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Magnesium-enriched coronary sinus retroperfusion during acute coronary artery occlusion
S Fehmi Katircioğlu1, A Tulga Ulus, Zülfikar Saritaş
1Department of Cardiovascular Surgery, Türkiye Yüksek Ihtisas Ankara Hospital, Ankara, Turkey. uluss@yahoo.com
Insights
Retrograde coronary sinus perfusion with magnesium sulfate significantly protects the ischaemic myocardium. This method improves cardiac index and left ventricular stroke work index, reducing reperfusion injury.
Area of Science:
- Cardiovascular Research
- Myocardial Protection
- Ischaemic Heart Disease
Background:
- Coronary sinus retroperfusion is known to protect ischaemic myocardium by restoring blood flow, reducing infarct size, and improving left ventricular function.
- Understanding the role of specific agents in conjunction with retroperfusion is crucial for optimizing therapeutic outcomes.
Purpose of the Study:
- To investigate the effects of coronary sinus retroperfusion combined with magnesium sulfate on myocardial haemodynamics.
- To evaluate the protective potential of this combined approach against ischaemic reperfusion injury.
Main Methods:
- Four groups of animals were studied: control (occlusion only), magnesium sulfate infusion, retrograde coronary sinus perfusion, and combined perfusion with magnesium sulfate.
- Haemodynamic measurements, including cardiac index and dP/dt, were recorded during occlusion and reperfusion periods.
Main Results:
- Retrograde coronary sinus perfusion (groups III and IV) significantly increased cardiac index during reperfusion compared to controls.
- The combined approach (group IV) demonstrated superior haemodynamic function, including higher left ventricular stroke work index, compared to other groups.
- dP/dt values were significantly higher in groups with retrograde perfusion, indicating improved myocardial contractility.
Conclusions:
- Magnesium sulfate administered antegrade had limited effects on myocardial protection.
- Magnesium-enriched retrograde coronary sinus perfusion significantly protects the ischaemic myocardium against reperfusion injury.
- This combined strategy offers a promising therapeutic approach for managing ischaemic heart conditions.
Background:
The protective effect of coronary sinus retroperfusion in cases of ischaemic myocardium is clearly known. It restores the blood flow to the ischaemic tissue, reduces the infarct size, and improves the left ventricular pump function.
Methods:
In this study, we investigated the effects of coronary sinus retroperfusion with the addition of magnesium sulphate on myocardial haemodynamics. A total of sixteen animals were entered into the study and divided equally into four groups: group I, control group, left anterior descending (LAD) coronary artery occlusion only; group II, LAD artery occlusion and Mg SO infusion; group III, LAD occlusion and retrograde coronary sinus perfusion; and group IV, LAD occlusion, retrograde coronary sinus perfusion and Mg SO infusion.(4) (4)
Results:
Haemodynamic measurements were obtained throughout the study, at baseline, during the first and third hour of occlusion, and in the second, fourth and sixth hour of reperfusion. Although, the cardiac index was decreased in all groups, in the second hour of reperfusion it was significantly higher in groups III and IV compared to the control group. In the second hour of reperfusion cardiac index values were 56 +/- 5 and 63 +/- 6 ml/kg per min in groups III and IV respectively (P < 0.05) and as time passed this incremental change in groups III and IV became more apparent. In the fourth hour of reperfusion, group II showed significantly higher values than the control group. Group IV had higher values compared to group III at the fourth and sixth hours post-reperfusion. In general there were significant differences between groups II, III and IV at four and six hours post-reperfusion. The first derivative of pressure measured over time-the dP/dt value-was higher in groups III and IV compared to the control group in the first hour of occlusion (being 1650 +/- 55 and 1700 +/- 35 in groups III and IV respectively, and 1420 +/- 45 in the control group) and these differences continued throughout the occlusion and the reperfusion periods (P < 0.05). Group IV had the highest left ventricular stroke work index (LVSWI) values compared to the other groups in various pulmonary capillary wedge pressure (PCWP) measurements (P < 0.05). It was 0.78 g.m/kg at the 20 mmHg PCWP.
Conclusions:
Magnesium, if administered in an antegrade direction had only a limited effect, whereas magnesium-enriched retrograde coronary sinus perfusions appeared to significantly protect the ischaemic myocardium against the hazardous effects of ischaemic reperfusion injury.