Diastolic heart failure

Diastolic heart failure is a distinct clinical entity increasingly seen in older patients and requires special awareness to make the diagnosis. Although no single laboratory test is identified for making a confident diagnosis of diastolic dysfunction as the pathogenetic mechanism for heart failure, a constellation of echocardiographic and radionuclear findings are helpful in most cases. Invasive assessment of LV diastole is laborious, requiring high-fidelity pressures and accurate measures of volumes, and these are rarely needed to diagnose the condition. It appears that prognosis is significantly better for those with normal systolic function, when compared with congestive heart failure caused by impaired systolic pump function. Finally, the therapeutic approaches are substantially different for the two groups. It must be emphasized that even patients with predominant myocardial systolic dysfunction have some combined diastolic dysfunction as well. This latter group is difficult to treat. However, improvement in systolic pump function, when markedly impaired, must take precedence in management strategies.     

Diastolic heart failure

Diastolic heart failure (DHF) is estimated to occur in 40% to 50% of patients with heart failure. Evidence suggests that DHF is primarily a cardiogeriatric syndrome that increases from approximately 1% at age 50 years to 10% or more at 80 years. DHF is also more likely to occur in older women who are hypertensive or diabetic. Although survival is better in patients with DHF compared with systolic heart failure, mortality rates for patients with DHF are four times higher than those for healthy, community-dwelling older adults. The increase in DHF is anticipated to continue during the next several decades largely because of the aging of the population; increase in risk factors associated with hypertension, diabetes, and obesity; and ongoing technologic advances in the treatment of cardiovascular disease. Few clinical trials have evaluated therapy in this population, so evidence about the effectiveness of treatment strategies for DHF is limited. Future research should target novel interventions that specifically target patients with DHF who are typically older and female, and experience exertional intolerance and have a considerably reduced quality of life.     

Diastolic heart failure

Primary diastolic failure is typically seen in patients with hypertensive or valvular heart disease as well as in hypertrophic or restrictive cardiomyopathy but can also occur in a variety of clinical disorders, especially tachycardia and ischemia. Diastolic dysfunction has a particularly high prevalence in elderly patients and is generally associated, with low mortality but high morbidity. The pathophysiology of diastolic dysfunction includes delayed relaxation, impaired LV filling and/or increased stiffness. These conditions result typically in an upward displacement of the diastolic pressure-volume relationship with increased end-diastolic, left atrial and pulmo-capillary wedge pressure leading to symptoms of pulmonary congestion. Diagnosis of diastolic heart failure requires three conditions: (1) presence of signs or symptoms of heart failure; (2) presence of normal or slightly reduced LV ejection fraction (EF > 50%) and (3) presence of increased diastolic filling pressure. Assessment of diastolic function can be performed with several non-invasive (2D- and Doppler-echocardiography, color Doppler M-mode, Doppler tissue imaging, MR-myocardial tagging, radionuclide ventriculography) and invasive techniques (micromanometry, angiography, conductance method). Doppler-echocardiography is the most useful tool to routinely measure diastolic function. Different techniques can be used alone or in combination to assess LV diastolic function, but most of them are dependent on heart rate, pre- and afterload. The transmitral flow pattern remains the starting point, since it is easy to acquire and rapidly categorizes patients into normal (E > A), delayed relaxation (E < A), and restrictive (E > A) filling patterns. Invasive assessment of diastolic function allows determination of the time constant of relaxation from the exponential pressure decay during isovolumic relaxation, and the evaluation of the passive elastic properties from the slope of the diastolic pressure-volume (= constant of chamber stiffness) and stress-strain relationship (= constant of myocardial stiffness). The prognosis of diastolic heart failure is usually better than for systolic dysfunction. Diastolic heart failure is associated with a lower annual mortality rate of approximately 8% as compared to annual mortality of 19% in heart failure with systolic dysfunction, however, morbidity rate can be substantial. Thus, diastolic heart failure is an important clinical disorder mainly seen in the elderly patients with hypertensive heart disease. Early recognition and appropriate therapy of diastolic dysfunction is advisable to prevent further progression to diastolic heart failure and death. There is no specific therapy to improve LV diastolic function directly. Medical therapy of diastolic dysfunction is often empirical and lacks clear-cut pathophysiologic concepts. Nevertheless, there is growing evidence that calcium channel blockers, beta-blockers, ACE-inhibitors and AT2-blockers as well as nitric oxide donors can be beneficial. Treatment of the underlying disease is currently the most important therapeutic approach.     

Diastolic heart failure

Opinion statement  

Diastolic heart failure demystified

The mystery of diastolic heart failure (DHF), described by authorities as a "puzzle" and a "clinical paradox," stems from the following misperception: (1) that the normal ejection fraction implies normal cardiac output (CO), (2) that therefore low CO is not operative (it is rarely mentioned in relation to the pathophysiology of DHF), and (3) the congestive phenomena are due to the stiff left ventricle. In fact, a normal ejection fraction is not a reliable indicator of normal CO; low CO is the fundamental pathophysiologic abnormality of all heart failure (HF), whether systolic and/or diastolic (or, indeed, "high output"); and increased ventricular stiffness is not the principal cause of congestion in DHF. Pathophysiologic explorations supporting these understandings further reveal the following: (1) the premise that a clinical event as dramatic as acute pulmonary edema (systolic and/or diastolic) would be contingent on similarly dramatic acute hypertensive or ischemic ventricular dysfunction, while intuitive, is unsubstantiated, and there is an alternate explanation satisfying both theoretical and clinical observations; (2) contrary to general perception, DHF is no more vulnerable to diuretic-induced hypotension than systolic HF; (3) heart rate reduction should not yet be considered an established therapeutic goal in DHF; (4) since HF is HF whether systolic and/or diastolic, studies are likely to show that therapeutic similarities outweigh differences except as the various agents might modify the underlying structural and/or functional pathology; (5) although long evident that HF occurs by only two mechanisms (systolic dysfunction and/or diastolic dysfunction), it has only recently been acknowledged that the mere exclusion of one is diagnostic of the other; and (6) the definition of HF currently in widespread use is unnecessarily confounded by neglect of the fundamental distinction between ventricular dysfunction and failure.     

Diastolic heart failure: mechanisms and controversies

Epidemiological and experimental studies have documented both the rising burden of diastolic heart failure (DHF) and several mechanisms that distinguish this disease from systolic heart failure (SHF). Controversies continue to surround the term 'DHF' as well as its existence as a pathophysiological entity distinct from SHF. Approximately half of all patients who present with heart failure have near-normal systolic function and predominately abnormal diastolic function. Recent reports counter the commonly held belief that survival of patients with DHF is better than that of patients with SHF. The challenges associated with managing the DHF phenotype arise from the heterogeneous etiologies of the condition that include aging, diabetes mellitus, hypertension and ischemia. Lack of diastolic distensibility in DHF has been attributed primarily to hypertrophy and fibrosis. Extracellular matrix and cytoskeletal components including matrix metalloproteinases, titin isoforms, and the quality and quantity of collagen are implicated in DHF development. Impaired active relaxation of the contractile apparatus also contributes to DHF. Novel therapeutic targets that address the pathophysiology of this disease are being actively explored, although as yet there are no proven therapies for DHF. New epidemiologic and mechanistic data regarding DHF highlight the urgency with which the scientific community must address this important public health problem.     

Diastolic heart failure: definitions and terminology

Patients with chronic heart failure can be divided into 2 broad categories: systolic heart failure and diastolic heart failure. There are significant differences in demographics, prognosis, left ventricular structure, as well as systolic and diastolic function between these 2 groups of patients. The purpose of this presentation is to define the terminology used to describe these 2 broad categories of heart failure and to characterize the functional measurements that constitute their pathophysiological mechanisms.     

Diastolic heart failure in older people

OBJECTIVES: To determine the prevalence of diastolic heart failure in older people in the community, identify associated risk factors and measure its impact on function and quality of life. DESIGN: Cross-sectional population-based study. METHODS: A two-stage random sample of 500 subjects was drawn from 5,002 subjects aged 70 years and over living at home. Diastolic heart failure was diagnosed by a panel of three physicians, based on clinical assessment and echocardiographic indicators of diastolic dysfunction. MAIN OUTCOME MEASURES: Prevalence of diastolic heart failure and its effect on function and quality of life as measured by Nottingham Extended Activities of Daily Living, Hospital Anxiety and Depression and SF-36 questionnaires. RESULTS: The prevalence of diastolic heart failure was 5.54% (95% CI = 3.71, 7.87) and was higher in women (8.32%) than in men (1.25%), P = 0.008. On multivariate analysis of variance, diastolic heart failure was associated with female gender and history of ischaemic heart disease. Subjects with diastolic heart failure had significantly poorer functional status and physical health than those without heart failure. CONCLUSIONS: Diastolic heart failure is relatively common in older people and is associated with adverse affects in older people's lives.     

Diastolic heart failure: a myth

PURPOSE OF REVIEW: Until recently, patients with heart failure and preserved ejection fraction (HFprEF) have been excluded from nearly all large clinical trials in heart failure. Based on the conjecture that this clinical picture of heart failure, also known as diastolic heart failure, may be different from other forms of heart failure, several recent and ongoing clinical trials have targeted more specifically this patient population. The present review critically re-evaluates the pathophysiological rationale for such trials. RECENT FINDINGS: Novel techniques to evaluate cardiac performance have revealed that HFprEF is a consequence of significant systolic dysfunction of the ventricular muscular pump in the presence of a preserved performance of the ventricular hemodynamic pump. Diastolic and systolic heart failure are the mere extremes of a spectrum of different phenotypes of one and the same disease. Ongoing research explores the various disease modifiers, or protective pathways, that delay the progression of remodeling in patients with HFprEF. Although, currently, therapy to improve the prognosis of HFprEF is essentially the same as for other forms of heart failure, the latter ongoing studies may help, in addition, in developing novel and more patient-specific therapeutic strategies in these patients. SUMMARY: HFprEF constitutes a heterogenous group of different phenotypes within one continuous spectrum reflecting heart failure as one disease entity. No pathophysiological basis currently warrants setting up empirical clinical trials based on an arbitrary subdivision of patients with heart failure.     

Diastolic heart failure in the elderly

Heart failure with preserved left ventricular function is a common problem among elderly patients.Given that diastolic heart failure(DHF)occurs in up to 50% of all heart failure admissions,and that incidence increases with age,knowledge of current recommendations for its diagnosis and treatment are extremely important for the elderly population.Causes of DHF include the aging process itself,hypertension,left ventricular hypertrophy,aortic stenosis,and hypertrophic obstructive cardiomyopathy.The patient with DHF may present with signs and symptoms similar to those observed in systolic heart failure.Treatment goals for the patient with DHF include achieving normal volume status,improving relaxation of the left ventricle,regression of hypertrophy if possible,and management of any co-morbidities that may aggravate the clinical status of patients with DHF.Hopefully,in the future,further data from randomized clinical trials will allow a more defined approach to care in these patients.