Remote Postconditioning Alone and Combined with Hypothermia Improved Postresuscitation Cardiac and Neurological Outcomes in Swine

Objective. Previously, we demonstrated that remote ischemic postconditioning (RIpostC) improved postresuscitation myocardial and cerebral functions in rat. Here, we investigated the effects of RIpostC alone and combined with therapeutic hypothermia (TH) on cardiac and neurological outcomes after CPR in swine. Methods. Twenty-one pigs were subjected to 10 mins of VF and then 5 mins of CPR. The animals were randomized to receive RIpostC alone, or its combination with TH, or sham control. RIpostC was induced by 4 cycles of limb ischemia followed by reperfusion. TH was implemented by surface cooling to reach a temperature of 32–34°C. Results. During 72 hrs after resuscitation, lower level of cardiac troponin I and greater stroke volume and global ejection fraction were observed in animals that received RIpostC when compared to the control. RIpostC also decreased serum levels of neuron-specific enolase and S100B and increased neurologic alertness score after resuscitation. The combination of RIpostC and TH resulted in greater improvement in cardiac and neurological outcomes than RIpostC alone. Conclusion. RIpostC was conducive to improving postresuscitation myocardial and cerebral functions and reducing their organ injuries. Its combination with TH further enhanced its protective effects.

Vergleich von Belastungs- EKG und Radionuklid- Ventrikulographie bezüglich des Nachweises einer Myokardischämie bei isolierten Stenosen des Ramus interventricularis anterior

21 patients with LAD-stenoses of at least 70% and 21 patients with LAD- stenoses and additional intramural anterior wall infarctions were studied. 20 patients without heart disease or after successful transluminal coronary angioplasty and 18 patients with intramural anterior wall infarction after successful transluminal dilatation of the LAD (remaining stenosis maximal 30%) served as controls. The normal range of global and regional left ventricular ejection fraction response to exercise was defined based on the data of 25 further patients without relevant coronary heart disease. Thus, a decrease in global ejection fraction and regional wall motion abnormalities were judged pathological. All patients were comparable with respect to age, ejection fraction at rest and work load. Myocardial ischemia could be detected by the exercise ECG in 81 % of all patients without infarction and in 71 % of patients with infarction. The corresponding values for global left ventricular ejection fraction were 76% and 81 %, respectively, and for regional ejection fraction 95% in both groups. No false-positive exercise ECGs were observed in the healthy controls and 2 (11 %) in the corresponding group with intramural infarction. The global ejection fraction was pathological in 1 (5%) healthy subject without infarction and in 3 (17%) corresponding patients with infarction. Sectorial analysis revealed 5 and 22%, respectively. Our findings suggest that the exercise ECG has a limited sensitivity to detect myocardial ischemia in patients with isolated LAD-stenoses and intramural myocardial infarction. Radionuclide ventriculography yields pathological values more often; however, false-positive results also occur more frequently.

Accuracy and Reproducibility of the Assessment of the Global Ejection Fraction Using 195mAu and a Single-Crystal Digital Gamma Camera: Influence of Collimator Design

A sequence of RAO first-pass studies (first with 99mTc and then twice with 195mAu) was performed in 18 normal volunteers and in 12 CAD patients using two different types of collimator for medium energy: a standard collimator (MEMS) and a special high-sensitivity collimator (MEHS). The following data were compared: the peak count rate, the net LV end-diastolic counts and the LVEF. Using MEMS the end-diastolic counts acquired were so low (12% of 99mTc average value) that EF standard deviation had a mean value of 0.061 (range 0.045-0.081). With MEHS the following results were obtained: 1. the peak count rate and LV net end-diastolic counts with 195mAu were 55% and 50% respectively, of 99mTc values; 2. a good correlation was shown between LVEF values either with 99mTc and 195mAu (r =.97), or with 195mAu sequential studies (r =.98).