1/74. The electrocardiographic diagnosis of acute myocardial infarction in patients with ventricular paced rhythms.The electrocardiographic diagnosis of ischemic heart disease is more difficult in the setting of ventricular-paced rhythms (VPR). ST segment/T wave configurations are changed by the altered intraventricular conduction associated with ventricular pacing. The anticipated, or expected, morphology in patients with VPR is one of QRS complex-ST segment/T wave discordance. An awareness of the anticipated ST segment morphologies of VPR is mandatory for the emergency physician. This knowledge is not dependent on additional diagnostic testing, medical records, or expertise in pacemaker function. Two cases are presented in which an analysis of the electrocardiogram in the setting of VPR assisted the treating physicians in establishing the correct diagnosis of acute myocardial infarction and arranging for urgent revascularization.- - - - - - - - - - ranking = 1keywords = physician (Clic here for more details about this article) |
2/74. Arrhythmias in the coronary-care unit. I. Physiologic bases of ectopic beats.Ectopic beats appearing in the wake of an acute myocardial infarction are best explained with a fundamental knowledge of myocardial cellular electrophysiology. When the physician or nurse has knowledge of the electrical events of intracellular recordings then normal as well as abnormal states of automaticity and conductivity are better understood.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
3/74. Wide QRS complex tachycardia: ECG differential diagnosis.Wide QRS complex tachycardias (WCT) present significant diagnostic and therapeutic challenges to the emergency physician. WCT may represent a supraventricular tachycardia with aberrant ventricular conduction; alternatively, such a rhythm presentation may be caused by ventricular tachycardia. Other clinical syndromes may also demonstrate WCT, such as tricyclic antidepressant toxicity and hyperkalemia. Patient age and history may assist in rhythm diagnosis, especially when coupled with electrocardiographic (ECG) evidence. Numerous ECG features have been suggested as potential clues to origin of the WCT, including ventricular rate, frontal axis, QRS complex width, and QRS morphology, as well as the presence of other characteristics such as atrioventricular dissociation and fusion/capture beats. Differentiation between ventricular tachycardia and supraventricular tachycardia with aberrant conduction frequently is difficult despite this clinical and electrocardiographic information, particularly in the early stages of evaluation with an unstable patient. When the rhythm diagnosis is in question, resuscitative therapy should be directed toward ventricular tachycardia.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
4/74. cocaine induced myocardial infarction.The case of a 29 year old man who presented with chest pains after the use of cocaine is reported. The diagnosis of myocardial infarction was made on the electrocardiogram changes and lactate dehydrogenase profile. The diagnosis may be overlooked if there is no direct questioning about the use of drugs such as cocaine. diazepam has an important role in the management of cardiac complications after cocaine use and should be used early in management. The use of thrombolysis should be a joint decision between the emergency physician and cardiologist.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
5/74. Successful cricothyrotomy after thrombolytic therapy for acute myocardial infarction: a report of two cases.Cricothyrotomy is an emergency airway procedure that is generally performed after failure of primary methods for securing the airway. Coagulopathy has traditionally been considered a relative contraindication to cricothyrotomy, but there is little evidence in the literature to support this. There have been no reports of successful cricothyrotomy in a patient who had received systemic thrombolytic therapy. This report, from the National Emergency Airway Registry, is the first to describe successful cricothyrotomy in this context. We describe 2 patients who received thrombolytic therapy and then had cricothyrotomy performed after failure of other airway measures. The first patient was a 67-year-old man who developed severe pulmonary edema and respiratory failure less than 30 minutes after administration of tissue plasminogen activator using an accelerated regimen. Both intubation and attempts at ventilation using an esophageal/tracheal double-lumen airway (Combitube, Kendall-Sheridan, Argyle, NY) were unsuccessful, and the emergency physician then performed an uneventful cricothyrotomy using a vertical midline incision. There were no complications, and bleeding was minimal. The second patient was a 45-year-old man who developed severe angioedema with respiratory compromise after receiving streptokinase for acute myocardial infarction. intubation was impossible, and a cricothyrotomy was performed. Significant bleeding was controlled initially with packing and was semielectively explored later in the ICU with ligation of several small bleeding vessels. Prior administration of thrombolytic therapy does not preclude successful cricothyrotomy.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
6/74. tissue plasminogen activator in pediatric myocardial infarction.Children rarely present to emergency physicians during an acute myocardial infarction. However, this may occur in the setting of Kawasaki disease with thrombosed coronary aneurysms. We present the first case in which intravenous tissue plasminogen activator was used to successfully treat a 7-year-old child having an acute myocardial infarction caused by a thrombosed coronary aneurysm.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
7/74. Some hazards of invasive cardiology.Since the introduction of cardiac catheterization by Andre Cournand and Dickinson Richards, the valuable diagnostic and therapeutic device has encouraged many action-minded physicians to use cardiac catheterization to develop a new specialty, invasive cardiology. The data to be presented here derive from a catastrophe that occurred during an invasive treatment of a 54-year-old man who had experienced an ordinary myocardial infarction.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
8/74. Artifactual electrocardiographic change mimicking clinical abnormality on the ECG.Electrocardiographic artifact is a common finding in patients requiring evaluation and monitoring in the prehospital, emergency department, or intensive care unit settings. Artifact results from both internal (physiological) and external (nonphysiological) sources. In most instances, artifact is recognized as an incorrect electrocardiographic signal--its only impact producing interference in electrocardiogram interpretation; artifact may also produce electrocardiographic signals which mimick disease--these signals the physician must recognize as artifact.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
9/74. Dynamic left ventricular outflow tract obstruction: an unusual mechanism mimicking anterior myocardial infarction with cardiogenic shock.Cardiogenic shock is a frequent and threatening complication in the course of acute myocardial infarction. Besides the well known causes (left ventricular failure, acquired interventricular defect, papillary muscle rupture, free wall rupture) other less frequent mechanisms recognize a functional substrate. The recognition of such mechanisms makes us to revert to the treatments with completely different prognostic implications. In our Coronary Care Unit we encountered, in a period of 12 months, 4 patients who presented clinical, electrocardiographic and/or echographic signs and symptoms of acute myocardial infarction, with different degrees of heart failure up to cardiogenic shock. Only 1 patient showed a severe stenosis of the left anterior descending coronary artery and a significant creatine kinase reduction. Left ventriculography, performed at admission, was unable to disclose the true mechanism of clinical presentation. Only a thorough echographic examination disclosed the presence of a dynamic left ventricular outflow tract obstruction as the cause of heart failure culminating in cardiogenic shock. Once recognized, pathophysiological treatment (administration of beta-blockers and withdrawal of vasodilators, inotropic drugs and intra-aortic balloon pump) led to a dramatic improvement, with an almost complete left ventricular function recovery. Left ventricular outflow tract obstruction is a mechanism that can lead to severe heart failure as a complication of an acute myocardial infarction. Conversely such a mechanism can be precipitated by other causes (hypotension, hypovolemia, especially in hypertensive patients) and can mimic an acute myocardial infarction. Its incidence is not negligible: in our Coronary Care Unit it accounted for about 15% of all cases of myocardial infarction requiring inotropic support. An accurate echocardiographic examination is mandatory even after coronary angiography, and always permits the physician to select the appropriate therapy.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
10/74. Electrocardiographic ST-segment elevation: correct identification of acute myocardial infarction (AMI) and non-AMI syndromes by emergency physicians.OBJECTIVE: To determine the emergency physician's (EP's) ability to identify the cause of ST-segment elevation (STE) in a hypothetical chest pain patient. methods: Eleven electrocardiograms (ECGs) with STE were given to EPs; the patient in each instance was a 45-year-old male with a medical history of hypertension and diabetes mellitus with the chief complaint of chest pain. The EP was asked to determine the cause of the STE and, if due to acute myocardial infarction (AMI), to decide whether thrombolytic therapy (TT) would be administered (the patient had no contraindication to such treatment). Rates of TT administration were determined; appropriate TT administration was defined as that occurring in an AMI patient, while inappropriate TT administration was defined as that in the non-AMI patient. RESULTS: Four hundred fifty-eight EPs completed the questionnaire; levels of medical experience included the following: postgraduate year 2-3, 193 (42%); and attending, 265 (58%). The overall rate of correct interpretation of the study ECGs was 94.9% (4,782 correct interpretations out of 5,038 instances). Acute myocardial infarction with typical STE, ventricular paced rhythm, and right bundle branch block were never misinterpreted. The remaining conditions were misinterpreted with rates ranging between 9% (left bundle branch block, LBBB) and 72% (left ventricular aneurysm, LVA). The overall rate of appropriate thrombolytic agent administration was 83% (1,525 correct administrations out of 1,832 indicated administrations). The leading diagnosis for which thrombolytic agent was given inappropriately was LVA (28%), followed by benign early repolarization (23%), pericarditis (21%), and LBBB without electrocardiographic AMI (5%). Thrombolytic agent was appropriately given in all cases of AMI except when associated with atypical STE, where it was inappropriately withheld 67% of the time. CONCLUSIONS: In this survey, EPs were asked whether they would give TT based on limited information (ECG). Certain syndromes with STE were frequently misdiagnosed. Emergency physician electrocardiographic education must focus on the proper identification of these syndromes so that TT may be appropriately utilized.- - - - - - - - - - ranking = 3keywords = physician (Clic here for more details about this article) |
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