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Biomedical subjects

S Morán

Publications and source records attributed to S Morán.

At least 37 records · Page 2Linked to original sources

[Papillary muscle rupture in myocardial infarction].

We report nine patients with acute mitral regurgitation secondary to post-infarction papillary rupture operated between 1980 and 1992. Seven cases had posterior papillary muscle rupture. All patients were in critical conditions with pulmonary edema at the moment of surgery. In eight cases, mitral valve replacement was performed (4 with mechanical prostheses) and in one, the valve was repaired with papillary muscle reimplantation. Six cases were also subjected to myocardial revascularization with sapheneous vein grafts. Two patients (22%) died during the postoperative period and 4 had postoperative complications. The seven survivors have been followed during 6 to 115 month. Of theses, one died six month after surgery due to congestive heart failure, three are in functional class I and the rest in functional class II. It is concluded that, although mitral valve replacement for papillary muscle rupture has a high operative mortality and morbidity, long term results are satisfactory.

Aged↗

Portal-systemic encephalopathy and gastrointestinal bleeding after cardioselective beta-blocker (metoprolol) administration to patients with portal hypertension.

The use of the non-selective beta-blocker propranolol has been widely recommended to prevent gastrointestinal bleeding in patients with portal hypertension. We conducted a prospective, randomized controlled trial of metoprolol, a selective beta-blocker for prevention of gastrointestinal bleeding from portal hypertension in 29 non-selected patients with liver disease and previous gastrointestinal bleeding. Fifteen patients received placebo treatment for 40 +/- 18 months and 14 patients received metoprolol for 31 +/- 17 months. A sustained reduction in resting pulse was observed in those patients treated with metoprolol. There was no significant difference in acute re-bleeding episodes between the two groups. Of the 14 patients treated with metoprolol, three (21%) re-bled, all three requiring blood transfusion. Four (26.5%) of the 15 patients treated with the placebo re-bled, two cases with acute bleeding and the remaining two cases presented a positive stool guaiac test. All cases who bled during the metoprolol therapy required exclusion from the trial, and surgical procedures or sclerotherapy as well. After both metoprolol or placebo treatments, similar deterioration of standard liver function tests was observed. Further, at the end of the trial, 11 patients on metoprolol (78%) and four of the patients treated with the placebo (27%) required treatment for clinical portal-systemic encephalopathy (p < 0.01). The risk of poor sympathomimetic response after cardioselective beta 1-blocker during acute bleeding episodes and the appearance of hepatic encephalopathy deserve further investigation. The selective beta-blocker metoprolol seems to be an inadequate choice to prevent gastrointestinal re-bleeding in patients with portal hypertension.

Adrenergic beta-Antagonists↗

[Retrograde cerebral perfusion during circulatory arrest with deep hypothermia. A new technique for brain protection in surgery of ascending aorta and aortic arch].

Between May 1993 and August 1994, 15 patients (10 men) with type A aortic dissection (9 acute) had a replacement of the ascending aorta and/or aortic arch with circulatory arrest with profound hypothermia and retrograde cerebral perfusion. Mean circulatory arrest time was 47.5 min (range 23 to 68 min). Three patients (20%) died in relation to postoperative bleeding. No patient had a new neurologic damage related to surgery. Ten patients were awake and oriented before 24 hours of the operation and another one before 48 hours; 4 patients required more than 48 hours to be completely awake and oriented. Two patients were operated on with a recent stroke. One of them recovered without sequelae before hospital discharge and the other one had a major regression of his brain damage. Two other patients had emergency surgery because of cardiac tamponade and cardiogenic shock. Both of them had a satisfactory recovery. Six patients presented azotemia but only 2 of them needed dialysis. There was no case of Q wave infarction nor congestive heart failure in the perioperative period. Follow-up was 100% completed (12 patients) with a mean of 9.8 months (range 5 to 18 months). One patient died on the 10th postoperative month because of a late infectious process. Eight patients are in functional class I and 3 in II. Ten of them are back to their usual activities'. Although retrograde cerebral perfusion is a new surgical technique, it seems to be a very valuable complement for brain protection in ascending aorta and/or aortic arch surgery with circulatory arrest with profound hypothermia.

Aged↗

[Reactivity of internal mammary artery and saphenous vein used in human myocardial revascularization: studies with endogenous vasoconstrictors and vasodilators].

Biopsies of human internal mammary artery and saphenous vein were examined to ascertain the functional integrity of these vessels employed in myocardial revascularization. Studies were performed in vascular rings derived from 28 patients without previous consideration of age, sex, underlying additional pathology or drug treatments previous to and during surgery. Isometric muscle contraction of the circular muscle layer was monitored. Endothelin-1 (ET) is equipotent as a vasoconstrictor in arteries and veins, with a potency at least 10 to 100-fold that of noradrenaline (NA) or serotonin (5-HT). The potency of ET, NA or 5-HT is unaltered by mechanical removal of the endothelial cell layer. Arterial rings precontracted with NA relaxed in a concentration-dependent fashion in the presence of acetylcholine and sodium nitroprusside. Whereas the potency of nitroprusside was unaltered by removal of the endothelium, the efficacy of acetylcholine was greatly reduced. Saphenous vein rings were refractory to acetylcholine but not nitroprusside. Results open new perspectives to explain the larger patency of internal mammary artery grafts as compared to that of saphenous vein grafts in human myocardial revascularization.

Endothelium, Vascular↗

[Surgery of acute mitral valve insufficiency].

Between January 1980 and December 1990, 16 patients with acute mitral insufficiency were operated on an emergency basis at our institution. They represented 1.8% of all mitral surgical cases. All of them were in acute pulmonary edema and 7 in cardiogenic shock. The etiology was ischemic in 6, degenerative in 4, infectious in 3, degenerative and infectious in 2 and traumatic in 1. The pathologic mechanism was chordal rupture in 8 patients (5 anterior) and papillary muscle rupture in the other 8 (5 posterior). A mitral valve replacement was performed in all cases. Two patients died and 7 had morbidity in the postoperative period. One patient died 6 months after surgery of congestive heart failure. Ten patients are in NYHA functional class I at a mean follow-up of 48.1 months. Acute mitral insufficiency has different etiologies and pathologic mechanisms. In spite of the severe clinical condition of these patients, mitral valve replacement has good immediate and long-term results.

Acute Disease↗

[Dissection of the ascending aorta (type A): diagnostic aspects, surgical treatment and long-term follow-up].

Aortic replacement is the treatment of choice and improves the natural history of dissections involving the ascending aorta. Forty patients (23 male), aged 49.4 years, have been operated at the hospital Clínico de la Universidad Católica. Twenty six presented with acute dissections. Angiography conformed the dissection in 63.3% and computed axial tomography in 84.6% of patients; lately, transesophageal echocardiography has become the most sensitive diagnostic method. Twenty three patients (57.5%) were subjected to emergency operations and 17 to semielective procedures. In 24 patients (60%) ascending aorta was replaced and in 16 a composite graft was used. Operative mortality was 27.5%. Univariate analysis showed that the period in which the operation was performed and the presence of limb ischemia were the only independent predictors of operative mortality. Long term follow up was achieved in 26 patients (89.6%). Actuarial 5 year survival without considering operative mortality was 87.9%. It is concluded that patients with acute dissections involving the ascending aorta should be operated as soon as the imaging diagnosis is complete and, since this is a palliative procedure, a close follow up is required for early detection of complications.

Adult↗

[Interventricular rupture following myocardial infarction. Surgical treatment and long-term follow-up].

The natural course of post myocardial infarction ventricular septal defect is towards cardiogenic shock and death. 50% in the first week, over 90% a year latter. Between 1973-1989, 28 patients where operated on. Before surgery 14 patients (53%) where in Killip IV, 5 patients (19%) in III, 5 patients (19%) in II and 2 patients in I. The repair was accomplished under hypothermia and cardioplegia, with the insertion of a Teflon patch to close the defect in 20 patients (70%). Complementary procedures (CABG, Pacemaker, repair of dissections) were performed in 12 patients (47%). Three patients (10%) could not be weaned from the pump; another 10 (36%) died before discharge: 2 with multisystem failure and sepsis, the other 8 with cardiogenic shock (4 with residual VSD). The only independent predictor of operative mortality, by univariate analysis, was preoperatory cardiogenic shock. All 15 survivors (100%) where followed between 5 months and 14.5 years (mean 104.5 months). Two patients died at 4 years, one at 10, another at 10.5 years. The actuarial probability of being alive after discharge was 100% at 4 years, 75% at 5, and 50% at 10 years. At last follow up only 2 patients had mild dyspnea, the remaining where asymptomatic. Surgical treatment provides an opportunity to improve this otherwise dismal survival and offers a surprising good long term result. An early diagnosis and efficient repair, before the onset of cardiogenic shock, should provide better results.

Actuarial Analysis↗

Characterization of acetylcholinesterase from human heart auricles: evidence for the presence of a G-form sensitive to phosphatidylinositol-specific phospholipase c.

1. Acetylcholinesterase (AChE) is an important enzyme of the cholinergic system in mammals. 2. We report here the subcellular association of the AChE molecular forms in the normal human heart auricle. 3. Both globular (G) and asymmetric (A) forms were identified using velocity sedimentation and sequential extraction procedures. 4. G forms corresponds to 84% and A forms account for 16% of the total AChE activity. 5. Of G forms 64% of AChE activity correspond to the G1 monomer and of the A forms the class I-A account for 80% of AChE activity. 6. In addition, treatment of the cardiac membranes with the enzyme phosphatidylinositol-specific phospholipase c (PIPLC) results in the solubilization of AChE activity. 7. This means that a G2 AChE dimer with a glycolipid anchoring domain is present in the human heart.

Acetylcholinesterase↗

[Wolff-Parkinson-White syndrome: late results of surgical treatment].

We followed 25 patients operated on for Wolff-Parkinson-White syndrome between August 1985 and October 1989. Their mean age was 37 +/- 12 years and arrhythmia had been present for 5 to 30 years. A mean of 3.3 +/- 1.2 antiarrhythmic agents had failed in controlling recurrences. Tachycardia was orthodromic in 21 patients and antidromic in 1, while 3 patients presented rapid atrial fibrillation with hemodynamic deterioration. Drug refractoriness (n = 23) or intolerance (n = 2) were the main surgical indications. The location of accessory pathways was lateral in 19 patients, anteroseptal in 3, posteroseptal in 2, postero lateral in 1 and right lateral in 1 patient. One patient had a double pathway. There was no surgical mortality. After a follow-up period ranging from 1 to 50 months recurrence of arrhythmia was observed in one patient and electrophysiologic evaluation showed persistence of a left lateral pathway in another. The remaining 24 patients are free of symptoms at the end of follow up. Thus, surgical treatment is a curative therapy for most patients with WPW.

Adolescent↗

[The long-term evolution of aortic valve replacement with a mechanical prosthesis: experience with the Starr-Edwards (1965-1974) and Bjork-Shiley (1973-1981) prostheses].

We compared the short- and long-term results of isolated aortic valve replacement in 98 patients receiving a Starr-Edwards (SE) prosthesis from 1965 to 1974 and 80 pts receiving a Bjork-Shiley (BS) prosthesis from 1973 to 1981 at our institution. Operative mortality was 20% (SE) and 6% (BS). Follow-up information was obtained in 88% (SE) and 96% (BS) of pts discharged alive. The mean period of follow up was 8.2 and 6.7 years respectively. The 5 and 10 year actuarial survival rates were 72% and 61% (SE) vs 89% and 83% (BS). Complications per 100 pt-years among pts with SE and those with BS were: systemic emboli 2.8 vs 0.6, major hemorrhagic events 1.25 vs 1.36, perivalvular leak 1.6 vs 1.15, endocarditis 0.31 vs. 0.39, prosthetic thrombosis 0 vs 0.58 and ball variance 0.47 vs 0, respectively. Some of these differences may reflect shortcomings of the initial surgical experience during the period in which the SE prosthesis was used, rather than different performance of both valves.

Adolescent↗

[The heart transplant: the current status].

Interest in cardiac transplantation started with the investigations of Carrel in 1905. Clinical experience started in 1967 but early results were discouraging mainly due to difficulties with diagnosis and treatment of rejection. The introduction of cardiac biopsy to diagnose and cyclosporine to treat rejection vastly improved the success of the procedure. Large number of patients have been operated in different centers and criteria for selecting or excluding patients have emerged. Selection of the donor and improvements in surgical technique have also contributed to better results. Currently, 80% survival in the first year and 70% at 5 years are to be expected, and cardiac transplantation is a definite therapeutic option for selected patients with end-stage cardiac disease. However, significant problems remain to be solved, such as cyclosporin nephrotoxicity, secondary hypertension and occlusive vascular disease of the transplanted heart.

Follow-Up Studies↗

[Atrial ectopic tachycardia. A variety of incessant tachycardia].

A 19 year old patient with incessant supraventricular tachycardia was submitted to electrophysiologic study. An ectopic left atrial focus was demonstrated. Intraoperative mapping localized the focus to the upper left atrial quadrant. Successful surgical isolation of the focus was possible. The patient is currently asymptomatic and arrhythmia free.

Electrocardiography↗

[Surgery of evolving myocardial infarction].

Limitation of infarct size has been proven to improve the prognosis in patients with recent myocardial infarction (MI). Emergency coronary bypass surgery may be used for this aim. We operated on 44 such patients within 15 days of onset of MI. Operation was done within 6 hr in 11 patients and later on in the other 33, due to post infarction angina or incomplete MI. One patient died in the perioperative period. Thirty nine patients were followed at a mean of 33 months: 2 have angina, one dyspnea and the rest is asymptomatic. We believe that bypass surgery is an effective treatment in selected patients with recent MI.

Adult↗