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1.
Malays Orthop J ; 12(1): 31-35, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29725510

RESUMEN

Introduction: Osteoporosis (OP) is a major health problem in the older population. The aim of the study was to assess the role of serum osteoprotegerin (OPG) as a diagnostic indicator of primary osteoporosis in peri- and post-menopausal women in an Indian population. Materials and Methods: After ethical approval, 90 cases (45 cases and 45 controls) of peri- and post-menopausal females above 40 years of age presenting to our outpatient department were included in the study. It was a case controlled study conducted between July 2014 to July 2015. Based on the clinical features, t-score and radiological evidence from the DEXA scan, they were equally divided into two groups (cases and controls). Serum osteoprotegerin (OPG) levels were measured amongst cases and controls. Results: The total calcium (mg/dl) level was lower among the cases and the difference was significant (p-Value= <0.001). Similarly, alkaline phosphatase (u/l), osteoprotegerin (u/ml) levels were higher in the cases as compared to controls and the difference was significant (p-Value= <0.001). The mean osteoprotegerin level showed a slight increase with increase in severity of the grading of BMD of spine. The results suggested a cut-off value of ≥10.5 u/ml (86.7% sensitive and 80% specific with accuracy of 84.5%) between normal and osteoporosis. Conclusion: From the present study, we conclude that osteoprotegerin is a valid biomarker to diagnose postmenopausal women with low bone mineral density.

2.
Am J Transplant ; 16(12): 3522-3531, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27184686

RESUMEN

When transplanted simultaneously, the liver allograft has been thought to have an immunoprotective role on other organs; however, detailed analyses in simultaneous heart-liver transplantation (SHLT) have not been done to date. We analyzed patient outcomes and incidence of immune-mediated injury in 22 consecutive SHLT versus 223 isolated heart transplantation (IHT) recipients between January 2004 and December 2013, by reviewing 3912 protocol- and indication-specific cardiac allograft biopsy specimens. Overall survival was similar (86.4%, 86.4%, and 69.1% for SHLT and 93.3%, 84.7%, and 70.0% for IHT at 1, 5, and 10 years; p = 0.83). Despite similar immunosuppression, the incidence of T cell-mediated rejection (TCMR) was lower in SHLT (31.8%) than in IHT (84.8%) (p < 0.0001). Although more SHLT patients had preexisting donor-specific HLA antibody (22.7% versus 8.1%; p = 0.04), the incidence of antibody-mediated rejection was not different in SHLT compared with IHT (4.5% versus 14.8%, p = 0.33). While the left ventricular ejection fraction was comparable in both groups at 5 years, the incidence and severity of cardiac allograft vasculopathy were reduced in the SHLT recipients (42.9% versus 66.8%, p = 0.03). Simultaneously transplanted liver allograft was associated with reduced risk of TCMR (odds ratio [OR] 0.003, 95% confidence interval [CI] 0-0.02; p < 0.0001), antibody-mediated rejection (OR 0.04, 95% CI 0-0.46; p = 0.004), and cardiac allograft vasculopathy (OR 0.26, 95% CI 0.07-0.84; p = 0.02), after adjusting for other risk factors. These data suggest that the incidence of alloimmune injury in the heart allograft is reduced in SHLT recipients.


Asunto(s)
Aloinjertos/inmunología , Rechazo de Injerto/prevención & control , Supervivencia de Injerto/inmunología , Trasplante de Corazón , Trasplante de Hígado , Complicaciones Posoperatorias/prevención & control , Femenino , Estudios de Seguimiento , Rechazo de Injerto/epidemiología , Rechazo de Injerto/inmunología , Cardiopatías/cirugía , Humanos , Incidencia , Hepatopatías/cirugía , Masculino , Persona de Mediana Edad , Minnesota/epidemiología , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/inmunología , Pronóstico , Factores de Riesgo
4.
Clin Pharmacol Ther ; 91(1): 94-100, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22113236

RESUMEN

Congestive heart failure is associated with poor quality of life (QoL) and low survival rates. The development of state-of-the-art cardiac devices holds promise for improved therapy in patients with heart failure. The field of implantable cardiac assist devices is changing rapidly with the emergence of continuous-flow pumps (CFPs). The important developments in this field, including pertinent clinical trials, registry reports, innovative research, and potential future directions are discussed in this paper.


Asunto(s)
Desfibriladores Implantables/tendencias , Insuficiencia Cardíaca/cirugía , Trasplante de Corazón/tendencias , Corazón Auxiliar/tendencias , Animales , Ensayos Clínicos como Asunto/tendencias , Desfibriladores Implantables/normas , Insuficiencia Cardíaca/fisiopatología , Trasplante de Corazón/normas , Corazón Auxiliar/normas , Humanos
5.
Transplant Proc ; 43(5): 1871-6, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21693292

RESUMEN

BACKGROUND: We analyzed the results of combined heart-kidney transplantation (CHKTx) over a 10-year period. METHODS: Between September 1996 and May 2007 at Mayo Clinic, 12 patients (age 52 ± 12.2 years) underwent CHKTx as a simultaneous procedure in 10 recipients and as a staged procedure in two recipients with unstable hemodynamics after heart transplantation. RESULTS: There was no operative mortality. Patient survival rates for the CHKTx recipients at 1 and 3 months and 6 years were 91%, 83%, and 83% and did not differ from isolated heart transplantation (IHTx) recipients (97%, 95%, and 79%, P = 0.61). The freedom from cardiac allograft rejection (≥ grade 2) at 3 months was 73% for CHKTx and had not changed during further follow-up; for IHTx, freedom from rejection at 3 months and 1 and 6 years was 61%, 56%, and 42% (P = .08). Heart and renal allograft survival was 100% with and left ventricular ejection fraction 66% ± 8.4% and glomerular filtration rate 61 ± 25 at last follow-up. There were no signs of cardiac allograft vasculopathy in the CHKTx recipients. CONCLUSION: CHKTx yields favorable long-term outcome, with a low incidence of cardiac rejection and vasculopathy. Simultaneous CHKTx appears feasible, if hemodynamics is satisfactory. This approach expands the selection criteria for transplantation in patients with coexisting end-stage cardiac and renal disease.


Asunto(s)
Vasos Coronarios/trasplante , Rechazo de Injerto , Trasplante de Corazón , Trasplante de Riñón , Adulto , Vasos Coronarios/patología , Femenino , Humanos , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia
6.
Transplant Proc ; 43(5): 1893-9, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21693296

RESUMEN

A 53-year-old Caucasian male suffering from idiopathic dilated cardiomyopathy underwent cardiac transplantation. Fifty-seven days following transplant, he developed posttransplant lymphoproliferative disorder (PTLD), which was Epstein-Barr virus positive. The initial episode of PTLD was treated with a dose reduction in cyclosporine (CsA) and a 4-week course of rituximab. Subsequent biopsies showed resolution of PTLD. One year posttreatment, his evaluation revealed severe cardiac allograft vasculopathy (CAV). The patient was switched to sirolimus-based immunosuppression regimen with gradual up-titration of sirolimus in combination with complete withdrawal of previously administered Calcineurin-based immunosuppression approach. The switchover was carried out over a 6-week period. In the following 3 years, there was CAV regression as well as PTLD remission, without any significant episode of rejection. Despite frequent relapses with this form of PTLD, the patient remains in remission, 8 years posttransplantation. In summary, sirolimus has been demonstrated to attenuate the progression of CAV, and this case report illustrates that regression of CAV is possible. In addition to preventing rejection, mammalian target of rapamycin inhibitors directly suppress signaling pathways leading to PTLD and may be effective monotherapy for preventing rejection and suppressing PTLD.


Asunto(s)
Anticuerpos Monoclonales de Origen Murino/uso terapéutico , Ciclosporina/uso terapéutico , Trasplante de Corazón/efectos adversos , Trastornos Linfoproliferativos/tratamiento farmacológico , Anticuerpos Monoclonales de Origen Murino/administración & dosificación , Inhibidores de la Calcineurina , Ciclosporina/administración & dosificación , Humanos , Inmunosupresores/administración & dosificación , Inmunosupresores/uso terapéutico , Masculino , Persona de Mediana Edad , Rituximab , Sirolimus/administración & dosificación , Sirolimus/uso terapéutico
7.
Am J Transplant ; 9(1): 132-9, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19067662

RESUMEN

The aim of this study was to assess the patterns, predictors and outcomes of left ventricular remodeling after heart transplantation (HTX). Routine echocardiographic studies were performed and analyzed at 1 week, 1 year and 3-5 years after HTX in 134 recipients. At each study point the total cohort was divided into three subgroups based on determination of left ventricle mass and relative wall thickness: (1) NG-normal geometry (2) CR-concentric remodeling and (3) CH-concentric hypertrophy. Abnormal left ventricular geometry was found as early as 1 week after HTX in 85% of patients. Explosive mode of donor brain death was the most significant determinant of CH (OR 2.9, p = 0.01) at 1 week. CH at 1 week (OR 2.72, p = 0.01), increased body mass index (OR 1.1, p = 0.01) and cytomegalovirus viremia (OR - 4.06, p = 0.02) were predictors of CH at 1 year. CH of the cardiac allograft at 1 year was associated with increased mortality as compared to NG (RR 1.87, p = 0.03). CR (RR 1.73, p = 0.027) and CH (RR 2.04, p = 0.008) of the cardiac allograft at 1 year is associated with increased subsequent graft arteriosclerosis as compared to NG.


Asunto(s)
Vasos Coronarios/fisiopatología , Trasplante de Corazón , Tasa de Supervivencia , Remodelación Ventricular , Adulto , Estudios de Cohortes , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trasplante Homólogo
9.
Am J Cardiol ; 82(11): 1377-81, 1998 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-9856923

RESUMEN

This study tests the hypothesis that myocardial blood flow and coronary microvascular dilator capacity vary as a function of time after orthotopic heart transplantation in humans. Positron emission tomography measurements of myocardial blood flow were obtained at rest and during adenosine in 24 patients between 1 and 86 months after heart transplantation. At the time of the study all patients were clinically well and had angiographically normal epicardial coronary artery vessels. Patients were divided into 3 groups based on time from transplant to positron emission tomography measurement of myocardial blood flow: group 1 to 12 months (n = 9); group 13 to 34 months (n = 8); and group > or = 37 months (n = 7). Basal myocardial blood flow in group 1 to 12 months (1.86+/-1.01 ml/min/g) exceeded (p <0.05) that of group 13 to 34 months (1.17+/-0.73) and group > or = 37 months (0.98+/-0.34). In group 13 to 34 months, basal myocardial blood flow and maximal dilator capacity (minimal coronary vascular resistance with adenosine 36+/-12 mm Hg/ml/min/g) were comparable to that of normal volunteers (1.01+/-0.20 and 37+/-, respectively). In group > or = 37 months, maximal flow response to adenosine was reduced (2.54+/-1.25 vs 3.16+/-0.52, respectively, p = 0.06). Maximal dilator capacity in group > or = 37 months (60+/-34) was impaired versus group 1 to 12 months (36+/-10) and group 13 to 34 months (36+/-12; both p <0.05) as well as normals (37+/-9, p <0.05). During the first year after cardiac transplantation basal myocardial blood flow is elevated out of proportion to external determinants of myocardial oxygen demand, but maximal dilator capacity of the coronary microcirculation is normal. Between 1 and 3 years both basal myocardial blood flow and microvascular function tend to normalize. After 3 years, although basal myocardial blood flow is normal, microvascular dilator capacity is impaired.


Asunto(s)
Circulación Coronaria/fisiología , Trasplante de Corazón/fisiología , Adulto , Anciano , Femenino , Estudios de Seguimiento , Trasplante de Corazón/diagnóstico por imagen , Humanos , Masculino , Microcirculación , Persona de Mediana Edad , Complicaciones Posoperatorias , Factores de Tiempo , Tomografía Computarizada de Emisión
10.
Int J Cardiol ; 65(1): 71-4, 1998 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-9699934

RESUMEN

Preexcitation developed post-operatively in a cardiac transplant recipient whose donor electrocardiogram was normal. An electrophysiology study revealed evidence of a mid-septal atrioventricular (AV) bypass tract. The patient is clinically well fourteen months after transplant and has intermittent preexcitation.


Asunto(s)
Arritmias Cardíacas/etiología , Sistema de Conducción Cardíaco/anomalías , Trasplante de Corazón/fisiología , Complicaciones Posoperatorias/etiología , Arritmias Cardíacas/fisiopatología , Electrocardiografía , Femenino , Humanos , Persona de Mediana Edad
11.
J Heart Lung Transplant ; 17(4): 395-8, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9588584

RESUMEN

BACKGROUND: Diagnosis of acute rejection remains a major concern in heart transplant recipients. Currently, endomyocardial biopsy is the gold standard for detecting rejection. Given the risks and cost of endomyocardial biopsy, a noninvasive marker for rejection would be ideal. Cardiac troponin T (cTnT) is an established marker of myocyte damage, and a rat transplantation model of heart transplant rejection has suggested that cTnT may be of value in detecting rejection. METHODS: The cTnT levels were measured in 90 transplant recipients (67 men and 23 women) at the time of endomyocardial biopsy. There were a total of 256 cTnT levels and 256 biopsy samples. The cTnT levels were compared by use of International Society of Heart and Lung Transplantation rejection grades. RESULTS: Only one of the 12 grade 3 biopsy specimens had a corresponding elevated cTnT level. Of the 29 biopsy specimens with myocyte necrosis (grade 2 or grade 3), three had a corresponding elevated cTnT. The cTnT levels were elevated during the first 1 to 2 months after transplantation. There was no correlation between ischemic time and cTnT levels. CONCLUSION: CTnT is an insensitive marker of acute rejection, both early and late after heart transplantation. Elevation of cTnT after transplantation does not seem to be directly related to ischemic time.


Asunto(s)
Biomarcadores/sangre , Rechazo de Injerto/diagnóstico , Trasplante de Corazón , Troponina/sangre , Enfermedad Aguda , Animales , Biomarcadores/análisis , Biopsia/economía , Costos y Análisis de Costo , Modelos Animales de Enfermedad , Femenino , Rechazo de Injerto/sangre , Rechazo de Injerto/clasificación , Humanos , Isquemia/fisiopatología , Masculino , Persona de Mediana Edad , Miocardio/química , Miocardio/patología , Necrosis , Ratas , Factores de Riesgo , Factores de Tiempo , Troponina/análisis , Troponina T
12.
J Am Coll Cardiol ; 30(2): 533-8, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9247529

RESUMEN

OBJECTIVES: We sought to assess the relation between glucose metabolism, myocardial perfusion and cardiac work after orthotopic heart transplantation. BACKGROUND: The metabolic profile of the transplanted cardiac muscle is affected by the lack of sympathetic innervation, impaired inotropic function, chronic vasculopathy, allograft rejection and immunosuppressive therapy. In relation to myocardial perfusion and cardiac work, glucose metabolism has not previously been studied in heart transplant recipients. METHODS: Regional myocardial blood flow (ml.min-1.g-1) and 18F-2-fluoro-2-deoxyglucose (18FDG) uptake rate (ml.s-1.g-1) were measured after an overnight fast in 9 healthy male volunteers (mean age +/- SD 32 +/- 7 years) and in 10 male patients (mean age 50 +/- 10 years) who had a nonrejecting heart transplant, normal left ventricular function and no angiographic evidence of epicardial coronary sclerosis. Measurements were made by using dynamic positron emission tomography (PET) with 15O-labeled water and 18FDG, respectively. Heart rate and blood pressure were also measured for calculation of rate-pressure product. RESULTS: 18FDG uptake was similar in all heart regions in the patients and volunteers (intrasubject regional variably 12 +/- 8% and 16 +/- 12%, respectively, p = 0.51). Regional myocardial blood flow was similarly evenly distributed (intrasubject regional variability 14 +/- 10% and 12 +/- 8%, respectively, p = 0.67). Mean 18FDG uptake and myocardial blood flow values for the whole heart are given because no regional differences were identified. 18FDG uptake was on average 196% higher in the patients than in the volunteers (2.90 +/- 1.79 x 10(-4) vs. 0.98 +/- 0.38 x 10(-4) ml.s-1.g-1, p = 0.006). Regional myocardial blood flow and rate-pressure product were similarly increased in the patient group, but by only 41% (1.14 +/- 0.3 vs. 0.81 +/- 0.13 ml.min-1.g-1, p = 0.008) and 53% (11,740 +/- 2,830 vs. 7,689 +/- 1,488, p = 0.001), respectively. CONCLUSIONS: 18FDG uptake is homogeneously increased in normally functioning nonrejecting heart transplants. This finding suggests that glucose may be a preferred substrate in the transplanted heart. The magnitude of this observed increase is significantly greater than that observed for myocardial blood flow or cardiac work. In the patient group, the latter two variables were increased to a similar degree over values in control hearts, indicating a coupling between cardiac work load and myocardial blood flow. The disproportionate rise in 18FDG uptake may be accounted for by inefficient metabolic utilization of glucose by the transplanted myocardium or by the influence of circulating catecholamines, which may stimulate glucose uptake independently of changes in cardiac work load.


Asunto(s)
Desoxiglucosa/análogos & derivados , Radioisótopos de Flúor , Glucosa/metabolismo , Trasplante de Corazón , Corazón/diagnóstico por imagen , Miocardio/metabolismo , Radiofármacos , Tomografía Computarizada de Emisión , Adulto , Animales , Circulación Coronaria , Fluorodesoxiglucosa F18 , Humanos , Masculino , Persona de Mediana Edad
15.
J Thorac Cardiovasc Surg ; 110(2): 453-62, 1995 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7543635

RESUMEN

The internal mammary artery has greater long-term patency than the saphenous vein when used for coronary bypass grafting. Therefore, bilateral use of the internal mammary artery for grafting with the right internal mammary artery used as a "free" graft may result in improved graft survival. The study objectives were to compare the endothelial-dependent and -independent vasodilatory response in free and pedicled internal mammary artery grafts in patients who had previously undergone coronary surgery. Free (group 1, n = 8) and pedicled (group 2, n = 7) internal mammary artery grafts were studied by comparing the response to selective infusion of the endothelial-dependent vasodilator substance P (1.4 up to 22.4 pmol/min in doubling dose increments) followed by isosorbide dinitrate (2 mg over 2 minutes), in patients undergoing coronary angiography, 1 month to 6 years after coronary surgery. Maximal dilatory response to substance P was 8.7% +/- 1.8% in pedicled grafts compared with 8.8% +/- 2.3% in free grafts (p = not significant), with the dose response for both groups being similar. Infusion of isosorbide dinitrate produced only minimal further dilatation in both groups. No significant difference was found in endothelium-dependent and -independent vasodilatory response between free and pedicled internal mammary artery grafts, suggesting that the use of the free right internal mammary artery and other arterial grafts may enhance graft survival.


Asunto(s)
Endotelio Vascular/fisiopatología , Anastomosis Interna Mamario-Coronaria , Arterias Mamarias/fisiopatología , Vasodilatación , Adulto , Anciano , Angiografía Coronaria , Femenino , Humanos , Dinitrato de Isosorbide/farmacología , Masculino , Arterias Mamarias/citología , Arterias Mamarias/trasplante , Persona de Mediana Edad , Sustancia P/farmacología , Factores de Tiempo , Vasodilatación/efectos de los fármacos
16.
Br Heart J ; 71(5): 431-6, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-7912095

RESUMEN

OBJECTIVE: To determine the effects of a small dose of beta blocker on neurohumoral and cardiopulmonary responses after cardiac transplantation. BACKGROUND: Cardiac transplant recipients have a reduced exercise capacity and abnormal cardiovascular responses to exercise. The sympathoadrenal response to exercise has been shown to be abnormal with high venous noradrenaline. The effect of beta blockade on these neurohumoral mechanisms has not been defined. METHODS: 10 non-rejecting cardiac transplant recipients were studied. Patients carried out graded exercise to a symptom limited maximum. Blood samples were taken during exercise. Concentrations of noradrenaline, adrenaline, and atrial natriuretic peptide and plasma renin activity were measured. The next day, the exercise and sampling procedure were repeated after an oral dose of propranolol (40 mg). RESULTS: Patients tolerated exercise poorly after beta blockade, which was reflected in the maximum workload reached. Heart rate and blood pressure were significantly higher at rest and during exercise before beta blockade. Although there was no significant difference when resting, mean (SEM) noradrenaline concentrations during peak exercise were higher after beta blockade (16.2 (2) v 23.6 (2.9) nmol/l, p = 0.001). Adrenaline concentrations at peak exercise were also greater after beta blockade (0.89 (0.31) v 1.18 (0.38) nmol/l, p = 0.055). Atrial natriuretic peptide concentrations tended to be higher after beta blockade (118.75 (50.2) v 169.79 (39.3) pmol/l, p = 0.36). There was no significant change in plasma renin activity. CONCLUSIONS: A small oral dose of a competitive beta blocker such as propranolol has an adverse effect on exercise tolerance and cardiovascular response to exercise in cardiac transplant recipients. There are also increased concentrations of circulating noradrenaline and therefore, sympathetic activity during exercise. beta blockers should be used with caution in cardiac transplant recipients.


Asunto(s)
Ejercicio Físico/fisiología , Trasplante de Corazón/fisiología , Corazón/efectos de los fármacos , Pulmón/efectos de los fármacos , Neurotransmisores/fisiología , Propranolol/farmacología , Administración Oral , Adulto , Factor Natriurético Atrial/sangre , Presión Sanguínea/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Norepinefrina/sangre , Propranolol/administración & dosificación , Renina/sangre
17.
Coron Artery Dis ; 5(2): 147-54, 1994 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7514075

RESUMEN

BACKGROUND: Previous studies with the endothelium-dependent vasodilator substance P have shown a preserved vasodilator response in cardiac transplant recipients with angiographically normal coronary arteries. Although endothelial dysfunction is known to occur in cardiac transplant recipients with accelerated coronary disease, the degree to which the endothelium is affected is not known precisely. The aim of the present study was to examine endothelial function in accelerated coronary disease following cardiac transplantation. METHODS: Thirteen cardiac transplant recipients with epicardial coronary disease underwent substance P infusion. The response to incremental doses of substance P was measured in smooth segments of affected coronary arteries. Substance P was infused over 2 min with a starting dose of 1.4 pmol/min and a maximum of 22.4 pmol/min, reached by doubling the dose in steps, followed by an infusion of 2 mg isosorbide dinitrate over 2 min. RESULTS: Substance P caused less vasodilation at lower concentrations, with a significantly higher dose required to achieve half maximal dilation compared with cardiac transplant recipients with no coronary disease. The mean maximal dilatation achieved with substance P was 22.98 +/- 4.62% compared to 21.95 +/- 4.9% with isosorbide dinitrate; the latter value was not significantly different from the maximal dilation achieved in cardiac transplant recipients without coronary disease. CONCLUSIONS: In cardiac transplant recipients with accelerated coronary disease the functional vasodilatory ability of the coronary endothelium is impaired in segments of apparently unaffected epicardial arteries, which may lead to an increase in the resting vasoconstrictor tone and have important functional and therapeutic implications.


Asunto(s)
Enfermedad Coronaria/fisiopatología , Vasos Coronarios/efectos de los fármacos , Vasos Coronarios/fisiología , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/fisiología , Trasplante de Corazón , Sustancia P/farmacología , Adulto , Presión Sanguínea/efectos de los fármacos , Angiografía Coronaria , Enfermedad Coronaria/patología , Vasos Coronarios/patología , Relación Dosis-Respuesta a Droga , Endotelio Vascular/patología , Estudios de Seguimiento , Frecuencia Cardíaca/efectos de los fármacos , Trasplante de Corazón/patología , Trasplante de Corazón/fisiología , Humanos , Dinitrato de Isosorbide/administración & dosificación , Dinitrato de Isosorbide/farmacología , Masculino , Persona de Mediana Edad , Sustancia P/administración & dosificación , Vasodilatación/fisiología
19.
Br Heart J ; 67(5): 368-76, 1992 May.
Artículo en Inglés | MEDLINE | ID: mdl-1389716

RESUMEN

OBJECTIVE: This study investigated the changes in regional myocardial ultrasonic backscatter, measured as myocardial echo amplitude, that occur during reversible myocardial ischaemia in humans. DESIGN: Left anterior descending coronary angioplasty was used to produce reversible myocardial ischaemia in human subjects. Regional myocardial echo amplitude was studied in the interventricular septum and left ventricular posterior free wall before, during, and after coronary occlusion with the angioplasty balloon. Wall motion analysis of the left ventricle was performed from simultaneous cross sectional echocardiographic imaging. Patients were studied prospectively. PATIENTS: Six patients (mean age 56 (SD 11), range 46 to 69 years) with single vessel, left anterior descending coronary artery stenoses, were investigated during elective coronary angioplasty. A total of 11 balloon inflations were studied. SETTING: All patient studies were performed at Harefield Hospital. Echo amplitude analysis was performed at the Royal Brompton Hospital. INTERVENTIONS: Angioplasty was performed by the usual procedure at Harefield Hospital for elective coronary angioplasty. All routine medication including beta blockers and calcium antagonists were continued. Inflation pressures were up to 12 atm (1212 kPa) and mean inflation time ranged from 30 to 120 (86 (31)) s. In four studies the first inflation was examined, in three the second, in two the third, and in one each the fourth and fifth inflations. Echo amplitude and cross sectional echo-cardiographic studies were recorded with a 3.5 MHz Advanced Technology Laboratories (ATL) (720A/8736 series) mechanical sector scanner and an ATL Mark III (860-1 series) echocardiograph system with 45 dB logarithmic grey scale compression. MAIN OUTCOME MEASURES: Regional echo amplitude was examined in four regions of the left ventricle--namely, the basal and mid-septum, and basal and mid-posterior wall. Consecutive end diastolic and end systolic frames were analysed and cyclic variation was determined as the difference between the level of echo amplitude at end diastole and at end systole. Measurements were made before balloon inflation, at peak inflation, and after balloon deflation. Regional wall motion and systolic wall thickening were analysed qualitatively. RESULTS: Before balloon inflation, cyclic variation in echo amplitude was noted in all regions (basal septum, 2.4 (SD 1.1) dB; mid-septum, 2.5 (1.1) dB; basal posterior wall, 3.3 (2.1) dB; mid-posterior wall, 3.9 (1.6) dB). During balloon inflation there was a significant fall in cyclic variation to 0.4 (0.9) dB (p < 0.0002) in the mid-septum. This was predominantly owing to an increase in end systolic echo amplitude from 5.4 (2.0) dB to 9.3 (1.9) dB (p < or = 0.01). This was associated with the development of severe hypokinesis or akinesis in the mid-septum. No significant changes in echo amplitude occurred in the three other regions examined. Changes were completely reversed after balloon deflation. CONCLUSIONS: These results suggest a causal relation between occlusion of the supplying coronary artery and blunting of myocardial echo amplitude cyclic variation. It is suggested that balloon occlusion produced myocardial ischaemia. The resultant impairment of myocardial contraction then caused a blunting of cyclic variation in echo amplitude. The results of this study provide further data about the ability of quantitative studies of ultrasonic backscatter to identify alterations in the myocardium during injury.


Asunto(s)
Arteriopatías Oclusivas/diagnóstico por imagen , Enfermedad Coronaria/diagnóstico por imagen , Ecocardiografía , Anciano , Angioplastia Coronaria con Balón , Arteriopatías Oclusivas/fisiopatología , Enfermedad Coronaria/fisiopatología , Femenino , Tabiques Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Movimiento/fisiología , Estudios Prospectivos
20.
J Am Coll Cardiol ; 19(1): 100-6, 1992 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-1729318

RESUMEN

To assess coronary vasodilator reserve after orthotopic heart transplantation, regional myocardial perfusion was measured with oxygen-15-labeled water and dynamic positron emission tomography in 14 cardiac allograft recipients who were not experiencing rejection and who had no angiographic evidence of epicardial coronary sclerosis 15 to 73 months (mean +/- SD 43 +/- 19) after transplantation (group I). Twelve normal men with an average age of 31 years (group II) served as a control group. Regional perfusion was measured at rest and after the intravenous administration of 0.6 mg/kg body weight of dipyridamole. Rest regional myocardial blood flow was homogeneously distributed throughout the left ventricle and was significantly higher in transplant recipients (mean 1.16 +/- 0.26 ml/g per min [range 0.8 to 1.73] than in normal subjects (mean 0.85 +/- 0.13 ml/g per min [range 0.57 to 0.99]; p = 0.001) as was rest heart rate-systolic blood pressure product (rate-pressure product 11,255 +/- 2,540 vs. 7,073 +/- 1,306; p less than 0.001). After dipyridamole, perfusion in the transplant recipients was homogeneous and slightly lower (2.73 +/- 1.03 vs. 3.40 +/- 1.09 ml/g per min; p = NS), whereas rate-pressure product was slightly higher (12,179 +/- 2,266 vs. 10,885 +/- 1,895; p = NS) than the value in normal subjects. Dipyridamole vasodilator response (dipyridamole/rest myocardial blood flow) ranged from 1.23 to 4.92 (mean 2.50 +/- 1.13) in group I and from 2.65 to 5.45 (3.97 +/- 0.89) in group II (p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Dipiridamol , Trasplante de Corazón/fisiología , Radioisótopos de Oxígeno , Tomografía Computarizada de Emisión/métodos , Vasodilatación/efectos de los fármacos , Adulto , Circulación Coronaria/efectos de los fármacos , Circulación Coronaria/fisiología , Dipiridamol/administración & dosificación , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/cirugía , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Factores de Tiempo , Tomografía Computarizada de Emisión/instrumentación , Vasodilatación/fisiología
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