Impact of the prehospital ECG on door-to-balloon time in ST elevation myocardial infarction.

BACKGROUND: National guidelines have been set to achieve door-to-balloon time (D2B) is less than 90 minutes to improve outcomes for patients with STEMI. The purpose of this study is to see if a more aggressive approach utilizing prehospital ECGs could improve reperfusion times. METHODS: The EMS personnel obtained a 12-lead ECG during initial assessment in the field from patients with chest pain. The ECG was immediately transmitted to the ER physician by cellular link to a computer receiving station. The ER physician reviewed the ECG digital tracing. The cardiac catheterization laboratory (CCL) team was activated from the patients' homes. Patients were transported from the field directly to the CCL by EMS bypassing the emergency department. RESULTS: The mean D2B for patients with initial ECG in hospital in all three hospitals combined was 90.5 minutes, compared to 60.2 minutes in patients with prehospital ECG. (P < 0.0001). When analyzing the mean D2B in regards to times of presentation, we found a significant reduction in mean D2B in patients presenting during working hours (75 minutes) compared with those presenting during off hours (98 minutes) in the control group. However, with the use of prehospital ECGs, there was a significant reduction in D2B regardless of what time the patient arrived in the ER. CONCLUSIONS: Utilizing the prehospital ECG as a tool to bypass ER triage significantly decreases D2B times in patients with STEMI. This technology has the potential to substantially expedite reperfusion therapy in patients with STEMI.

Common scenarios to clarify the interpretation of cardiac markers.

The authors present a practical approach for physicians in clinical practice to use cardiac troponins in the interpretation of heart disease and myocardial damage. Laboratory results that fall within the intermediate area of facility-specific cutoff reference values for elevated troponin levels confer lower risks to patients than do higher levels of cardiac troponin. Perhaps not surprisingly, the actual anatomy of the vessels at cardiac catheterization does not correlate well with the troponin level. In the six cases presented here, the patients' low levels of troponin release are discussed using the new term minimal myocardial infarction, which is synonymous with conditions that would previously have been diagnosed as unstable angina. Elevated levels of cardiac troponin provide a very sensitive measure for clinicians diagnosing patients with myocardial necrosis, but such measures are also useful in defining a broad spectrum of disease. Whenever the troponin levels are elevated (barring laboratory error), the patient has a poorer prognosis. The greatest challenge for physicians is in determining which patients with cardiac troponin elevation will best benefit from heart catheterization and percutaneous intervention.

Troponin I in the diagnosis of acute myocardial infarction in pregnancy, labor, and post partum.

Cardiac troponin I has become the marker of choice for the diagnosis of acute myocardial infarction. There are specific characteristics of this test that makes it desirable for the diagnosis of acute myocardial infarction in pregnancy, labor, and post partum.