[Vascular damage in arterial hypertension: its noninvasive assessment]

Arterial hypertension is a definite risk factor for the atherosclerotic disease and thus has a primary role in the genesis of cardiovascular diseases, but it acts also though a direct structural damage of great and small arteries and arterioles. Up to date, clinical research and technological advancements have made possible the development of instruments and methods for the evaluation of the vascular damage. Ultrasonographic methods are now the better non invasive tools for the study of arterial diseases, allowing a definition power comparable to angiography, and giving useful data on characters and composition of plaques, also minimal, at the level of the arterial district of lower limbs, epiaortic, renal, and abdominal vessels. These methods allow the study of the vascular lesion under the hemodynamic (CW or pulsed Doppler with spectral signal analysis) and the morphological profile (high resolution echotomography) or both echo-Doppler duplex scanning or color flow imaging). Arterial compliance of great vessels can be studied through the Doppler evaluation of pulsed wave velocity along the arterial tree. Other useful parameters are the aortic distensibility (ratio between % change in arterial volume and blood pressure), the elastic module, the index of arterial rigidity and the aortic index (ratio between pulse pressure and stroke volume). By using this latter parameter we demonstrated a significant decrease of arterial compliance that is proportional to the severity of blood pressure values. Small vessels may be studied through strain-gauge plethysmography, that allows to obtain the regional blood flows at the hand and forearm (skin circulation) and the calf (muscular circulation) both in basal conditions and after ischaemic stimulus. From the ratio between mean arterial pressure and post-ischemic blood flow it is possible to obtain minimal vascular resistances, expression of the maximal vasodilatation capacity in the arteriolar bed. With this method we showed that minimal vascular resistances increase proportionally with the increase of blood pressure in borderline hypertensives, in mild, moderate and severe stable arterial hypertension and in hypertension of the aged. The cutaneous microcirculation may be studied also by laser Doppler and capillaroscopy, that show a reduced capillary perfusion in hypertension. Clinically, these diagnostic tools are also extremely useful for studying the effects of antihypertensive treatment on structure and function of arterial vessels, as it seems that some drugs are able to counteract the structural alterations related to hypertension.

[The noninvasive evaluation of the cardiovascular changes in physiological aging]

The physiological aging is frequently associated with structural alterations determining a loss of elasticity both of left ventricular wall (that goes towards hypertrophy), and of great and small arteries and arterioles (that have their compliance reduced). In fact, in our experience, the elderly have, in comparison with younger people, greater values of end diastolic thickness of the septum and of the posterior wall (respectively 10.7 +/- 1.5 vs 9.4 +/- 1 and 10.4 +/- 1.7 vs 9.0 +/- 0.9), of the aortic index, that is inversely related to arterial compliance (0.74 +/- 0.06 vs 0.66 +/- 0.05) as well as of minimal vascular resistances, expression of an impaired maximal vasodilation capacity of the arteriolar bed (4.27 +/- 1.08 vs 3.68 +/- 0.91). At cardiac level the global effect of these changes is a remodelling able to maintain a normal function both at rest and after exercise, i.e., a greater intervention of Frank-Starling mechanisms with increase of the end diastolic volume, in order to counteract the lower chronotropic response to catecholamines. At peripheral level the structural changes in the arterial tree (consequent to an increased collagen content in the intimal and medial components of the vessel walls) lead to an increase in blood pressure with aging: in our study by non-invasive blood pressure monitoring mean 24-hours blood pressure values have been the following ones: 116.4 +/- 3.8/72.1 +/- 7.2 mmHg in 25-35 years aged; 121.8 +/- 9.1/75.9 +/- 5.3 mmHg in 45-55 years aged; and 128.4 +/- 10.1/76.4 +/- 7.8 mmHg in aged more than 60 years. On the other hand, the greater cardiac output during stress, together with the lower arterial vasodilation (consequent also to the impaired function of the baroceptor reflexes) determines an exaggerated systolic blood pressure increase after exercise.

[Cardiac arrhythmias in hypertensive subjects with and without left ventricular hypertrophy compared to the circadian profile of the blood pressure]

To evaluate possible correlations between cardiac arrhythmias and circadian pattern of blood pressure (BP) and of heart rate (HR), we studied 2 groups of 20 males with stable arterial hypertension of mild to moderate entity, with (Group I) or without (Group II) left ventricular hypertrophy (LVH). In patients with LVH the mean age (56 vs 46 years), the duration of the hypertensive state (48.1 vs 15.7 months), the thickening of interventricular septum (IVS; 13.7 vs 9.6 mm) and of the posterior wall of the left ventricle (13.2 vs 9.2 mm) and the mass of LV (149.8 vs 99.7 g/m2) were significantly greater (p less than 0.01). On the contrary, the 2 groups did not show significant differences concerning casual BP determined in the morning (178.3/108.4 vs 171.5/106.2 mmHg). After a pharmacological washout of 2 weeks, patients underwent a noninvasive, intermittent, monitoring of BP (every 15 min during daytime and every 30 min from 11 pm to 7 am), using a pressure meter II Del Mar Avionics, and a continuous monitoring of ECG for 24 hours, employing an instrument 445/B Del Mar Avionics. Mean 24-hour BP was not different in the 2 groups of patients (161.7/99.0 vs 158.2/98.3 mmHg); however, patients with LVH showed a significantly greater variability of BP in the morning (7 am-3 pm), while mean 24-hour HR was significantly less (71.6 vs 78.2 b/min).(ABSTRACT TRUNCATED AT 250 WORDS)

[Intestinal parasitoses in the Galician population]

To evaluate the relative importance of the different intestinal parasites in Galicia, we report the results of the investigation of 6,554 samples of feces in the Microbiology Service of the Hospital General de Galicia (Santiago) from 1983 to 1987. The results indicate that the yearly frequency of parasitism has been reduced from 27.8% of the investigated samples en 1983 to 12.1% in 1987. The mean value for the study period was 16.8% (15.6% simple parasitism and 1.2% multiple parasitism). There were no differences in incidence depending on sex. The enteric parasites most commonly found were G. lamblia, T. trichiura, A. lumbricoides and E. coli.

[Cardiac arrhythmia in relation to the leaflet morphology in subjects with mitral valve prolapse]

Aim of this study was to verify the prevalence of cardiac arrhythmias in subjects with mitral valve prolapse (MVP) and redundant leaflets in comparison with subjects with MVP without leaflets redundance. So, 60 subjects (aged 13 to 39 years), were subdivided in 3 groups on the basis of mitral leaflets shape at 2D-echocardiography; a continuous ECG monitoring (24 hours) was also performed. Arrhythmias were more frequent and more severe in the Group III (subjects with MVP and redundant leaflets), in comparison with both Group II (subjects with MVP without leaflets redundance) and Group I (control subjects). In particular, analysing the mean values of the single arrhythmias in the 24 hours, ventricular ectopic beats (VEB), were more frequent in Group II (p less than 0.01) and Group III (p less than 0.05) in comparison with Group I; the couplets and the runs of ventricular tachycardia were more frequent in Group III than in the other groups (p less than 0.001). The number of the subjects with a Lown class greater than 3 was higher in Group III than in the other groups (p less than 0.01). In conclusion, this study confirms that MVP is a disease presenting a large variability arrhythmic risk, that seems to be real only for a subgroup of these subjects.

Noninvasive blood pressure monitoring evaluation of verapamil slow-release 240-mg antihypertensive effectiveness

The aim of our study was to evaluate the antihypertensive effectiveness of verapamil slow-release (SR), administered once a day. We studied 11 patients, 7 male and 4 female, with an average age of 53.6 +/- 12.86 years, who had essential hypertension. After a drug washout period of at least 15 days, placebo was administered (one tablet per day), and then patients received verapamil SR 240 mg/day at 8:00 a.m. for at least 2 weeks. At the end of the washout, placebo, and active drug treatment periods we performed ambulatory intermittent blood pressure monitoring for 24 h using a Squibb Spacelabs pressurometer. After verapamil treatment, in comparison to placebo, a significant reduction of systolic (SBP) and diastolic blood pressure (DBP) (154.91 +/- 13.34/94.29 +/- 9.48 vs. 143.73 +/- 11.39/84.6 +/- 7.99 mm Hg; p less than 0.005), was observed without significant changes of the circadian blood pressure pattern. Moreover, we observed a significant reduction of SBP and DBP variability mainly during daytime, whereas this behavior was not evident for heart rate. In conclusion, verapamil SR seems useful to obtain a constant and significant reduction of 24-h blood pressure values with a significant reduction of SBP and DBP variability.

Changes of angiotensin converting enzyme (ACE) levels during activation of the renin-angiotensin-aldosterone system (RAAs)

The aim of this study was to evaluate the changes of ACE levels during RAAs activation induced by: 1) a continuous graded bicycle ergometer test performed in a group of 15 males health youths aged between 21 and 30 years, with average age of 25.8 +/- 2.85 years; 2) i.m. injection of 20 mg of frusemide in 11 health youths (10 males and 1 female), aged between 20 and 30 years, with average age of 24.09 +/- 2.77 years; 3) dialytic treatment in 25 patients (12 males and 13 females), suffering from chronic renal failure, aged between 26 and 68 years, with average age of 54 +/- 15.42 years. Plasmatic renin activity (PRA), aldosterone (ALD) and ACE levels were determined by RIA in basal conditions and at peak of exercise in group 1, 15 minutes after i.m. injection of frusemide in group 2 and after a session of dialysis in group 3. In all the experimental conditions studied there was an activation of the renin-angiotensin system with significant increase of the PRA, ALD and ACE levels.

Analysis of exercise-induced R-wave-amplitude changes in detection of coronary artery disease in patients with typical or atypical chest pain under digitalis treatment

Specificity and sensitivity of exercise ECG were compared to exercise stress thallium 201 scanning and coronary arteriograms in 70 male patients with typical or atypical chest pain complaints, without previous myocardial infarction. 50 patients (group I) did not receive any treatment; 20 patients (group II) received digitalis as preventive treatment of atrial arrhythmias or for no particular reason. Only subjects with concordant results in radionuclide and angiography examinations were considered as coronary artery disease patients. Exercise stress tests were performed sitting on the bicycle ergometer using a progressive loading profile (30 W for 3 min), to the symptom-limited capacity (VO2SL). Positive exercise ECG were confirmed on ST decrease (1.5 mm) or on absence or increase in R-wave-amplitude modifications (V5). In the group I patients, ECG-ST-modification sensitivity, specificity, predictive value (+) and efficiency were, respectively, 92, 82, 86 and 88%. R-wave-variation sensitivity, specificity, predictive value (+) and efficiency were, respectively, 41, 74, 65 and 56%. In the group II patients, ST-depression sensitivity, specificity, predictive value (+) and efficiency were, respectively, 100, 33, 59 and 65%. R-wave-variation sensitivity, specificity, predictive value (+) and efficiency were, respectively, 50, 70, 63 and 60%. It was concluded that R-wave-amplitude variations induced lower false positive responses than ST-segment depression in patients under digitalis treatment. False negative responses were unfortunately 50% using the R-wave criterion. Exercise ECG was finally judged as a poor indicator of CAD in patients under digitalis treatment.