Current modalities for invasive and non-invasive monitoring of volume status in heart failure

Heart failure (HF) represents a major health and economic burden worldwide. In spite of best current therapy, HF progresses with unpredictable episodes of deterioration that often require hospitalisation. These episodes are often preceded by accumulation or redistribution of fluid causing haemodynamic overload on the heart. Remote and telemonitoring of the HF patient, assessing symptoms and signs, thoracic impedance derived fluid status follow-up or direct haemodynamic measurements with chronic implanted devices are presently under investigation for the potential to detect impending HF decompensation early. The current evidence for volume status monitoring in HF using those novel management strategies is reviewed.     

Devices in heart failure: potential methods for device-based monitoring of congestive heart failure

Congestive heart failure has long been one of the most serious medical conditions in the United States; in fact, in the United States alone, heart failure accounts for 6.5 million days of hospitalization each year. One important goal of heart-failure therapy is to inhibit the progression of congestive heart failure through pharmacologic and device-based therapies. Therefore, there have been efforts to develop device-based therapies aimed at improving cardiac reserve and optimizing pump function to meet metabolic requirements. The course of congestive heart failure is often worsened by other conditions, including new-onset arrhythmias, ischemia and infarction, valvulopathy, decompensation, end-organ damage, and therapeutic refractoriness, that have an impact on outcomes. The onset of such conditions is sometimes heralded by subtle pathophysiologic changes, and the timely identification of these changes may promote the use of preventive measures. Consequently, device-based methods could in the future have an important role in the timely identification of the subtle pathophysiologic changes associated with congestive heart failure.     

Pharmacotherapy in congestive heart failure: Hyperkalemia in congestive heart failure

Hyperkalemia is not an uncommon occurrence in the congestive heart failure patient, particularly when renal failure coexists. Hyperkalemia in CHF is typically medication-related. Its occurrence is inevitably linked to the simultaneous ingestion of angiotensin-converting enzyme inhibitors and beta-blockers, and more recently, aldosterone receptor antagonists, such as spironolactone. The most devastating consequence of hyperkalemia is its cardiotoxicity that can be fairly insidious in its rate of development. The therapy of hyperkalemia in congestive heart failure can involve both acute and semiacute management phases. Acute hyperkalemia management includes measures that block the adverse membrane effects of hyperkalemia, such as intravenous calcium administration, and efforts to shift potassium intracellularly, such as occurs with intravenous bicarbonate and/or inhaled beta-agonists. Semiacute management of hyperkalemia includes measures to increase urinary potassium excretion and administration of binding resins, such as Kayexalate?. Prevention is the cornerstone of hyperkalemia management in the heart failure patient and requires that careful attention be directed to both identifying exogenous sources of potassium and pinpointing the maximum tolerable dose of either an angiotensin-converting enzyme inhibitor or an angiotensin-receptor blocker. (c)2001 by CHF, Inc.     

The brain in congestive heart failure

In the present paper we discuss two issues about relationships between congestive heart failure and the brain. First, major acute cerebrovascular events are very frequent among elderly people, but stroke does not appear to be frequently associated with congestive heart failure. Second, some cardiovascular conditions may determine progressive damage of cerebral tissue, with consequent impairment of cognitive functions. The association of cognitive impairment and cardiovascular diseases may dramatically increase morbility and mortality risks in the elderly. Recent studies seem to show that hypotension and congestive heart failure are risk factors for dementia in elderly people. In view of this data, an Italian multicentric study on congestive heart failure in hospitalized elderly patients (CHF Italian Study I) included a brief screening of cognitive abilities (MMSE). The presence of congestive heart failure induced a significant decrease of MMSE scores: mean MMSE score after statistical adjustment for the other variables was about one point lower in patients with congestive heart failure respect to elderly patients affected by heart disease but without congestive heart failure. A novel multicentric study (CHF Italian Study II) has been performed to identify cognitive functions more specifically impaired during congestive heart failure in the elderly. Preliminary data relative to 385 patients, confirmed that congestive heart failure may induce a generalized impairment of cognitive functions. These data have relevant clinical implications because they demonstrate that a multidisciplinary approach is necessary in these patients, both for prevention and rehabilitation therapy.     

The myocardium in congestive heart failure

It is now apparent that the myocardium in patients with congestive heart failure (CHF) is not normal, because important structural and molecular changes modify function in these hearts. It appears likely that the myocardium in these patients with CHF becomes unable to provide enough chemical energy to meet its mechanical requirements. If this interpretation is correct, the resulting condition of "energy starvation" would have several important implications for therapy. For example, inotropic stimulation, by increasing energy expenditure, could contribute to the progressive myocardial cell death that characterizes end-stage cardiac hypertrophy. Conversely, the reduction in myocardial contractility that develops in the chronically over-loaded heart reduces myocardial energy expenditure, and changes in the expression of myosin isoforms improve cardiac efficiency. Therefore, an important goal of therapy in the patient with CHF is to reduce energy expenditure by unloading the failing heart and, in some cases, by administration of negative inotropic drugs.     

Quality of life and functional status in congestive heart failure]

OBJECTIVE: To assess health related quality of life of patients with congestive heart failure (CHF), to correlate quality of life with other functional parameters; maximal oxygen uptake (peak VO2) with submaximal tests (two minute walking test and shuttle walk test) and New York Heart Association (NYHA) with other clinical variables. METHODS: We evaluated 35 stable congestive heart failure patients (NYHA II-III). Functional status was assessed by NYHA classification, maximal oxygen uptake (peak VO2) and submaximal tests (two minute walk test and shuttle walk test). Health related quality of life was measured with short form 36 health survey (SF 36). RESULTS: NYHA functional class was correlated with social functioning of SF 36, peak VO2 and shuttle walk test. Peak VO2 was correlated with most of the parameters of SF 36. On the other hand 2 minute walk test and shuttle walk test were correlated with social functioning of SF 36. There was a correlation between peak VO2 and submaximal test, but there was no correlation between left ventricular ejection fraction, peak VO2 and NYHA class. CONCLUSION: Social functioning is impaired in patients with congestive heart failure. There is a correlation between maximal and submaximal tests. The maximal and submaximal tests can explain some degree of quality of life. Functional status can be explained with peak VO2 and shuttle walk test apart from NYHA class.     

充血性心力衰竭患者的动态血压变化

目的 :观察充血性心力衰竭 （CHF）的昼夜血压变化。方法 :CHF患者 5 1例 ,依心功能分为 A组 （心功能 级 ）和 B组 （心功能 , 级 ） ,作动态血压监测 ,同时与 2 5例正常人 （C组 ）比较 ,分析各组的动态血压变化规律。结果 :CHF患者中 （A组与 B组 ） 82 .4%血压昼夜节律消失或减小 ,其中 A组为 6 9% ,B组为 96 % ;而正常人 （C组 ）仅 8%血压昼夜节律减弱。结论 :CHF患者血压昼夜节律有明显变化 ,与心功能受损程度呈正相关 ,动态血压监测对 CHF患者的心功能评价有一定的临床意义。     

Pharmacotherapy in congestive heart failure: ACE inhibitors and anemia in congestive heart failure

The use of angiotensin-converting enzyme inhibitors can be accompanied by a number of adverse events, including cough, angioedema, and hyperkalemia, as well as a peculiar form of functional renal insufficiency. Other, less obvious side effects accompany ACE inhibitor use, such as a reduction in red blood cell production. This feature of ACE inhibitor use may be employed to good effect, as in the management of post-transplant erythrocytosis. Alternatively, the suppressive effect of ACE inhibitors on red blood cell production may intensify the anemia of chronic renal failure and/or congestive heart failure. The untreated congestive heart failure patient typically has an increased red blood cell mass as a consequence of increased erythropoietin levels, with the latter governed by congestive heart failure-related renal hypoxia. This is not expressed as an increase in hemoglobin concentration because of the increase in plasma volume that marks advanced congestive heart failure. ACE inhibitor therapy can be expected to both reduce plasma volume and decrease red blood cell production. As a result, the hemoglobin concentration changes very little in the ACE inhibitor-treated congestive heart failure patient and usually falls in the low normal range. Recently, erythropoietin has been employed to good effect in congestive heart failure patients with borderline anemia. (c)2000 by CHF, Inc.     

充血性心力衰竭患者预后因素探讨

目的：探讨充血性心力衰竭（CHF）患者的预后因素。方法：前瞻性研究163例CHF患者临床、心电图及血流动力学的预后价值，用多因素Cox回归模型分析各因素对预后的影响。结果：平均随访29个月，心脏性死亡59例，其中猝死34例，泵衰竭死亡19例，心肌梗死死亡6例；多因素分析示，平均主动脉压、平均肺动脉压和QTc是心脏性死亡的独立危险因素；生存率分析示，平均主动脉压≤12kPa，平均肺动脉压≥3．33kPa，QTc≥440ms，射血分数≤25％及有束支阻滞者，生存率显著降低。结论：低血压、QTc延长及伴肺动脉高压者预后不良，治疗中应防止过度降压和延长心肌复极。