Hemodynamic effects at rest and during exercise in long-term treatment with prazosin in chronic congestive heart failure

The long-term effects of prazosin in chronic congestive heart failure were studied in 10 patients (New York Heart Association class III-IV) in a double-blind cross-over study. Patients with systolic blood pressure greater than 120 mmHg and left ventricular filling pressure greater than 15 mmHg were included. Prazosin lowered the arteriovenous oxygen difference both at rest and during exercise (p less than 0.05), increased cardiac index (p less than 0.01) and reduced right atrial pressure and systemic vascular resistance (p less than 0.05) during exercise. Left ventricular filling pressure was also reduced, but not significantly, during exercise. Our data show that prazosin has beneficial long-term effects during exercise in patients with chronic congestive heart failure.     

Plasma norepinephrine as a guide to prognosis in patients with chronic congestive heart failure

Hemodynamics, plasma norepinephrine, and plasma renin activity were measured at supine rest in 106 patients (83 men and 23 women) with moderate to severe congestive heart failure. During follow-up lasting 1 to 62 months, 60 patients died (57 per cent); 47 per cent of the deaths were sudden, and 45 per cent were related to progressive heart failure. Statistically unrelated to the risk of mortality were cause of disease (60 patients had coronary disease, and 46 had cardiomyopathy), age (mean, 54.8 years), cardiac index (mean, 2.11 liters per minute per square meter of body-surface area), pulmonary wedge pressure (mean, 24.5 mm Hg), and mean arterial pressure (mean, 83.2 mm Hg). A multivariate analysis of the five significant univariate prognosticators--heart rate (mean, 84.4 beats per minute), plasma renin activity (mean, 15.4 ng per milliliter per hour), plasma norepinephrine (mean, 700 pg per milliliter), serum sodium (mean, 135.7 mmol per liter), and stroke-work index (mean, 21.0 g-meters per square meter)--found only plasma norepinephrine to be independently (P = 0.002) related to the subsequent risk of mortality. Norepinephrine was also higher in patients who died from progressive heart failure than in those who died suddenly. These data suggest that a single resting venous blood sample showing the plasma norepinephrine concentration provides a better guide to prognosis than other commonly measured indexes of cardiac performance.     

Renal effects of left atrial distension in dogs with chronic congestive heart failure.

The renal response to left atrial balloon inflation in normal dogs was compared with that in dogs with chronic congestive heart failure (CHF). CHF was induced by the production of an aortocaval fistula below the level of the renal arteries. CHF dogs showed elevated left ventricular end-diastolic pressure, enlarged hearts, a depression of myocardial contractility, pulmonary edema, ascites, and peripheral edema. They also showed significant decreases in urine flow, creatinine clearance, para-aminohippurate clearance, sodium and potassium excretion, fractional sodium excretion, osmolar clearance, arterial blood pressure, and heart rate. Balloon distension of the left atrium evoked a significant increase in urine flow and free-water clearance in the normal group. The reflex nature of this response was indicated by its blockade after bilateral cervical vagotomy. In contrast, the CHF group did not exhibit significant changes in urine flow or free-water clearance during balloon inflation. Plasma antidiuretic hormone (ADH) was significantly elevated in the CHF group; however, balloon distension reduced plasma ADH in both groups of dogs. Plasma renin activity was significantly elevated in the CHF dogs and was not changed by balloon distension in either group of dogs. It is concluded that animals with high-output CHF do not exhibit the atrial-diuretic reflex in spite of their ability to reduce ADH levels by atrial distension.     

家庭无创正压通气在慢性左室心力衰竭中的疗效

目的:探讨家庭无创正压通气在慢性左室心力衰竭中的治疗作用.方法:选择2016年1月至12月于保定市第一医院就诊的51例慢性左室心力衰竭患者进行观察,根据患者是否同意使用呼吸机分为两组:对照组给予常规抗心力衰竭治疗,治疗组给予常规抗心力衰竭和家庭无创正压通气治疗,治疗1年后观察两组临床症状、动脉血氧分压(arterial partial pressure of oxygen,PaO2)、6分钟步行试验(6-minute walking test,6MWT)、脑钠肽(brain natriuretic peptide,BNP)水平、左室射血分数(left ventricular ejection fraction,LVEF).结果:治疗1年后,治疗组临床症状、PO2、6MWT、BNP水平、LVEF均有显著改善,明显优于对照组,差异有统计学意义(P<0.05).结论:家庭无创正压通气有助于改善慢性左室心力衰竭患者的心功能,维持心功能的稳定,提高患者生活质量.     

Left ventricular diastolic dysfunction in patients with congestive heart failure

This study reviewed 372 male patients with congestive heart failure. Two hundred and eighty-three (77%) had congestive heart failure due to systolic dysfunction as demonstrated by radionuclide angiography. Eighty-seven (23%) with congestive heart failure were identified who had normal ejection fractions. All patients met the Framingham criteria for congestive heart failure. These 87 individuals had unrecognized diastolic heart failure. It is important to distinguish between systolic and diastolic heart failure because the pathophysiology, treatment, and prognosis differ significantly. The most frequent cause of diastolic heart failure in this study was hypertension. Diastolic dysfunction should be considered in patients with acute heart failure and severe uncontrolled hypertension, or in patients with ischemic heart disease who develop acute pulmonary edema. Patients who do not respond or deteriorate when treated for heart failure using conventional therapy may also have diastolic dysfunction. These patients warrant special recognition and tailored management.     

The reliability of continuous measurement of mixed venous oxygen saturation during exercise in patients with chronic heart failure

Continuous assessment of mixed venous oxygen saturation (cSvO₂) during exercise using a fiber optic pulmonary artery catheter can provide valuable information on the physiological determinants of the exercise capacity in patients with chronic heart failure (CHF). Since its accuracy is not well established during exercise, this study evaluated the reliability of a fiber optic pulmonary artery catheter for measuring SvO₂ during exercise in CHF patients. Ten patients with stable CHF performed steady-state exercise tests at 30 and 80% of the ventilatory threshold and consequently a symptom-limited incremental exercise test. During the tests, SvO₂ was monitored continuously using a fiber optic pulmonary artery catheter (CCOmbo, Edwards Lifesciences, Irvine, CA, USA) and by oximetric analysis of mixed venous blood samples obtained at rest (n = 26), steady state (n = 17) and peak exercise (n = 8). There was a significant correlation between oximetrically determined SvO₂ and cSvO₂ values (r = 0.97). The bias between both methods was 0.6% with limits of agreement from −8 to 9%. The limits of agreement for SvO₂ values <30% (n = 16) were slightly wider than for SvO₂ values >30% (n = 35) (from −10 to 12% and from −7 to 8%, respectively). In conclusion, continuous measurement of SvO₂ during exercise using a fiber optic pulmonary catheter is reliable in patients with CHF, with somewhat less accurate measurements of SvO₂ below 30%.     

Changes in atrial natriuretic factor during preload reduction with nitroglycerin in patients with congestive heart failure

Nine patients with congestive heart failure, New York Heart Association class II-III, were evaluated with right heart catheterization. Plasma atrial natriuretic factor (ANF) was determined in blood samples from the pulmonary artery simultaneously with recordings of right atrial, pulmonary arterial, pulmonary capillary wedge and systemic arterial pressures and heart rate during preload reduction with 0.5 mg nitroglycerin sublingually. Basal plasma ANF levels were higher in patients with congestive heart failure compared to normal controls, and correlated to right atrial, pulmonary arterial, and pulmonary capillary wedge pressures. After nitroglycerin all patients had reductions in right atrial, pulmonary arterial, and pulmonary capillary wedge pressures and a simultaneous decrease in plasma ANF concentrations, reaching lowest values after 10 min. Central pressures and plasma ANF rose to baseline values within 30 min. After nitroglycerin plasma ANF concentrations correlated to pulmonary arterial and pulmonary capillary wedge pressures, while changes in plasma ANF correlated to changes in right atrial and pulmonary arterial pressures. These results provide further evidence that ANF is released by a pressure-sensitive mechanism and demonstrates that ANF secretion in relation to central pressure variations is preserved in patients with congestive heart failure and that the response is rapid.     

Coping and mortality among patients with congestive heart failure

This study was undertaken to evaluate the effects of different coping styles on mortality risk among patients with symptomatic congestive heart failure (CHF). Proportional hazard models were used to evaluate the effects of different coping styles on mortality among 119 clinically stable patients (71.4% men, mean age 65.7 ± 9.6 years), recruited from an outpatient cardiology practice. Twenty deaths were registered during the 24-month period of data collection, all from cardiac causes. The findings showed that behavioral disengagement was a significant predictor of mortality with a hazard ratio of 1.64 (p ≤ .049), whereas acceptance of the CHF condition showed a marginally significant association with mortality (hazard ratio .64; p ≤ .09). The results suggest that behavioral disengagement in relation to coping with disease-related strain is a significant predictor of mortality among heart failure patients. This finding is of concern to clinicians and should have implications for treatment of patients with CHF. Given the link between behavioral disengagement and mortality demonstrated in this study, it is important to explore ways in which counseling in active coping skills might help patients who behaviorally disengage to manage their disease and thereby increase their longevity.     

Diabetes mellitus and congestive heart failure: the prevalence of congestive heart failure in patients with and without diabetes in Poland

IntroductionDiabetes mellitus is a systemic disease and has a negative effect on the cardiovascular system. This paper aimed to present a retrospective analysis of morbidity associated with heart failure in subgroups of patients with and without diabetes in Poland in 2012.Material and methodsData from the National Health Fund were used for the study. In general, 656,937 patients with heart failure, including 281,538 males and 375,354 females, were studied. In this population, additionally, 201,043 patients with heart failure (main diagnosis) and diabetes were studied, including 82,117 males and 118,926 females.ResultsThe mean index of morbidity associated with heart failure in the whole subpopulation of diabetes patients was 9.03%; 8.42% for males and 9.50% for females. Morbidity associated with heart failure in the population of patients diagnosed with diabetes in Poland in 2012 was seven times higher compared to morbidity associated with heart failure in non-diabetes patients. Morbidity associated with heart failure in females was significantly higher compared to morbidity in males in the whole population, in both the subpopulations of patients with and without diabetes.ConclusionsDiabetes mellitus significantly increases risk of heart failure in both women and men. The risk is significantly high after the age of 60 years and higher in females.     

Optimal timing in screening patients with congestive heart failure and healthy subjects during circadian observation

Congestive heart failure (CHF) is a major medical challenge in developed countries. In order to screen patients with CHF and healthy subjects during circadian observation, accurate judgment and fast response are imperative. In this study, optimal timing during circadian observation via the heart rate variability (HRV) was sought. We tested 29 CHF patients and 54 healthy subjects in the control group from the interbeat interval databases of PhysioBank. By invoking the α1 parameter in detrended fluctuation analysis of HRV, we found that it could be used as an indicator to screen the patients with CHF and subjects in normal sinus rhythm (NSR) under Kruskal–Wallis test. By invoking Fano factor, the optimal timing to screen CHF patients and healthy subjects was found to be from 7 PM to 9 PM during the circadian observation. In addition, this result is robust in a sense that the same result can be achieved by using different ECG recording lengths of 2, 5, 10, … , and 120 min, respectively. Furthermore, a support vector machine was employed to classify CHF and NSR with α1 parameter of a moving half-hour ECG recordings via leave-one-out cross validation. The results showed that the superlative screening performance was obtained in the 7 pm–9 pm period during circadian observation. It is believed that this result of optimal timing will be helpful in the non-invasive monitoring and screening of CHF patients and healthy subjects in the clinical practice.     

ANF in experimental congestive heart failure.

The plasma and cardiac levels of immunoreactive (IR) atrial natriuretic factor (ANF) were measured during the entire lifespan of cardiomyopathic hamsters, which eventually develop spontaneous congestive heart failure, and were correlated with immunohistochemical, ultrastructural, and immunocytochemical changes in the secretory apparatus of atrial and ventricular cardiocytes. Plasma IR-ANF rose in the early stages of the disease, reached a maximum in moderate heart failure, and declined thereafter but remained above control values. The peptide decreased constantly in the atria during the evolution of the disease but increased markedly in the ventricles. Its highest levels were found in the inner half of the left ventricle. In atrial cardiocytes, the size and complexity of the Golgi complex increased with the progression of the disease, whereas the number, size, and IR-ANF content (as assessed by the immunogold technique) of secretory granules decreased constantly. In ventricular cardiocytes, the size of the Golgi complex increased, and typical secretory granules were present in approximately 20% of these cells, regardless of their localization in the myocardium. The results suggest that stimulation of ANF secretion in atrial cardiocytes leads to a dissociation between synthesis and release, the latter being maximal according to ultrastructural and immunocytochemical criteria. In ventricular cardiocytes, the same stimulation culminates in increased synthesis and the possibility of release via two pathways: one constitutive, the other regulated. Thus, the elevated plasma levels of IR-ANF in congestive heart failure may be derived from secretion by both atrial and ventricular cardiocytes.     

Baroreflex control of the circulation in patients with congestive heart failure

Vagal and glossopharyngeal afferents from cardiopulmonary and arterial baroreceptors exert supraspinal tonic restraint on sympathetic efferent outflow. The baroreceptor inhibitory influence is directly related to physiological changes in cardiac filling and arterial pressures. Increased cardiac pressures and dimensions during CHF may provide chronic stimulation that reduces responsiveness of these receptors and thereby influence the neurohumoral control of the circulation. Patients with chronic and severe CHF of ischemic cause were compared with control subjects whose ischemic heart disease did not affect cardiac performance. Orthostatic pooling of blood with use of upright tilt (45 degree), provided an apparently sufficient stimulus to unload baroreceptors in patients like controls. In contrast to peripheral vasoconstriction in controls, the patients dilated their resistance vessels during upright tilt. This abnormal vasodilation was systemic and uniform in skeletal muscle and subcutaneous tissue of the forearm remaining at heart level. Such an inability to vasoconstrict in the patients, could not be attributed to depression of local vasoconstrictor reflex or autoregulatory responsiveness of forearm vascular beds. Neural blockade carried out separately or in combination with blockades of forearm vascular effector receptors revealed; increased neural efferent activity to the forearm during tilting the patients which mediated beta-adrenergic vasodilation in both vascular beds. The patients had augmented circulating catecholamine levels, those for epinephrine increased in venous effluents but were maintained in brachial arterial inflow, and those for norepinephrine increased in arterial rather than venous plasma in the forearm. Following the patients during a course of therapy with a selective vasodilator calcium antagonist, the beta-adrenergic reflex vasodilation became substantially attenuated but was preserved during a placebo course of therapy. The beta-adrenergic reflex effect evidenced in the studied patients is most probably a manifestation of reduced baroreceptor afferent restraint and it could subsequently relate to the severity of depression of baroreceptor sensitivity during the course of CHF.     

再同步心脏起搏治疗在慢性充血性心力衰竭中应用

再同步心脏起搏治疗慢性充血性心力衰竭是非药物治疗的新方法.文章介绍了心脏再同步起搏治疗心力衰竭的机制、适应证及禁忌证、并发症及相关的临床试验.     

Chronotropic incompetence response to exercise in congestive heart failure, relationship with the cardiac autonomic status.

In chronic congestive heart failure (CHF), attenuated heart rate response to exercise, a manifestation of chronotropic incompetence (CI), contributes to limiting exercise capacity. The present study was thus conducted to evaluate the respective role of chronic attenuation of cardiac vagal tone associated with depressed baroreflex sensitivity or affected cardiac sympathetic responsiveness in CHF patients with CI. Spontaneous cardiac baroreflex sensitivity (BRS) assessed by sequence method and spectral- and time-domain analysis of heart rate variability (HRV) were analysed in 21 chronic CHF patients. All patients performed a symptom-limited exercise test with measurement of gas exchange. Chronic incompetence which was defined as failure to achieve > or =80% of the heart rate reserve (%HRR) given by (HRpeak - HRrest)/(predictive maximal heart rate - HRrest) was observed in 14 (66%) patients. There was no significant difference in age, heart rate, peak oxygen uptake or left ventricular ejection fraction between the patients with and without CI. Although there was no significant difference in BRS, low frequency power of HRV in normalized units (LFnu) and SDNN were significantly lower in CI patients. Percentage of HRR correlated significantly with LFnu on 15 min (r=0.64, P<0.005) and, with LFnu on 24 h (r=0.52, P<0.01), SDNN (r=0.48, P=0.03) and SDANN (r=0.48, P=0.03), but not BRS (r=0.04, P=NS). Autonomic nervous system derangement is a complex process in CHF. The role of basal depressed cardiac sympathetic tone seems to contribute more closely than depressed baroreflex sensitivity to the impaired heart rate response to exercise frequently observed in CHF patients.