Emotional stressors trigger cardiovascular events.

AIMS: To describe the relation between emotional stress and cardiovascular events, and review the literature on the cardiovascular effects of emotional stress, in order to describe the relation, the underlying pathophysiology, and potential therapeutic implications. MATERIALS AND METHODS: Targeted PUBMED searches were conducted to supplement the authors' existing database on this topic. RESULTS: Cardiovascular events are a major cause of morbidity and mortality in the developed world. Cardiovascular events can be triggered by acute mental stress caused by events such as an earthquake, a televised high-drama soccer game, job strain or the death of a loved one. Acute mental stress increases sympathetic output, impairs endothelial function and creates a hypercoagulable state. These changes have the potential to rupture vulnerable plaque and precipitate intraluminal thrombosis, resulting in myocardial infarction or sudden death. CONCLUSION: Therapies targeting this pathway can potentially prevent acute mental stressors from initiating plaque rupture. Limited evidence suggests that appropriately timed administration of beta-blockers, statins and aspirin might reduce the incidence of triggered myocardial infarctions. Stress management and transcendental meditation warrant further study.

Use of lipid-lowering medications at discharge in patients with acute myocardial infarction: data from the National Registry of Myocardial Infarction 3.

BACKGROUND: The present study aimed to assess use of lipid-lowering medication at discharge in a current national sample of patients hospitalized with acute myocardial infarction and to evaluate factors associated with prescribing patterns. METHODS AND RESULTS: Demographic, procedural, and discharge medication data were collected from 138 001 patients with acute myocardial infarction discharged from 1470 US hospitals participating in the National Registry of Myocardial Infarction 3 from July 1998 to June 1999. Lipid-lowering medications were part of the discharge regimen in 31. 7%. Among patients with prior history of CAD, revascularization, or diabetes, less than one half of the patients were discharged on treatment. In multivariate analysis, factors independently related to lipid-lowering use included history of hypercholesterolemia (odds ratio [OR] 4.93; 95% CI 4.79 to 5.07), cardiac catheterization during hospitalization (OR 1.29; 95% CI 1.24 to 1.34), care provided at a teaching hospital, (OR 1.26; 95% CI 1.22 to 1.32), use of ss-blocker (OR 1.43; 95% CI 1.39 to 1.48), and smoking cessation counseling (OR 1.51; 95% CI 1.44 to 1.59). Lipid-lowering medications were given less often to patients who were older (65 to 74 versus <55 years of age; OR 0.82; 95% CI 0.78 to 0.86), those with a history of hypertension (OR 0.92; 95% CI 0.89 to 0.95), and those undergoing coronary artery bypass graft surgery (OR 0.58; 95% CI 0.55 to 0.60). CONCLUSIONS: Analysis of current practice patterns for the use of lipid-lowering medications in patients hospitalized with acute myocardial infarction reveals that a significant proportion of high-risk patients did not receive treatment at time of discharge.

Clinical experience with primary percutaneous transluminal coronary angioplasty compared with alteplase (recombinant tissue-type plasminogen activator) in patients with acute myocardial infarction: a report from the Second National Registry of Myocardial Infarction (NRMI-2).

OBJECTIVES: We sought to compare outcomes after primary percutaneous transluminal coronary angioplasty (PTCA) or thrombolytic therapy for acute myocardial infarction (MI). BACKGROUND: Primary PTCA and thrombolytic therapy are alternative means of achieving reperfusion in patients with acute MI. The Second National Registry of Myocardial Infarction (NRMI-2) offers an opportunity to study the clinical experience with these modalities in a large patient group. METHODS: Data from NRMI-2 were reviewed. RESULTS: From June 1, 1994 through October 31, 1995, 4,939 nontransfer patients underwent primary PTCA within 12 h of symptom onset, and 24,705 patients received alteplase (recombinant tissue-type plasminogen activator [rt-PA]). When lytic-ineligible patients and patients presenting in cardiogenic shock were excluded, baseline characteristics were similar. The median time from presentation to initiation of rt-PA in the thrombolytic group was 42 min; the median time to first balloon inflation in the primary PTCA group was 111 min (p < 0.0001). In-hospital mortality was higher in patients in shock after rt-PA than after PTCA (52% vs. 32%, p < 0.0001). In-hospital mortality was the same in lytic-eligible patients not in shock: 5.4% after rt-PA and 5.2% after PTCA. The stroke rate was higher after lytic therapy (1.6% vs. 0.7% after PTCA, p < 0.0001), but the combined end point of death and nonfatal stroke was not significantly different between the two groups (6.2% after rt-PA and 5.6% after PTCA). There was no difference in the rate of reinfarction (2.9% after rt-PA and 2.5% after PTCA). CONCLUSIONS: These findings suggest that in lytic-eligible patients not in shock, PTCA and rt-PA are comparable alternative methods of reperfusion when analyzed in terms of in-hospital mortality, mortality plus nonfatal stroke and reinfarction.

Prognostic significance of cardiac cinefluoroscopy for coronary calcific deposits in asymptomatic high risk subjects.

OBJECTIVES: This research investigated the prognostic significance of radiographically detectable coronary calcific deposits. BACKGROUND: Coronary calcific deposits are almost always associated with coronary atherosclerosis. We investigated the association between fluoroscopically determined coronary calcium and coronary heart disease end points at 1 year of follow-up. METHODS: This prospective population-based cohort study was conducted in the suburbs of Los Angeles. Fourteen hundred sixty-one asymptomatic adults with an estimated > or = 10% risk of having a coronary heart disease event within 8 years underwent cardiac cinefluoroscopy for assessment of coronary calcium at initiation of the study. Clinical status including angina, documented myocardial infarction, myocardial revascularization and death from coronary heart disease were determined after 1 year. RESULTS: The prevalence of calcific deposits was high (47%). A follow-up examination at 1 year was successfully completed in 99.9% of subjects. Six subjects (0.4%) had died from coronary heart disease and 9 (0.6%) had had a nonfatal myocardial infarction. Thirty-seven subjects (2.5%) reported angina pectoris, and 13 (0.9%) had undergone myocardial revascularization. Fifty-three subjects had at least one event during the 1-year period. Radiographically detectable calcium was associated with the presence of at least one of these end points, with a risk ratio of 2.7 (confidence limits 1.4, 4.6). The presence of coronary calcium was an independent predictor of at least one end point when controlling for age, gender and risk factors. However, three deaths due to coronary heart disease and two nonfatal myocardial infarctions occurred in subjects without detectable coronary calcium. CONCLUSIONS: The presence of coronary calcific deposits incurs an increased risk of coronary heart disease events in asymptomatic high risk subjects at 1 year. This increased risk is independent of that incurred by standard risk factors.

The prehospital electrocardiogram in acute myocardial infarction: is its full potential being realized? National Registry of Myocardial Infarction 2 Investigators.

OBJECTIVES: This study sought to examine the management and subsequent outcomes of patients with a prehospital electrocardiogram (ECG) in a large, voluntary registry of myocardial infarction. BACKGROUND: The prehospital ECG has been proposed as a means of rapidly identifying patients with acute myocardial infarction who might be eligible for reperfusion therapy. METHODS: The characteristics and outcomes of patients with a prehospital ECG were compared with those without a prehospital ECG in the National Registry of Myocardial Infarction 2 data base. Included in the analysis were those patients who presented to the hospital within 12 h of an acute myocardial infarction. Excluded were patients with an in-hospital infarction, transferred-in referrals and self-transported patients. RESULTS: Prehospital ECGs were obtained in 3,768 (5%) of 66,995 National Registry of Myocardial Infarction 2 patients meeting study criteria. Median time from myocardial infarction symptom onset until hospital arrival was longer among those having a prehospital ECG (152 vs. 91 min, p < 0.001). However, once in the hospital, the prehospital ECG group experienced a shorter median time to the initiation of either thrombolysis (30 vs. 40 min, p < 0.001) or primary angioplasty (92 vs. 115 min, p < 0.001). The prehospital ECG group was more likely to receive thrombolytic therapy (43% vs. 37%, p < 0.001) and to undergo primary angioplasty (11% vs. 7%, p < 0.001). Also, the prehospital ECG group was more likely to undergo coronary arteriography (55% vs. 40%, p < 0.001), angioplasty (24% vs. 16%, p < 0.001) or bypass surgery (10% vs. 6%, p < 0.001). The in-hospital mortality rate was 8% in patients with a prehospital ECG and 12% in those without a prehospital ECG (p < 0.001). After adjusting for baseline covariates utilizing multiple logistic regression analysis, this mortality difference remained statistically significant (odds ratio 0.83, 95% confidence interval 0.71 to 0.96, p = 0.01). CONCLUSIONS: The prehospital ECG is infrequently utilized for diagnosing myocardial infarction, and among patients with a prehospital ECG, is associated with a longer time from symptom onset to hospital arrival. Despite these shortcomings, the prehospital ECG is a test that may potentially influence the management of patients with acute myocardial infarction through wider, faster in-hospital utilization of reperfusion strategies and greater usage of invasive procedures, factors that may possibly reduce shortterm mortality. Efforts to implement the prehospital ECG more widely and more rapidly may be indicated.

Underuse of coronary revascularization procedures: application of a clinical method.

OBJECTIVES: Our main objective was to apply a new method to determine whether coronary revascularization procedures are underused, especially among African-Americans and uninsured patients. BACKGROUND: Although overuse of revascularization procedures has been studied, underuse as defined clinically has not been examined before. METHODS: The study was conducted at four public and two academically affiliated private hospitals in Los Angeles; 671 patients who underwent coronary angiography between June 1, 1990 and September 30, 1991 and met explicit clinical criteria for coronary revascularization were included. The main outcome measure was the proportion of patients undergoing an indicated procedure within 12 months (ascertained by medical record review and confirmed with a telephone survey). Adjusted relative odds of undergoing an indicated procedure for African-Americans and patients in public hospitals compared with whites and patients in private hospitals were calculated. RESULTS: Overall, 75% of patients underwent a revascularization procedure. Of 424 patients requiring bypass surgery, 107 angioplasty and 140 either bypass surgery or angioplasty, 59%, 66% and 75% underwent the procedure, respectively. African-Americans were less likely than whites to undergo operation (adjusted odds ratio [OR] 0.49, p < 0.05) and angioplasty (adjusted OR 0.20, p < 0.05). Patients in public hospitals were less likely than those in private hospitals to undergo angioplasty (adjusted OR 0.10, p < 0.005). CONCLUSIONS: Underuse of coronary revascularization procedures is measurable and occurs to a significant degree even among insured patients attending private hospitals. Underuse is especially pronounced among African-Americans and patients attending public hospitals. Future cost-containment efforts must incorporate safeguards against underuse of necessary care.

A composite view of cardiac rupture in the United States National Registry of Myocardial Infarction.

OBJECTIVES: This study was done to determine the incidence, timing and prevalence as a cause of death from cardiac rupture in patients with acute myocardial infarction. BACKGROUND: Several clinical trials and overview analyses have suggested that the survival benefit conferred by thrombolytic therapy may be offset by a paradoxic increase in early deaths from cardiac rupture. METHODS: Demographic, procedural and outcome data from patients with acute myocardial infarction were collected at 1,073 United States hospitals collaborating in the United States National Registry of Myocardial Infarction. RESULTS: Among the 350,755 patients enrolled, 122,243 received thrombolytic therapy. In-hospital mortality for the overall patient population, those not treated with thrombolytics (n = 228,512) and those given thrombolytics were 10.4%, 12.9% and 5.9%, respectively (p<0.001). Cardiogenic shock was the most common cause of death in each patient group. Although the incidence of cardiac rupture was low (<1.0%), it was responsible for 7.3%, 6.1% and 12.1%, respectively, of in-hospital deaths (p<0.001). Death from rupture occurred earlier in patients given thrombolytic therapy, with a clustering of events within 24 h of drug administration. Despite the early risk, death rates were comparatively low in thrombolytic-treated patients on each of the first 30 days. By multivariable analysis, thrombolytics, prior myocardial infarction, advancing age, female gender and intravenous beta-blocker use were independently associated with cardiac rupture. CONCLUSIONS: This large registry experience, including over 350,000 patients with myocardial infarction, suggests that thrombolytic therapy accelerates cardiac rupture, typically to within 24 to 48 h of treatment. The possibility that rupture represents an early hemorrhagic complication of thrombolytic therapy should be investigated.

Influence of payor on use of invasive cardiac procedures and patient outcome after myocardial infarction in the United States. Participants in the National Registry of Myocardial Infarction.

OBJECTIVES: We sought to determine the influence of payor status on the use and appropriateness of cardiac procedures. BACKGROUND: The use of invasive procedures affects the cost of cardiovascular care and may be influenced by payor status. METHODS: We compared treatment and outcomes of myocardial infarction among four payor groups: fee for service (FFS), health maintenance organization (HMO), Medicaid and uninsured. Multivariate comparison was performed on the use of invasive cardiac procedures, length of hospital stay and in-hospital mortality in 17,600 patients <65 years old enrolled in the National Registry of Myocardial Infarction from June 1994 to October 1995. To determine the appropriateness of coronary angiography, we compared its use in patients at low and high risk for cardiac events. RESULTS: Angiography was performed in 86% of FFS, 80% of HMO, 61% of Medicaid and 75% of uninsured patients. FFS patients were more likely to undergo angiography than HMO (odds ratio [OR] 1.27, 95% confidence interval [CI] 1.13 to 1.42), Medicaid (OR 2.43, 95% CI 2.11 to 2.81) and uninsured patients (OR 1.99, 95% CI 1.76 to 2.25). Similar patterns for the use of coronary revascularization were found. Among those at low risk, FFS patients were as likely to undergo angiography as HMO patients but more likely than Medicaid and uninsured patients. For those at high risk, FFS patients were more likely to undergo angiography than patients in other payor groups. Adjusted mean length of stay (7.3 days) was similar among all payor groups, but adjusted mortality was higher in the Medicaid group (Medicaid vs. FFS: OR 1.55, 95% CI 1.19 to 2.01). CONCLUSIONS: Payor status is associated with the use and appropriateness of invasive cardiac procedures but not length of hospital stay after myocardial infarction. The higher in-hospital mortality in the Medicaid cohort merits further study.

Payer status and the utilization of hospital resources in acute myocardial infarction: a report from the National Registry of Myocardial Infarction 2.

BACKGROUND: Prior studies have suggested that payer status may be an important determinant of medical resource utilization and outcome in acute myocardial infarction (AMI). METHODS: A national cohort of 332,221 patients with AMI enrolled from June 1994 to July 1996 were compared within 5 payer groups to ascertain the influence of payer status on hospital resource allocation for AMI in the United States. RESULTS: Medicare comprised the largest proportion (56%), followed by commercial insurance (25%), health maintenance organization (HMO) (10%), uninsured (6%), and Medicaid (3%). Compared with commercially insured patients, Medicare and Medicaid patients received fewer reperfusion therapies, underwent fewer invasive cardiac procedures, and had longer hospitalizations. After adjusting for differences in clinical characteristics, Medicare recipients were as likely as commercially insured patients to receive acute reperfusion therapies or any invasive cardiac procedure. Uninsured and HMO patients tended to utilize hospital resources with intermediate frequency. Medicare recipients aged 65 years or older and the HMO group had similar hospital mortality rates compared with the commercial group (odds ratio [OR], 1.07; 95% confidence interval [CI], 0.96-1.20 and OR, 0.93; 95% CI, 0.83-1.04, respectively), but Medicaid and uninsured groups had higher hospital mortality rates compared with the commercial group (OR, 1.30; 95% CI, 1.14-1.48 and OR, 1.29; 95% CI, 1.12-1.48, respectively). CONCLUSION: This report suggests significant variation by payer status in the management of AMI throughout the United States, but no important differences in mortality among the 3 largest payer groups.

Observations of the treatment of women in the United States with myocardial infarction: a report from the National Registry of Myocardial Infarction-I.

BACKGROUND: To determine whether there are sex differences in the demographics, treatment, and outcome of patients with acute myocardial infarction in the United States, data from the National Registry of Myocardial Infarction-I from September 1990 to September 1994 were examined. METHODS: The National Registry of Myocardial Infarction-I is a national observational database consisting of 1234 US hospitals in which each hospital submits data from each patient with acute myocardial infarction to a central data collection center. For these analyses, the following variables were examined in 354 435 patients with acute myocardial infarction: demographics; use of medical therapy including thrombolytic agents; use of procedures including cardiac catheterization, percutaneous transluminal coronary angioplasty, and coronary artery bypass surgery; length of hospital stay; adverse events (stroke, major bleeding, or recurrent myocardial infarction); and causes of death. RESULTS: In comparison with men, women experiencing acute myocardial infarction in the United States are older, with 55.7% older than 70 years. Women have a higher mortality rate than men even when controlled for age and die less often from arrhythmia but more often from cardiac rupture whether or not thrombolytic therapy is used. Treatment with aspirin, heparin, or beta-blockers is less frequent in women. When thrombolytic therapy is used, women are treated an average of almost 14 minutes later than men and experience a greater incidence of major bleeding. Cardiac catheterization, percutaneous transluminal coronary angioplasty, and coronary artery bypass surgery are used less often in women. CONCLUSIONS: Observations from the National Registry of Myocardial Infarction-I document important sex differences in demographics, treatment, and outcome of patients with acute myocardial infarction in the United States.

Stress ventricular function test in conscious, nonthoracotomised dogs to assess cardiac drug efficacy.

The measurement of left ventricular (LV) function is frequently performed in unconscious or thoracotomised animals in the resting state; these conditions may seriously affect the basal haemodynamic state. To assess myocardial function in conscious animals, a technique was developed to place a catheter across the atrial septum into the left ventricle without a thoracotomy. A stress ventricular function test (SVFT) was performed by raising the systemic blood pressure with methoxamine in the conscious dog. In order to demonstrate the effectiveness of the SVFT in the detection of a decrease in ventricular function, a SVFT was performed before and after the acute infusion of verapamil to determine resting and reserve LV function. A slope relating systolic aortic pressure to the LV end-diastolic pressure was obtained in 10 dogs using a low dose (0.005) and in four dogs a high dose (0.01 microgram X kg-1 X min-1) verapamil (V). The mean slope before V was 3.6 +/- 1.2 and after 2.0 +/- 0.92 (p less than 0.001). The day-to-day variability of the SVFT was less than 22% (coefficient of variability). The SVFT is a sensitive, reproducible method to assess resting and increased or decreased myocardial contractility and is useful in selecting appropriate doses of cardiac drugs to determine their effect on the myocardium during acute and chronic infusion studies in the conscious, nonthoracotomised dog.

Verapamil induced ventricular hypertrophy in conscious dogs.

Verapamil is used clinically in the treatment of various cardiac diseases including hypertrophic cardiomyopathy. Its long term effects on ventricular mass are not well known. In 11 conscious dogs heart rate, aortic and left ventricular pressures, cardiac output, a methoxamine induced stress ventricular function test and left ventriculography were performed. These variables were measured prior to and following a mean 7.2 month infusion of verapamil at 0.005 or 0.01 mg.kg-1.min-1 using a subcutaneously implanted pump. Resting haemodynamic variables and left ventricular ejection fraction [60(SD 6) v 55(6)%] were unchanged between baseline and chronic verapamil studies, but the slope of the methoxamine induced stress ventricular function test decreased from 3.9(0.8) to 2.1 (1.3). After verapamil was discontinued the mean slope of the stress ventricular function test returned to the baseline 4.0(1.7). Total ventricular weight increased 22% from 176.1(17.5) g.m-2 in controls to 215.6(29.5) g.m-2 (p less than 0.01) in the verapamil animals. The right ventricular weight increased 25% from 46(5.9) to 57.6(9.1) g.m-2 (p less than 0.01); the septum weight increased 26% from 42.5(4.1) to 53.7(7.2) g.m-2 (p less than 0.001); and the left ventricular free wall weight increased 19% from 87.4(9.8) to 103.9(15.7) g.m-2 (p less than 0.01). The increase in ventricular weights was not due to fibrosis or oedema since hydroxyproline contents and wet/dry ratios were not increased. In conclusion, a chronic infusion of verapamil in conscious dogs caused no change in resting haemodynamic variables but produced reversible depression of stress ventricular function and biventricular and septal hypertrophy.

Underuse and overuse of diagnostic testing for coronary artery disease in patients presenting with new-onset chest pain.

PURPOSE: To determine the extent of overuse and underuse of diagnostic testing for coronary artery disease and whether the socioeconomic status, health insurance, gender, and race/ethnicity of a patient influences the use of diagnostic tests. SUBJECTS AND METHODS: We identified patients who presented with new-onset chest pain not due to myocardial infarction at one of five Los Angeles-area hospital emergency departments between October 1994 and April 1996. Explicit criteria for diagnostic testing were developed using the RAND/University of California, Los Angeles, expert panel method. They were applied to data collected by medical record review and patient questionnaire. RESULTS: Of the 356 patients, 181 met necessity criteria for diagnostic cardiac testing. Of these, 40 (22%) failed to receive necessary tests. Only 7 (3%) of the 215 patients who received some form of cardiac testing had tests that were judged to be inappropriate. Underuse was significantly more common in patients with only a high school education (30% vs 15% for those with some college, P = 0.02) and those without health insurance (34% vs 15% of insured patients, P = 0.01). In a multivariate logistic regression model, only the lack of a post-high school education was a significant predictor of underuse (odds ratio 2.2, 95% confidence interval 1.0 to 4.4). CONCLUSION: Among patients with new-onset chest pain, underuse of diagnostic testing for coronary artery disease was much more common than overuse. Underuse was primarily associated with lower levels of patient education.

Evaluation of valvular regurgitation by factor analysis of first-pass angiography.

We have evaluated left ventricular regurgitation by means of factor analysis of 99mTc first-pass radionuclide angiography (FPRNA) and time-activity curve deconvolution. The FPRNA regurgitant fraction (RF) was computed in 26 individuals: 13 patients (eight mitral, three aortic, and two mitral-aortic) and 13 controls. The reference method was contrast ventriculography (CV) performed within 1 hr after FPRNA. In 19 patients, CV was preceded by the determination of cardiac output, using indocyanine green dye (n = 16) or thermodilution technique (n = 3), to determine a catheterization regurgitant fraction (CATH-RF). Lung and left ventricular (LV) time-activity curves were gathered by factor analysis and the FPRNA regurgitant fraction assessed by a lagged normal deconvolution of these curves. In valvular regurgitation, the LV deconvolved curve demonstrates the appearance of a long transit time component that is amenable to quantification. The presence of regurgitation was determined by contrast ventriculography. With a 10% RF as an acceptable upper limit of normal for nonregurgitant patients, FPRNA yielded one false-negative and no false-positive studies (n = 26), while CATH-RF yielded two false-negative and four false-positive determinations (n = 19). The following are results of quantitative determination of RF (mean +/- s.d.): FPRNA 0.39 +/- 0.19 (n = 13 Valvular), 0.01 +/- 0.03 (n = 13 Controls); CATH 0.34 +/- 0.24 (n = 11 Valvular), 0.13 +/- 0.12 (n = eight controls). FPRNA was able to differentiate (p less than 0.001) between control patients (CV grading 0) and mild/moderate regurgitation (CV grading 1+ or 2+) and severe regurgitation (3+ or 4+) (p less than 0.025).

Simultaneous technetium-99m MIBI angiography and myocardial perfusion imaging.

Resting first-pass radionuclide angiography (FPRNA) was performed with the myocardial perfusion agent technetium-99m MIBI. In 27 patients, it was compared with technetium-99m diethylenetriamine pentaacetic acid FPRNA. A significant correlation was present in left (r = 0.93, p less than 0.001) as well as right (r = 0.92, p less than 0.001) ventricular ejection fraction measured with both radiopharmaceuticals. In 13 patients, MIBI derived segmental wall motion was compared with contrast ventriculography. A high correlation was present (p less than 0.001), and qualitative agreement was found in 38/52 segments. In 19 patients with myocardial infarction a significant correlation was present between MIBI segmental wall motion and perfusion scores (p less than 0.001). In ten patients with a history of myocardial infarction, 18 myocardial segments demonstrated diseased coronary vessels and impaired wall motion at contrast angiography. These segments were all identified by the MIBI wall motion and perfusion study. We conclude that MIBI is a promising agent for simultaneous evaluation of cardiac function and myocardial perfusion at rest.

Trends in acute myocardial infarction management: use of the National Registry ofMyocardial Infarction in quality improvement.

Cardiovascular disease, including acute myocardial infarction (AMI), is the leading cause of death in the United States and was the primary disease category among hospital discharges in 1996. Efforts to improve hospital care of patients with AMI should be measured and assessed routinely for appropriateness of care and improvement of medical staff performance. The National Registry of Myocardial Infarction (NRMI), an observational Phase IV study, has enrolled > 1 million AMI patients since 1990, and is now in its third phase. NRMI 3 collects patient data and facilitates the measurement of improvement in care and outcomes, while allowing participating institutions to benchmark their performance against national, state, and like-hospital data. Three measures from NRMI 3 are accepted for the Joint Commission on Accreditation of Healthcare Organizations' ORYX initiative: (1) aspirin use within 24 hours of AMI diagnosis; (2) door-to-drug time for fibrinolysis; and (3) no initial reperfusion strategy given to eligible patients.

Accuracy of left atrial and pulmonary artery wedge pressure in pure mitral regurgitation in predicting left ventricular end-diastolic pressure.

In most clinical conditions pulmonary artery (PA) wedge pressure accurately reflects left ventricular (LV) end-diastolic pressure. In the presence of mitral regurgitation (MR), large V waves can distort PA wedge pressure and result in incorrect estimation of LV end-diastolic pressure. In 52 patients with MR simultaneous measurement of PA wedge pressure or left atrial pressure and LV end-diastolic pressure was recorded. Twenty-one (40%) patients had large V waves (V wave greater than A wave by greater than 10 mm Hg, group 1), and 31 (60%) patients had small V waves (group 2). Group 1 had significantly higher V waves than group 2 (46 +/- 3 vs 21 +/- 2 mm Hg, p less than 0.001). The LV end-diastolic pressure was similar in both groups (21 +/- 2 vs 19 +/- 2 mm Hg, difference not significant). The mean PA wedge or left atrial pressure in group 1 (26 +/- 2 mm Hg) overestimated LV end-diastolic pressure (21 +/- 2 mm Hg) by 30% (p less than 0.01), but the trough of the X descent (20 +/- 2 mm Hg) was similar to the LV end-diastolic pressure. In group 2 patients with small V waves the mean PA wedge pressure was not significantly different from the LV end-diastolic pressure (16 +/- 2 vs 19 +/- 2 mm Hg, p = 0.06), but the trough of the X descent (13 +/- 2 mm Hg) underestimated LV end-diastolic pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular derived cardiac output.

Measurement of cardiac output (CO) requires right-sided cardiac catheterization. However, to save time and reduce costs, only left-sided cardiac catheterization is usually performed in most patients with suspected coronary artery disease. Thus, CO is not measured. To determine if CO can be measured from the left side of the heart, 24 patients undergoing cardiac catheterization had near-simultaneous determination of CO after indocyanine green dye was injected into the pulmonary artery and left ventricular (LV) cavity. There was close agreement between pulmonary artery and LV derived cardiac outputs (Pulmonary artery = 0.93 LV + 0.12). The pulmonary artery derived CO was 5.7 +/- 2.0 liters/min and the LV derived CO was 6.1 +/- 2.2 liter/min. Also, there was a close relation between pulmonary artery derived stroke volume (82 +/- 33 ml) and LV derived stroke volume (86 +/- 36 ml). Thus, CO can be accurately measured after injection of indocyanine green dye into the LV cavity.

Magnesium use in the treatment of acute myocardial infarction in the United States (observations from the Second National Registry of Myocardial Infarction).

The use of magnesium in patients with acute myocardial infarction (AMI) is debated, largely as a result of conflicting data from randomized controlled trials. This study evaluated the use and impact on mortality of intravenous magnesium in the treatment of patients with AMI in the United States based on data from the Second National Registry of Myocardial Infarction. Only 5.1% of 173,728 patients from 1,326 hospitals received intravenous magnesium within the first 24 hours after an AMI, and this was more common in the 59,798 patients who received thrombolytic therapy or who underwent primary percutaneous transluminal coronary angioplasty (PTCA) or coronary bypass grafting (CABG) than in the 113,930 patients who did not receive any reperfusion therapy (8.5% vs 3.4%, p <0.01). Magnesium use was associated with younger age, Q-wave AMI, congestive heart failure on admission, thrombolytic therapy, primary PTCA or CABG, ventricular tachycardia or ventricular fibrillation, and beta blocker or lidocaine use in the first 24 hours (all odds ratio > 1.2, p <0.001). Magnesium use was associated with increased mortality (odds ratio 1.25, 95% confidence interval 1.12 to 1.34) and with a higher mortality in patients without initial reperfusion therapy (20.2% vs 13.2%, p <0.0001) or who underwent primary PTCA or CABG (10.2% vs 7.3%, p = 0.002), but not in patients who received thrombolytic therapy (6.2% vs 5.9%, p = NS). Thus, magnesium is used infrequently in the treatment of AMI and may be associated with worse outcome.

Consultation before thrombolytic therapy in acute myocardial infarction. Second National Registry of Myocardial Infarction (NRMI 2) Investigators.

Among 57,398 thrombolytic recipients in the National Registry of Myocardial Infarction 2, consultation with another physician was sought in 64% before initiating lytic therapy, although presenting features were typical, rather than atypical, in most patients. Consultation significantly delayed the administration of lytic therapy and was associated with increased hospital mortality.