An Unusual Case of Alternating Ventricular Morphology on the 12-Lead Electrocardiogram.

BACKGROUND: One of the principal tasks of an emergency physician is identifying potentially life-threatening conditions in the undifferentiated patient; cardiac dysrhythmia is an example of such a condition. A systematic approach to a patient with atypical dysrhythmia enables proper identification of such-life threatening conditions. CASE REPORT: We describe a 31-year-old man presenting to the emergency department with an undifferentiated dysrhythmia after naloxone reversal of an opiate overdose. A systematic approach to the electrocardiogram led to the rare diagnosis of Wolff-Parkinson-White (WPW) alternans. We review the differential diagnosis of this dysrhythmia and the initial evaluation of a patient with the WPW pattern present on their electrocardiogram. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians should be prepared to use a systematic approach to an undifferentiated dysrhythmia to identify potentially life-threatening conditions.

Lateral canthotomy and cantholysis: emergency management of orbital compartment syndrome.

BACKGROUND: Orbital compartment syndrome is a sight-threatening emergency. Vision may be preserved when timely intervention is performed. OBJECTIVE: To present a case of orbital compartment syndrome caused by traumatic retrobulbar hemorrhage and the procedure of lateral canthotomy and cantholysis, reviewed with photographic illustration. DISCUSSION: Lateral canthotomy and cantholysis are readily performed at the bedside with simple instruments. The procedure may prevent irreversible blindness in cases of acute orbital compartment syndrome. CONCLUSIONS: Emergency physicians should be familiar with lateral canthotomy and cantholysis in the management of orbital compartment syndrome to minimize the chance of irreversible visual loss.

An interesting cause of wide complex tachycardia: Ashman's phenomenon in atrial fibrillation.

BACKGROUND: Ashman's phenomenon is an aberrant intraventricular conduction abnormality that occurs in response to a change in QRS cycle length. In atrial fibrillation, Ashman's phenomenon will present as a long RR cycle followed by a short RR cycle, with the subsequent QRS complex manifesting a right bundle branch block morphology. This morphologic variation can create difficulty with electrocardiographic interpretation, and can alter management in patients with this dysrhythmia. OBJECTIVES: This report presents a case, describes the Ashman's phenomenon in atrial fibrillation, and discusses interpretation of this electrocardiographic finding. CASE REPORT: This is a 27-year-old woman who presented with palpitations and chest pain. The patient was symptomatic with a heart rate >200 beats/min and a wide complex tachycardia on electrocardiogram. CONCLUSIONS: Ashman's phenomenon should be suspected in atrial fibrillation when there is a long cycle followed by a short cycle, with the subsequent QRS complex manifesting a right bundle branch block pattern. Emergency physician awareness of this phenomenon may improve diagnostic certainty and have an impact on dysrhythmia management.

Alternative treatments of pneumothorax.

BACKGROUND: Pneumothorax has traditionally been treated in the Emergency Department by tube thoracostomy. However, this is an invasive procedure with high risk of complication and prolonged hospitalization. DISCUSSION: In select settings, there are alternative forms of management of pneumothorax that carry lower risks and may reduce hospital stay. This article reviews the settings in which less invasive treatment, including observation alone, may be indicated. This article also reviews the techniques for simple aspiration and small-bore catheter insertion (by either Seldinger or catheter-over-wire technique) with Heimlich valve, as well as the indications, contraindications, and potential risks and benefits of each. CONCLUSIONS: The practices of observation, simple aspiration, and small-bore catheter insertion with Heimlich valve for selected patients may decrease complications, time, and costs by avoiding invasive procedures and hospital admissions.

Electrocardiographic electrode misplacement, misconnection, and artifact.

BACKGROUND: Electrocardiograms (ECGs) are performed by humans, and thus are subject to human error. An underappreciated source of electrocardiographic abnormality is electrode misconnection, both limb and precordial, and improper placement, which is principally an issue with the precordial electrodes due to anatomic variation. Patterns of abnormality exist; recognition allows the emergency physician to avoid mistaking the resulting electrocardiographic findings for true pathology. OBJECTIVES: The purpose of this clinical review is to describe the patterns of electrocardiographic electrode reversal, misplacement, and artifact and thus make them recognizable to the Emergency Physician. DISCUSSION: Common limb electrode reversals feature distinctive patterns manifesting as unexpected morphologic and frontal plane axis changes in the QRS complexes in the limb and augmented leads. Precordial electrode misplacement (improper positioning of the electrodes on the chest) is common and may mimic a pseudoinfarction pattern, or ST-segment/T-wave changes, which must be recognized as the result of the misplacement rather than true cardiac ischemia. Precordial electrode reversal should be suspected when the normal R/S wave amplitude transition is violated. Electrocardiographic artifact must be distinguished from dysrhythmia to avoid a potentially hazardous progression to unnecessary diagnostics and therapeutics. CONCLUSIONS: The hallmarks of electrode misconnection, misplacement, and electrocardiographic artifact can be easily mastered by the Emergency Physician; recognition of these findings can positively impact patient care by avoiding unnecessary intervention secondary to misattribution of findings on the 12-lead ECG to cardiac pathology.

Mandibular reduction.

Patients who dislocate their mandible often present to the Emergency Department for care. Dislocation can occur after a variety of activities that hyperextend the mandible or open the mouth widely, such as yawning, laughing, or taking a large bite. Anterior dislocation is the most common type, in which the condylar head of the mandible dislocates out of the glenoid fossa anterior to the articular eminence of the temporal bone. These dislocations are often complicated by muscle spasm and trismus, making reduction more difficult. The emergency physician can often reduce the anterior mandibular dislocation with or without procedural sedation or local anesthesia. A variety of methods are available for closed reduction, including the classic approach and various alternatives such as the recumbent, posterior, and ipsilateral approaches, as well as the wrist pivot method, alternative manual technique, and gag reflex induction. This article will review the pathophysiology and clinical presentation of acute mandibular dislocations, as well as discuss the various closed reduction methods available for the practitioner.

Evaluation and treatment of acute urinary retention.

Acute urinary retention is a common presentation to the Emergency Department and is often simply treated with placement of a Foley catheter. However, various cases will arise when this will not remedy the retention and more aggressive measures will be needed, particularly if emergent urological consultation is not available. This article will review the causes of urinary obstruction and systematically review emergent techniques and procedures used to treat this condition.

Temporary transvenous pacemaker placement in the Emergency Department.

Emergency Department placement of a temporary transvenous cardiac pacemaker offers potential life-saving benefits, as the device can definitively control heart rate, ensure effective myocardial contractility, and provide adequate cardiac output in select circumstances. The procedure begins with establishment of central venous access, usually by a right internal jugular or left subclavian vein approach, although the femoral vein is an acceptable alternative, especially in patients who are more likely to bleed should vascular access become complicated. The indications for the procedure, as well as the equipment needed, are reviewed. Both blind and ECG-guided techniques of insertion are described. Methods of verification of pacemaker placement and function are discussed, as are the early complications of the procedure.

Peripheral venous cutdown.

Timely establishment of vascular access is a critical component of the care of the acutely ill or injured patient. Peripheral venous cutdown, once a mainstay in the care of the severely traumatized patient, has progressively lost favor since the introduction of the Seldinger technique of central venous line placement. In fact, recent editions of the Advanced Trauma Life Support (ATLS) text refer to saphenous venous cutdown as an optional skill to be taught at the discretion of the instructor. In certain patients, percutaneous vascular access may be impossible to achieve or result in unacceptable time delays. In these situations, the ability to rapidly and proficiently perform peripheral venous cutdown techniques may prove invaluable and potentially lifesaving. This article reviews the anatomy of the most common sites used for peripheral venous cutdown, peripheral venous cutdown techniques, and the complications associated with peripheral venous cutdown.

Evaluation and treatment of patients with severely elevated blood pressure in academic emergency departments: a multicenter study.

STUDY OBJECTIVE: Current guidelines advise that emergency department (ED) patients with severely elevated blood pressure be evaluated for acute target organ damage, have their medical regimen adjusted, and be instructed to follow up promptly for reassessment. We examine factors associated with performance of recommended treatment of patients with severely elevated blood pressure. METHODS: Observational study performed during 1 week at 4 urban, academic EDs. Severely elevated blood pressure was defined as systolic blood pressure greater than or equal to 180 mm Hg or diastolic blood pressure greater than or equal to 110 mm Hg on at least 1 measurement. ED staff were blinded to the study purpose. Demographics, presenting complaints, vital signs, tests ordered, medications administered, disposition, and discharge instructions were recorded, and associations were tested in bivariate analyses. RESULTS: Severely elevated blood pressure was noted in 423 patients. Serum chemistry was obtained in 73% of patients, ECG in 53% of patients, chest radiograph in 46% of patients, urinalysis in 43% of patients, and funduscopy documented in 36% of patients. All studies were performed in 6% of patients and were associated with complaints of dyspnea (odds ratio [OR] 3.1; 95% confidence interval [CI] 1.1 to 8.7) and chest pain (OR 3.0; 95% CI 1.2 to 7.6). Oral antihypertensives were administered to 36% of patients and were associated with blood pressure-related complaints (OR 2.0 [1.2 to 3.3]), patient-suspected severely elevated blood pressure (OR 5.6, 95% CI 2.0 to 15.3), and being uninsured (OR 2.0; 95% CI 1.2 to 3.3). Intravenous antihypertensives were given to 4% of patients, associated only with chest pain (OR 3.2; 95% CI 1.1 to 9.5). Modification of antihypertensive regimen was documented in 19% of discharged patients and associated with patient-suspected severely elevated blood pressure (OR 5.5; 95% CI 2.5 to 12.2) and being uninsured (OR 1.8; 95% CI 1.1 to 2.9). CONCLUSION: The majority of ED patients with severely elevated blood pressure do not receive the evaluation, medical regimen modification, and discharge instructions advised by current guidelines. Further study is necessary to determine whether these recommendations are appropriate in this setting.

Electrode misconnection, misplacement, and artifact.

This article includes a discussion of limb electrode misconnection,precordial electrode misconnection and misplacement, and electro-cardiographic artifact.

ECG patterns confounding the ECG diagnosis of acute coronary syndrome: left bundle branch block, right ventricular paced rhythms, and left ventricular hypertrophy.

The ECG has limitations in the evaluation of the chest-pain patient, including the presence of confounding ECG patterns; the ECG patterns that confound the diagnosis of acute myocardial infarction(AMI) include left bundle branch block (LBBB), ventricular paced rhythms (VPR), and left ventricular hypertrophy (LVH). These patterns produce new ST-segment/T-wave abnormalities, which are the new normal findings in these patients and may lead the clinician astray in two distinct instances: (1) diagnosing ECG change related to acute coronary syndromes (ACS) when the abnormality results solely from the confounding pattern; and (2) not acknowledging the confounding nature of these ECG patterns in the evaluation of potential ACS, thereby placing excessive diagnostic confidence in the ECG. This article highlights the diagnostic dilemma encountered in these confounding ECG patterns; the discussion focuses on the expected ECG abnormalities in these patients and the findings seen in ACS.

Elevated blood pressure in urban emergency department patients.

OBJECTIVES: There has been little systematic study of emergency department (ED) patients with elevated blood pressure (BP) values. The authors sought to characterize ED patients with elevated BP values, assess presenting symptoms, and determine the prevalence of elevated BP after discharge. METHODS: This was a cross-sectional study performed in four academic EDs. Adults presenting with systolic BP >or=140 mm Hg or diastolic BP >or=90 mm Hg were enrolled over a one-week equivalent period. Demographics, medical history, and symptoms were obtained by chart abstraction and structured interview. A random patient subset underwent a three-week follow-up interview. BP measurements were staged, using Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-VI) criteria, according to the greatest value noted in the ED. RESULTS: A total of 1,396 patients were enrolled. Stage 1 BP values were noted in 44.3%, stage 2 in 25.3%, and stage 3 in 30.3%. African American patients more frequently had stage 2 and 3 BP values than other ethnic groups. BP measurements were repeated in 61.1% of patients and were the same or greater in 51.3% of patients. Dyspnea was associated with greater BP values. Among the 63.9% of patients who were interviewed, 52.7% were not being treated for hypertension, and 42.1% of those with hypertension had recently missed a medication dose. Follow-up was obtained in 74.7% of those targeted. A visit to a medical practitioner since discharge was reported by 63.2%; of these, 26.1% reported that their BP remained elevated. CONCLUSIONS: Elevated BP is common among ED patients. African American patients are more likely than those of other ethnic groups to have greater BP values. The ED visit may be a good opportunity to identify patients with unrecognized or poorly controlled hypertension.

Lack of relationship between hypertension-associated symptoms and blood pressure in hypertensive ED patients.

A number of cardiopulmonary and neurological symptoms are presumed to be associated with hypertension. We examined the prevalence of these symptoms in ED patients with elevated blood pressure (BP) and studied the relationship between symptom prevalence and BP value. We enrolled consecutive adult ED patients with sustained BP elevation (systolic BP>or=140 mm Hg, diastolic BP>or=90 mm Hg). BP values were categorized according to Joint National Committee on Prevention, Evaluation, and Treatment of High Blood Pressure, 6th Report criteria. Elevated BP was noted in 551 (29%) of 1908 patients. Unprompted complaints of hypertension-associated symptoms were noted in 26%, and there was no association between BP category and complaints other than dyspnea. Symptom interviews were conducted in 294 (56%) patients; 68% of this subset noted >or=1 current hypertension-associated symptom with no relationship between symptom prevalence and BP category. We conclude that symptoms putatively associated with hypertension are common among ED patients with elevated BP, and their prevalence appears unrelated to BP value.

Electrocardiographic manifestations: long QT Syndrome.

Long QT Syndrome is a cardiac disorder caused by an abnormal prolongation of the ventricular repolarization phase. The primary concern in this syndrome is the propensity towards polymorphic ventricular tachycardia and sudden cardiac death. This article presents several cases, highlighting the pathophysiology, clinical presentation, and management of this disorder.

Anterior shoulder dislocations: beyond traction-countertraction.

The shoulder is the most commonly dislocated large joint presenting to American Emergency Departments (ED). Anterior dislocations account for the great majority of these dislocations. Most anterior shoulder dislocations can be reduced in the ED using a variety of reduction techniques. The traction-countertraction technique is quite familiar to most Emergency Physicians, however, many other effective methods of reduction have been described. No method has proven 100% successful, and occasionally multiple attempts using different techniques are required to effect reduction. This article reviews some of the other techniques used to reduce anterior shoulder dislocations, variations reported on these techniques, and their success rates, advantages, and disadvantages.

Electrocardiographic manifestations: electrolyte abnormalities.

Because myocyte depolarization and repolarization depend on intra- and extracellular shifts in ion gradients, abnormal serum electrolyte levels can have profound effects on cardiac conduction and the electrocardiogram (EKG). Changes in extracellular potassium, calcium, and magnesium levels can change myocyte membrane potential gradients and alter the cardiac action potential. These changes can result in incidental findings on the 12-lead EKG or precipitate potentially life-threatening dysrhythmias. We will review the major electrocardiographic findings associated with abnormalities of the major cationic contributors to cardiac conduction-potassium, calcium and magnesium.

Electrocardiographic manifestations: acute inferior wall myocardial infarction.

The 12-lead electrocardiogram (EKG) is an important tool in evaluating the patient with acute myocardial infarction (MI). Patients with acute inferior wall myocardial infarction (IWMI) represent a heterogeneous group in terms of morbidity, mortality, Emergency Department (ED) management, and site of occlusion in the culprit coronary artery. The standard 12-lead EKG, right-sided chest leads and posterior chest leads, in conjunction with clinical findings often provide the necessary information for the Emergency Physician (EP) to predict complications, morbidity and mortality. IWMI patients may have associated right ventricular infarction (RVI) or lateral and posterior wall extension. Each of these entities is associated with specific hemodynamic abnormalities and increased mortality. In addition, various atrioventricular (AV) blocks are commonly associated with IWMI. This article presents several cases of IWMI with EKGs and a discussion of EKG interpretation in the setting of IWMI.