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1.
Minerva Cardioangiol ; 54(6): 695-713, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17167382

RESUMEN

Congestive heart failure is a common cardiovascular disorder among adults and is a major cause of morbidity and mortality worldwide. Diastolic heart failure (DHF) is implicated in 1/3 to 1/2 of all heart failure cases and results from an abnormality of ventricular relaxation, compliance or filling. DHF differs from heart failure with reduced ejection fraction in epidemiology, pathophysiology, and natural history. Recent advances have improved our understanding of DHF. This review summarizes these advances and discusses their clinical implications as they pertain to the diagnosis and management of patients with DHF.


Asunto(s)
Diástole , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Anciano , Envejecimiento , Ecocardiografía Doppler/métodos , Electrocardiografía , Femenino , Corazón/fisiopatología , Insuficiencia Cardíaca/terapia , Humanos , Hipertensión/complicaciones , Hipertrofia Ventricular Izquierda/diagnóstico , Hipertrofia Ventricular Izquierda/fisiopatología , Factores de Riesgo
2.
Circulation ; 103(5): 678-83, 2001 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-11156879

RESUMEN

BACKGROUND: It is still unclear whether substantial regression of hypertensive left ventricular hypertrophy (LVH) and normalization of chamber geometry are associated with improved left ventricular (LV) myocardial function. METHODS AND RESULTS: Midwall mechanics were evaluated in 152 patients undergoing 1 year of effective antihypertensive treatment. Two-dimensionally directed M-mode echocardiography was performed as follows: (1) after a 4-week placebo "run-in" period, (2) after 1 year of treatment with 20 mg/d lisinopril (alone or associated with 12.5 to 25 mg/d hydrochlorothiazide), and (3) after a final 1-month placebo period to allow blood pressure (24-hour average ambulatory monitoring) to return to pretreatment levels. Treatment-induced reductions in blood pressure (from 149+/-16/95+/-11 to 131+/-12/83+/-10 mm Hg, P:<0.05) and circumferential end-systolic wall stress (from 84+/-22 to 72+/-19 g/cm(2), P:<0.05) were associated with a marked reduction in LV mass index (from 159+/-30 to 133+/-26 g/m(2), P:<0.05). LVH regression was accompanied by an increase in midwall fractional shortening (from 19.7+/-2.7% to 20.9+/-2.7%, P:<0.05) and by a decrease in relative wall thickness (from 48.2+/-7.7% to 44.1+/-6.7%, P:<0.05). The improvement in midwall function associated with afterload reduction and substantial LVH regression persisted after antihypertensive therapy withdrawal and restoration of the hypertensive state. Despite a significant increase in end-systolic wall stress, further LV chamber remodeling did not occur. The preservation of relative wall thickness was associated with a persistent improvement in midwall systolic function. CONCLUSIONS: Regression of concentric LVH is associated with an improvement of midwall systolic function, which is more dependent on the normalization of LV geometry than on the reduction in LV systolic stress.


Asunto(s)
Hipertensión/complicaciones , Hipertrofia Ventricular Izquierda/fisiopatología , Remodelación Ventricular , Adulto , Anciano , Antihipertensivos/efectos adversos , Presión Sanguínea , Femenino , Pruebas de Función Cardíaca , Humanos , Hipertensión/fisiopatología , Hipertrofia Ventricular Izquierda/etiología , Masculino , Persona de Mediana Edad , Contracción Miocárdica
3.
Circulation ; 104(7): 779-82, 2001 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-11502702

RESUMEN

BACKGROUND: The diagnosis of diastolic heart failure is generally made in patients who have the signs and symptoms of heart failure and a normal left ventricular (LV) ejection fraction. Whether the diagnosis also requires an objective measurement of parameters that reflect the diastolic properties of the ventricle has not been established. METHODS AND RESULTS: We hypothesized that the vast majority of patients with heart failure and a normal ejection fraction exhibit abnormal LV diastolic function. We tested this hypothesis by prospectively identifying 63 patients with a history of heart failure and an echocardiogram suggesting LV hypertrophy and a normal ejection fraction; we then assessed LV diastolic function during cardiac catheterization. All 63 patients had standard hemodynamic measurements; 47 underwent detailed micromanometer and echocardiographic-Doppler studies. The LV end-diastolic pressure was >16 mm Hg in 58 of the 63 patients; thus, 92% had elevated end-diastolic pressure (average, 24+/-8 mm Hg). The time constant of LV relaxation (average, 51+/-15 ms) was abnormal in 79% of the patients. The E/A ratio was abnormal in 48% of the patients. The E-wave deceleration time (average, 349+/-140 ms) was abnormal in 64% of the patients. One or more of the indexes of diastolic function were abnormal in every patient. CONCLUSIONS: Objective measurement of LV diastolic function serves to confirm rather than establish the diagnosis of diastolic heart failure. The diagnosis of diastolic heart failure can be made without the measurement of parameters that reflect LV diastolic function.


Asunto(s)
Diástole , Insuficiencia Cardíaca/diagnóstico , Volumen Sistólico , Disfunción Ventricular Izquierda/diagnóstico , Cateterismo Cardíaco , Diagnóstico Diferencial , Ecocardiografía Doppler , Femenino , Insuficiencia Cardíaca/clasificación , Insuficiencia Cardíaca/fisiopatología , Hemodinámica , Humanos , Hipertrofia Ventricular Izquierda/diagnóstico , Hipertrofia Ventricular Izquierda/fisiopatología , Masculino , Manometría , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Disfunción Ventricular Izquierda/fisiopatología
4.
J Am Coll Cardiol ; 37(4): 1042-8, 2001 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-11263606

RESUMEN

OBJECTIVES: We sought to assess the ability of echocardiographic indices of systolic and diastolic function to predict incident congestive heart failure (CHF). BACKGROUND: Noninvasive indices of subclinical systolic and/or diastolic dysfunction that can be used to identify patients in a transition phase between normal cardiac function and clinical CHF would be valuable. Though midwall shortening and Doppler mitral inflow patterns are seemingly well suited to predict subsequent CHF, the predictive value of these indices has not been investigated. METHODS: We studied 2,671 participants in the Cardiovascular Health Study who were free of coronary heart disease, CHF or atrial fibrillation. Clinical and quantitative echocardiographic data were obtained in all participants. RESULTS: At a mean follow-up of 5.2 years (range 0 to 6 years), 170 participants (6.4% of the cohort) developed CHF. Although 96% of these participants had normal or borderline ejection fraction (EF) at baseline, only 57% had normal or borderline EF at the time of hospitalization. In multivariate modeling, fractional shortening at the endocardium (relative risk [RR] 1.85 per 10-unit decrease, confidence interval [CI] 1.27 to 2.39), fractional shortening at the midwall (RR 1.29 per five-unit decrease, 95% CI 1.11-1.51) and peak Doppler peak E (RR 1.15 for each 0.1 M/s increment; CI 1.02 to 1.21) independently predicted incident CHF. Both high and low Doppler E/A ratios were predictive of incident CHF. CONCLUSIONS: Roughly half the occurrences of CHF in this population are associated with normal or borderline EF. Echocardiographic findings suggestive of subclinical contractile dysfunction and diastolic filling abnormalities are both predictive of subsequent CHF. The standard (FSendo) and refined (FSmw) parameters of systolic function performed similarly in this regard, though subjects with left ventricular hypertrophy and depressed FSmw are at particularly high risk for subsequent CHF.


Asunto(s)
Ecocardiografía , Insuficiencia Cardíaca/diagnóstico por imagen , Factores de Edad , Anciano , Anciano de 80 o más Años , Diástole , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Análisis Multivariante , Contracción Miocárdica , Valor Predictivo de las Pruebas , Pronóstico , Modelos de Riesgos Proporcionales , Factores de Riesgo , Sístole
5.
J Am Coll Cardiol ; 26(1): 195-202, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7797752

RESUMEN

OBJECTIVES: This study of hypertensive left ventricular hypertrophy 1) assessed myocardial shortening in both the circumferential and long-axis planes, and 2) investigated the relation between geometry and systolic function. BACKGROUND: In hypertensive left ventricular hypertrophy, whole-heart studies have suggested normal systolic function on the basis of ejection fraction-systolic stress relations. By contrast, isolated muscle data show that contractility is depressed. It occurred to use that this discrepancy could be related to geometric factors (relative wall thickness). METHODS: We studied 43 patients with hypertensive left ventricular hypertrophy and normal ejection fraction (mean +/- SD 69 +/- 13%) and 50 clinically normal subjects. By echocardiography, percent myocardial shortening was measured in two orthogonal planes; circumferential shortening was measured at the endocardium and at the midwall, and long-axis shortening was derived from mitral annular motion (apical four-chamber view). Circumferential shortening was related to end-systolic circumferential stress and long-axis shortening to meridional stress. RESULTS: Endocardial circumferential shortening was higher than normal (42 +/- 10% vs. 37 +/- 5%, p < 0.01) and midwall circumferential shortening lower than normal in the left ventricular hypertrophy group (18 +/- 3% vs. 21 +/- 3%, p < 0.01). Differences between endocardial and midwall circumferential shortening are directly related to differences in relative wall thickness. Long-axis shortening was also depressed in the left ventricular hypertrophy group (18 +/- 6% in the left ventricular hypertrophy group, 21 +/- 5% in control subjects, p < 0.05). Midwall circumferential shortening and end-systolic circumferential stress relations in the normal group showed the expected inverse relation; those for approximately 33% of the left ventricular hypertrophy group were > 2 SD of normal relations, indicating depressed myocardial function. There was no significant relation between long-axis shortening and meridional stress, indicating that factors other than afterload influence shortening in this plane. CONCLUSIONS: High relative wall thickness allows preserved ejection fraction and normal circumferential shortening at the endocardium despite depressed myocardial shortening in two orthogonal planes.


Asunto(s)
Hipertrofia Ventricular Izquierda/fisiopatología , Contracción Miocárdica/fisiología , Volumen Sistólico , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Ecocardiografía , Endocardio/fisiología , Endocardio/fisiopatología , Femenino , Humanos , Hipertensión/complicaciones , Hipertrofia Ventricular Izquierda/diagnóstico por imagen , Hipertrofia Ventricular Izquierda/etiología , Masculino , Persona de Mediana Edad
6.
J Am Coll Cardiol ; 31(1): 180-5, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9426038

RESUMEN

OBJECTIVES: We tested the hypothesis that postoperative left ventricular (LV) systolic wall stress can be predicted from the change in LV diastolic dimension and ejection fraction (EF) after surgical correction of chronic mitral regurgitation (MR). We used a simple mathematic model to predict postoperative systolic stress from end-diastolic dimension and EF. The validity of this model was assessed using data from 21 patients undergoing mitral valve replacement (MVR) for chronic MR. BACKGROUND: The decline in EF after MVR for chronic MR is traditionally thought to be a consequence of a postoperative increase in afterload, caused by closure of a low resistance runoff into the left atrium. However, consideration of the Laplace relation suggests that afterload does not necessarily increase after the operation. METHODS: A spherical mathematical model of the left ventricle was used to define the relations between LV end-diastolic dimension, systolic wall stress and EF. To test the validity of this model, clinical and echocardiographic data were obtained from 21 patients with chronic MR before and 10 to 14 days after MVR. These echocardiographic data were examined with reference to plots derived from the mathematical model. RESULTS: Patients were categorized as those in whom end-diastolic dimension declined after the operation (group I, n = 15) and those with no reduction in end-diastolic dimension (group II, n = 6). Group I patients were subclassified into those undergoing MVR with chordal preservation (group Ia) and those undergoing MVR with chordal transection (group Ib). In groups Ib and II, there were significant reductions in EF (56 +/- 3% to 48 +/- 3% in group Ib and 50 +/- 2% to 40 +/- 3% in group II, both p < 0.05), but the changes in end-diastolic dimension and wall stress differed. In group Ib, end-diastolic dimension decreased and systolic wall stress was unchanged; in group II, end-diastolic dimension was unchanged and wall stress increased. In contrast, group Ia patients experienced a substantial reduction in end-diastolic dimension, no change in EF and a reduction in stress. The corresponding length-force-shortening coordinates closely approximate those predicted from a mathematic model relating end-diastolic dimension to EF and systolic wall stress. CONCLUSIONS: Concordant echocardiographic and mathematical model results indicate that postoperative changes in systolic stress are directly related to changes in chamber size and that LV afterload may fall when chordal preservation techniques are used in combination with MVR.


Asunto(s)
Insuficiencia de la Válvula Mitral/cirugía , Función Ventricular Izquierda , Enfermedad Crónica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/fisiopatología , Modelos Cardiovasculares , Contracción Miocárdica , Periodo Posoperatorio , Volumen Sistólico
7.
J Am Coll Cardiol ; 37(4): 1080-4, 2001 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-11263612

RESUMEN

OBJECTIVES: We sought to determine whether the cardiocyte microtubule network densification characteristic of animal models of severe pressure overload cardiac hypertrophy occurs in human patients. BACKGROUND: In animal models of clinical entities causative of severe right and left ventricular (LV) pressure overload hypertrophy, increased density of the cellular microtubule network, through viscous loading of active myofilaments, causes contractile dysfunction that is normalized by microtubule depolymerization. These linked contractile and cytoskeletal abnormalities, based on augmented tubulin synthesis and microtubule stability, progress during the transition to heart failure. METHODS: Thirteen patients with symptomatic aortic stenosis (AS) (aortic valve area = 0.6 +/- 0.1 cm2) and two control patients without AS were studied. No patient had aortic insufficiency, significant coronary artery disease or abnormal segmental LV wall motion. Left ventricular function was assessed by echocardiography and cardiac catheterization before aortic valve replacement. Left ventricular biopsies obtained at surgery before cardioplegia were separated into free and polymerized tubulin fractions before analysis. Midwall LV fractional shortening versus mean LV wall stress in the AS patients was compared with that in 84 normal patients. RESULTS: Four AS patients had normal LV function and microtubule protein concentration; six had decreased LV function and increased microtubule protein concentration, and three had borderline LV function and microtubule protein concentration, such that there was an inverse relationship of midwall LV fractional shortening to microtubule protein. CONCLUSIONS: In patients, as in animal models of severe LV pressure overload hypertrophy, myocardial dysfunction is associated with increased microtubules, suggesting that this may be one mechanism contributing to the development of congestive heart failure in patients with AS.


Asunto(s)
Estenosis de la Válvula Aórtica/complicaciones , Hipertrofia Ventricular Izquierda/metabolismo , Miocardio/química , Tubulina (Proteína)/análisis , Anciano , Femenino , Humanos , Hipertrofia Ventricular Izquierda/etiología , Hipertrofia Ventricular Izquierda/fisiopatología , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Función Ventricular Izquierda
8.
J Am Coll Cardiol ; 22(6): 1679-83, 1993 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-8227838

RESUMEN

OBJECTIVES: We investigated the relation between the extent and pattern of left ventricular hypertrophy and surgical outcome in 54 patients undergoing aortic valve replacement for severe aortic stenosis. BACKGROUND: Previous work from our laboratory has demonstrated that a subgroup of patients, mostly elderly women with Doppler evidence of abnormal intracavitary flow acceleration, had an unexpectedly high in-hospital mortality rate after aortic valve replacement for aortic stenosis. We hypothesized that marked concentric hypertrophy, rather than the Doppler signal itself, was related to the poor outcome. METHODS: A retrospective analysis of the clinical, hemodynamic and echocardiographic data in patients who survived aortic valve replacement versus those who died in the hospital was performed. RESULTS: There were no differences between the 42 survivors and 12 nonsurvivors with regard to the clinical or hemodynamic variables. Of the echocardiographic variables analyzed, diastolic relative wall thickness was found to be significantly different between the two groups. Patients who died had significantly greater relative wall thickness (mean +/- SD) than those who survived (0.72 +/- 0.38 vs. 0.56 +/- 0.15, p = 0.04). Analysis by gender demonstrated that the relation between ventricular geometry and mortality held true only for women. CONCLUSIONS: We conclude that excessive ventricular hypertrophy, manifested as a markedly increased relative wall thickness, is associated with a significantly increased risk of postoperative mortality after aortic valve replacement for aortic stenosis.


Asunto(s)
Estenosis de la Válvula Aórtica/cirugía , Prótesis Valvulares Cardíacas/efectos adversos , Hipertrofia Ventricular Izquierda/complicaciones , Anciano , Anciano de 80 o más Años , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/mortalidad , Estenosis de la Válvula Aórtica/patología , Femenino , Prótesis Valvulares Cardíacas/mortalidad , Humanos , Hipertrofia Ventricular Izquierda/etiología , Hipertrofia Ventricular Izquierda/mortalidad , Masculino , Persona de Mediana Edad , Miocardio/patología , Estudios Retrospectivos , Caracteres Sexuales , Resultado del Tratamiento
9.
J Am Coll Cardiol ; 35(6): 1628-37, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10807470

RESUMEN

OBJECTIVES: We sought to characterize the predictors of incident congestive heart failure (CHF), as determined by central adjudication, in a community-based elderly population. BACKGROUND: The elderly constitute a growing proportion of patients admitted to the hospital with CHF, and CHF is a leading source of morbidity and mortality in this group. Elderly patients differ from younger individuals diagnosed with CHF in terms of biologic characteristics. METHODS: We analyzed data from the Cardiovascular Health Study, a prospective population-based study of 5,888 elderly people >65 years old (average 73 +/- 5, range 65 to 100) at four locations. Multiple laboratory measures of cardiovascular structure and function, blood chemistries and functional assessments were obtained. RESULTS: During an average follow-up of 5.5 years (median 6.3), 597 participants developed incident CHF (rate 19.3/1,000 person-years). The incidence of CHF increased progressively across age groups and was greater in men than in women. On multivariate analysis, other independent predictors included prevalent coronary heart disease, stroke or transient ischemic attack at baseline, diabetes, systolic blood pressure (BP), forced expiratory volume 1 s, creatinine >1.4 mg/dl, C-reactive protein, ankle-arm index <0.9, atrial fibrillation, electrocardiographic (ECG) left ventricular (LV) mass, ECG ST-T segment abnormality, internal carotid artery wall thickness and decreased LV systolic function. Population-attributable risk, determined from predictors of risk and prevalence, was relatively high for prevalent coronary heart disease (13.1%), systolic BP > or =140 mm Hg (12.8%) and a high level of C-reactive protein (9.7%), but was low for subnormal LV function (4.1%) and atrial fibrillation (2.2%). CONCLUSIONS: The incidence of CHF is high in the elderly and is related mainly to age, gender, clinical and subclinical coronary heart disease, systolic BP and inflammation. Despite the high relative risk of subnormal systolic LV function and atrial fibrillation, the actual population risk of these for CHF is small because of their relatively low prevalence in community-dwelling elderly people.


Asunto(s)
Evaluación Geriátrica , Insuficiencia Cardíaca/diagnóstico , Anciano , Anciano de 80 o más Años , Enfermedad Coronaria/diagnóstico , Enfermedad Coronaria/mortalidad , Femenino , Insuficiencia Cardíaca/mortalidad , Humanos , Ataque Isquémico Transitorio/diagnóstico , Ataque Isquémico Transitorio/mortalidad , Masculino , Estudios Prospectivos , Factores de Riesgo , Tasa de Supervivencia
10.
J Am Coll Cardiol ; 32(1): 230-6, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9669275

RESUMEN

OBJECTIVES: This study was performed to compare the safety and efficacy of intravenous 2% dodecafluoropentane (DDFP) emulsion (EchoGen) with that of active control (sonicated human albumin [Albunex]) for left ventricular (LV) cavity opacification in adult patients with a suboptimal echocardiogram. BACKGROUND: The development of new fluorocarbon-based echocardiographic contrast agents such as DDFP has allowed opacification of the left ventricle after peripheral venous injection. We hypothesized that DDFP was clinically superior to the Food and Drug Administration-approved active control. METHODS: This was a Phase III, multicenter, single-blind, active controlled trial. Sequential intravenous injections of active control and DDFP were given 30 min apart to 254 patients with a suboptimal echocardiogram, defined as one in which the endocardial borders were not visible in at least two segments in either the apical two- or four-chamber views. Studies were interpreted in blinded manner by two readers and the investigators. RESULTS: Full or intermediate LV cavity opacification was more frequently observed after DDFP than after active control (78% vs. 31% for reader A; 69% vs. 34% for reader B; 83% vs. 55% for the investigators, p < 0.0001). LV cavity opacification scores were higher with DDFP (2.0 to 2.5 vs. 1.1 to 1.5, p < 0.0001). Endocardial border delineation was improved by DDFP in 88% of patients versus 45% with active control (p < 0.001). Similar improvement was seen for duration of contrast effect, salvage of suboptimal echocardiograms, diagnostic confidence and potential to affect patient management. There was no difference between agents in the number of patients with adverse events attributed to the test agent (9% for DDFP vs. 6% for active control, p = 0.92). CONCLUSIONS: This Phase III multicenter trial demonstrates that DDFP is superior to sonicated human albumin for LV cavity opacification, endocardial border definition, duration of effect, salvage of suboptimal echocardiograms, diagnostic confidence and potential to influence patient management. The two agents had similar safety profiles.


Asunto(s)
Medios de Contraste , Ecocardiografía , Fluorocarburos , Cardiopatías/diagnóstico por imagen , Adulto , Anciano , Emulsiones , Endocardio/diagnóstico por imagen , Femenino , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Inyecciones Intravenosas , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Método Simple Ciego
11.
Arch Intern Med ; 152(10): 2089-93, 1992 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1417383

RESUMEN

BACKGROUND: To determine the relative value of two-dimensional (2D) echocardiography vs carotid duplex scanning and to devise an optimal, cost-effective diagnostic approach for older patients with cerebral ischemia, 68 consecutive patients in sinus rhythm who suffered focal cerebral ischemia were studied. All patients underwent 2D echocardiography and carotid duplex scanning in addition to routine clinical evaluation. METHODS: Twenty-five of 68 patients had Q-wave myocardial infarction by electrocardiography; nine (36%) of these 25 had left ventricular mural thrombi demonstrated by 2D echocardiography. In contrast, none of 43 patients without Q-wave myocardial infarction had clinically unsuspected findings diagnosed by 2D echocardiography. Duplex scanning, however, identified significant, abnormal findings in the carotid artery ipsilateral to the involved cerebral hemisphere in 23 patients (34%). CONCLUSIONS: Thus, in older patients in sinus rhythm who suffer a cerebral ischemic event, carotid duplex scanning has a higher diagnostic yield than 2D echocardiography and appears to be a more cost-effective initial test. Our data suggest that in patients with carotid distribution cerebral ischemic events and no obvious cardiac source for emboli by history and physical examination, 2D echocardiography should be limited to those with evidence of Q-wave myocardial infarction by electrocardiography; such management should optimize diagnostic yield and cost effectiveness.


Asunto(s)
Estenosis Carotídea/diagnóstico por imagen , Ecocardiografía , Cardiopatías/diagnóstico por imagen , Ataque Isquémico Transitorio/diagnóstico por imagen , Ataque Isquémico Transitorio/etiología , Trombosis/diagnóstico por imagen , Anciano , Algoritmos , Estenosis Carotídea/complicaciones , Análisis Costo-Beneficio , Electrocardiografía , Femenino , Cardiopatías/complicaciones , Humanos , Masculino , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/diagnóstico por imagen , Sensibilidad y Especificidad , Trombosis/complicaciones
12.
Hypertension ; 30(4): 777-81, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9336372

RESUMEN

Hypertensive patients with concentric remodeling (relative wall thickness > or = 0.45 and normal left ventricular [LV] mass index) may have poor outcomes. It is unclear whether systolic function abnormalities, shown to be present in some patients with concentric LV hypertrophy (increased LV mass index and relative wall thickness > or = 0.45), are also present in patients with concentric remodeling. To assess LV pump, chamber, and myocardial function in hypertensive men with concentric remodeling, clinical and echocardiographic data of 118 hypertensive men with concentric remodeling were compared with data from 104 hypertensive men with normal relative wall thickness and normal LV mass index. Chamber function was assessed by relating endocardial fractional shortening to end-systolic circumferential stress, myocardial function was assessed by relating midwall fractional shortening to circumferential stress, and pump performance was assessed by stroke volume (Teichholz method). Compared with hypertensive men with normal relative wall thickness, concentric-remodeling patients had lower stroke volume (84 +/- 20 versus 111 +/- 20 mL, P < .001). Endocardial shortening was no different between the two groups (38 +/- 7% versus 40 +/- 7%, P=NS), but midwall shortening was lower in patients with concentric remodeling (20 +/- 3% versus 22 +/- 3%, P < .001), despite lower end-systolic stress (81 +/- 25 versus 117 +/- 37 g/cm2, P < .001). Endocardial and midwall stress-shortening regression plots classified 28% and 42%, respectively, of the concentric remodeling patients below the fifth percentile of hypertensive patients with normal geometry. These data indicate that indexes of chamber and myocardial function are lower than those observed in hypertensive patients with normal geometry. Thus, indices of chamber, myocardial, and pump performance indicate potential abnormalities in systolic function in men with concentric remodeling.


Asunto(s)
Hipertensión/diagnóstico por imagen , Hipertensión/fisiopatología , Miocardio/patología , Función Ventricular Izquierda/fisiología , Anciano , Ecocardiografía , Humanos , Hipertensión/complicaciones , Masculino , Persona de Mediana Edad , Contracción Miocárdica/fisiología , Obesidad/complicaciones , Sístole/fisiología
13.
J Hypertens ; 15(8): 801-9, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9280201

RESUMEN

The strong relation between increased left ventricular mass and cardiovascular events makes accurate measurement of left ventricular mass a high priority, especially in patients with hypertension. M-mode echocardiography is used most widely to measure left ventricular mass because of its wide availability, moderate expense, anatomic and prognostic validation and lack of radiation or claustrophobia; however, this technique is expertise-dependent and may give erroneous results in distorted ventricles. Two-dimensional and especially three-dimensional echocardiography increase the precision with which left ventricular mass is measured but they are more time-consuming and difficult to perform on a large scale. Magnetic resonance imaging provides highly accurate left ventricular mass measurements and permits tissue imaging but its use is limited by expensive, fixed facilities and claustrophobia. Cine computed X-ray tomography also measures left ventricular mass accurately and permits perfusion assessment with contrast injection but it involves radiation and the use of fixed facilities of limited availability. Understanding the strengths and limitations of available techniques can facilitate selection of the most appropriate method to measure left ventricular mass in a particular setting.


Asunto(s)
Diagnóstico por Imagen/métodos , Ventrículos Cardíacos/patología , Hipertensión/patología , Hipertrofia Ventricular Izquierda/diagnóstico , Animales , Ecocardiografía , Humanos , Imagen por Resonancia Magnética , Tomografía Computarizada por Rayos X
14.
J Hypertens ; 16(12 Pt 1): 1813-22, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9869016

RESUMEN

BACKGROUND: Increased sympathetic activity contributes to the progression of heart failure. Adenosine counteracts sympathetic activity by inhibition of presynaptic norepinephrine release and attenuation of the metabolic and contractile responses to beta-adrenergic stimulation. In this study, we tested the hypothesis that the adenosinergic effects (uptake blockade) of dipyridamole may retard the progression of pressure overload hypertrophy in the rat. METHODS AND RESULTS: To verify that the administration of dipyridamole increases myocardial adenosine levels in the rat, epicardial adenosine concentrations were measured from 12 isolated, perfused rat hearts exposed to 10(-7) and 10(-6) mol/l dipyridamole. Adenosine concentrations were increased with both doses of dipyridamole. Also, 9 weeks of dipyridamole treatment resulted in decreased sensitivity to the adenosine A1-receptor agonist, 2-chloro-N6-cyclopentyl adenosine, suggesting that dipyridamole increases adenosine levels in the intact rat. In the second part of the study, rats were divided into either abdominal aortic-banded or sham-operated groups and were treated with either dipyridamole or saline. After 9 weeks of treatment, two-dimensional Doppler echocardiographic studies were performed and the adrenergic responsiveness to 10(-8) mol/l isoproterenol was assessed in vitro. The saline-treated banded group demonstrated concentric left ventricular hypertrophy, abnormal diastolic filling, increased wet lung weights and attenuation of adrenergic responsiveness. In contrast, the dipyridamole-treated banded rats exhibited more concentric geometry (higher relative wall thickness with similar left ventricular mass), normal left ventricular filling characteristics and preserved adrenergic responsiveness. Systolic left ventricular chamber and myocardial function, as assessed by stress-endocardial and midwall shortening relationships, were not significantly altered by banding or dipyridamole treatment. CONCLUSIONS: Dipyridamole treatment prevented the development of abnormal left ventricular chamber filling, preserved adrenergic responsiveness and appeared to attenuate detrimental chamber remodeling in rats with pressure overload hypertrophy.


Asunto(s)
Adenosina/antagonistas & inhibidores , Dipiridamol/farmacología , Hipertrofia Ventricular Izquierda/metabolismo , Receptores Adrenérgicos beta/metabolismo , Función Ventricular Izquierda/efectos de los fármacos , Adenosina/sangre , Animales , Presión Sanguínea/efectos de los fármacos , Peso Corporal , Dipiridamol/uso terapéutico , Corazón/efectos de los fármacos , Hipertrofia Ventricular Izquierda/tratamiento farmacológico , Pulmón , Masculino , Miocardio/química , Miocardio/metabolismo , Miocardio/patología , Tamaño de los Órganos , Perfusión , Ratas , Ratas Sprague-Dawley , Receptores Adrenérgicos beta/fisiología , Receptores Purinérgicos P1/fisiología , Sensibilidad y Especificidad , Sobrevida , Sístole/efectos de los fármacos , Sístole/fisiología , Función Ventricular Izquierda/fisiología
15.
Am J Cardiol ; 70(2): 259-62, 1992 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-1626517

RESUMEN

Magnetic resonance imaging (MRI) has been used to measure left ventricular (LV) mass in animals with superior accuracy. However, its use in cardiac patients has been limited by the long total scan times necessitated by imaging the heart at end-diastole at each of 8 to 10 slice locations. Recent canine studies showed that LV mass may be determined accurately, with considerable timesavings, by use of sequential images throughout the cardiac cycle (single-phase MRI). Twenty normal subjects underwent spin-echo MRI to determine the relationship between LV mass computed from single-phase MRI and results obtained from the more time-consuming end-diastolic MRI (which was used as the reference standard for this study). The left ventricle was spanned with 2 interleaved series of 5 short-axis 1 cm thick slices. 5 images, evenly spaced throughout the cardiac cycle, were obtained at each slice location in all subjects. LV mass ranged from 86 to 198 g. Although end-diastolic LV mass exceeded single-phase results by an average of 5 g (p less than 0.002), there was a close correlation between the 2 (slope = 0.99; r = 0.96). Although LV mass derived from end-diastolic images exceeded single-phase results, this difference is unlikely to be clinically significant and is small compared with the standard error of echocardiographic methods. Furthermore, when the order in which single-phase images were selected was reversed, there was improved agreement with end-diastolic MRI.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Corazón/anatomía & histología , Imagen por Resonancia Magnética/métodos , Ventrículos Cardíacos/anatomía & histología , Humanos , Imagen por Resonancia Magnética/estadística & datos numéricos , Tamaño de los Órganos , Valores de Referencia , Análisis de Regresión , Volumen Sistólico
16.
Am J Cardiol ; 66(5): 621-5, 1990 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-2392982

RESUMEN

We used cine magnetic resonance imaging (MRI) to assess mitral regurgitation (MR) in 40 patients with coronary and/or valvular disease and 10 normal subjects and compared results to pulsed (n = 30) or color flow Doppler mapping (n = 20). Mitral regurgitation produced a dynamic signal void in the left atrium in systole in 15 of 16 patients with MR by pulsed Doppler and in an additional 15 of 16 patients whose MR was demonstrated by color flow Doppler. There were no false positives (sensitivity 94%, specificity 100% for both). The ratio of single-plane, maximal jet area to left atrial area was used to grade MR severity with mild defined as less than 20%, moderate between 20 and 40% and severe greater than 40%. Cine MRI classification was identical to pulsed Doppler echocardiography in 26 of 30 patients and to color flow Doppler in 16 of 20 patients with no differences of greater than 1 grade. Cine MRI consistently depicted smaller flow disturbances than pulsed Doppler (slope = 0.65) or color flow Doppler (slope = 0.60). Nonetheless, the cine MRI area ratio correlated well with pulsed Doppler (r = 0.78) and with color flow Doppler (r = 0.74). Thus, planar analysis of cine MRI in patients with MR of varying severity gave results that were similar to Doppler echocardiography. At present, for routine clinical assessment of MR, the benefits of cine MRI may be limited to patients in whom transthoracic Doppler echocardiography is not adequate.


Asunto(s)
Imagen por Resonancia Magnética , Insuficiencia de la Válvula Mitral/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Ecocardiografía Doppler , Humanos , Persona de Mediana Edad , Películas Cinematográficas
17.
Am J Cardiol ; 74(8): 794-8, 1994 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-7942552

RESUMEN

In aortic stenosis, gender and other differences in the adaptive remodeling of the left ventricle have been described, but the influence of left ventricular (LV) geometry on systolic function is not widely appreciated. This study tested the hypothesis that the increased ejection fraction seen in some elderly women with aortic stenosis is due to changes in LV geometry, not increased myocardial mass or enhanced myocardial function. We therefore investigated gender-related differences in LV and myocardial function by analysis of end-systolic circumferential stress versus shortening relations in 65 patients (29 men and 36 women) with aortic stenosis who underwent cardiac catheterization and echocardiography. Despite similar degrees of aortic stenosis, there were significant differences between men and women with regard to LV geometry and function. When compared with men, women had higher peak LV pressures (205 +/- 27 vs 188 +/- 27 mm Hg, p < 0.01), higher ejection fractions (66 +/- 14% vs 57 +/- 18%, p < 0.05), smaller LV end-diastolic dimensions (43 +/- 8 vs 51 +/- 6 mm, p < 0.01) and higher relative wall thickness (0.66 +/- 0.27 vs 0.50 +/- 0.10, p < 0.01). LV mass was similar in the 2 groups. Mean values for stress were lower in women and there was a predominance of women at extremely low levels of stress; this subgroup had very high values for relative wall thickness and endocardial shortening, but overall stress-shortening relations were normal.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Estenosis de la Válvula Aórtica/fisiopatología , Ventrículos Cardíacos/patología , Caracteres Sexuales , Volumen Sistólico/fisiología , Anciano , Anciano de 80 o más Años , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/patología , Ecocardiografía Doppler , Femenino , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Hemodinámica , Humanos , Hipertrofia Ventricular Izquierda/etiología , Hipertrofia Ventricular Izquierda/patología , Hipertrofia Ventricular Izquierda/fisiopatología , Masculino , Persona de Mediana Edad , Sístole , Función Ventricular Izquierda/fisiología
18.
Am J Cardiol ; 76(10): 702-5, 1995 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-7572629

RESUMEN

We studied the relation between relative wall thickness, left ventricular systolic pump performance, and myocardial contractile function in 77 older patients with normal ejection fraction who were free of valvular and myocardial ischemic disease. Group 1 comprised 49 patients with relative wall thickness > or = 0.45; group 2 (n = 28) had normal relative wall thickness. Pump performance was characterized by stroke volume index, cardiac index, and stroke work; myocardial function was characterized by midwall shortening and circumferential stress versus shortening relations. Group 1 patients had lower end-diastolic volume (83 +/- 3 vs 124 +/- 5 ml, p < 0.05), cardiac index (2.6 +/- 0.2 vs 3.5 +/- 0.1 L/min/m2, p < 0.05), and stroke work/100 g left ventricular mass (43 +/- 2 vs 53 +/- 3 g-m/100 g, p < 0.005). Although there was no significant difference with regard to ejection fraction or fractional shortening at the endocardium, fractional shortening at the midwall was significantly lower in group 1 than in group 2 (16 +/- 1% vs 19 +/- 1%, p < 0.005). This lower value for midwall shortening was observed despite lower values for endsystolic stress, implying decreased myocardial contractile function. Lower stroke volume index in group 1 patients, likely due to small chamber size, was not offset by increased heart rate, resulting in a low-normal cardiac index; in 33% of group 1 patients, cardiac index was < 2.2 L/min/m2, indicating reduced pump performance. Our data indicate an abnormality in pump performance and myocardial function in patients who have high relative wall thickness and normal ejection fraction.


Asunto(s)
Hipertrofia Ventricular Izquierda/fisiopatología , Contracción Miocárdica , Volumen Sistólico , Función Ventricular Izquierda , Factores de Edad , Anciano , Distribución de Chi-Cuadrado , Ecocardiografía , Ecocardiografía Doppler , Femenino , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Hipertrofia Ventricular Izquierda/diagnóstico por imagen , Masculino , Estudios Retrospectivos , Sístole
19.
Am J Cardiol ; 83(5): 792-4, A10, 1999 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-10080443

RESUMEN

To assess the incremental value of velocity of shortening velocity parameters compared with simpler, more widely used, extent of shortening parameters in compensated left ventricular hypertrophy, we studied 52 patients with left ventricular hypertrophy and 63 age-matched controls. Velocity parameters did not provide incremental information beyond that obtained by extent of shortening parameters.


Asunto(s)
Endocardio/fisiopatología , Corazón/fisiopatología , Hipertensión/fisiopatología , Hipertrofia Ventricular Izquierda/fisiopatología , Contracción Miocárdica/fisiología , Anciano , Presión Sanguínea/fisiología , Estudios de Casos y Controles , Ecocardiografía , Ecocardiografía Doppler , Endocardio/diagnóstico por imagen , Estudios de Evaluación como Asunto , Ventrículos Cardíacos/fisiopatología , Humanos , Hipertensión/diagnóstico por imagen , Hipertrofia Ventricular Izquierda/diagnóstico por imagen , Persona de Mediana Edad , Sístole , Presión Ventricular/fisiología
20.
Am J Cardiol ; 81(12A): 13G-16G, 1998 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-9662221

RESUMEN

The clinical arena in which we must consider the role of echocardiography is characterized by 2 fundamental findings: (1) most patients with chest pain and suspected acute myocardial infarction (MI) do not present diagnostic electrocardiograms; and (2) an early and correct diagnosis is necessary to match the patient with the most adequate treatment. Echocardiography may be very useful in the coronary care unit, allowing a correct diagnosis of ischemic heart disease when electrocardiography is unclear, even before the rise of cardiac enzymes is detected. It may also play a role in decision-making for thrombolytic therapy. In addition, echocardiography provides useful information for early risk stratification. In fact, although high-risk patients are well identified by simple clinical or instrumental variables (i.e., Killip classification, enzymatic data, blood-gas analysis, electrocardiogram, etc.), most patients (>60%) are identified as low risk, and several subjects classified into the low-risk groups have a poor prognosis and are not detected using a single variable. In our experience, 2-dimensional echocardiography was able to further stratify between patients of low-risk classes. Therefore, echocardiography plays an important role in the early stratification of acute MI patients, especially in those without signs or symptoms of heart failure.


Asunto(s)
Ecocardiografía Doppler/métodos , Infarto del Miocardio/diagnóstico por imagen , Infarto del Miocardio/patología , Anciano , Unidades de Cuidados Coronarios , Diagnóstico Diferencial , Femenino , Humanos , Italia , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Pronóstico
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