Graded compression for preventing deep venous thrombosis.

The physiological effects of static compression of the leg have recently been reinvestigated. Graded compression extending from the ankle to the upper thigh produces the maximum increase in velocity of femoral vein blood flow and the maximum decrease in clearance times of contrast media and radioisotopes from the deep veins of the calf. This type of compression may be easily produced by a specially designed elastic stocking. Graded compression was used in a controlled clinical trial of 98 patients undergoing major operations to assess its effect on isotopically diagnosed deep vein thrombosis. The incidence of deep vein thrombosis was 49% in the control group and 23% in the treated groups. No complications were caused by the stockings. Carefully designed and correctly applied static compression is a safe and effective method of reducing the incidence of deep vein thrombosis.     

Detection of deep venous thrombosis by scanning of 99mtechnetium-labelled red-cell venous pool.

A comparative study of 32 patients with suspected deep venous thrombosis was carried out using blood-pool radionuclide scanning and conventional x-ray phlebography. Results of the two methods showed close agreement, the sensitivity (positive correlation) of the scan being 100% and its specificity 89%. We conclude that a patient''s red cells labelled with 99mtechnetium (99mTc) provide an excellent medium for this type of scanning. The technique has particular advantages in visualising the whole venous system, giving a persisting image, and obviating the need to inject into a vein of the affected limb. In view of the inherent disadvantages of contrast phlebography, 99mTc-red-cell scanning is clearly an acceptable alternative.     

Arterial endothelial dysfunction and idiopathic deep venous thrombosis

Recent epidemiological studies have highlighted higher risk of subsequent development of atherosclerotic disease in patients with deep venous thrombosis (DVT). We evaluated the Flow Mediated Dilation (FMD) looking for arterial endothelial dysfunction, predictive for future ischaemic cardiovascular events, in patients with idiopathic DVT. FMD was measured in the brachial artery in 60 subjects with idiopathic DVT (age 60.1±17.4) and in 60 subjects without idiopathic DVT (age 61.2±15.1), with a similar cardiovascular risk factor profile. DVT patients showed lower FMD (6.78%±5.53% vs 10.88±3.31%, p<0.001). Univariate linear models showed that obesity (p=0.010), dyslipidemia (p=0.004), arterial hypertension (p=0.046), use of platelet anti-aggregating agents (p=0.018) and DVT (p<0.001) were associated to lower levels of FMD. In multivariate linear model, only DVT (p<0.001) remained an independent predictor of lower levels of FMD. Furthermore, an 8.5% cut-off value of FMD was chosen in a ROC curve analysis. Values of FMD ≤ 8.5% were more frequent in DVT patients (71.67% vs 41.67%, p<0.001). Univariate logistic regression models showed that dyslipidemia (p=0.008), use of platelet anti-aggregating agents (p=0.004) and DVT (p<0.001) were associated to a higher risk of having FMD ≤ 8.5%. Multivariate logistic regression model showed that DVT was the unique independent predictor for FMD ≤ 8.5% (p<0.001). In conclusion, DVT patients more frequently have impaired FMD, recognized as an indicator of arterial endothelial dysfunction and a marker for increased cardiovascular risk.     

Some haemostatic parameters in patients with deep and superficial venous thrombosis.

Some haemostatic parameters (AT III, alpha 2-AP, C1-INH, kallikrein, F.XII, fibrinogen, plasminogen, euglobulin lysis time, FDP and ethanol test) were studied in patients with deep (DVT) and superficial (SVT) venous thrombosis. The patients with DVT revealed significantly decreased AT III activity, increased alpha 2-AP, C1-INH activity, fibrinogen and FDP concentrations and prolongation of euglobulin lysis time. Ethanol gelation test was positive in 61% in DVT group. Plasminogen level was unchanged in patients with DVT. No significant changes in these parameters were found in SVT group. Only the ethanol gelation test was positive in 21% in this group. These results show a markedly expressed phenomenon of hypercoagulability in the group of patients with DVT and suggest that in the treatment different therapeutic procedures should be considered which influence these specific changes in these coagulation parameters.     

Subclinical myocardial infarction presenting as free wall rupture

A 50-year-old man presented twice within a period of two weeks with symptoms and electrocardio-graphic (ECG) findings suggesting postinfarct angina. The ECG showed sinus tachycardia with Q waves, ST-segment elevation and terminally negative T waves in lead II, III and aVF, suggesting remote inferior myocardial infarction. During the first hospitalisation the ECG also showed signs of pericarditis. Troponin I levels were only slightly elevated. Echocardiographic evaluation at the second presentation demonstrated a posterolateral false aneurysm following ischaemic left ventricular rupture (figure 1).