[The influence of stress hyperglycemia on the prognosis of patients with acute myocardial infarction and temporary electrical cardiac pacing].

INTRODUCTION: Elevated glucose levels on admission in many emergency conditions, including acute myocardial infarction (AMI), have been identified as a predictor of hospital mortality. OBJECTIVE: Since there are no data in the literature related to stress hyperglycaemia (SH) in patients with both AIM and temporary electrical cardiac pacing, we aimed to investigate the influence of stress hyperglycaemia on the prognosis of patients with AMI and temporary electrical cardiac pacing. METHODS: The prospective study included 79 patients with diagnosed AMI with ST-segment elevation (STEMI), admitted to the Coronary Care Unit of the Clinic for Cardiovascular Diseases, Clinical Centre Nis, from 2004 to 2007, who were indicated for temporary electrical cardiac pacing. The blood was sampled on admission for lab analysis, glucose levels were determined (as well as markers of myocardial necrosis troponin I, CK-MB). Echocardiographic study was performed and ejection fraction was evaluated by using area length method. RESULTS: The ROC analysis indicated that the best glycaemic level on admission, which could be used as a predictor of mortality, was 10.00 mmol/l, and the area under the curve was 0.82. In the group without SH, hospital mortality was 3-fold lower 11/48 (22.91%) compared to the group with SH 19/31 (61.29%), p < 0.0001. Patients with SH were more likely to have higher troponin levels, Killip >1, lower ejection fraction and heart rate, as well as systolic blood pressure. CONCLUSION: The best cut-off value for SH in patients with AMI (STEMI) and temporary electrical cardiac pacing is 10 mmol/l (determined by ROC curve) and may be used in risk stratification; patients with glucose levels <10 mmol/l on admission are at 3-fold lower risk compared to those with glucose levels >10 mml/l. Our results suggest that SH is a more reliable marker of poor outcome in AMI patients with temporary pace maker, without previously diagnosed DM.

[Prognostic significance of sinus deceleration during dobutamine stress echocardiography test following acute myocardial infarction].

BACKGROUND/AIM: Chronotropic incompetence during exercise stress testing after acute myocardial infarction is an indicator of ischemia or impaired left ventricular function. On the other side, infusion of dobutamine leads to a typical dose-dependent increase in heart rate. The aim of this study was to evaluate of paradoxical sinus deceleration during dobutamine stress echocardiography (DSE), as the sign of ischemia and impaired left ventricular function, or the consequence of infarction localization, and the estimation of prognostic significance after acute myocardial infarction. METHODS: Our investigation comprised 81 patients hospitalized because of the acute myocardial infarction, and all of them had uncomplicated infarction. Fifty five patients were treated with thrombolytic therapy (67.9%); 53 patients (65.4%) had anterior myocardial infarction, and 28 patients (34.6%) had inferoposterior localization of myocardial infarction. After 10-12 days all of them underwent dobutamine stress echocardiography examination. During the next 3-6 months, the patients underwent coronary angiography. The average follow-up period was 36 +/- 22 months. RESULTS: A decrease in heart rate occurred at the dobutamine doses increasing from 15-40mcg/kg/min in 9 (11.1%) of the patients, in 1 patient with an anterior localization and in 8 patients with an inferoposterior localization. The decrease was sudden in 4 (44.4%), and gradual in 5 (55.6%) of the patients. In 3 patients (33.3%) junction rhythm was developed, and in 2 patients (22.2%) AV block II-III. Only in 2 of them, there was a worsening of regional function during a high dose dobutamine infusion, but 7 of them showed an improvement during a low dose. In 7 (77.8%) of the patients there was a simultaneous decrease in blood pressure. Coronary angiographic examination showed that in 4 (44.4%) of the patients there was a significant coronary artery disease and they underwent the revascularisation procedure. During the follow up period, there was not any significant arrhythmic disorder in that group of the patients or repeated hospitalization because of postinfarction angina, re-infarction, or heart failure. CONCLUSION: We could conclude that paradoxical sinus deceleration is not only an indicator of a significant coronary artery disease and "bad left ventricle". It also may occur as a consequence of vasodepressor reflex (Bezold-Jarisch), even after acute myocardial infarction, withont influencing a long-term prognosis.