Electrocardiographic diagnosis of ST segment elevation myocardial infarction: An evaluation of three automated interpretation algorithms

To assess the validity of three different computerized electrocardiogram (ECG) interpretation algorithms in correctly identifying STEMI patients in the prehospital environment who require emergent cardiac intervention

What's the Risk? Older Women Report Fewer Symptoms for Suspected Acute Coronary Syndrome than Younger Women.

The purpose of the study was to determine whether older (≥65 years) and younger (<65 years) women presenting to the emergency department (ED) with symptoms suggestive of acute coronary syndrome (ACS) varied on risk factors, comorbid conditions, functional status, and symptoms that have implications for emergent cardiac care. Women admitted to five EDs were enrolled. The ACS Symptom Checklist was used to measure symptoms. Comorbid conditions and functional status were measured with the Charlson Comorbidity Index and Duke Activity Status Index. Logistic regression models were used to evaluate symptom differences in older and younger women adjusting for ACS diagnosis, functional status, body mass index (BMI), and comorbid conditions. Analyses were stratified by age, and interaction of symptom by age was tested. Four hundred women were enrolled. Mean age was 61.3 years (range 21-98). Older women (n = 163) were more likely to have hypertension, hypercholesterolemia, never smoked, lower BMI, more comorbid conditions, and lower functional status. Younger women (n = 237) were more likely to be members of minority groups, be college-educated, and have a non-ACS discharge diagnosis. Younger women had higher odds of experiencing chest discomfort, chest pain, chest pressure, shortness of breath, nausea, sweating, and palpitations. Lack of chest symptoms and shortness of breath (key symptoms triggering a decision to seek emergency care) may cause older women to delay seeking treatment, placing them at risk for poorer outcomes. Younger African American women may require more comprehensive risk reduction strategies and symptom management

Impact of comorbidities by age on symptom presentation for suspected acute coronary syndromes in the emergency department

It is estimated half of acute coronary syndrome (ACS) patients have one or more associated comorbid conditions

Optimizing Pre-hospital Electrocardiography to Improve the Early Diagnosis of Acute Coronary Syndrome

Myocardial ischemia is dynamic and unpredictable which, if not identified and treated promptly, can lead to devastating outcomes. Pre-hospital electrocardiography may facilitate early intervention by identifying patients with acute coronary syndrome (ACS) promptly. The goal of this dissertation research was to determine the prevalence and clinical significance of electrocardiographic (ECG) abnormalities of ischemia that occur in the pre-hospital setting in patients who contact `911' for chest pain and other anginal equivalent symptoms. While previous investigations have examined the impact of a snapshot 12-lead pre-hospital ECG (PH ECG), this study is the first to analyze ST-segment monitoring triggered 12-lead ECGs that have been acquired in the pre-hospital setting. The diagnostic and prognostic capabilities of PH ECG in the management of ACS have been examined and described. The first paper is a critical literature review of the scientific literature about pre-hospital electrocardiography. Several themes that emerged from the literature and form the bases of this paper include: clinical effects of PH ECG (timing, roles, effects on patient outcome and characteristics of patients with PH ECG), diagnostic performance, and prognostic/predictive value of PH ECG. The second paper is a secondary analysis of data from patients (n=620) who activated `911' for chest pain symptoms to determine the sensitivity and specificity of 12-lead ECG ST-segment monitoring in the pre-hospital period for diagnosing acute ACS. Both the PH ECG and the initial hospital ECG data for each patient were included in this study. The sensitivity of the ECG for diagnosing ACS was significantly improved when used in conjunction with the initial hospital ECG. The third paper is a secondary analysis of data from the same cohort as previously described above, but includes only the PH ECG data for each patient (n=630). The purpose of the study was to determine whether manifestations of acute myocardial ischemia on the PH ECG are predictive of adverse hospital outcomes. Patients with evidence of PH ECG ischemia had a significantly higher proportion of adverse hospital outcomes than those without PH ECG ischemia. Furthermore, PH ECG ischemia was found to be an independent predictor of adverse hospital outcomes

Normal prehospital electrocardiography is linked to long-term survival in patients presenting to the emergency department with symptoms of acute coronary syndrome

AIMS/METHODS: We studied 735 patients who activated “911” for chest pain and/or anginal equivalent symptoms and received 12-lead ECG monitoring with specialized ischemia monitoring software in the ambulance. Prehospital electrocardiograms (PH ECG) were analyzed to determine the proportion of patients who present with completely normal PH ECG findings (absence of ischemia/infarction, arrhythmia, or any other abnormality) and to compare outcomes amongst patients with and without any PH ECG abnormality. RESULTS: Of 735 patients (mean age 70.5, 52.4% male), 68 (9.3%) patients had completely normal PH ECG findings. They experienced significantly less adverse hospital outcomes (12% vs 37%), length of stay (1.19 vs 3.86 days), and long-term mortality (9% vs 28%) than those with any PH ECG abnormality (p<.05). CONCLUSION: Normal PH ECG findings are associated with better short and long-term outcomes in ambulance patients with ischemic symptoms. These findings may enhance early triage and risk stratification in emergency cardiac care

Electrocardiographic indicators of acute coronary syndrome are more common in patients with ambulance transport compared to those who self-transport to the emergency department journal of electrocardiology

INTRODUCTION: The American Heart Association recommends individuals with symptoms suggestive of acute coronary syndrome (ACS) activate the Emergency Medical Services’ (EMS) 911 system for ambulance transport to the emergency department (ED), which enables treatment to begin prior to hospital arrival. Despite this recommendation, the majority of patients with symptoms suspicious of ACS continue to self-transport to the ED. The IMMEDIATE AIM study was a prospective study that enrolled individuals who presented to the ED with ischemic symptoms. OBJECTIVES: The purpose of this secondary analysis was to determine differences in patients presenting the ED for possible ACS who arrive by ambulance versus self-transport on: 1) Time-to-initial hospital electrocardiogram (ECG), 2) presence of ischemic ECG changes, and 3) patient characteristics. METHODS: Initial 12-lead ECGs acquired upon patient arrival to the ED were evaluated for ST-elevation, ST-depression, and T-wave inversion. ECG signs of ischemia were analyzed both individually and collapsed into an independent dichotomous variable (ED ECG ischemia yes/no) for statistical analysis. Patient characteristics tested included: gender, age, race, ethnicity, English speaking, living alone, mode of transport, and presenting symptoms (chest pain, jaw pain, shortness of breath, nausea/vomiting, syncope, and clinical history). RESULTS: In 1299 patients (mean age 63.9, 46.7% male), 384 (29.6%) patients arrived by ambulance to the ED. The mean time-to-initial ECG was 47 minutes for ambulance patients versus 53 minutes for self-transport patients (p<0.001). Mode of transport was found to be an independent predictor for time-to-initial ECG controlling for age, gender, and race (p=0.004). There were significantly higher rates of ECG changes of ischemia for patients who arrived by ambulance versus self-transport (p=0.02), and patient characteristics differed by mode of transport to the ED. DISCUSSION: Our findings indicate that less than 30% of individuals with symptoms of ACS activate the EMS ‘911’ system for ambulance transport to the ED. Individuals more likely to activate 911 have timelier ECG but higher rates of ischemic changes, specifically ST-depression and T-wave inversion. Individuals least likely to activate 911 are women, younger individuals, Latino ethnicity, live with a significant other, and those experiencing chest or jaw pain

Arrhythmias in patients with acute coronary syndrome in the first 24 hours of&nbsp;hospitalization

ObjectivesIn patients with acute coronary syndrome (ACS), we sought to: 1) describe arrhythmias during hospitalization, 2) explore the association between arrhythmias and patient outcomes, and 3) explore predictors of the occurrence of arrhythmias.MethodsIn a prospective sub-study of the IMMEDIATE AIM study, we analyzed electrocardiographic (ECG) data from 278 patients with ACS. On emergency department admission, a Holter recorder was attached for continuous 12-lead ECG monitoring.ResultsApproximately 22% of patients had more than 50 premature ventricular contractions (PVCs) per hour. Non-sustained ventricular tachycardia (VT) occurred in 15% of patients. Very few patients (≤ 1%) had a malignant arrhythmia (sustained VT, asystole, torsade de pointes, or ventricular fibrillation). Only more than 50 PVCs/hour independently predicted an increased length of stay (p &lt; .0001). No arrhythmias predicted mortality. Age greater than 65 years and a final diagnosis of acute myocardial infarction independently predicted more than 50 PVCs per hour (p = .0004).ConclusionsPatients with ACS seem to have fewer serious arrhythmias today, which may have implications for the appropriate use of continuous ECG monitoring

A simple strategy improves prehospital electrocardiogram utilization and hospital treatment for patients with acute coronary syndrome (from the ST SMART Study).

Although the American Heart Association recommends a prehospital electrocardiogram (ECG) be recorded for all patients who access the emergency medical system with symptoms of acute coronary syndrome (ACS), widespread use of prehospital ECG has not been achieved in the United States. A 5-year prospective randomized clinical trial was conducted in a predominately rural county in northern California to test a simple strategy for acquiring and transmitting prehospital ECGs that involved minimal paramedic training and decision making. A 12-lead ECG was synthesized from 5 electrodes and continuous ST-segment monitoring was performed with ST-event ECGs automatically transmitted to the destination hospital emergency department. Patients randomized to the experimental group had their ECGs printed out in the emergency department with an audible voice alarm, whereas control patients had an ECG after hospital arrival, as was the standard of care in the county. The result was that nearly 3/4 (74%) of 4,219 patients with symptoms of ACS over the 4-year study enrollment period had a prehospital ECG. Mean time from 911 call to first ECG was 20 minutes in those with a prehospital ECG versus 79 minutes in those without a prehospital ECG (p &lt;0.0001). Mean paramedic scene time in patients with a prehospital ECG was just 2 minutes longer than in those without a prehospital ECG (95% confidence interval 1.2 to 3.6, p &lt;0.001). Patients with non-ST-elevation myocardial infarction or unstable angina pectoris had a faster time to first intravenous drug and there was a suggested trend for a faster door-to-balloon time and lower risk of mortality in patients with ST-elevation myocardial infarction. In conclusion, increased paramedic use of prehospital ECGs and decreased hospital treatment times for ACS are feasible with a simple approach tailored to characteristics of a local geographic region

The association between symptom onset characteristics and prehospital delay in women and men with acute coronary syndrome

BackgroundA decision to delay seeking treatment for symptoms of acute coronary syndrome increases the risk of serious complications, disability, and death.AimsThe purpose of this study was to determine if there was an association between gradual vs abrupt symptom onset and prehospital delay for patients with acute coronary syndrome and to examine the relationship between activities at symptom onset and gradual vs abrupt symptom onset.MethodsThis was a secondary analysis of a large prospective multi-center study. Altogether, 474 patients presenting to the emergency department with symptoms of acute coronary syndrome were included in the study. Symptom characteristics, activity at symptom onset, and prehospital delay were measured with the ACS Patient Questionnaire.ResultsMedian prehospital delay time was four hours. Being uninsured (β=0.120, p=0.031) and having a gradual onset of symptoms (β=0.138, p=0.003) were associated with longer delay. A diagnosis of ST-elevation myocardial infarction (β=-0.205, p=0.001) and arrival by ambulance (β=-0.317, p&lt;0.001) were associated with shorter delay. Delay times were shorter for patients who experienced an abrupt vs gradual symptom onset (2.57 h vs 8 h, p&lt;0.001). Among men with an abrupt onset of symptoms and a ST-elevation myocardial infarction diagnosis, 54% reported that symptoms were triggered by exertion (p=0.046).ConclusionPatients should be counselled that a gradual onset of symptoms for potential acute coronary syndrome is an emergency and that they should call 911. Men with ischemic heart disease or with multiple risk factors should be cautioned that symptom onset following exertion may represent acute coronary syndrome