The stability of the ST segment estimation of myocardial area at risk between the prehospital and hospital electrocardiograms in patients with ST elevation myocardial infarction.

PURPOSE: Several ST segment deviation scores have been developed to estimate the myocardial area at risk (AAR) during acute myocardial infarction (AMI), which can be used to measure the effectiveness of reperfusion therapy. The purpose of this study was to assess whether one of these ST segment deviation scores (the Aldrich score) is sufficiently stable between the electrocardiogram (ECG) recorded in the ambulance (ECG 1) and the ECG recorded at the time of admission to the hospital (ECG 2) to be used as a baseline estimation of the AAR. METHODS: The Aldrich scores were compared between ECG 1 and ECG 2 in 77 patients who met the criteria for ST elevation myocardial infarction. The ECGs had a time interval of at least 5 minutes and were recorded before reperfusion therapy. Sufficiently stable was defined as 95% of the patients did not show a temporal change of the Aldrich score of more than 4.5%. RESULTS: The mean time interval between ECG 1 and ECG 2 was 20 ± 9 minutes. Forty-three percent of the total study population showed an "unstable Aldrich score" between ECG 1 and ECG 2. Fifty-seven percent showed a "stable Aldrich score", which means that the 95% standard for sufficiently stable was not fulfilled. By dividing the population based on infarct location, the group with inferior AMI (n = 43) showed more stability (67%) than the group with anterior AMI (n = 34) (44%) (P < .05). However, this remains less than the 95% stability standard. CONCLUSION: For both inferior and anterior AMI locations, the Aldrich score was not sufficiently stable to be used as a reliable baseline estimation of the AAR in AMI.

Paramedics as decision makers on the activation of the catheterization laboratory in the presence of acute ST-elevation myocardial infarction.

MATERIALS AND METHODS: To minimize delays in time to reperfusion in an urban-suburban North Carolina County, Guilford County Emergency Medical Services (EMS) and Moses Cone Hospital, Greensboro, NC, have collaborated to use the acquisition of 12-lead electrocardiographs and their paramedic interpretation to initiate the catheterization laboratory team and cardiologist; independent of over read by a physician. The study population of 91 patients was divided into the catheterization laboratory activation by EMS and catheterization laboratory activation by the emergency department physician (ED-MD) groups, and also by EMS and self-transported groups. RESULTS: The EMS group had shorter median time intervals from hospital door to percutaneous coronary intervention (PCI) with balloon inflation than those patients who self-transported to the hospital. Also, patients who were treated during the EMS activation of the catheterization laboratory phase had shorter median hospital door to PCI times than those who were treated during ED-MD activation of the catheterization laboratory. CONCLUSION: The time from hospital arrival to PCI with balloon inflation was significantly shorter during the period in which EMS activated the catheterization laboratory than during the period the laboratory was activated by hospital staff. Thus, paramedics with quality electrocardiogram interpretation training and education can identify patients with acute ST-elevation myocardial infarction and properly activate the catheterization laboratory.

Overcoming barriers to developing seamless ST-segment elevation myocardial infarction care systems in the United States: recommendations from a comprehensive Prehospital 12-lead Electrocardiogram Working Group.

BACKGROUND: Reducing time to reperfusion treatment for patients with ST-segment elevation myocardial infarction (STEMI) improves patient outcomes. Few medical systems consistently meet current benchmarks regarding timely access to treatment. Studies have widely demonstrated that prehospital 12-lead electrocardiography can facilitate early catheterization laboratory activation and is the most effective means of decreasing patients' time to treatment. METHODS: We gathered experts to examine the barriers to implementation of prehospital 12-lead electrocardiographic monitoring and transmission to in-hospital cardiologists in creating seamless STEMI care systems (STEMI-CS) and propose multidisciplinary approaches to overcoming these barriers. RESULTS AND CONCLUSIONS: Physicians, hospital systems, and emergency medical services often lack coordination of care delivery and receive fragmented funding and oversight. Clinical and regulatory guidelines do not emphasize local solutions to achieving clinical benchmarks, do not target incentives at all components of the STEMI-CS, and underemphasize risk-based approaches to protecting patient health. Integration of the multiple complex components involved in STEMI-CS is essential to improving care delivery.

Effectiveness of prehospital wireless transmission of electrocardiograms to a cardiologist via hand-held device for patients with acute myocardial infarction (from the Timely Intervention in Myocardial Emergency, NorthEast Experience [TIME-NE]).

Percutaneous coronary intervention for patients with ST-segment elevation myocardial infarction (STEMI) decreases morbidity and mortality if performed within the first 2 hours of symptom onset. However, the American College of Cardiology/American Heart Association guideline for percutaneous coronary intervention door-to-balloon time (<90 minutes) in patients with STEMI is a infrequently accomplished goal. This study enrolled 277 patients with STEMI who were self-transported or transported by emergency medical services to NorthEast Medical Center for primary percutaneous coronary intervention. This study tested the hypothesis that prehospital wireless transmission of an electrocardiogram to a cardiologist's hand-held device results in shorter emergency department door-to-reperfusion time. A comparison was made between patients whose electrocardiogram was successfully transmitted during the intervention phase with (1) patients transported by the emergency medical services in the preintervention, (2) patients self-transported in the intervention phase, and (3) patients whose wireless transmission failed in the intervention phase. During the preintervention phase (2001 to 2003), 48 patients were enrolled. During the intervention phase (2003 to 2005), the following patients were enrolled: 101 self-transported patients, 24 patients with successful electrocardiographic transmission, and 19 patients for whom transmission failed. The median door-to-reperfusion time for patients with successful electrocardiographic transmission was 50 minutes, which was significantly shorter than a preintervention time of 101 minutes (p <0.0001), an intervention phase self-transport time of 96 minutes (p <0.0001), and a failed transmission time of 78 minutes (p <0.0001). In conclusion, prehospital wireless electrocardiographic transmission to a cardiologist's hand-held device significantly decreased emergency department door-to-reperfusion time, thus achieving the American College of Cardiology/American Heart Association guideline for patients with STEMI.

Effectiveness of prehospital continuous positive airway pressure in the management of acute pulmonary edema.

OBJECTIVE: To compare the effectiveness of continuous positive airway pressure (CPAP) with standard pharmacologic treatment in the management of prehospital acute pulmonary edema. METHODS: Using a nonrandomized control group design, all consecutive patients presenting to two participating emergency medical services (EMS) systems with a field impression of acute pulmonary edema between July 1, 2004, and June 30, 2005, were included in the study. The control EMS system patients received standard treatment with oxygen, nitrates, furosemide, morphine, and, if indicated, endotracheal intubation. The intervention EMS system patients received CPAP via face mask at 10 cm H2O in addition to standard therapy. RESULTS: Ninety-five patients received standard therapy, and 120 patients received CPAP and standard therapy. Intubation was required in 8.9% of CPAP-treated patients compared with 25.3% in the control group (p = 0.003), and mortality was lower in the CPAP group than in the control group (5.4% vs. 23.2%; p = 0.000). When compared with the control group, the CPAP group had more improvement in respiratory rate (-4.55 vs. -1.81; p = 0.001), pulse rate (-4.77 vs. 0.82; p = 0.013), and dyspnea score (-2.11 vs. -1.36; p = 0.008). Using logistic regression to control for potential confounders, patients receiving standard treatment were more likely to be intubated (odds ratio, 4.04; 95% confidence interval, 1.64 to 9.95) and more likely to die (odds ratio, 7.48; 95% confidence interval, 1.96 to 28.54) than those receiving standard therapy and CPAP. CONCLUSION: The prehospital use of CPAP is feasible, may avert the need for endotracheal intubation, and may reduce short-term mortality.

The failure of years of experience with electrocardiographic transmission from paramedics to the hospital emergency department to reduce the delay from door to primary coronary intervention below the 90-minute threshold during acute myocardial infarction.

INTRODUCTION: Emergency medical services (EMS), hospital emergency departments, and cardiologists have taken steps to reduce time to reperfusion therapy by implementation of aggressive acute myocardial infarction treatment and triage protocols. Data indicate that significant myocardial salvage requires reperfusion within 2 hours, and the current American College of Cardiology guideline is 90 minutes after hospital emergency department admission. MATERIALS AND METHODS: To minimize delays in time to reperfusion in an urban-rural North Carolina County, Guilford County EMS and the Moses Cone Hospital have collaborated to implement transmission of EMS electrocardiographs (ECGs) to the emergency department. The study population included 92 patients who were transported by EMS and received primary coronary intervention during the second, third, and fourth years after initiation of this intervention in 1993. RESULTS: The median time from symptom onset to the initial ECG was 77 minutes. There was an additional 23 minutes between the availability of this ECG and the arrival of the patient at the emergency department. In the first year of the intervention, the time from hospital arrival to percutaneous coronary intervention was 80 minutes. In years 2 through 4, they were 93, 85, and 94 minutes, respectively. In 2003, 10 years after the intervention, the time from hospital arrival to percutaneous coronary intervention was 113 minutes. CONCLUSION: Initial gains in the time from hospital arrival to percutaneous coronary intervention, attributed to acquisition of the ECG in the prehospital setting, were not sustained over 10 years.