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Biomedical subjects

S Olvera

Publications and source records attributed to S Olvera.

13 recordsLinked to original sources
PubMed1992

Total anomalous pulmonary venous connection in adults. Long-term follow-up.

Between 1961 and 1989, 19 patients with total anomalous pulmonary venous connection underwent surgical correction. Ages ranged from 18 to 38 years (mean 26.2 +/- 6.5 years). The anatomic variants included 10 patients with total anomalous pulmonary venous connection to the vertical vein, 6 patients with total anomalous pulmonary venous connection to the coronary sinus, and 2 with total anomalous pulmonary venous connection directly to the right atrium. The last patient had mixed connection to the coronary sinus and left vertical vein. Two patients died, one because of left atrial rupture and another of low cardiac output. Long-term follow-up after surgical repair ranged from 2 to 24 years (mean 7 +/- 6.2 standard deviation). Preoperative disability, assessed according to New York Heart Association criteria, showed 12 patients in functional class II and seven in class III. After treatment, 16 patients were in class I and one in class II (p less than 0.001). Echocardiographic evaluation of six patients revealed in all a normal left ventricular ejection fraction; the diastolic function was also normal except in one patient. The postoperative evaluation of the pulmonary arterial systolic pressure performed by both Doppler echocardiography and right cardiac catheterization in 14 patients showed a significant reduction of the mean pulmonary arterial systolic pressure from 51.1 +/- 3.4 to 37.4 +/- 14.4 mm Hg (p less than 0.01). The remaining three patients evaluated in the follow-up period only by clinical examination are in New York Heart Association functional class I. The anatomic characteristics of our patients were responsible for the long-term outcome without correction. Surgical treatment of older patients can be performed with satisfactory results and excellent long-term survival.

Adult↗
PubMed1985

The etiology and implications of dense cavitary "photopenia" on myocardial perfusion scintigraphy.

Dense cavitary "photopenia" was observed on 21 of 200 consecutive stress perfusion scintigrams. A prominent finding in many cases, it sometimes occupied only a portion of the region overlying the ventricular cavity, was often seen in some projections and not others, and was frequently adjacent to myocardial perfusion defects. To distinguish an etiology among reduced cavitary radioactivity, relatively increased background radioactivity, or reduced radioactivity in overlying myocardium, quantitative analysis of cavitary, lung and myocardial radioactivity was performed in patients with dense cavitary "photopenia," with and without lung uptake, and compared with results from studies showing increased lung uptake without cavitary photopenia and with normal studies. The results showed that dense cavitary photopenia was related to reduced radioactivity in overlying myocardium. Correlative imaging studies performed with echocardiography and contrast ventriculography confirmed this relationship to myocardial scar in 15 of 21 patients in whom associated akinesis or dyskinesis was seen. Hence, dense cavitary photopenia on stress perfusion scintigraphy is due to a dense myocardial perfusion abnormality, and is often indicative of related scar and an associated severe contraction abnormality.

Adult↗
PubMedDate not supplied

Usefulness of low-dose, once-daily quinapril as monotherapy for patients with hypertension.

A drug surveillance study was performed to determine the tolerance and safety of quinapril in the treatment of patients with stage 1 or 2 hypertension. The trial was noncomparative, open-label, uncontrolled, and nonrandomized. Patients with secondary hypertension, heart failure, other heart diseases, and other serious conditions were excluded. After a washout period of 2 weeks, 752 patients (316 men and 436 women) with diastolic blood pressure (DBP) between 90 and 115 mm Hg and systolic blood pressure (SBP) between 140 and 200 mm Hg were entered into the treatment phase. The mean age of patients (+/- SD) was 53.1 +/- 11.4 years. Patients initially received 10 mg/d quinapril for 4 weeks. For nonresponders, the dosage was titrated up to a maximum of 40 mg. Active treatment continued for 12 weeks. Initial blood pressures (mean +/- SD) were DBP, 102 +/- 6.1 mm Hg, and SBP, 163 +/- 14.4 mm Hg. Final blood pressures were DBP, 83 +/- 6.5 mm Hg, and SBP, 135 +/- 11.6 mm Hg. The response rate for the therapeutic goal (DBP < 90 mm Hg and SBP < 140 mm Hg, or a reduction in SBP > or = 20 mm Hg) was 67.1%; 41 patients did not complete the study. The most common adverse events were cough, headache, and dizziness; only 10 patients (1.3%) failed to complete the study because of adverse events. Quinapril, as used in current private clinical practice, is well tolerated and effective for the treatment of patients with stage 1 or 2 hypertension.

Adult↗
PubMedDate not supplied

[Partial pericardial tamponade immediately after cardiac surgery].

Partial pericardial tamponade is a critical situation frequently misdiagnosed. We describe five patients with this entity during an urgent surgical reintervention performed few hours after the initial one. We found clots compressing cardiac cavities in all, usually in the right atrium. In one of them we found also a clot compressing the left atrium. None of the patients studied had the classical clinical features of cardiac tamponade (Kussmaul's sign: pulsus paradoxus) and we found no difference in blood pressure, quantity of bleeding or pulmonary capillary pressure, considering the reinterventional moment in comparison to the values taken immediately after the initial surgery and the ones registered during the surgical reintervention. There was significative increase in the central venous pressure value, decreased urine output and drop in the cardiac index. Based on this observation, we believe it is possible to have a presumptive diagnosis of partial pericardial tamponade by bidimensional echocardiographic studies just before the surgical reintervention.

Adult↗
PubMedDate not supplied

[Fever and infection after heart surgery. A prospective study of 75 cases].

We prospectively studied 75 patients who underwent elective cardiac surgery, they were otherwise health and were not using inflammation modifying drugs. Their febrile response and inflammatory conditions after surgery were monitored. Most of them had fever, 52/75 (64%). Postoperative infection was rare (13%) and when present, it was due to pathogens easily treated. Contamination-/infection of genitourinary tract occurred in 10/24 cases (16%), only one case was symptomatic. There was no difference in febrile response between infected and not-infected patients, neither the "routine" laboratory evaluation allowed differentiation, therefore the diagnosis of postoperative infection remains clinical. There is difference in febrile response between patients who had or had not extracorporeal circulation during the surgical procedure. In the later, fever developed 2 days later and it had longer duration.

Adolescent↗
PubMedDate not supplied

[Sudden deafness in patients undergoing cardiac surgery with extracorporeal circulation].

Between January 1974 and December 1986, 5,975 patients underwent open heart surgery at National Institute of Cardiology "Ignacio Chávez". We reviewed all open heart cases carried out at this Center. Eleven patients (1.8/1000) presented unilateral sudden hearing loss following cardiopulmonary bypass surgery. Pure tone audiograms, speech reception threshold, discrimination testing, tympanometry and stapedius reflex testing were carried out. We then studied the relationship between the auditory deficit and the type of surgical procedure, length of time on the pump, preexisting ear disease, coexistence of diabetes, use of ototoxic drugs and occurrence of hemodynamic complications. There are 3 possible causes for hearing loss in cardiopulmonary bypass: 1) Microembolism from the cardiopulmonary bypass pump to the arteries that supply only the cochlea. 2) Decreasing cerebral flow, or 3) Microhemorrhage of the internal ear. Ototoxic drugs are used frequently, but the hallmark of these drugs is bilateral toxicity, and all the cases under discussion have been unilateral. Unilateral sudden deafness after open heart surgery constitutes another complication, fortunately rare and benign in most cases. Further studies should be undertaken to clarify the pathophysiology of this entity.

Adult↗
PubMedDate not supplied

[Hypertensive cardiopathy. Phonomechanocardiographic study and review of its physiopathological mechanisms].

Sixty four patients with essential hypertension were studied by phonocardiographic systolic time intervals. Prolongation of the pre-ejection period (PEP) at expense of the isovolume contraction time and of the true isovolume contraction time, which suggests myocardial contractile depression due to the increase in after-load. The significant increase, in rise of mean velocity of ventricular pressure suggests that the Anrep phemomena is used by the human heart as a compensatory mechanism in systemic hypertension. Ejection fraction in hypertensives was significantly lower (P less than 0.001) than that of normal controls, which indicates subclinical depression of ventricular function in the former. Myocardial hypertrophy can be considered as a compensatory mechanism which appears late in systemic hypertension and helps normalize ventricular performance and MVO2. It is clinically detected by an s-4 (registered by phonocardiographic tracings) and by an increase in the "A" index and the apexcardiogram (14.5 +/- 8%). The authors conclude that hypertensive heart disease can be identified early through the functional adaptations wich produce detrimental physiopathological reactions to the heart compensated initially by homeometric autorregulation and latter by myocardial hypertrophy.

Adult↗
PubMedDate not supplied

[Prevention of recurrence of rheumatic cardiopathy in 564 patients].

In a group of 564 patients with rheumatic heart disease seen in the period from 1971 to 1975, who were under benzatinic prophylaxis, 23% were seen in the clinic and 77% at home. The object of this revision is to analyze the latter group in order to obtain the frequency of pharyngoamigdaline infections, and of relapses. 1. During the observation, those patients who did not present pharyngeal infections had no relapses. On the other hand, all relapses were observed in those patients who presented infections. 2. Those patients who carried out the prophylaxis incorrectly and who also presented pharyngeal infections, had almost twice the percentage of relapses as those who carried out the prophylaxis correctly. 3. In the group with effective prophylaxis, including those cases with or without pharyngeal infection, 5% had recurrences. In the group with ineffective prophylaxis, 16% had relapses. 4. Those patients with subsequent attacks doubled the percentage of relapses in comparison with those with initial attacks. 5. The plurivalvular patients have a higher frequency of recurrences than the univalvular patients. 6. During the first year of post-attack prophylaxis, the incidence of relapses is only 1.7%, in comparison with the following years in which there is a higher incidence of around 10%. 7. The total number of recurrences in 564 patients was 8%.

Adolescent↗
PubMedDate not supplied

[Aldosteronism after hypokalemia in diuretic therapy of systemic arterial hypertension].

Twenty-two cases with essential arterial hypertension were studied in the final part of a chronic period of treatment with Chlortalidona and in the first 30 days after treatment. Measurements of the following parameters were made: 1) Change in the excretion of urinary aldosterone (aldo). 2) Change in the arterial pressure (delta P). 3) Transtherapeutic serum potassium (delta K). 4) Change in the Q-T (delta QT) in the electrocardiogram. The measurements were made 3 days after the suppression of the drug and afterwards every 3 to 6 days for a month. The correlation of the K and QT was significant (r = 0.63). The P did not correlate with the K nor with the aldo (r = 0.14). The aldo was -5.92 +/- 3.1 ug./24 hs (p = 0.01) in those cases responsive to the drug. The disappearance of the antihypertensive effect occurred at 9.61 +/- 3.7 days and correlated with the normalization of the QT (r = 0.83) and the serum potassium. The delta aldo correlated with K (r = 0.56) and normalized 6.7 days after the suspension of the drug. The secondary aldosteronism participates in the parogenia of the transtherapeutic hypokalemia although with a slightly significant correlation. The important correlation between the disappearances of the antihypertensive effects and the electrocardiographic signs of hypokalemia may dwell in changes which directly or indirectly exercise the diuretic in the intracellular metabolism of K without necessarily cousing an antihypertensive effect additive of the same hypokalemia.

Adult↗
PubMedDate not supplied

[The renin-angiotensin-aldosterone system in compensated and uncompensated cardiac insufficiency].

Renin Activity (PRA), Aldosterone (PA), Sodium (PNa) and Potassium (PK) in plasma and Aldosterone (UA), Sodium (UNa) and Potassium (UK) in 24 hrs urine were measured in 11 cases of heart failure compensated with treatment (HFCT) consisting in digoxin 0.25 mg daily, furosemide 40 to 80 mg daily, potassium chloride 1.5 g daily and low salt diet and in 12 cases of refractory heart failure (RHF). Mean and standard deviation of PRA, PA, PNa, PK, UA, UNa and UK were 9.7 +/- 8.2 mg/cc/hr. 24.2 +/- 14.0 mg/100 cc, 142.2 +/- 4.7 mEq/1, 4.9 +/- 0.3 mEq/1, 8.7 +/- 9.1 ug/24 hrs, 89.3 +/- 50.0 mEq/24 hrs and 50.0 +/- 26.7 mEq/24 hrs, respectively for cases with HFCT and 61.7 +/- 37.5, 120.3 +/- 125.8, 133.1 +/- 4.3, 4.9 +/- 0.4, 21.3 +/- 19.2, 9.9 +/- 19 and 33.3 +/- 12.0 respectively for subjects with RHF. The statistical analysis of PRA, PA, PNa and UNa, revealed differences between the two groups with p values of less than or equal to 0.05, less than or equal to 0.001, less than or equal to 0.001, less than or equal to 0.001, respectively. The other values were statistically non significant. These data suggest the existence of an stimulatory state of the renin-angiotensin-aldosterone system (RAAS) in the RHF and a normal state in HFCT. The lack of electrolytic changes suggestive of aldosteronism in RHF may be due to an alteration of aldosterone receptors or to hemodynamic renal factors. In heart failure hemodynamic changes rather than humoral factor seems to control RAAS.

Adult↗
PubMedDate not supplied

[Hepato-splenic scintigraphy in finding indications of bacterial endocarditis. Preliminary report].

Hepato-splenic scintigraphy with 99mTc-S-colloid was performed in twelve patients with bacterial endocarditis. These images showed that the size of the liver varied from normal to a severe hepatomegaly, depending on the presence of congestive heart failure. Intrahepatic distribution of the radiocolloid was slighty irregular in all cases. The spleen was conspicuously enlarged, and showed irregular distribution of the radiopharmaceutical. In some cases intrasplenic concentration defects caused by infarcts, abscesses or cysts, were observed. The relative uptake of radiocolloid by the spleen, varied from hypo- to hyperconcentration according to the degree of lymphoid hyperplasia caused by the infection. In two cases, both with congestive heart failure, concentration of the radiocolloid was evident in the bone marrow. The scintigraphic pattern observed in these patients with bacterial endocarditis can be easily differentiated from that caused by only congestive heart failure, which is similar to the observed in patients with cirrhosis of the liver and/or portal hypertension.

Adolescent↗