Evaluation of the vasodilator capacity in normotensive offsprings of hypertensive parents

Background: blood pressure [BP] levels appear to have strong familial tendencies. An estimated 30-60% of the variation of the BP between individuals, after adjustment of age and sex, is attributed to gene factors. Recent reports suggest occurrence of endothelial dysfunction in development of essential hypertension. The defective nitric oxide production resulting in reduced vasodilator capacity of the peripheral blood vessels, with consequent increase in the peripheral resistance and BP

Aim of work: is to address the genetic familial factor in hypertension through the evaluation of vasodilator capacity in normotensive offsprings of hypertensive patients

Patients and methods: 53 Subjects age from 15 to 35 years old were included: Group I: 20 subjects with normal BP but one or both of their parents is hypertensive, 12 subjects having only one of their parents is hypertensive [Group 1A], while 8 subjects of this group [40%] having both parents are hypertensives [Group 1B]. Group 2: 20 subjects with normal BP and their parents are of normal BP too, as a control group and 13 subjects were excluded as they were discovered to be hypertensives [By APBM]. Subjects were divided into two groups according to family history of hypertension: Both groups were subjected to: History taking, Clinical Examination, FBS and PPBS, lipogram, Ambulatory blood pressure monitoring, Coloiured duplex ultrasound to test the vasodilator capacity before and after reactive hyperaemia and GTN

Results: there is significant difference between both groups for mean post FMD [p=0.014], mean FMD% [p<0.001] and mean Dil.ratio [p<0.001]. While there is no statistical significance between both groups as regard mean pre FMD, mean pre and post GTN-MD and GTN-MD%. There is significant difference between group 1A and group 1B for mean post FMD [p=0.033], mean FMD% [p<0.001] and Dil.ratio [p=0.001].While there is no statistical significance between both groups as regard mean pre FMD, mean pre and post GTN-MD, and GTN-MD%

Conclusion: there is an obvious endothelial dysfunction in offsprings of hypertensive parents, preceding their development of hypertension. Those traits are inherited to them from their hypertensive parents, and being more if they are inherited from both parents. This endothelial dysfunction may be due to a genetic defect in nitric oxide [NO] synthesis pathway either in production of NO synthase enzyme [NOS] isoforms, co-factors for NOS induction and inhibition andlor L-arginine which is the. NO substrate or its analogues. Also the autonomic disturbance is due to a genetic defect, which makes them more susceptible to environmental stresses resulting in a high sympathetic tone in those subjects. Finally, the inherited impaired baroreceptors sensitivity and autonomic dysfunction together with the endothelial dysfunction and defective nitric oxide may represent mechanisms through which subjects with familial predisposition for hypertension may develop hypertension later on in their life

Ventricular late potentials: pattern in normal and different cardiac congenital abnormalities

Pediatric mortality represents a major problem all over the world. During infancy, arrhythmia may be an important factor in the pathogenesis of some of these life-threate ling events. Congenital heart diseases increase the liability for many cardiac arrhythmias. Ventricular late potentials have shown to be markers for risk of ventricular arrhythmias. There is only limited data on normal reference values for signal- averaged electrocardiogram [SFECG] in pediatric population. In this sturdy, we tried to establish ranges for SAECG parameters in normal children and in patients with congenital cardiac defects. One hundred and fifty infant's and children were the study population. Fifty [50] children had congenital a cyanotic heart disease, 29 were males with a mean age +/- SD of 18.75 +/- 13.9 months and 50 children had congenital cyanotic heart diseases, 18 were males with a mean age of 5.62 +/- 3.0 months. 50 age- and sex- matched healthy individuals were served as controls. The SAECG parameters include QRS duration in milliseconds [msec], Root Mean Square voltage [RMS] in microvolts [micro v], Root Mean Square of the last 40 millisecond of the QRS comply [RMS 40] in micro V and the duration of low amplitude signal [< 40 micro V] at the terminal QRS [LAS] in msec. The results showed that, in normal subjects, the QRS duration ranged iron 80.5 to 100.5 msec, RMS voltage ranged from 158.6 to 240.0 micro V, RMS-4O voltage ranged from 44.5 to 126.1 micro V and the duration of LAS ranged from 2.7 to 10.3 msec. In acyanotics, the mean +/- SD for QRS duration was 101.2 +/- 85.2 msec, for RMS was 197.9 +/- 92.7 micro V, for RMS-40 was +/- 79.9 + 118.0 micro V and for LAS was 10.5 +/- 7.4 msec. In cyanotic, QRS duration was 127. +/- 11.8 msec, RMS was 128.5 +/- 60.1 micro V, RMS-40 was 35.34 + 2.4 micro V and LAS was 22.8 + 2.3 msec. Cyanotic patients had a significantly wide QRSD 8 LAS and significantly low RMS and RMS-40 than a cyanotic [p > 0.05]

Conclusion: our result; provide a basis for interpretation of SAECG in Children. Normal ranges for the various parameters were determined. In cyanotic, the late potentia3 are markedly abnormal in comparison to the little change in cyanotic rendering patients with cyanotic heart defects are highly susceptible for arrhythmia and arrhythmia-induced complications

Hemodynamic exercise response in rheumatic mitral stenosis: an echo-doppler study

The effects of exercise on patients with rheumatic mitral stenosis were investigated using echocardiography. Twenty-five patients in sinus rhythm with no contraindication to exercise were subjected to sub-maximal treadmill exercise according to modified Bruce protocol. A heterogeneous response depending mainly on the degree of mitral valve destruction was noticed. Patients with the same valve areas at rest did not have the same response to exercise. This might explain the difference in severity of symptoms in patients with the same valve areas at rest. It has been concluded that hemodynamic exercise response in patients with mitral stenosis evaluated by Doppler echocardiography immediately after sub-maximal exercise treadmill test is a useful method for evaluation of these patients and gives a better insight of the disease