Noninvasive evaluation of diastolic function: need for hemodynamically and clinically relevant variables.
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BACKGROUND: Although heart failure with a normal ejection fraction (HFNEF) is a clinically heterogeneous syndrome, a single pathophysiologic mechanism, diastolic dysfunction, is often ascribed to explain this condition. In view of the clinical heterogeneity of these patients, we hypothesized that subgroups of HFNEF patients may have different underlying pathophysiologic mechanisms. METHODS AND RESULTS: Freehand 3-dimensional echocardiography was used to measure left ventricular end-systolic and end-diastolic volumes in 99 asymptomatic normal controls and 2 groups with chronic heart failure: 35 patients with normal ejection fraction with longstanding hypertension (hypertensive HFNEF) and 11 patients with hypertrophic cardiomyopathy without a history of hypertension (nonhypertensive HFNEF). These data, combined with cuff sphygmomanometry and Doppler estimates of LV end-diastolic pressure (EDP) yielded estimated pressure-volume loops and slope (E es,sb ) of the end-systolic pressure-volume relationship, a load independent index of chamber contractility. Nonhypertensive HFNEF patients required high EDPs (21 +/- 2 versus 15 +/- 3 mm Hg in normals, P < .0001) to achieve normal EDVs (98 +/- 25 versus 95 +/- 21 mL in normals, P = NS). Although systolic function (E es,sb ) did not differ from normal, systolic blood pressure was lower than normal in these patients (114 +/- 10 versus 124 +/- 14 mm Hg in normals, P < .05). Hypertensive HFNEF patients also had increased EDP (20 +/- 2 mm Hg), but this was observed at higher than normal EDVs (118 +/- 29 mL, P < .05). Among patients with hypertensive HFNEF, 2 subgroups emerged, 1 with a high E es,sb (4.23 +/- 0.54 versus 2.1 +/- 0.7 mm Hg/mL) and 1 with normal E es,sb (2.31 +/- 0.51 mm Hg/mL). The former group was composed of elderly women with small body size (body surface area 1.7 +/- 0.2 versus 1.9 +/- 0.2 m 2 , P = .02) who had concentrically remodeled ventricles and low stroke volumes. The latter group was more diverse in age, body size, and included patients of both genders with increases in ventricular volumes, stroke volume, and mass consistent with a volume overload state. CONCLUSION: Although HFNEF is commonly thought of as being the result of a single hemodynamic mechanism, these data indicate that subgroups exist with distinctly different underlying pathophysiologies.
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BACKGROUND: While Tacrolimus (Tac) and Cyclosporine (Cya) immunosuppression are used after cardiac transplantation (tx), few studies have evaluated their use in pediatric patients. METHODS: We randomized 26 heart transplant recipients (pts) in a prospective, open-label trial to Tac (n = 14) or Cya (n = 12) to compare their efficacy and side-effects. Mean age at tx was 4.2 years for Tac and 5.8 years for Cya. Mean follow-up was 26 months (range: 11-39 months) for Tac and 24 months for Cya (range: 33-13 months). RESULTS: Our data suggest that both regimens are efficacious in the pediatric population. Conversion from Cya to Tac was useful for dealing with persistent rejection, although this sample did not suggest lower incidence of acute cellular rejection in the Tac group. CONCLUSIONS: Further studies are required to establish pharmacokinetic parameters to enhance therapeutic monitoring of these patients to minimize side effects and enhance outcomes.
Peripheral edema often poses a dilemma for the clinician because it is a nonspecific finding common to a host of diseases ranging from the benign to the potentially life threatening. A rational and systematic approach to the patient with edema allows for prompt and cost-effective diagnosis and treatment. This article reviews the pathophysiologic basis of edema formation as a foundation for understanding the mechanisms of edema formation in specific disease states, as well as the implications for treatment. Specific etiologies are reviewed to compare the diseases that manifest this common physical sign. Finally, we review the clinical approach to diagnosis and treatment strategies.
BACKGROUND: Children with advanced heart failure, particularly those with elevated pulmonary vascular resistance, pose a difficult management problem because the normal donor right ventricle cannot cope with the high pulmonary resistance and because of the relative shortage of donor organs of an appropriate size for this age group. METHODS: In an attempt to address these issues and evaluate the role of heterotopic transplantation in this context, we operated on 12 children, six boys and six girls, in the period between January 1, 1991, and March 31, 1996. Their ages ranged from 11 months to 15.2 years (mean 81.6 +/- 62.8 months) and their mean weight was 23.3 kg (range 7.6 to 56.8 kg). Eight patients (66.6%) had significant elevation of pulmonary artery pressure (pulmonary artery systolic pressure = 66 +/- 9.4 mm Hg, mean transpulmonary gradient = 22.3 +/- 3.4 mm Hg). In all patients the donor pulmonary artery was anastomosed to the recipient right atrium without the use of any prosthetic material. Ischemic times varied between 135 and 255 minutes (mean 182.1 +/- 30.7 minutes). The immunosuppression regimen included cyclosporine and azathioprine. Steroids were not routinely used. RESULTS: One patient died in the hospital of acute rejection on postoperative day 16. Three patients had lobe collapse within 1 week and all were treated successfully. Two late deaths (18.2%) occurred as a result of cardiac rejection 3 months and 2 years after the operations. Nine survivors (75%) are alive, active, and growing normally at a mean follow-up of 2.2 years (range 11 months to 4.75 years). Repeated cardiac catheterization performed in seven patients with preoperative pulmonary hypertension showed a slow progressive drop in mean pulmonary artery pressure. No significant change was observed in the function of the recipient hearts. CONCLUSION: We conclude that heterotopic heart transplantation is feasible for a selected group of children with good medium-term results, notably regression of pulmonary artery pressure, normal growth, and lack of long-term chest complications.
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Cardiomyopathies include a wide variety of cardiac diseases. The value of MR imaging is not only to provide information about cardiac function, but also to detect the underlying cause of the disease.
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Over the past decade, Doppler echocardiography has become a well-established tool for the diagnosis of left ventricular diastolic dysfunction. Unfortunately, in many clinical situations traditional Doppler indices of transmittal and pulmonary venous flow are inconclusive, primarily due to their dependence on left atrial pressure. Recently, new Doppler indices that are much less dependent on preload have been developed, based on intraventricular flow propagation and intrinsic myocardial velocity. These methodologies provide direct assessment of ventricular relaxation and the small intraventricular pressure gradients essential to efficient filling of the ventricle. We review in this article the theoretical and experiment background of these new echo techniques as well as how they can be implemented in routine clinical practice.
We report a case of right-sided heart failure associated with multiple myeloma. Amyloidosis was proven by rectal biopsy. In this case we were able to demonstrate myocardial disease by using tissue Doppler echocardiography, even in the presence of cardiac tamponade.
Major advances have been made over the last decade in our understanding of the molecular basis of several cardiac conditions. Hypertrophic cardiomyopathy (HCM) was the first cardiac disorder in which a genetic basis was identified and as such, has acted as a paradigm for the study of an inherited cardiac disorder. HCM can result in clinical symptoms ranging from no symptoms to severe heart failure and premature sudden death. HCM is the commonest cause of sudden death in those aged less than 35 years, including competitive athletes. At least ten genes have now been identified, defects in which cause HCM. All of these genes encode proteins which comprise the basic contractile unit of the heart, i.e. the sarcomere. While much is now known about which genes cause disease and the various clinical presentations, very little is known about how these gene defects cause disease, and what factors modify the expression of the mutant genes. Studies in both cell culture and animal models of HCM are now beginning to shed light on the signalling pathways involved in HCM, and the role of both environmental and genetic modifying factors. Understanding these mechanisms will ultimately improve our knowledge of the basic biology of heart muscle function, and will therefore provide new avenues for treating cardiovascular disease in man.
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