Microcirculation, blood coagulation and blood phospholipids in acute pneumonia

The state of conjunctival microcirculation, thromboelastographic hemocoagulation by 10 indices and 8 fractions of citrated blood plasma phospholipids was studied in 145 patients with acute pneumonia. Microcirculatory disorders with an increase in all conjunctival indices, marked hypercoagulation with raised concentration of phosphatidylethanolamine, lysophosphatidylcholines in parallel with a decrease in the level of phosphatidylcholines of the blood plasma, particularly at the peak of an inflammatory pulmonary process, were found. The relationship of phospholipids with plasma coagulation and microcirculation as a result of the development of a pathological pulmonary process was revealed.     

Relaxing Responses to Hydrogen Peroxide and Nitric Oxide in Human Pericardial Resistance Arteries Stimulated with Endothelin‐1

In human pericardial resistance arteries, effects of the endothelium‐dependent vasodilator bradykinin are mediated by NO during contraction induced by K⁺ or the TxA₂ analogue U46619 and by H₂O₂ during contraction by endothelin‐1 (ET‐1), respectively. We tested the hypotheses that ET‐1 reduces relaxing effects of NO and increases those of H₂O₂ in resistance artery smooth muscle of patients with cardiovascular disease. Arterial segments, dissected from the parietal pericardium of 39 cardiothoracic surgery patients, were studied by myography during amplitude‐matched contractions induced by K⁺, the TXA₂ analogue U46619 or ET‐1. Effects of the NO donor Na‐nitroprusside (SNP) and of exogenous H₂O₂ were recorded in the absence and presence of inhibitors of cyclooxygenases, NO synthases and small and intermediate conductance calcium‐activated K⁺ channels. During contractions induced by either of the three stimuli, the potency of SNP did not differ and was not modified by the inhibitors. In vessels contracted with ET‐1, the potency of H₂O₂ was on average and in terms of interindividual variability considerably larger than in K⁺‐contracted vessels. Both differences were not statistically significant in the presence of inhibitors of mechanisms of endothelium‐dependent vasodilatation. In resistance arteries from patients with cardiovascular disease, ET‐1 does not selectively modify smooth muscle relaxing responses to NO or H₂O₂. Furthermore, the candidate endothelium‐derived relaxing factor H₂O₂ also acts as an endothelium‐dependent vasodilator.     

Does Left Atrial Appendage Amputation During Routine Cardiac Surgery Reduce Future Atrial Fibrillation and Stroke?

Purpose of Review

Stroke is the most feared complication of atrial fibrillation. To prevent stroke, left atrial appendage exclusion has been targeted, as it is the prevalent site for formation of heart thrombi during atrial fibrillation.We review the historic development of methods for exclusion of the left atrial appendage and the evidence to support its amputation during routine cardiac surgery.

Recent Findings

Evidence is not yet sufficient to routinely recommend left atrial exclusion during heart surgery, despite a high prevalence of postoperative atrial fibrillation. Observational studies indicate that electrical isolation of scarring from clip or suture techniques reduces the arrhythmogenic substrate.

Summary

Randomized studies comparing different methods of closure of the left atrial appendage before amputation do not exist. Such studies are therefore warranted, as well as studies that can elucidate whether amputation is superior to leaving the left atrial appendage stump. Potentially, thrombogenic remaining pouch after closure should be addressed.

     

Total arterial coronary revascularization - Single or double inlet system?

Background The study assessed the graft flow to the coronary arteries during coronary artery bypass grafting in 175 patients receiving a composite single or double mammary grafts. Methods 128 patients with single inlet and 47 with double inlet composite arterial grafts were evaluated. In on pump — prior to, and following release of aortic cross clamp-and in off pump settings, graft blood flow was measured using an ultrasonic Transit Time Volume flowmeter. Results On pump, unrestricted blood flow was lower in single inlet than in double inlet grafts (119.9 ± 6.9 ml/min versus 161.0 ± 14.0ml/min (P=0.0042). There was also significantly less blood flow through the single inlet system when the heart was beating (74.7 ± 3.7 ml/min versus 98.0 ± 8.1 ml/min (P=0.0018)). We also found that patients operated on pump had larger graft flow than patients operated off pump (85.6 ± 4.6 ml/min versus 69.5 ± 3.8ml/min (P = 0.042)). Gender and number of anastomoses to the coronary arteries, were not predictive for graft flow. Conclusions Double inlet arterial graft systems supply the heart with larger graft flow than single inlet arterial graft systems. This benefit was obtained at the price of a longer duration of the operation, corresponding to the time it takes to harvest the right ITA.