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Biomedical subjects

G S Aldea

Publications and source records attributed to G S Aldea.

At least 37 records · Page 2Linked to original sources
PubMed1997

Repair of left ventricular aneurysm: long-term results of linear repair versus endoaneurysmorrhaphy.

BACKGROUND: Recently, endoaneurysomorrhaphy has been proposed as a more physiologic repair of postinfarction left ventricular aneurysm than is linear repair. There are only a few studies comparing the short-term and long-term results of the two techniques. METHODS: Clinical outcomes and echocardiographic measurements of left ventricular volume and sphericity in 27 patients who underwent endoaneurysmorrhaphy were compared with those in 20 patients who had linear repair. RESULTS: The two groups were matched with respect to age, gender, comorbid risk factors, functional class, urgency of the operation, and concomitant procedures. Preoperatively, left ventricular ejection fraction was lower in the endoaneurysmorrhaphy group (0.25 +/- 0.08 versus 0.30 +/- 0.09; p = 0.03). Follow-up was available in 44 patients (94%) and ranged from 2 to 86 months (mean, 41.0 +/- 26.5 months). Thirty-day operative mortality, perioperative complications, 5-year survival, and freedom from cardiac death were similar. Early postoperative percentage increase in left ventricular ejection fraction was greater after endoaneurysmorrhaphy (0.51 +/- 0.64 versus 0.18 +/- 0.48; p = 0.036). Long-term functional improvement was significantly better in the endoaneurysmorrhaphy group: At the time of last follow-up, 88% of patients were in New York Heart Association class I/II, compared with 53% after linear repair (p = 0.01). There were no measurable differences between the groups with respect to left ventricular ejection fraction (0.28 +/- 0.11 versus 0.27 +/- 0.11; p = 0.90), left ventricular volume (171.6 +/- 59.1 versus 169.9 +/- 54.4 mL; p = 0.94), and sphericity index (0.61 +/- 0.09 versus 0.61 +/- 0.12; p = 1.0). CONCLUSIONS: Despite having a similar effect on left ventricular geometry, endoaneurysmorrhaphy resulted in a greater increase in postoperative left ventricular ejection fraction and a substantially improved long-term clinical outcome.

Case-Control Studies↗
PubMed1997

Heparin-bonded circuits decrease myocardial ischemic damage: an experimental study.

BACKGROUND: Heparin-bonded cardiopulmonary bypass circuits reduce complement activation, but their effect on myocardial function is unknown. This study was undertaken to determine whether heparin-bonded circuits reduce myocardial damage during acute surgical revascularization. METHODS: In 16 pigs, the second and third diagonal vessels were occluded with snares for 90 minutes followed by 45 minutes of cardioplegic arrest and 180 minutes of reperfusion with the snares released. During the period of coronary occlusion, all animals were placed on percutaneous bypass followed by standard cardiopulmonary bypass during the periods of cardioplegic arrest and reperfusion. In 8 pigs, heparin-bonded circuits were used, whereas 8 other pigs received nonbonded circuits. RESULTS: Animals treated with heparin-bonded circuits had the best preservation of wall motion scores (3.5 +/- 0.3 versus 2.3 +/- 0.2; 4 = normal to -1 = dyskinesis; p < 0.05), least tissue acidosis (change in pH = -0.31 +/- 0.02 versus -0.64 +/- 0.08; p < 0.05), smallest increase in lung H2O (1.7% +/- 0.7% versus 6.1% +/- .5%; p < 0.05), and the lowest area of necrosis/area of risk (20.3% +/- 2.2% versus 40.4% +/- 1.6%; p < 0.05). CONCLUSIONS: We conclude that heparin-bonded circuits significantly decrease myocardial ischemic damage during acute surgical revascularization.

Acid-Base Equilibrium↗
PubMed1997

Factors influencing mortality after emergency coronary artery bypass grafting for failed percutaneous transluminal coronary angioplasty.

BACKGROUND: Emergency coronary artery bypass grafting after failed percutaneous transluminal coronary angioplasty is associated with increased mortality. METHODS: From 1981 through 1995, 117 patients at our institution underwent emergency coronary artery bypass grafting after failed percutaneous transluminal coronary angioplasty, with an in-hospital mortality rate of 13.6%. Univariate and multivariate analyses were used to identify the factors that influenced the risk of death. RESULTS: Univariate analysis revealed that patients who died more often were women and had chronic renal failure, lower ejection fractions, and more diffuse coronary artery disease; less often received an internal mammary artery graft or an antegrade perfusion catheter; required inotropic support in the cardiac catheterization laboratory; and experienced myocardial infarction. Multivariate analysis demonstrated that the need for inotropic support in the cardiac catheterization laboratory was the best predictor of perioperative death. CONCLUSIONS: Patients with a reduced ejection fraction in whom percutaneous transluminal coronary angioplasty fails, antegrade perfusion does not produce a response, and myocardial infarction occurs are more likely to die after coronary artery bypass grafting. The risk appears to be highest for patients who require inotropic support in the cardiac catheterization laboratory.

Analysis of Variance↗
PubMed1997

Prognosis and quality of life after valve surgery in patients older than 75 years.

BACKGROUND: Assessment of quality of life has become an increasingly important aspect of the risk-benefit analysis of any therapeutic intervention, particularly in high-risk populations, such as the elderly. METHODS: Clinical outcomes of 147 consecutive patients older than 75 years undergoing valve surgery between 1992 and 1995 were reviewed. Long-term quality of life was assessed using a modified version of the Duke University Medical Outcomes Study system. RESULTS: Mean age was 79.3+/-4 years, range was 75 to 89 years, and 67% (99/147) were male. Preoperatively, 128 patients (87%) were in New York Heart Association (NYHA) functional class III/IV. Fifty-two percent (77/147) of the operations were nonelective. Concomitant coronary artery bypass grafting was performed in 69 patients (47%). Thirty-day hospital mortality was 7.5% (11/147). Mean follow-up for 98% (133/136) of hospital survivors was 30+/-13 months (range, 2 to 55 months). Actuarial survival at 55 months was 71+/-6%-equivalent to a general age-, race-, and gender-matched population reported in the Life Tables of the US National Center for Health Statistics. At the time of follow-up, 112 patients (96%) lived at home, 78% (91/116) defined their health between good to excellent, and 81% (93/114) stated that the operation improved their health status. Ninety-seven percent (112/116) were able to bathe and dress independently, 92% (104/113) could walk at least one block, and 88.5% (100/113) could climb at least one flight of stairs. Moderate to vigorous activities could be performed by 59.2% (67/113). Overall, at the time of follow-up, 81% (95/117) were in NYHA class I/II. CONCLUSION: In a selected patient population, valve surgery in the elderly is associated with acceptable early morbidity and mortality. Long-term survival and quality of life are excellent. These facts strongly support the performance of these procedures in patients older than 75 years.

Activities of Daily Living↗
PubMed1996

Salvage of ischemic myocardium with simplified and even delayed coronary sinus retroperfusion.

BACKGROUND: Despite the proven efficacy of pressure-controlled intermittent coronary sinus obstruction (PICSO) and synchronized retrograde perfusion (SRP) in salvaging ischemic myocardium, wide application of these coronary sinus (CS) retroperfusion techniques has been limited by concerns about their safety and complexity and in particular the need for repeated occlusion of the CS with a balloon. To address these concerns a simplified retroperfusion technique (SR) was developed that continuously infuses superior vena caval blood at 7 mL/min into the CS catheter without balloon occlusion. METHODS: Thirty pigs underwent 90 minutes of ischemia imposed by snaring the two largest diagonal branches of the left anterior descending artery and were randomized to one of five treatment groups: One group received no retroperfusion (control). Three groups had immediate (Im) institution of PICSO, SRP, or SR. In a final group, an initial 60 minutes of ischemia was followed by 30 minutes of delayed SR with superior vena caval blood. All animals were then placed on cardiopulmonary bypass and, after a 60-minute cardioplegic arrest, the coronary artery obstructions were removed, to simulate surgical revascularization. This was followed by 3 hours of reperfusion. The area of myocardium at risk and the area of infarction were determined by methylene blue and triphenyltetrazolium chloride staining with planimetric quantification. RESULTS: Results are reported as mean +/- standard deviation. The area of the left ventricle at risk for infarction was similar in all the treatment groups and represented 22.3% +/- 4.1% of the left ventricular mass. The area of infarction after 3 hours of reperfusion was 48.5% +/- 11.0% for the control group, 26.8% +/- 7.3% for Im-PICSO, 24.9% +/- 4.8% for Im-SRP, 22.4% +/- 6.6% for Im-SR, and 27.7% +/- 7.2% for delayed SR (p < 0.01 for each group versus control). The mean CS pressure (in mm Hg) during treatment was 6.3 +/- 1.7 for the control group, 25.7 +/- 4.5 for Im-PICSO, 22.8 +/- 3.7 for Im-SRP, 5.0 +/- 1.5 for Im-SR, and 6.3 +/- 2.1 for delayed SR (p < 0.01 for Im-PICSO and Im-SRP versus control). CONCLUSIONS: The simplified retroperfusion technique is as effective as PICSO and SRP in salvaging ischemic myocardium, but is considerably simpler. The simplified retroperfusion technique is inherently safer because of the lower CS pressures imposed by low flows and the lack of CS balloon obstruction. The efficacy of delayed SR has profound implications on possible mechanisms of ischemic myocardial salvage. Further investigation is warranted.

Animals↗
PubMed1996

Heparin-bonded circuits with a reduced anticoagulation protocol in primary CABG: a prospective, randomized study.

BACKGROUND: A substantial proportion of patients undergoing primary coronary revascularization require homologous transfusions. To address this problem, a comprehensive strategy to diminish perioperative blood loss was developed. METHODS: A prospective randomized trial was undertaken to test the hypothesis that "tip-to-tip" heparin-bonded cardiopulmonary bypass circuits (HBC) can further enhance blood conservation and clinical outcomes in patients undergoing primary coronary artery bypass grafting. Two hundred thirty-four patients were treated with either HBC and lower anticoagulation therapy (activated clotting time > 280 seconds) or with conventional, nonheparin-bonded circuits and full anticoagulation therapy (activated clotting time > 480 seconds). RESULTS: Preoperative and intraoperative risk profiles and characteristics were similar in both groups, with 69.7% of the patients undergoing nonelective coronary artery bypass grafting. Compared with the group with nonheparin-bonded circuits, patients treated with HBC had a lower chest tube output in the first 24 hours (561 +/- 257 versus 651 +/- 403; p = 0.04), were less likely to receive blood products (31.6% versus 47.9%; p = 0.01), and required substantially fewer homologous donor units (1.98 +/- 4.8 versus 4.29 +/- 10.1; p = 0.029). Patients treated with HBC required a shorter duration of ventilatory support (13.2 +/- 16.9 versus 23.4 +/- 50.0 hours; p = 0.04), spent less time in the surgical intensive care unit (20.7 +/- 17.4 versus 35.5 +/- 61.7 hours; p = 0.01), spent fewer days in the hospital (6.0 +/- 2.5 versus 7.3 +/- 5.2 days; p = 0.02), and had fewer postoperative complications (25.6% versus 39.3%; p = 0.03). The use of HBC with a lower anticoagulation protocol was not associated with any adverse events. CONCLUSIONS: This study demonstrates that the use of HBC with a lower anticoagulation protocol in primary coronary artery bypass grafting safely and effectively reduces the incidence and magnitude of homologous transfusion, the duration of ventilation, and surgical intensive care unit and hospital stays.

Aged↗
PubMed1995

Determinants of length of stay after coronary artery bypass graft surgery.

BACKGROUND: Rising healthcare costs have prompted limitations in the length of stay (LOS) for patients undergoing coronary artery bypass graft surgery (CABG). Because not all patients are candidates for early discharge, in the present study our aim was to determine factors that prolong LOS. METHODS AND RESULTS: In 194 consecutive patients undergoing CABG procedures, LOS was > 7 days in 37%. Stepwise multiple regression procedures and chi 2 testing were used to determine what factors prolonged LOS for > 7 days. Preoperative factors that significantly (P < .05) prolonged LOS included repeat CABG, CABG plus valve surgery, congestive heart failure, preoperative coronary care unit stay, renal failure, and insulin-dependent diabetes mellitus. Patients with at least one risk factor had a significantly higher incidence of LOS of > 7 days (47% versus 17%; P < .001). Significant (P < .05) postoperative factors prolonging LOS included arrhythmias, respiratory insufficiency, pneumonia, and wound infection. Of patients with at least one risk factor, 83% had LOS of > 7 days (P < .001). CONCLUSIONS: The presence of certain preoperative and post-operative risk factors can be predicted to prolong LOS after CABG surgery. This should be taken into consideration when defining reimbursement policies.

Aged↗
PubMed1995

Pulmonary venous flow in constrictive pericarditis.

A 35-year-old white female patient presented with radiation-induced constrictive pericarditis. Intraoperative transesophageal echocardiography revealed a uniphasic diastolic flow pattern. This pulmonary flow pattern reverted to a normal biphasic systolic/diastolic profile immediately following radical pericardiectomy. This abnormal flow pattern was previously described as typical for restrictive cardiomyopathy. However, in this case it is most likely due to a marked decrease in left atrial compliance induced by the thick fibrous scar encasing the atrial.

Adult↗
PubMed1995

Gastrointestinal complications following cardiac surgery.

This study sought to determine which factors influence the mortality rate in patients developing gastrointestinal complications following cardiac surgery. Between July 1988 and January 1992, 2054 patients underwent cardiac surgical procedures at the Boston University Medical Center. Of these, 29 (1.4%) developed postoperative gastrointestinal complications. The overall mortality rate among these patients was 27% (8/29). Those who died following such complications had a higher incidence of New York Heart Association (NYHA) class IV and unstable symptoms (8/8, 100% versus 3/21, 14%; P < 0.0001), and an increased need for preoperative intra-aortic balloon pump support (4/8, 50% versus 1/21, 5%; P < 0.004). The need for gastrointestinal surgical intervention increased the mortality rate significantly compared with patients managed medically (8/18, 44% versus 0/11, 0%; P < 0.01). Patients with ischemic bowel also had a significantly higher mortality (5/5, 100% versus 3/24, 12%; P < 0.001). It is concluded that most patients with gastrointestinal complications following cardiac surgery can be treated, and with acceptable mortality rates. The presence of unstable symptoms, preoperative intra-aortic balloon pump support, ischemic bowel and the need for gastrointestinal surgical intervention adversely affect mortality.

Aged↗
PubMed1995

Rupture of the right atrium secondary to blunt cardiac injury.

Occult cardiac injury following blunt trauma is underestimated in frequency of occurrence. Recent reports indicate that it rivals thoracic aortic transection as the cause of death following traffic fatalities. The most common mechanisms include rapid cardiac rotation while the great vessels remain fixed, transfer of hydraulic pressure from the abdomen or extremities, and direct myocardial compression by the sternum. Presentation can be diverse and findings can include jugular venous distention, upper extremity cyanosis, unexplained hypotension, and muffled heart sounds. An enlarged cardiac silhouette is occasionally seen on roentgenographic evaluation. A surprisingly large number of these patients are noted to have no significant signs of external thoracic trauma. Possible mechanisms include rapid rotation and deceleration of the heart with fixation of the great vessels, transmission of a large venous pressure wave to the heart following abdominal or extremity compression, and direct compression of the heart by the sternum. Following prompt diagnosis and rapid surgical intervention, a large number of these patients can be expected to survive this otherwise fatal injury.

Adult↗
PubMed1994

Increased left ventricular diastolic chamber stiffness immediately after coronary artery bypass surgery.

OBJECTIVES: The aim of this study was to assess the incidence and severity of left ventricular diastolic dysfunction immediately after coronary artery bypass surgery by utilizing simultaneous transesophageal echocardiographic and hemodynamic monitoring. BACKGROUND: Left ventricular diastolic dysfunction has been documented after coronary bypass surgery, but its measurement has been technically difficult to acquire and limited by dependence on loading conditions. METHODS: End-diastolic pressure-area curves were constructed before and immediately after coronary bypass surgery in 20 patients. Transesophageal echocardiographic images at the midpapillary level of the left ventricle and hemodynamic data were recorded. Volume status was manipulated to alter loading conditions, and multiple measurements were taken at each loading condition. RESULTS: Diastolic function worsened in all patients, as manifested by a postoperative leftward shift of the end-diastolic pressure-area curve. At a comparable preload, mean end-diastolic area +/- SEM decreased by 15% from 17.6 +/- 0.8 to 14.9 +/- 0.8 cm2 postoperatively (p = 0.0001). CONCLUSIONS: Left ventricular diastolic chamber stiffness frequently increases immediately after coronary artery bypass surgery. Simultaneous hemodynamic and transesophageal echocardiographic monitoring, through the construction of end-diastolic pressure-area curves, is a useful method to evaluate diastolic function and guide management after cardiac surgery.

Aged↗
PubMed1994

Enhanced preservation of acutely ischemic myocardium with transseptal left ventricular assist.

Mechanical support for acute regional ischemia without hemodynamic collapse may be achieved percutaneously with an intraaortic balloon pump (IABP) or with transseptal left ventricular assist (TLVA) while awaiting revascularization. The relative benefits of these two percutaneous transfemoral techniques for the treatment of ischemia were compared in a representative animal model. During 90 minutes of regional coronary occlusion, four groups of 8 pigs were treated with either no support (control), IABP, TLVA, or both IABP and TLVA. Cardioplegic arrest for 30 minutes to simulate coronary grafting was followed by 180 minutes of global reperfusion on bypass. In all groups regional wall motion and interstitial pH in the area at risk were significantly depressed with ischemia, but wall motion fully recovered after reperfusion. However, histochemical staining of the area of necrosis/area at risk was significantly reduced with IABP versus control (20.2% versus 34.1%; p < 0.05) and further significantly reduced with TLVA and IABP + TLVA (10.7% and 6.7% versus IABP alone; p < 0.05). We conclude that in supporting even a modest-sized myocardial region at risk (12% of the left ventricle) the area that went on to infarction was significantly reduced with the use of TLVA over IABP. Regional wall motion and myocardial pH measurements did not reflect this difference in the early reperfusion period. The benefit of TLVA over IABP during more extensive or prolonged ischemia may have real clinical significance.

Acute Disease↗
PubMed1994

Thoracotomy for repair of left ventricular aneurysm in a patient with patent coronary bypass grafts.

A 72-year-old man presented with a posterior left ventricular aneurysm 5 years after undergoing quadruple coronary artery bypass grafting. An angiogram demonstrated patent saphenous vein grafts, but also showed incidental asymptomatic aortic aneurysms. Left ventricular endoaneurysmorrhaphy was performed through a left thoracotomy. This approach affords excellent exposure of a posterior left ventricular aneurysm, averts many of the risks associated with reoperation, and should be considered in patients who have undergone a median sternotomy and who do not require myocardial revascularization.

Aged↗
PubMed1994

Inhomogeneous and complementary antegrade and retrograde delivery of cardioplegic solution in the absence of coronary artery obstruction.

Inhomogeneous delivery of cardioplegic solution may result in postischemic myocardial injury. This study compares the distribution of warm blood antegrade and retrograde cardioplegia to multiple discrete left ventricular myocardial regions in pigs with unobstructed coronary arteries. Cardioplegic solution was delivered antegradely and retrogradely at 150 ml/min, and flows to 1152 individual myocardial regions were determined twice for each route with four different radiolabeled microspheres. The antegrade system delivered greater flow to each gram of myocardium than did the retrograde system (1.37 +/- 0.31 versus 0.39 +/- 0.09 ml/gm per minute, p < 0.001). Flow to individual myocardial regions was significantly inhomogeneous for both antegrade and retrograde cardioplegia, but much more so for retrograde cardioplegia (coefficient of variation was 48% +/- 17% for antegrade cardioplegia and 106% +/- 16% for retrograde cardioplegia; p < 0.001). The pattern of flow to individual myocardial regions was highly reproducible for a given route of delivery as confirmed by repeated measurements with different radioactive microsphere isotopes (correlation coefficients 0.88 +/- 0.12 for AC1-AC2 and 0.84 +/- 0.10 RC1-RC2), but antegrade cardioplegia and retrograde cardioplegia patterns were significantly different and therefore complementary (correlation coefficients 0.03 +/- 0.04, p < 0.001). These findings support the routine combined use of antegrade cardioplegia and retrograde cardioplegia to enhance delivery of cardioplegic solution to all regions of the heart and minimize the potential risk of postischemic myocardial dysfunction.

Animals↗
PubMed1993

A simplified method for implantation of automatic cardioverter defibrillator in patients with previous cardiac surgery.

A method of extrapericardial automatic cardioverter defibrillator implantation using bilateral limited anterior thoracotomy approach is described. The approach was used in six patients who have had previous open heart surgery. The defibrillation threshold was 15 joules in four patients and 20 joules in two. One patient died of pulmonary embolism in the tenth postoperative day. All patients were extubated within 0-18 hours. Drainage of a recurrent pleural effusion was required in one patient. This approach was found to be simple, safe, and effective in patients with previous median sternotomy. It may also be useful in patients in whom a cardiac operation may be indicated later in the course of their disease.

Anesthesia, Endotracheal↗