained human observers.

Guidelines for internal peer review in the cardiac catheterization laboratory. Laboratory Performance Standards Committee, Society for Cardiac Angiography and Interventions.

The Laboratory Performance Standards Committee of the Society for Cardiac Angiography and Interventions has proposed guidelines for establishing an internal peer review program in the cardiac catheterization laboratory. The first step is to establish a committee and a data base. This data base should include quality indicators that reflect: physician qualifications, outcomes of procedures, and processes of care. The outcomes must be risk-adjusted to account for the variable severity of illness. Data should be collected by catheterization laboratory personnel and entered into a laboratory-specific computerized data base. These data must be analyzed and organized into profiles that reflect the quality of care. Based on this information, the Committee would institute the following interventions to improve physician performance: education, clinical practice standardization, feedback and benchmarking, professional interaction, incentives, decision-support systems, and administrative interventions. The legal aspects of peer review are reviewed briefly.

Systemic anaphylactoid reactions to iodinated contrast media during cardiac catheterization procedures: guidelines for prevention, diagnosis, and treatment. Laboratory Performance Standards Committee of the Society for Cardiac Angiography and Interventions.

This report represents the first guidelines for prevention, diagnosis, and treatment of anaphylactoid reactions to contrast media occurring specifically during cardiac catheterization. The incidence of contrast media complications in the catheterization laboratory is 0.23% with 1 death per 55,000. Anaphylactoid reactions are nonimmune mediated, but histamine release and other mediators produce a clinical presentation indistinguishable from anaphylaxis. In patients with known previous reactions, pretreatment with steroids and diphenhydramine and the use of nonionic contrast media have significantly reduced the potential of recurrent reaction. Minor reactions such as limited urticaria may be watched for progression or treatment with diphenhydramine, whereas more serious reactions such as angioedema or laryngeal edema require airway stability and ephinephrine administration. Shock should be vigorously treated simultaneously with intravenous epinephrine and large volumes of normal saline. If the patient can be stabilized, the study should be completed as histamine, leukotrienes, and other vasoactive products should be relatively depleted.

Left ventricular to right atrial fistula after aortic homograft replacement for endocarditis.

The treatment is described of a patient who had severe bacterial endocarditis with aortic valve destruction and septal abscess complicated by left ventricular to right atrial fistula 3 months after aortic homograft root replacement and septal debridement and repair. The status of the aortic homograft and anatomy of the fistula were defined precisely by echocardiography, making successful repair through a right atriotomy possible without disturbing the aortic homograft and the implanted coronary arteries.

Guidelines for continuous quality improvement in the cardiac catheterization laboratory. Laboratory Performance Standards Committee of the Society for Cardiac Angiography & Interventions.

The Laboratory Performance Standards Committee of the Society for Cardiac Angiography and Interventions has compiled guidelines for a quality improvement program for the cardiac catheterization laboratory. The first step is to identify "quality indicators" in order to quantify the results. The indicators must be risk-adjusted to assure validity of comparative data. The second step is development of a data collection process that continues after the patient has left the catheterization laboratory. The third step, data evaluation, requires determination of normal ranges of occurrence rates and identification of adverse events that exceed these rates. An investigation should be undertaken to determine the processes and systems that may produce the undesirable outcome. The fourth step is creation of a solution to correct the deficiency. This may involve education, administrative intervention, or feedback. The final step is reassessment of the quality indicators to determine if the corrective action has been effective.

Infection prevention guidelines for cardiac catheterization laboratories. Society for Cardiac Angiography and Interventions Laboratory Performance Standards Committee.

The following guidelines for prevention of catheterization laboratory infections are based on standard precautions for infection prevention in surgical wounds. Specific recommendations for patient preparation include proper methods for hair removal, skin cleaning and draping, antibiotic prophylaxis, wound irrigation and dressing, and sheath removal. Sterile precautions should be more vigorous for cutdown procedures compared to percutaneous. Caps, masks, gowns, and gloves help to protect both the patient and operator. Handwashing is the most important procedure for preventing infections. Maintenance of the catheterization laboratory environment includes appropriate cleaning, limitation of traffic, and maintenance of adequate ventilation. Proper catheterization technique and appropriate use of sterile equipment will decrease the wound infection rate. Protection of personnel may be accomplished by proper gowning and gloving, disposal of contaminated equipment, and care of puncture wounds and lacerations. All personnel should receive vaccination for hepatitis B.

Electrocardiographic evidence suggestive of myocardial infarction without significant organic heart disease.

One hundred nineteen catheterized patients had ECG evidence of myocardial infarction in the absence of significant narrowing of coronary arteries or localized contractile abnormalities of the left ventricle. Eighty-seven had organic heart disease, but 32 had no demonstrable abnormality. ECG alterations in the latter group were almost equally divided between those in lead aVF and in the right precordial leads. Although certain depolarization defects are highly suggestive of myocardial infarction, similar changes may rarely be seen in normal people.

Initial coronary air embolus in the differential diagnosis of coronary artery spasm.

Angiographic and electrocardiographic manifestations of initial coronary air embolism were seen in 4 patients and in a dog. All 4 patients had angina pectoris, 2 had ST elevation, 1 patient had ST depression and 1 had no electrocardiographic change after the air embolus. Although the initial diagnosis in these 4 patients was coronary artery spasm, a subsequent ergonovine test response for coronary artery spasm was negative in the 3 patients in whom it was performed. In a dog, initial injection of air in a coronary artery produced ST-segment elevation and delayed clearance of contrast material. The angiographic appearance of initial air embolus was similar in the 4 patients and in the dog. The leading edge of contrast material that followed an air embolus stopped abruptly, appeared hazy and blunt, and pulsated back and forth. The air embolus produced temporary cessation of flow in the main artery and its branches. Initial injection of air during coronary arteriography mimics coronary artery spasm by producing a syndrome characterized by angina, ischemic changes on the electrocardiogram, and delayed flow of contrast material. An initial air embolus may be differentiated from true coronary spasm by several distinctive angiographic features.

Variant angina: comparison of patients with and without fixed severe coronary artery disease.

To determine if the clinical features of variant angina are predictive of the severity of underlying coronary artery disease, 43 patients with variant angina who had less than 50% fixed coronary luminal diameter narrowing (group 1) were compared with 65 patients with variant angina who had 70% or greater diameter narrowing (group 2). Statistically significant differences were found in 3 clinical features between group 1 and group 2: (1) a more than 3-month history of angina at rest before diagnosis (80% vs 23%, p less than 0.001); (2) an abnormal electrocardiogram at rest (19 vs 48%, p less than 0.01); and (3) an abnormal stress test (26% [8 of 30] vs 84% [15 of 18], p less than 0.01). However, these features were not clinically reliable in separating patients with variant angina with and without fixed severe obstructions because of overlap between the 2 groups. No difference was found between the 2 groups in age, sex, predominant symptom at the time of catheterization, history of exertional angina, syncope with angina, prolonged angina, previous myocardial infarction or risk factors for coronary artery disease. There was also no difference in the location of ST elevation or occurrence of major arrhythmias during angina. Thus, among patients with Prinzmetal's variant angina, those with normal or mildly abnormal coronary arteriograms cannot be differentiated reliably by clinical features from those with fixed severe coronary obstructions. Coronary arteriography should be performed to define the underlying coronary anatomy and to determine optimal therapy in patients with variant angina.

What is the long-term prognosis of patients with coronary spasm and normal coronary arteries?

The clinical course of patients with pure coronary artery spasm is variable. Some patients have a chronic course characterized by recurrent angina at rest. Others develop spontaneous remission of symptoms. Most patients have a poor response to long-acting nitrate therapy and a good response to calcium antagonists. Despite the morbidity associated with this syndrome, cardiac mortality is low. When death occurs, it is usually sudden and probably secondary to an arrhythmia.

Calcium blockers in angina. How they work, when to prescribe.

The calcium channel blocking drugs--nifedipine, verapamil, and diltiazem--are an important adjunct to treatment of typical exertional angina and are the treatment of choice for angina due to coronary artery spasm. These drugs are as effective as nitrates and beta-adrenergic blocking agents in treatment of patients with ischemic heart disease. With certain precautions, they may also be used in combination with nitrates and beta blockers. The three calcium blockers are not completely interchangeable because each has distinctive therapeutic applications and side effects. Detailed knowledge of each drug is important for its intelligent application in treatment of angina pectoris.

Natural history of pure coronary artery spasm in patients treated medically.

The clinical course of 59 patients with coronary artery spasm and no fixed severe coronary obstruction was analyzed for an average of 5.9 years. The study group consisted of 27 men and 32 women. Angina at rest was the predominant symptom in 93% of the patients. Myocardial infarction occurred in 19% and syncope during angina in 27%. During spontaneous anginal episodes, 64% of the patients showed ST segment elevation, 17% ST segment depression and 15% no electrocardiographic changes. Major arrhythmias during angina occurred in 24% of the patients. Permanent pacemakers were required in 10% of the patients. Stress tests were positive in 32% of the patients. Long-acting nitrate therapy controlled symptoms in only 31%, and calcium antagonist agents controlled symptoms in 83% of the patients unresponsive to nitrates. Spontaneous remission of angina for at least 1 month while receiving no medical treatment occurred in 39% of the patients. Fifteen percent of patients had an indefinite remission with no recurrence of symptoms for at least 2 years. There were no cardiac deaths. The natural history of medically treated patients with pure coronary spasm is characterized by recurrent angina at rest, frequent spontaneous remission, a poor response to long-acting nitrate therapy and a good response to calcium antagonists. Although myocardial infarction and major arrhythmias are common, cardiac mortality is low in medically treated patients.

Randomized withdrawal from nifedipine: placebo-controlled study in patients with coronary artery spasm.

A multicenter randomized double-blind withdrawal study was conducted to compare the efficacy of nifedipine to that of placebo in vasospastic angina. Following a 2-week single-blind nifedipine baseline period, during which nifedipine was maintained at prestudy levels, 38 patients, 19 taking placebo and 19 continuing nifedipine therapy, either completed a 4-week randomized phase or were prematurely withdrawn because of therapeutic failure. During the randomized phase, an increase in median anginal frequency (2.8 attacks/wk, p less than 0.003) and nitroglycerin usage (0.5 tablets/wk, p less than 0.03) occurred only in the placebo group. The randomized phase was prematurely terminated because of anginal exacerbation in 7 of 19 placebo patients (37%) (only 1 patient receiving nifedipine [p = 0.02] experienced anginal exacerbation). Double-blind therapy was judged effective in 16 patients (84%) receiving nifedipine and in 3 patients (16%) receiving placebo (p less than 0.001). Nifedipine was well tolerated. This study establishes the efficacy of nifedipine in the treatment of variant and validates previous clinical experience.

Coronary artery spasm: recognition and treatment.

Coronary artery spasm may produce angina, major arrhythmias, syncope, myocardial infarction, and death in patients with normal or nearly normal coronary arteriograms. The clinical picture in patients with symptomatic coronary artery spasm is characterized by: (1) predominant angina at rest, with little or no exertional angina; (2) changes of myocardial ischemia, especially ST segment elevation, on the electrocardiogram during pain: and (3) major arrhythmias and syncope during angina. A complete electrocardiogram during pain, or at least a Holter monitor recording, is important in establishing a diagnosis. The ergonovine maleate provocative test is a reliable method of establishing the diagnosis, but it is associated with some risks. Calcium flux antagonists are more effective than nitrates or beta blockers in the treatment of coronary spasm. Coronary bypass surgery is generally ineffective in the treatment of coronary spasm unless the spasm is superimposed on a fixed severe coronary obstruction.