value of pulse-wave doppler tissue imaging during dobutamine stress echocardiography in detection of right coronary artery narrowing

The importance of right ventricalar function in acute and chronic cardiac affection is well established. Is to assess the value of pulse wave Doppler tissue imaging [PWTDI] during dobutamine stress echocardiography in detection of right coronary artery narrowing. 40 subjects were divided into two groups according to the presence [patient group] or absence [control group] of significant > 70% isolated right coronary artery narrowing proved by coronary angiography. All patients studied had right coronary artery dominance, they were subjected to the following: complete history taking and thorough clinical examination, 12 leads resting surface electrocardiography, resting standard echo Doppler study, coronary angiography, doubtamine-atropine stress echocardiography with pluse-wave Doppler tissue sampling. There was no statistically significant difference between the two groups as regard to early [E] and late diastolic [A] velocity in cm/sec by pulse wave tissue Doppler at rest, low dose and high dose dobutamine. p > 0.05. Regarding the ejection phase velocity in cm/sec. [EJ] by pulse-wave Doppler tissue there was no statistically significant difference between the control and the patient groups at rest and low dose dobutamine p > 0.05., however at higdose dubutamine there was a highly statistically significant difference [p < 0.01] and it was found that a progressive increase of the ejection phase velocity [EJ], expressed by a more than 25% increase from 10 microg/kg/min [low dose] to peak dobutamine stress was predictive of normal or insignificantly narrowed right coronary artery [RCA]. Whereas a blunted increase, expressed by < 25% increase of velocity, was predictive of a significantly narrowed RCA. The sensitivity, specificity, negative predictive value, positive predictive value and accuracy of pulse-wave Doppler tissue sampling in detection of right coronary artery narrowing was 80%, 75%, 79.2%, 76.9% and 78% respectively. Analysis of the right ventricular wall was accessible using the pulsed wave tissue Doppler sampling in all cases while visual assessment was not. Pulsed wave tissue Doppler sampling is a valuable tool to detect right coronary artery narrowing when combined with dobuta-mine-atropine stress echocardiography

Comparative study of cardiovascular effects of losartan and captopril in rabbits

Drugs that interfere with renin - angiotensin system [RAS] play a prominent role in treatment of cardiovascular diseases. These drugs include two groups, angiotensin converting enzyme inhibitors e.g. captopril and angiotensin II receptor blockers e.g. losartan. This work was performed to investigate the effects of chronic administration [60 days] of each of losartan and captopril on the progression of atherosclerosis, serum lipids, glutathione peroxidase activity and on arterial blood pressure in rabbits fed with 1% cholesterol enriched diet. Specimens from different levels of aorta, heart, liver and kidneys of each rabbit were formalin-fixed, paraffin-embedded and stained with haematoxylin and eosin and Verhoff's stains. The serum lipids were estimated by enzymatic colorimetric tests. The glutathione peroxidase activity in the aortic tissues was determined by a modified spectrophotometric method. Our results showed that administration of each of losartan and captopril had the ability to attenuate the progression of atherosclerosis in hypercholesterolemic rabbits. The antiatherogenic effect of losartan was more pronounced than that of captopril. Both drugs also prevented the effect of hypercholesterolemia on the heart and liver compared to the non-medicated hypercholesterolemia rabbits. On the other hand, cholesterol-fed rabbits treated with each of losartan and captopril demonstrated significant decrease in total cholesterol, triglycerides and low density lipoprotein with an insignificant increase in high density lipoprotein compared to untreated hypercholesterolemia rabbits. However, the intensity of changes produced by losartan was of greater extent than that produced by captopril. This study revealed an increase in the glutathione peroxidase activity in aortic tissues of groups of atherosclerotic animals treated with either losartan or captopril in comparison with the non-mediated atherosclerotic rabbits. Moreover, a lowering in the blood pressure was recorded in cholesterol-fed rabbits treated with either losartan or captopril. In conclusion, these results are encouraging and the beneficial antiatherosclerotic effects of both drugs are presumably attributed to then ability to interrupt influences on the RAS. In addition, their contributory role of the possible antioxidant properties of these drugs must not be ruled out. Besides, the documented ability of these drugs to accumulate kinins and nitric oxide as well as prevention of the vascular endothelial dysfunction can not be neglected

Insulin tolerance test and tolbutamide tolerance test in acromegaly

Five healthy normal volunteers and seven nor diabetic aeromegalic patients were studied during the last 10 years augmented I.T.T .and i.v. tolbutamide test were done. Results were compared to the normal controls. All the 7 patients showed abnormal curves and a high in sulin resistance index. The drop of blood sugar after i.v. tolbutamide was less than 20%; of the starting level, indicating resistance to endogenous insulin. Also the ratio between the nadirs in Tolbutamide test and augmcntcr I.T.T. was more than 2.5 : 1, compared to the ratio in normal controls of less than 2 : 1. In absence of facilities for growth hormone radio-immuno assay in most of our hospitals, the importance of these indirect measures for growth hormone activity is stressed