Exercise Ventilatory Parameters for the Diagnosis of Reactive Pulmonary Hypertension in Patients With Heart Failure

BackgroundReactive pulmonary hypertension (PH) in left heart disease is associated with poor prognosis. This study aimed to evaluate the diagnostic utility of exercise ventilatory parameters on cardiopulmonary exercise testing for the diagnosis of reactive PH in patients with heart failure (HF) and reduced ejection fraction.MethodsThis was a single-center, retrospective analysis of a prospectively collected database of 131 patients with HF who underwent in-hospital assessment for heart transplantation. Pulmonary hemodynamics was assessed by direct cardiac catheterization. Minute ventilation/carbon dioxide production (VE/VCO₂) slope, partial pressure of end-tidal carbon dioxide (ETCO₂) changes on exercise, oxygen pulse, and exercise oscillatory ventilation were determined from cardiopulmonary exercise testing.ResultsSixty-one of 131 consecutive patients had reactive PH. VE/VCO₂ slope (>41), change in ETCO₂ on exercise (<1.2 mm Hg) and exercise oscillatory ventilation were independently associated with reactive PH. These 3 parameters in combination produced 3 possible diagnostic scenarios: (1) if all 3 criteria (“if all”) were present, (2) if any 2 of the 3 criteria (“2 of 3”) were present, and (3) if any of the criteria (“if any”) were present. The corresponding positive/negative likelihood ratios for reactive PH if all 3 criteria were present were 3.73/0.83, if 2 of the 3 criteria were present were 2.19/0.45, and if any of the 3 criteria were present were 1.75/0.11. The posttest probability increased from 46% to 76% (“if all” present) and reduced to 9% (if none of the criteria was present).ConclusionVentilatory parameters on cardiopulmonary exercise test are associated with reactive PH in patients with HF. The absence of abnormalities in these 3 ventilatory parameters can effectively exclude reactive PH in patients with HF and poor ejection fraction.     

Pulmonary Hypertension in Advanced Heart Failure

Abstract The diagnosis of pulmonary hypertension is easy during routine evaluation of patients with chronic heart failure by means of Doppler echocardiography. However, one must remember that an accurate hemodynamic characterization of the pulmonary circulation requires right heart catheterization to measure pulmonary vascular resistance and, if necessary, to test the reversibility of pulmonary hypertension. In addition, the importance of combining the right heart hemodynamic variables with a functional evaluation of the right ventricle is emphasized: in fact, the clinical impact of pulmonary hypertension in advanced heart failure patients (in terms of both exercise intolerance and prognosis) seems to be modulated by right ventricular function.     

Diastolic Heart Failure in the Elderly

It is now clear that diastolic heart failure (DHF) is an important, perhaps even dominant form of heart failure in older Americans. However, our knowledge base regarding the epidemiology, pathophysiology, natural history, and therapy of this relatively recently recognized disorder is limited. A number of normal age related changes in the heart and vascular system may predispose to or lower the threshold for expression of DHF. Recent reports from large population-based observational studies indicate that over 50% of persons 65 years and older who have heart failure have normal LV systolic function (presumed DHF). Among these, 45% have no other confounding variables (coronary, valvular, or pulmonary disease) and meet the criteria for isolated DHF. DHF is substantially more common in older women than men. A history of systemic hypertension and left ventricular hypertrophy are almost invariably present. Mortality rates are about 50% lower in DHF than in systolic heart failure (SHF) when stable outpatients are considered. However, in hospitalized and very elderly patients, the mortality rate appears similar in DHF and SHF. Furthermore, due to its higher prevalence, the total mortality in the older population attributable to DHF exceeds that of SHF. Morbidity in DHF is substantial and approaches that of SHF.In the chronic setting, DHF patients can have severe exercise intolerance related to failure of the Frank-Starling mechanism with reduced peak cardiac output, heart rate, and stroke volume and increased LV filling pressure. DHF patients also appear to have increased vascular stiffness, accelerated systolic blood pressure response to exercise, neuroendocrine activation, and reduced quality of life. Acute exacerbations (pulmonary edema) frequently occur and are associated with severe hypertension, sodium indiscretion, and medication non-compliance. Surprisingly, overt myocardial ischemia appears to infrequently play a role in these acute exacerbations.Therapy is currently empiric and multicenter, randomized, controlled trials are urgently needed. Anecdotally, control of blood pressure appears to improve symptoms and reduce the frequency of acute exacerbations. In addition, non-pharmacologic intervention, including multi-disciplinary case management is useful.     

Murine Models of Diastolic Dysfunction and Heart Failure With Preserved Ejection Fraction

Left ventricular diastolic dysfunction leads to heart failure with preserved ejection fraction, an increasingly prevalent condition largely driven by modern day lifestyle risk factors. As heart failure with preserved ejection fraction accounts for almost one-half of all patients with heart failure, appropriate nonhuman animal models are required to improve our understanding of the pathophysiology of this syndrome and to provide a platform for preclinical investigation of potential therapies. Hypertension, obesity, and diabetes are major risk factors for diastolic dysfunction and heart failure with preserved ejection fraction. This review focuses on murine models reflecting this disease continuum driven by the aforementioned common risk factors. We describe various models of diastolic dysfunction and highlight models of heart failure with preserved ejection fraction reported in the literature. Strengths and weaknesses of the different models are discussed to provide an aid to translational scientists when selecting an appropriate model. We also bring attention to the fact that heart failure with preserved ejection fraction is difficult to diagnose in animal models and that, therefore, there is a paucity of well described animal models of this increasingly important condition.     

Pulmonary Hypertension,Sleep-Disordered Breathing,and Beta Blockers in Heart Failure Patients

Heart failure patients with pulmonary hypertension have a worse prognosis than heart failure patients with normal pulmonary artery pressures. Heart failure is usually considered the cause of the pulmonary hypertension when the two conditions coincide. However, there is evidence that sleep-disordered breathing may be responsible for the pulmonary hypertension in these patients, and the worsened outcomes in heart failure patients with pulmonary hypertension may be due to sleep-disordered breathing. In addition, sleep-disordered breathing may provide an explanation for the beneficial effect of beta-adrenergic antagonists in heart failure patients.     

Load Dependent Diastolic Dysfunction in Heart Failure

Congestive heart failure may result from cardiovascular overload, from systolic or from diastolic dysfunction. Diastolic left ventricular dysfunction may result from structural resistance to filling such as induced by pericardial constraint, right ventricular compression, increased chamber stiffness (hypertrophy) and increased myocardial stiffness (fibrosis). A distinct and functional etiology of diastolic dysfunction is slow and incomplete myocardial relaxation. Relaxation may be slowed by pathological processess such as hypertrophy, ischemia and by asynchronous left ventricular function. The present contribution analyses the occurrence of slow and incomplete myocardial relaxation in response to changes in systolic pressure and in response to changes in venous return. The regulation of myocardial relaxation by load is critically dependent on the transition from myocardial contraction to relaxation, which occurs in dogs when 82% of peak isovolumetric pressure has developed or at a relative load of 0.82. This corresponds to early ejection in normal hearts, but is situated even before aortic valve opening in severely diseased hearts. When load is developed beyond this transition, relaxation becomes slow and even incomplete. This is load dependent diastolic dysfunction. Load dependent diastolic dysfunction occurs in normal hearts facing heavy afterload and in severely diseased hearts even with normal hemodynamic parameters. This dysfunction should contribute to elevating filling pressures in most patients with severe congestive heart failure. This dysfunction can be reverted by decreasing systolic pressures or by decreasing venous return. Load dependent diastolic dysfunction gives us an additional reason to agressively treat CHF patients with diuretics and vasodilators.     

舒张功能不全性心力衰竭分子机制的研究进展

舒张功能不全性心力衰竭是一种以心力衰竭的症状和体征,正常的射血分数和异常的舒张功能为特征的病理生理综合征。在分子水平上,舒张功能受到心肌肌质网钙泵、钠钙交换体、细胞外基质以及它们的调节蛋白的活动等因素的影响。因此,任何影响上述代谢的因素都可能影响心肌的舒张,并最终发展为舒张功能不全性心力衰竭。现主要阐述近年来舒张功能不全性心力衰竭分子机制的研究进展。     

Novel Strategies for the Detection of Systolic and Diastolic Heart Failure

The incidence and prevalence of dyspnea increases with age. Frequently, for the general practitioner with his limited diagnostic facilities, it is impossible to separate dyspnea from cardiac causes and non-cardiac causes. Without cardiac imaging it is also impossible to separate systolic dysfunction from diastolic dysfunction. After a thorough physical examination, initial screening of systolic and diastolic heart failure can be done by measurement of plasma NT-pro BNP or plasma BNP. Additionally a Chest X-Ray or ECG can be performed. To improve diagnostic performance an open access echocardiographic service can be initiated. Recent studies showed, that open access echocardiography can easily detect systolic and diastolic dysfunction in the community and can separate cardiac from non-cardiac dyspnea.     

Prevalence of Suspected Diastolic Dysfunction in Patients with a Clinical Diagnosis of Congestive Heart Failure

Introduction: The prevalence of diastolic left ventricular (LV) dysfunction in a population presenting with a suspected diagnosis of congestive heart failure (CHF) is questionable and widely variable in the current literature. To minimize the disparity, we evaluated a large echocardiographic database to investigate the prevalence of systolic and suspected diastolic LV dysfunction in those with a suspected clinical diagnosis of CHF. Methods: We retrospectively reviewed echocardiograms performed at our institution and evaluated the prevalence of abnormal LV systolic and diastolic function in those with a suspected clinical diagnosis of CHF. Diastolic dysfunction was defined as the presence of left atrial enlargement, left ventricular hypertrophy and reverse trans-mitral inflow ratio (E/A reversal). Results: Of the 636 echocardiograms with CHF as the primary diagnosis, 461 had measured LV function. Normal LV systolic function were found in 238 of the patients (48%). Isolated diastolic LV dysfunction was found in 166 patients (36%). Twelve percent of the patients with a suspected clinical diagnosis of CHF had normal LV systolic and diastolic function. Conclusion: Normal LV systolic function was seen in nearly one-half of the echocardiograms with a suspected clinical diagnosis of CHF. Suspected LV diastolic dysfunction was observed in one-third of the echocardiograms with a suspected clinical diagnosis of CHF.     

高血压病患者左室舒张功能不全与U波关系探讨

目的 探讨高血压患者左室舒张功能不全与U波的关系。方法 用超声心动图对104例高压病患者的舒张早期最大峰值速度（E峰）,舒张晚期最大峰速度（A峰）,左室射血分数（LVEF）,左房内径进行测量。将其分为左室舒张功能正常及左室舒张功能不全组。另有46个年龄相当的正常人作为对照组。对所有病人及对照组行常规心电图检查,分析U波形态。结果 左室舒张功能不全的U波倒置发生率明显高于左室舒张功能正常组及正常对照组（24％vs 15% and 13%),前者与后二者相比有显著性差异（P＜0．01）。结论 U波倒置可能是高血压病左室舒张功能不全的标志之一。     

高血压与舒张功能不全的探讨

目的 探讨高血压与舒张功能不全的相关性.方法 对200例高血压患者从发病年龄、血压水平、降压效果、心功能情况来对比分析.结果 高血压患者舒张功能不全与患者年龄、最高血压水平,降压效果、病程密切相关.结论 高血压与舒张功能不全呈正相关关系.     

舒张功能不全心力衰竭研究的现状

约有50％充血性心力衰竭患者左室射血分数并未下降,这一亚群心力衰竭患者与左室射血分数下降心力衰竭患者存在许多明显的差异,目前已引起了相当的重视。现就其定义、诊断、流行病学调查情况、临床特点、治疗方法及预后等问题的现状作一简要的介绍。     

Atrioventricular Filling Dynamics, Diastolic Function and Dysfunction

Left ventricular diastolic dysfunction is associated with slowing of LV relaxation and a decrease in LV chamber compliance. This impairment of function leads to changes in filling velocities as measured by pulsed wave Doppler echocardiography in the pulmonary veins and across the mitral valve, and in intraventricular flow propagation velocity as measured by color M-mode Doppler. This paper explores some of the physiology of LV filling in a clinical context.