Usefulness of the response to sublingual nitroglycerin as a predictor of ischemic chest pain in the emergency department

High-Risk Chief Complaints I: Chest Pain-The Big Three (an Update)

Nontraumatic chest pain is a frequent concern of emergency department patients, with causes that range from benign to immediately life threatening. Identifying those patients who require immediate/urgent intervention remains challenging and is a high-risk area for emergency medicine physicians where incorrect or delayed diagnosis may lead to significant morbidity and mortality. This article focuses on the 3 most prevalent diagnoses associated with adverse outcomes in patients presenting with nontraumatic chest pain, acute coronary syndrome, thoracic aortic dissection, and pulmonary embolism. Important aspects of clinical evaluation, diagnostic testing, treatment, and disposition and other less common causes of lethal chest pain are also discussed.

Chest Pain in Emergency Department Patients: If the Pain is Relieved by Nitroglycerin, is it More Likely to be Cardiac Chest Pain?

Introduction:

It is often believed that chest pain relieved by nitroglycerin is indicative of coronary artery disease origin.

Objective:

To determine if relief of chest pain with nitroglycerin can be used as a diagnostic test to help differentiate cardiac chest pain and non-cardiac chest pain.

Design:

Prospective observational cohort study with a 4-week follow-up of patients enrolled.

Setting:

Academic tertiary care hospital, with 60 000 visits/year.

Inclusion criteria:

Adult patients presenting to the emergency department with active chest pain who received nitroglycerin and were admitted for chest pain.

Exclusion criteria:

Patients with acute myocardial infarction diagnosed after obtaining an ECG, patients whose chest pain could not be quantified, those for whom no cardiac work-up was done, or those who received emergent cardiac catheterization.

Results:

270 patients were enrolled. Nitroglycerin relieved chest pain in 66% of the subjects. The diagnostic sensitivity of nitroglycerin to determine cardiac chest pain was 72% (64%–80%), and the specificity was 37% (34%–41%). The positive likelihood ratio for having coronary artery disease if nitroglycerin relieved chest pain was 1.1 (0.96–1.34). Telephone follow-up at 4 weeks was performed, with a 95% follow-up rate.

Conclusions:

Relief of chest pain with nitroglycerin is not a reliable diagnostic test and does not distinguish between cardiac and non-cardiac chest pain.

Nanovesicles system for rapid-onset sublingual delivery containing sodium tanshinone IIA sulfonate: in vitro and in vivo evaluation

A novel formulation based on nanovesicles system for rapid-onset sublingual delivery of hydrophilic drug (sodium tanshinone IIA sulfonate, STS) was investigated. The nanovesicles system was composed of 1.5% soybean lecithin, 6% propylene glycol, and penetration enhancers (1% sodium dodecyl sulfate and 0.03% hyaluronan acid). The STS-loaded nanovesicles with an average diameter of 133 ± 9.04 nm and high entrapment efficiency of 85.65 ± 3.89% were characterized. The effects of permeation enhancers on the penetration of STS formulations were investigated using Franz diffusion cells in vitro, showing 86.1-235.8 times higher permeation rate than that of normal STS solution. The rapid symptom relief effect of the nanovesicles system on acute myocardial infarction rabbits was evaluated by in vivo study, ST-segment deviation(S and T wave abnormality in electrocardiogram) was attenuated markedly and rapidly within 5 min, infarct size of heart was significantly reduced and the biochemical indicators were substantially decreased, compared with the control groups (p < 0.05). This study provided a promising tool for the future sublingual delivery of hydrophilic compounds with the noninvasive and rapid onset clinical effect.

[Chest pains in emergency admission. Diagnostics and treatment]

Thoracic pain is a common symptom in the emergency medicine setting and represents a diagnostic and therapeutic challenge. A multitude of differential diagnoses must be considered many of which are associated with a high mortality. Management of this situation is complicated by the fact that rapid and unexpectedly occurring and rapidly progressing deterioration are not uncommon in patients who initially did not appear to be seriously ill. Also for some underlying pathologies the physical examination can have an inconspicuous or"false negative" result and atypical presentations can give rise to false interpretations. The clinical and technical diagnostic methods, the implementation and interpretation including possible sources of error and limitations will be described in detail.

Testing of low-risk patients presenting to the emergency department with chest pain: a scientific statement from the American Heart Association

The management of low-risk patients presenting to emergency departments is a common and challenging clinical problem entailing 8 million emergency department visits annually. Although a majority of these patients do not have a life-threatening condition, the clinician must distinguish between those who require urgent treatment of a serious problem and those with more benign entities who do not require admission. Inadvertent discharge of patients with acute coronary syndrome from the emergency department is associated with increased mortality and liability, whereas inappropriate admission of patients without serious disease is neither indicated nor cost-effective. Clinical judgment and basic clinical tools (history, physical examination, and electrocardiogram) remain primary in meeting this challenge and affording early identification of low-risk patients with chest pain. Additionally, established and newer diagnostic methods have extended clinicians' diagnostic capacity in this setting. Low-risk patients presenting with chest pain are increasingly managed in chest pain units in which accelerated diagnostic protocols are performed, comprising serial electrocardiograms and cardiac injury markers to exclude acute coronary syndrome. Patients with negative findings usually complete the accelerated diagnostic protocol with a confirmatory test to exclude ischemia. This is typically an exercise treadmill test or a cardiac imaging study if the exercise treadmill test is not applicable. Rest myocardial perfusion imaging has assumed an important role in this setting. Computed tomography coronary angiography has also shown promise in this setting. A negative accelerated diagnostic protocol evaluation allows discharge, whereas patients with positive findings are admitted. This approach has been found to be safe, accurate, and cost-effective in low-risk patients presenting with chest pain.

Comparison of frequency of inducible myocardial ischemia in patients presenting to emergency department with typical versus atypical or nonanginal chest pain

The present study was designed to assess the value of the presenting symptom of "typical" anginal pain, "atypical/nonanginal" pain, or the lack of chest pain in predicting the presence of inducible myocardial ischemia using cardiac stress testing in emergency department patients being evaluated for possible acute coronary syndrome. We performed a retrospective observational study of adult patients who were evaluated for acute coronary syndrome in an emergency department chest pain unit. The presenting symptoms were obtained from a structured questionnaire administered before stress testing. Patient chest pain was categorized according to the presence of substernal chest pain or discomfort that was provoked by exertion or emotional stress and was relieved by rest and/or nitroglycerin. Chest pain was classified as "typical" angina if all 3 descriptors were present and "atypical" or "nonanginal" if <3 descriptors were present. All patients underwent serial biomarker and cardiac stress testing before discharge. A total of 2,525 patients met the eligibility criteria. Inducible ischemia on stress testing was found in 33 (14%, 95% confidence interval 10% to 19%) of the 231 patients who had typical anginal pain, 238 (11%, 95% confidence interval 10% to 13%) of the 2,140 patients presenting with atypical/nonanginal chest pain, and 25 (16%, 95% confidence interval 11% to 22%) of the 153 patients who had no complaint of chest pain on presentation. Compared to patients with atypical or no chest pain, patients with typical chest pain were not significantly more likely to have inducible ischemia on stress testing (likelihood ratio +1.25, 95% confidence interval 0.89 to 1.78). In conclusion, in our study, the patients who presented with "typical" angina were no more likely to have inducible myocardial ischemia on stress testing than patients with other presenting symptoms.

An algorithm for the diagnosis and management of chest pain in primary care

This article focuses on the key clinical and investigatory features that help differentiate the multiple causes of chest pain in adults in assessment of patients with undifferentiated chest pain in primary care using history, physical examination, and basic initial investigations. The initial treatment of many of the causes is discussed. Some treatments not only relieve symptoms but also provide further diagnostic information based on the response to treatment. Guidance for referral for specialist assessment and further investigations is provided, but the diagnostic usefulness of these measures is not discussed.

High-risk chief complaints I: chest pain--the big three

Chest pain is one of the most frequently seen chief complaints in patients presenting to emergency departments, and is considered to be a "high-risk" chief complaint. The differential diagnosis for chest pain is broad, and potential causes range from the benign to the immediately life-threatening. Although many (if not most) emergency department patients with chest pain do not have an immediately life-threatening condition, correct diagnoses can be difficult to make, incorrect diagnoses may lead to catastrophic therapies, and failure to make a timely diagnosis may contribute to significant morbidity and mortality. Several atraumatic "high-risk" causes of chest pain are discussed in this article, including myocardial infarction and ischemia, thoracic aortic dissection, and pulmonary embolism. Also included are brief discussions of tension pneumothorax, esophageal perforation, and cardiac tamponade.

Evaluation of the Elderly Patient with Acute Chest Pain

Chest pain is one of the most common and serious chief complaints. Geriatricians must be well versed in evaluating elderly patients who have chest pain. This article discusses the initial diagnostic evaluation of elderly patients with chest pain. Specific emphasis is placed on identifying acute coronary syndromes, aortic dissection, pulmonary embolism, and pericarditis with cardiac tamponade. By understanding the different presentations of these potentially life-threatening emergencies, the geriatrician will be better prepared to distinguish them from less dire conditions and to initiate prompt treatment.

Changes in the numeric descriptive scale for pain after sublingual nitroglycerin do not predict cardiac etiology of chest pain

STUDY OBJECTIVE

We determine whether the change in numeric descriptive scale for pain after sublingual nitroglycerin use can predict cardiac etiology of chest pain.

METHODS

A prospective study of a convenience sample of patients who had chest pain, presented to the emergency department from May 24, 2001, to April 30, 2002, and received sublingual nitroglycerin during their evaluation was performed. The 11-point numeric descriptive scale for chest pain was recorded before and after the initial dose of sublingual nitroglycerin. Cardiac-related pain was defined as chest pain in a patient with a discharge diagnosis of myocardial infarction or the diagnosis of coronary artery disease based on a positive diagnostic study (cardiac catheterization or noninvasive stress imaging). Change in the numeric descriptive scale was divided into 4 categories: (1) significant/complete reduction; (2) moderate reduction; (3) minimal reduction; and (4) no change.

RESULTS

The study cohort was composed of 664 patients: 345 women (52%) and 319 men (48%), mean age 52 years (+/-12.4 years). Cardiac-related chest pain was identified in 122 patients (18%). In the overall patient population, 125 (19%) patients had no change in pain, 206 (31%) patients had minimal reduction, 145 (22%) patients had moderate reduction, and 188 (28%) patients had significant or complete reduction in pain. There was no significant difference in any subgroup of numeric descriptive scale response to sublingual nitroglycerin administration in patients with and without a diagnosis of cardiac chest pain.

CONCLUSION

In this convenience sample, the response of chest pain to sublingual nitroglycerin was not a reliable indicator of a cardiac etiology.

Mitochondrial aldehyde dehydrogenase-2 (ALDH2) Glu504Lys polymorphism contributes to the variation in efficacy of sublingual nitroglycerin

Glyceryl trinitrate (GTN), also known as nitroglycerin, has been used to treat angina and heart failure for more than 130 years. Recently, it was shown that mitochondrial aldehyde dehydrogenase-2 (ALDH2) is responsible for formation of NO, the metabolite needed for GTN efficacy. In the present study, we show that the common G-to-A polymorphism in exon 12 of ALDH2--resulting in a Glu504Lys replacement that virtually eliminates ALDH2 activity in both heterozygotes and homozygotes--is associated with a lack of efficacy of sublingual GTN in Chinese subjects. We also show that the catalytic efficiency (Vmax/Km) of GTN metabolism of the Glu504 protein is approximately 10-fold higher than that of the Lys504 enzyme. We conclude that the presence of the Lys504 allele contributes in large part to the lack of an efficacious clinical response to nitroglycerin; we recommend that this genetic factor be considered when administering nitroglycerin to patients, especially Asians, 30-50% of whom possess the inactive ALDH2*2 mutant allele.

Chest pain from gastroesophageal reflux disease in patients with coronary artery disease

Management of patients with coronary artery disease is a major challenge for physicians, patients, and the healthcare system. Chest pain experienced by patients with coronary disease can be of noncardiac origin, and symptoms frequently related to gastroesophageal etiologies. The distal esophagus and the heart share a common afferent nerve supply, suggesting that location and radiation of perceived pain may be identical. In addition, there is substantial overlap between the prevalence of coronary disease and gastroesophageal reflux disease. Many physicians, including cardiologists, prescribe acid-reducing therapy to coronary patients. However, no prospective, randomized studies to date have evaluated the potential benefit of such treatments to prevent chest pain symptoms for these patients. We review the studies on noncardiac chest pain demonstrating reflux in patients with and without coronary disease. Also, the association of reflux with exertional chest pain and cardiac syndrome X is discussed. A rationale is presented for prevention of noncardiac chest pain in coronary patients, and the potential role of acid-suppressive therapy in managing these patients is discussed.