Prehospital triage of acute myocardial infarction: wireless transmission of electrocardiograms to the on-call cardiologist via a handheld computer

Application of Telemedicine System to Prehospital Medical Control

Objectives

Although ambulance-based telemedicine has been reported to be safe and feasible, its clinical usefulness has not been well documented, and different prehospital management systems would yield different results. The authors evaluated the feasibility and usefulness of telemedicine-assisted direct medical control in the Korean emergency medical service system.

Methods

Twenty ambulances in the Busan area were equipped with a telemedicine system. Three-lead electrocardiogram, blood pressure, and pulse oximetry data from the patient and audiovisual input from the scene were transferred to a server. Consulting physicians used desktop computers and the internet to connect to the server. Both requesting emergency medical service (EMS) providers and consulting physicians were asked to fill out report forms and submit them for analysis.

Results

In the 41 cases in which telemedicine equipment was used, cellular phones were concomitantly used in 28 cases (68.35%) to compensate for the poor audio quality provided by the equipment. The EMS providers rated the video transmission quality with a 4-point average score (interquartile range [IQR] 2-5) on a 5-point scale, and they rated the biosignal transmission quality as 4 (IQR 3-5). The consulting physicians rated the video quality as 4 (IQR 2.5-4) and the biosignal quality as 4 (IQR 3-4). The physicians' ratings for usefulness for making diagnosis or treatment decisions did not differ significantly in relation to the method of communication used.

Conclusions

Our study did not find any significant advantage of implementing telemedicine over the use of voice calls in delivering on-line medical control. More user-friendly, smaller devices with clear advantages over voice communication would be required before telemedicine can be successfully implemented in prehospital patient care.

Interpretation of electrocardiogram images sent through the mobile phone multimedia messaging service

OBJECTIVE

In this study, the diagnostic accuracy of interpretations of electrocardiogram (ECG) images taken by a mobile phone and sent as multimedia message was investigated.

MATERIALS AND METHODS

The ECGs of 305 patients who were admitted to the emergency department with cardiac complaints were photographed with the camera of a Nokia (Espoo, Finland) N93 mobile phone. The images were sent via a multimedia messaging system to an identical mobile phone carried by a cardiologist and were interpreted on the screen of that mobile phone. Another cardiologist and an emergency physician interpreted ECG paper printouts separately. The findings of the core laboratory were used as the gold standard. The interpretation errors were scaled from 1 to 4 with respect to the significance of findings.

RESULTS

The total ratio of Grade 4 errors, which consisted of significant errors, did not show any significant difference (p=0.76) between the interpretations by the emergency medicine specialist and the cardiologist who interpreted the ECGs on the mobile phone; the cardiologist who interpreted the ECG paper printouts made significantly fewer mistakes than the other two specialists (p=0.025 and p=0.023, respectively). The separate assessment of the findings showed that in the diagnostic process of ST-segment elevation, depression, and supraventricular tachycardia, the consistency of the interpretations (κ=0.81, κ=0.81, and κ=1.0, respectively) made on the mobile phone screen was slightly better than that of the emergency medicine specialist (κ=0.73, κ=0.77, and κ=0.80, respectively) and was similar to that of the cardiologist (κ=0.91, κ=0.91, and κ=1.0, respectively) who interpreted ECG paper printouts.

CONCLUSIONS

Our findings suggest that sending the ECG images via a multimedia message service may be a practical and inexpensive telecardiology procedure.

Transtelephonic electrocardiography for managing out-of-hospital chest pain emergencies

BACKGROUND

Some healthcare facilities lack professionals qualified to interpret electrocardiograms. We aimed to assess the usefulness of transtelephonic electrocardiography in combination with patients' clinical histories in the diagnosis and management of patients with acute chest pain in out-of-hospital healthcare facilities with personnel without expertise in cardiology or electrocardiography.

METHODS

Data from 506 consecutive patients (53.9 ± 16.2 years old) referred from 55 healthcare facilities without professionals specialized in cardiology or electrocardiography form the basis of analysis. Patients were classified into 2 groups according to the results of transtelephonic electrocardiography: (A) patients without electrocardiographic abnormalities (n = 445) and (B) patients who presented abnormalities suggesting a cardiac origin (n = 61) of the chest pain. The presence of risk factors was evaluated by multivariate analysis.

RESULTS

The following risk factors were independent predictors of electrocardiographic abnormalities: male gender (P = .006), diabetes mellitus (P = .0001), and dyslipidemia (P = .001). The multivariate analysis yielded a high degree of specificity (99.6%). Follow-up visits confirmed the noncardiac origin of pain in 432 patients (97%) in group A and the cardiac origin of pain in 59 patients (97%) in group B.

CONCLUSIONS

Transtelephonic electrocardiography combined with awareness of the risk factors of patients presenting with chest pain is useful for the diagnostic management of these patients in health care facilities without the means to interpret electrocardiograms.

Hospital-based strategies contributing to percutaneous coronary intervention time reduction in the patient with ST-segment elevation myocardiaI infarction: a review of the "system-of-care" approach

A myriad of hospital-wide initiatives have been implemented with the goal of decreasing door-to-balloon time. Much of the evidence behind the common strategies used is unknown; multiple strategies have been suggested in the reduction to the use of this important time-sensitive intervention. Among 8 primary strategies, 2 have substantial evidence to support their implementation in the attempt to reduce door-to-balloon time in ST-segment elevation myocardial infarction (STEMI), including emergency physician activation of the cardiac catheterization laboratory and prehospital activation of the STEMI alert process. Two strategies have moderate evidence to support their use, including real-time data feedback to team members and team-based approach to STEMI management. The remaining 4 strategies have no quantitative evidence to support their use, including single call to a central paging system, expecting the cardiac catheterization laboratory personnel to arrive within 20 minutes of activation, attending cardiologist on site (within the hospital), and senior management commitment to the project. Although all the STEMI systems of care reviewed are associated with a decreased in time to treatment, only a few have sufficient quantitative evidence to support their implementation. To be effective, the movement to decrease time to treatment of STEMI at any hospital must be composed of an institutional response that includes multiple disciplines. Success also requires active participation from nurses, members of the catheterization team, and hospital leadership.

An overview of recent health care support systems for eEmergency and mHealth applications

Advances in mobile communications and medical technologies facilitate the development of emerging mobile systems and applications for healthcare. The objective of this paper is to provide an overview and the current status of mobile health care systems (mHealth) and their applications for Emergency healthcare support (eEmergency). Our paper reports on journal papers that use wireless, emergency telemedicine systems that appeared since 2000. The majority of the applications are focused on the transmission of crucial biosignals (mainly ECG) for the support of heart-related healthcare. A limited number of new studies were focused on supporting emergency healthcare for trauma by facilitating both 2D image or video transmission (eg: ultrasound). Alternatively, new studies have focused on integrated systems for specialized emergency scenaria such as stroke. This paper is an extension of work previously published by our group [1].

Time to reperfusion in acute myocardial infarction. It is time to reduce it!

BACKGROUND AND OBJECTIVES

Mortality from ST-segment elevation myocardial infarction remains high, with most deaths occurring before hospital admission. Despite effective pre- and in-hospital reperfusion strategies becoming standard over the past 2 decades, time-to-admission and time-to-treatment remain prolonged. We reviewed temporal trends in these times in published clinical trials.

METHODS

All major randomized clinical trials reporting on reperfusion strategies for acute myocardial infarction published between 1993 and 2003 were evaluated. Strategies included pre- and in-hospital thrombolysis, primary percutaneous coronary intervention (pPCI) with or without transfer, and "facilitated" PCI. We generated overall estimates of time-to-admission, time-to-treatment, door-to-balloon (DTB), and door-to-needle (DTN) times and evaluated temporal trends in the length of time-to-admission and time-to-treatment.

RESULTS

In studies that evaluated only in-hospital thrombolysis, the time-to-admission was 149 +/- 45 minutes; the mean time-to-treatment was 181 +/- 29 minutes. In studies that considered only in-hospital pPCI (without transfer), the mean time-to-admission was 153 +/- 41 minutes; the mean time-to-treatment was 234 +/- 43 minutes. In studies that compared in-hospital pPCI with in-hospital thrombolytic therapy, the mean time-to-admission was 155 +/- 47 and 150 +/- 48 minutes, respectively. The DTN time was 65 +/- 10 minutes, whereas DTB time was 81 +/- 39 minutes. In other trials evaluating in-hospital thrombolysis and pPCI with transfer to a referral center, the time-to-admission in subjects treated with thrombolysis (n = 1345) was 127 +/- 32 minutes vs 131 +/- 36 minutes for pPCI (n = 1528). For in-hospital thrombolysis, time-to-treatment was 151 +/- 23 minutes vs 203 +/- 15 minutes for pPCI patients with transfer. The DTN time in the thrombolysis group was 44 +/- 28 minutes as compared with DTB time of 78 +/- 38 minutes in the pPCI group. Throughout the last decade, time-to-admission decreased significantly (P = .02) but time-to-treatment remained unchanged (P = .38) for patients undergoing thrombolysis. In the pPCI arm, time-to-admission remained unchanged (P = .11) but a insignificant trend toward reduction was demonstrated in time-to-treatment (P = .11).

CONCLUSION

Time-to-admission and time-to-treatment for ST-segment elevation myocardial infarction are still prolonged. Resources should be directed to early recognition of the acute myocardial infarction, improved utilization of emergency services for transportation, and prehospital diagnosis and triaging. Ambulances equipped with wireless capability to transmit electrocardiograms to the on-call cardiologist seem to be promising tools to achieve earlier diagnosis and triaging with high diagnostic sensitivity and specificity.

Paramedic transtelephonic communication to cardiologist of clinical and electrocardiographic assessment for rapid reperfusion of ST-elevation myocardial infarction

BACKGROUND/PURPOSE

We tested the hypothesis that paramedic recognition of ST-elevation myocardial infarction (STEMI) and cardiologist activation of the cardiac catheterization laboratory without transmission of the electrocardiogram reduces door-to-balloon times.

METHODS

We studied a consecutive series of patients suspected to have STEMI who were taken to the cardiac catheterization laboratory in the 6-month period before hotline implementation (historical controls) and during the first year of hotline use (intervention group, hotline; emergency medical service patients without hotline, concurrent controls).

RESULTS

Emergency medical services activated the hotline 47 times, and 25 patients were subsequently taken to the catheterization laboratory. Patients who received PCI involving hotline use (n = 20) had significantly shorter door-to-balloon times (58 minutes; 25th-75th percentile, 52-73 minutes) than historical controls (n = 15) (112 minutes; 25th-75th percentile, 81-137; P < .0001) and concurrent controls (n = 15) (92 minutes; 25th-75th percentile, 76-112; P = .019).

CONCLUSIONS

Paramedic transtelephonic communication to cardiologist of clinical and electrocardiogram assessment resulted in a 54-minute reduction in door-to-balloon time for patients with STEMI.