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Notes: Early diagnosis and risk stratification of patients presenting to the emergency room for a suspected acute coronary syndrome is an emerging problem. In general, diagnosis is based on an ECG, clinical presentation, and elevated cardiac markers. In the past decade cardiac troponins and myoglobin have been identified as important markers for the global assessment and treatment of patients with acute coronary syndromes. Recent studies have identified patients with increased troponin I and T levels as a high risk population gaining benefit from the adjunctive treatment with glycoprotein (GP) IIb/IIIa receptor antagonists or low molecular weight heparin. Myoglobin was introduced as a sensitive marker of successful or failed reperfusion following thrombolytic therapy. These studies indicate that cardiac markers are important tools in the risk stratification of patients with acute coronary syndromes allowing adequate treatment decisions. However, certain limitations of cardiac markers have to be considered. These limitations mainly refer to the delay in time from presentation to the emergency room to the availability of the results of the blood sample. Thus, in the individual case, especially if an ECG and clinical presentation are unspecific or there is doubt concerning the success of thrombolytic therapy, early angiography remains the gold standard for diagnosis and establishment of adequate therapy. In this setting, early reperfusion by percutaneous coronary interventions will increase myocardial salvage, and therefore, should be preferred to the delayed confirmation of the diagnosis by repeated determination of cardiac markers.

Notes: Background: P-wave signal averaged ECG has been used to detect atrial late potentials that were found in paroxysmal atrial fibrillation. Ischemia is supposed to trigger ventricular late potentials, which indicate an elevated risk for ventricular tachycardia. Preexistent ventricular late potentials measured by ventricular signal averaged ECG is supposed to be eliminated by successful PTCA. Methods: We examined the incidence of atrial late potentials in patients with a proximal stenosis of the right coronary artery and new onset of atrial fibrillation. Furthermore, we investigated the anti-ischemic effect of a successful percutaneous transluminal coronary angioplasty.(PTCA) of the right coronary artery. P-wave signal averaged ECG from 23 patients who had a PTCA of the right coronary artery (group A) were compared to age, sex, and disease-matched control subjects (group B) one day before, one day after, and one month after PTCA. Results: A new appearance of paroxysmal atrial fibrillation was presented in eight patients before PTCA (group A1) of group A. Patients with a stenosis of the right coronary artery had a significantly higher incidence of supraventricular extrasystoles in a 24-hour-Holter ECG (131.1 ± 45.4 vs 17.1 ± 18.9, P 〈 0.0002). The duration of the filtered P wave was longer (124.8 ± 11.9 vs 118.5 ± 10.1 ms, P 〈 0.04) and the root mean square of the last 20 ms (RMS 20) was significantly lower in group A than in group B (2.87 ± 1.09 vs 3.97 ± 1.12 μV, P 〈 0.01). A successful PTCA caused an increase in RMS 20 (2.87 ± 1.11 vs 4.19 ± 1.19 μV, P 〈 0.02) and a decrease in filtered P-wave duration (124.8 ± 11.9 vs 118.4 ± 10.4 ms, P 〈 0.04). Preexistent atrial late potentials were found among 15 patients before PTCA. After successful PTCA only 3 out of 15 patients were affected (P 〈 0.0004) after one day, as well as after one month. All patients with a history of atrial fibrillation did not suffer from an arrhythmic recurrence within the following six months after successful PTCA. Conclusion: A stenosis of the right coronary artery is associated with atrial late potentials. A successful PTCA of the right coronary artery eliminates preexistent atrial late potentials and may reduce the risk of atrial fibrillation.