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Biomedical subjects

G Sánchez Torres

Publications and source records attributed to G Sánchez Torres.

At least 19 recordsLinked to original sources
PubMed1988

Systemic arterial hypertension and coronary atherosclerosis. Observations in survivors of a first myocardial infarction.

To determine the importance of systemic arterial hypertension (SAH) in the pathogenesis of coronary atherosclerosis (CA), the coronary stenosis (CSI), coronary diffuse atheromatous (CDAI) and coronary tortuosity (CTI) indices were assessed by selective coronary angiography (SCA) in 132 survivors of a definite first myocardial infarction (MI). Patients were divided into 2 groups according to the absence (group A, n = 60) or presence (group B, n = 72) of SAH. Group B was further subdivided into 2 subgroups: group B1, consisting of 62 patients receiving no antihypertensive treatment before admission, and group B2, consisting of 20 patients treated continuously for at least 2 years with a diuretic or diuretic + beta-blocker. There were no differences in age, topography of MI, serum total cholesterol and triglyceride concentrations, prevalence of diabetes mellitus or smoking habits, CSI and CTI among the groups or subgroups of patients. Group B had a higher CTI (7.2 +/- 2.8) than Group A (2.7 +/- 2.3, p less than or equal to 0.001). None of the above indices were statistically different between subgroups B1 and B2. Surprisingly, the degree and extent of CA assessed by CSI and CDAI were similar in this population, regardless of the presence or absence of SAH and whether or not patients were treated with a diuretic. Although hypertension was related to tortuosity of the coronary arteries, which does not have a strong role in the development of CA, it is possible that the hypertensive process is relevant to the installation of atheromatous disease but not to its progression. Further studies are needed to clarify this point.

Angiocardiography↗
PubMed1987

Two factors associated with increased uptake of calcium in platelets from essential hypertensive patients.

The relative rate of calcium transport into platelets from essential hypertensive patients and healthy normotensive donors was measured using the metallochromic indicator arsenazo III and recording net decrease in optical density per 5 minutes (O.D.U./5 min). When platelets from essential hypertensive patients were suspended in the patient's own serum, calcium was transported more rapidly than when suspended in normal sera (0.0166 vs 0.0113 O.D.U./5 min, P less than 0.01) indicating that the difference is due to a circulating factor. When platelets from healthy normotensive volunteers were suspended in the donor's own serum or in a pool of normal sera, the relative rate of transport was lower than in the case of platelets from hypertensives suspended in the pool of normal sera (0.005 vs 0.0113 O.D.U./5 min, P less than 0.01) which suggests a membrane alteration rendering the platelets from hypertensives more permeable to calcium. It was observed that the increase of calcium entry was inhibited by verapamil. The nature of these circulating and membrane-associated factors is at present unknown, but the circulating factor was capable of increasing the membrane permeability to calcium in normal human platelets (from 0.0057 to 0.011 O.D.U./5 min, P less than 0.01) and even in rat liver mitochondria, an effect that was inhibited by ruthenium red.

Adult↗
PubMedDate not supplied

[Provocation and measurement of retrograde pulsatile wave velocity in normal subjects and patients with systemic hypertension].

UNLABELLED: There are not published incruent methods of provocation and/or measurement of the velocity of the reflexive arterial pulse wave. This phenomenon is implicated in the pathogenesis of arterial hypertension. We describe that during compressive sphygmomanometry (CS) done in the forearm, reflexive waves are provoked that are register in the arm with an equipment developed by us, which measures the velocity of the antegrade (APWV) and the provoked retrograde (RPWV) pulse waves. The procedure consist in: 1) detection, capture and digitalization by pneumatic cuffs of oscillopulses of the arm and the forearm, 2) detection of finger photopulse to control the efficacy of CS, 3) measurement of APWV and RPWV by taking the conduction time travel distance of pulse wave between detectors arm-forearm and forearm-arm respectively. Thirty normal case (group A, GA) and 37 essential systemic hypertensive patients (group B, GB) were studied. Sixteen cases of GB had left ventricular hypertrophy (LVH). RESULTS: A reflexive wave was provoked in 99% of cases. The APWV (m/s) was 6.0 +/- 0.9 vs 7.5 +/- 1.3, p < 0.001 for GA and GB respectively. The RPWV (m/s) of the same groups were 1.8 +/- 0.3 vs 2.5 +/- 0.7, p < 0.001. The hypertensive cases with LVH had more RPWV than the cases without it (2.7 +/- 0.6 vs 2.3 +/- 0.6, p = 0.07). CONCLUSION: Hypertensive cases vs normals had higher antegrade and retrograde pulse wave velocities possible due to the major degree of arterial rigidity of the former. The method may be used in study of chronic arteriopathy.

Adult↗
PubMedDate not supplied

[Dopamine in essential arterial hypertension: excretion of its metabolite homovanillic acid].

The results obtained in a group of 66 hypertensive patients in which the AHV values were 5.7 plus and minus 0.4 mM/24 hrs., were reported. These values were compared to those obtained in 42 healthy subjects: 7.0 plus and minus 0.5 mM/24 hrs. The difference was statistically significant P less than 0.05. The values of excretion of urinary dopamine in both groups were also presented. A value of 225.7 plus and minus 13.0 mug/24 hrs. was obtained for the hypertensives, while the value for the healthy groups was 361.2 plus and minus 16.5. The statistical study in this case showed a high significance p smaller or less than 0.001. There were no changes in the levels of adrenaline and noradrenaline nor in the metabolite of these two amines, that is, AVM.

Adolescent↗
PubMedDate not supplied

[The importance of radiology in the localization of pheochromocytoma].

The usefulness of different radiologic studies in localizing the tumor was evaluated in 26 patients with a firmly established diagnosis of pheochromocytoma. The site of the lesion was correctly identified in 8% of the cases by the plain abdominal x-ray films: in 11% by the plain thoracic films; in 34% by uronephrotomography; in 88% by angiography and in 6 patients (100%) in whom computed tomography scans (CT) were performed. The tumors were intra-adrenal in 19 patients and extra-adrenal in the remaining 7 cases. Of the latter, two were found in the organ of Zuckerkandl, two were abdominal para-aortic, two others in the para-aortic region of thorax, and one with intra an extra-adrenal tumors. It is concluded that CT scans are quite successful in preoperative localization of pheochromocytoma. The non-invasive nature of the technique makes it the method of choice in the anatomical localization of this type of tumors.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

[Takayasu arteritis: usefulness of radiologic and angiographic studies].

With the purpose of learning the usefulness of radiologic and angiographic procedures for the evaluation of Takayasu's arteritis (TA), we studied 64 patients (ratio women: 8.1, average age: 23.5 years, range: 13-52 years) in which we performed arteriographic studies in the clinically affected area. All cases had chest films: 53 had thoracic aortogram, 60 abdominal aortogram, 16 pulmonary arteriography. According to the topography of the lesions we found 8% of the cases with damage exclusive to the supra-aortic trunk, 6% with isolated alteration of the intermediate thoraco-abdominal aorta, 62% with mixed pathology of the two categories above, and 21% with lesions in the pulmonary artery besides systemic arteriopathy. The results were as follows: 1) radiology of the chest: cardiomegaly (48%), irregularities in the ascending aorta (31%), calcification in the aortic wall (29%), calcified granulomas (25%) and signs of pulmonary venous hypertension (21%); 2) thoracic aortogram: irregularities in the descending aorta (56.6%), thickening of the wall of descending aorta (39.6%), dilatation of the ascending aorta (26.4%), of the descending aorta (26.4%); occlusions: of the left subclavian (24 cases), left mammary (16 cases), left carotid (8 cases) and left vertebral (8 cases); 3) abdominal aortogram: irregularities of the outline, stenosis, prominent "supplementary" arteries and aneurysms in 53%, 43.3%, 38% and 13.3 of the studies performed. The arteries most commonly affected were: renal (74.7%), both (31.6%), right (28.2%) and left (14.9%), superior mesenteric (26.6%) and hepatic (21.6%); 4) pulmonary arteriography: arterial occlusions: right superior lobar branch (37.5%), right medial (6.2%), right inferior (12.5%), without predilection by any lobe; 5) coronary arteriography: one case with occlusion of anterior descending artery and circumflex coronary artery (the other 8 cases without significant lesions). We concluded that TA affects independently the arteries of different areas, hence it is necessary to perform multiple angiographic studies for adequate evaluation of the extension of vascular damage.

Adolescent↗
PubMedDate not supplied

[Left aortic arch without a circumflex segment and a right descending aorta: a hypothetical case and a real example].

We studied a case of a patent left ductus arteriosus, with a left aortic arch connected to a right descending aorta without an aortic circumflex (retroesophageal) segment. We believe this is the first world-published example of this--so far--hypothetical anomaly, included in Kirkling and Edwards classification of vascular rings. The case was a 27-year-old deaf-mute female patient with a patent left ductus arteriosus, with important left to right shunt and moderate pulmonary arterial hypertension who underwent a successful closing surgical procedure. In the aortographic study a left (normal) aortic arch was seen, which after giving off a large left ductus arteriosus, crossed to the right and connected to a right descending aorta. In the upper part of the thorax the esophagus and trachea were displaced to the right by the left aortic arch. The esophagus in the middle and the upper inferior parts of the thorax was also displaced to the right by the descending right aortic segment. Complete vascular ring was not evident. The case--although without clinical importance--reinforces the pathogenic concept of the Rathke diagram of a complete double aortic primitive arch originating the pulmonary and supraaortic vascular structures which are formed by the obliteration or disappearance of particular segments of the structure. This knowledge explains the embryogenesis of these complex anomalies. Our case is believed to be formed by the very early disappearance of a frontal portion of the primitive left dorsal aorta.

Adult↗
PubMedDate not supplied

[Takayasu arteritis with calcified giant ventricular aneurysm. Presentation of a case].

Takayasu Arteritis (TA) was thought to only involve the aortic arch and its main branches, but subsequent studies demonstrated that the arteritis in not confined to these areas. The process can involve, among others, the coronary arterial tree and is capable to produce myocardial infarction. Many authors thought that when patients with TA presented with heart failure, it was generally a consequence of extramyocardial factors such as systemic or pulmonary hypertension and/or aortic regurgitation. We present the case of a young female with TA and calcified giant ventricular aneurysm. We discuss the probabilities of its origin and emphasize the relationship between the pathologic findings and the possibility of direct myocardial damage by TA, but our impression is that it is due to coronary involvement because we found a lesion in the anterior descending artery.

Adult↗
PubMedDate not supplied

[Evaluation of sympathetic tone in essential hypertension by the clonidine suppression test].

Recent evidences suggest that the sympathetic nervous system plays a major role in the pathogenesis and maintenance of several clinical forms of hypertensive disease. The clonidine suppression test allows us to uncover the subtle changes in neuronal noradrenaline release in essential hypertension. To prove this possibility, we selected 16 patients: 7 borderline hypertensives (BH) (4 males and 3 females), mean age: 24 years; and 9 established hypertensives (EH) (6 males and 3 females), mean age: 25 years. In both groups, the heart rate (HR) and blood pressure (BP) were registered every 30 min and by intravenous catheter plasma catecholamines (PCA) and plasma renin activity (PRA) were measured before and after (180 and 240 min) one oral dosis of clonidine (300 mcg) had been administered. Patients remained in clinostatism for 180 and and orthostatism for 60 min. HR and BP diminished in BH and EH after clonidine during clinostatism in comparison to preclonidine period. PCA also showed reduction in 180 min with respect to the basaline period. PRA did not present change in 180 min in either groups in relation to time O. During orthostatism, HR increased in both groups with respect to the baseline period. BP remained low in relation to baseline time. PCA were increased with respect to preclonidine period. PRA showed a slight tendency to increase in relation to time O in both groups. CAP baseline level are not reliable indexes of the role of the sympathetic tone in maintenance of high BP values in hypertensive disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[The P-wave in systemic arterial hypertension].

An abnormal electrocardiographic P wave (AEPW) has been interpreted as indicative of heart failure, hypertrophy or dilatation of left atrium, or diminished left ventricular compliance. In order to determine the significance of this electrocardiographic sign we studied 47 cases of systemic arterial hypertension (SAH) without heart failure or coronary obstruction. Patients were assigned at 2 groups: group A (22 cases with P wave duration greater than 0.11 seg. (LEAD D2); and group B 25 cases with P wave duration less than this. The following data were studied in all cases: left ventricular ejection fraction (LVEF), left ventricular presystolic filling fraction (LVPFF), Sokoloff electrocardiographic index (SEI), final diastolic pressure of LV (FDPLV), and systolic arterial pressure (SAP). Results were: (Table: see text). There were not statistical differences in these values between groups A and B (including the FDPLV value not shown in the table). Correlation coefficient between duration of P wave and the other parameters studied were also no significant. AEPW in SAH is not related to an specifically degree of left ventricular hypertrophy or disfunction; therefore, hypertensive heart disease should not be classified taking in account this electrocardiographic sign.

Blood Pressure↗
PubMedDate not supplied

[The P wave in systemic arterial hypertension. Comparison with the echocardiogram and apexcardiogram].

The cause of an abnormal electrocardiographic P wave (AEPW) in systemic arterial hypertension (SAH) has not been delucidated. In order to demonstrate if this sign is related to volume overload of the left atrial cavity -previously we found no correlation between pressure overload of the cavity and the presence of an AEPW- 34 patients with SAH were studied; population were divided in two groups: group A (GA, n = 13), formed by 13 cases with a P wave more than 0.10 s duration (D2 standard lead) and group B integrated by 21 cases with a P wave at 0.10 s or less duration. In each cases phonocardiographic and echocardiographic (Mode M) studies were performed and the following data were obtained: "A" index (AI), left atrial dimension (LAD) and, septal (SD) and left posterior wall dimension (LPWD); besides: Sokolow electrocardiographic index (SI) and systolic (SBP) and diastolic (DBP) blood pressure. Results are shown in the following table: (Table: see text). There were not statistical differences between groups (data of SBP and DBP not shown). Correlation between LAD and AI and duration of P wave were not statistical different (data not shown). An AEPW in SAH does not seem to be cause by a volume left atrial overload. Possible it is related to an interatrial conduction defect.

Adult↗
PubMedDate not supplied

[Effects of a calcium antagonist (nifedipine) in hypertensive and normotensive subjects].

We investigated the effect of the calcium antagonist nifedipine upon the following parameters: systolic and diastolic blood pressure (SBP and DBP) heart rate (HR), electrocardiogram (ECG) and the relative rate of calcium uptake in platelets. The possible correlation between this rate and blood pressure was one of the main points we tried to establish. The subjects studied were 1) 26 patients with uncomplicated essential hypertension and 2) 13 healthy normotensive subjects. SBP and DBP were measured with the subject both in a recumbent and a sitting position. 10 mg of nifedipine were given orally. In the hypertensive patients SBP and DBP decreased significantly in both positions after receiving the drug, as expected, while HR increased significantly (P less than 0.001), also in both positions. In the normotensive subjects BP decreased too, after taking the drug, but was only significantly modified in some instances i.e. SBP recumbent, DBP recumbent and sitting. HR increased significantly in the sitting position but not in the recumbent position. The ECG post-nifedipine showed a negative depression of the ST segment in four patients from the hypertensive group. The relative rate of calcium uptake in platelets measured before the subjects had taken the drug decreased after it was administered. The difference was significant (P less than 0.05) in the hypertensive group, but not in the normotensive group. Some correlation was found between DBP and the rate of calcium uptake.

Adult↗
PubMedDate not supplied

[Problem in the management of arterial hypertension resistent to drug treatment. Study of 28 cases].

The antihypertensive effect of the following therapeutic regimens: diuretic alone (DA), diuretic plus sympathetic inhibitor (DSI), diuretic plus betablocker (DB) and diuretic plus, betablocker plus vasodilator (DBV) was studied for 34.1 +/- 5.4 months in 28 patients with resistant essential hypertension (REH). Depending of treatment tolerability and the optimal antihypertensive action of drugs 21, 24, 26 and 10 cases were treated continuously or alternately with DA (9.9), DSI (15.0), DB (4.8), and DBV (14.6), respectively (in paragraph average duration of treatment in months). On admission the 89.3% and 42.8% of population had electrocardiographic signs of left ventricular hypertrophy or past-history of cardio-vascular complications, respectively. Arithmethic average and standard deviation of individual changes of systolic and diastolic blood pressure obtained during DA, DSI, DB and DBV treatment were -32.4 +/- 31.8, -19.3 +/- 27.2, -18.9 +/- 15.9 and -18.2 +/- 21.3 for systolic and -35.8 +/- 20.2, -12.3 +/- 17.2, -15.1 +/- 16.9 and -15 +/- 13.1 (mm. de Hg.) for diastolic blood pressure respectively. Average blood pressure before treatment was 222.4 +/- 30.3/128.0 +/- 20.8 (mm of Hg) and under the most effective treatment was 175.5 +/- 21.8/106.5 +/- 12.1 with a p less than or equal to 0.001 for either sistolic and diastolic pressure. There were not significant regressive electrocardiographic changes during the therapeutic period, neither significant changes in urea and creatinine blood values. 46.4% and 25% of cases exhibited collateral drug symptoms and cardio-vascular no fatal complications, respectively. Three of the last group patients died outside of the Hospital (2 sudden deaths and 1 renal insufficiency death). RH still constitutes a challenge to medical therapy. Nevertheless individualized therapy may modify the natural history of this hypertensive variety.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

[Effect of alpha, beta blocker, labetol on the angiotensin renin system in arterial hypertension].

The effect of labetalol, a new alpha and beta adrenergic blocker, on blood pressure, heart rate, plasma renin activity (PRA), and urinary aldosterone excretion was assessed in 23 essential hypertensive patients, divided in 2 subgroups: 11 with normal electrocardiogram and 12 with left ventricular hypertrophy (LVH). In the first subgroup significant differences were found in the arithmethyc mean for sistolic blood pressure in sitting position (control: 166.1 +/- 17.2 mm of Hg treatment: 153.9 +/- 13.8, p less than or equal to 0.005) and in standing position (control: 165.3 +/- 17.3, treatment: 152.8 +/- 13.8, p less than or equal to 0.005) and for diastolic blood pressure (control: 102.7 +/- 12.6 to 89.9 +/- 10.1, p less than or equal to 0.001 and 103.2 +/- 11.8 to 91.2 +/- 10.8, p less than or equal to 0.001; in sitting and orthostatic positions, respectively.). No significant differences were found in the group with LVH. Heart rate decreased in the total population during treatment (- 6.0 +/- 7.5, p less than or equal to 0.05 and - 5.4 +/- 7.5 beats per minute, p less than or equal to 0.05 in sitting and orthostatic positions, respectively. PRA diminished in 12 of 15 cases studied (- 2.5 +/- 4.65 ng/ml/hr., p greater than 0.5). Correlation coefficient between decrements of diastolic blood pressure (sitting position) and ARP was 0.637. Aldosterone decreased in a non significant way during treatment. These data support the thesis of an important role of the adrenergic system in the pathogenesis of non complicated essential hypertension and, therefore, simultaneous alpha and beta receptor blockade in these cases has a better therapeutic effect. The good correlation between the decrements of ARP and blood pressure suggests an intervention of the inhibition of renin angiotensine system, brought about by the blocker property of labetalol, in the antihypertensive mechanism of the drug.

Angiotensin II↗