Respiratory sleep disorders in patients with congestive heart failure

Respiratory sleep disorders (RSD) occur in about 40-50% of patients with symptomatic congestive heart failure (CHF). Obstructive sleep apnea (OSA) is considered a cause of CHF, whereas central sleep apnea (CSA) is considered a response to heart failure, perhaps even compensatory. In the setting of heart failure, continuous positive airway pressure (CPAP) has a definite role in treating OSA with improvements in cardiac parameters expected. However in CSA, CPAP is an adjunctive therapy to other standard therapies directed towards the heart failure (pharmacological, device and surgical options). Whether adaptive servo controlled ventilatory support, a variant of CPAP, is beneficial is yet to be proven. Supplemental oxygen therapy should be used with caution in heart failure, in particular, by avoiding hyperoxia as indicated by SpO₂ values >95%.     

Sleep disturbances in caregivers of patients with end-stage congestive heart failure: Part I--The problem

Up to 90% of caregivers report sleep disturbances, particularly congestive heart failure (CHF) caregivers. Sleep disturbances have numerous consequences that can negatively impact a wide domain of outcomes in both the caregiver and the patient for whom they care. Ultimately, these disturbances can lead to caregiver morbidity and CHF patient morbidity, readmission, and mortality. Nurses play a central role in patient education, especially with caregivers. Therefore, nurses can help to educate caregivers on the consequences of stress-related sleep disturbances, which are very prevalent in CHF caregivers.     

Psychosocial issues in patients with congestive heart failure

Psychosocial issues are important variables that need to be addressed in patients with congestive heart failure (CHF). Unfortunately, these issues are often overlooked. Depression and lack of social support have been shown to have a negative impact on patients with CHF. Patients with CHF who are depressed or who lack social support have been shown to have increased morbidity and hospital readmission rates, to be less adherent to their medical regimen, and to have an overall increase in cost of care. The variables are often interrelated, as high levels of social support may lessen the impact of depression on mortality. In addition, certain biologic factors may influence the impact of psychosocial factors in patients with CHF. This review addresses the effects of depression, treatment adherence, and social support in patients with CHF and suggests interventions targeted to these problems. Health care professionals must assess these issues in all patients with CHF, address their specific needs, and intervene appropriately when warranted.     

充血性心力衰竭炎性细胞因子的改变

目的 :探讨充血性心力衰竭 (CHF)时肿瘤坏死因子 α(TNF α)、白细胞介素 6 (IL 6 )、白细胞介素 1β(IL 1β)和一氧化氮 (NO)的变化 ,及其与CHF关系。 方法 :CHF患者 4 5例和年龄匹配的对照者 17例 ,根据NY HA分级将CHF患者分成Ⅱ、Ⅲ、Ⅳ级 3组 ;根据体重分成恶病质组及非恶病质组。用酶联免疫法测定IL 6 ,用放射免疫法测定IL 1β、TNF α ,用比色法测定NO。 结果 :CHF组血清IL 6、IL 1β、TNF α和NO较对照组明显升高 ,IL 6、NO在心功能Ⅱ、Ⅲ、Ⅳ级时均显著升高 ,TNF α在Ⅲ、Ⅳ级时显著升高 ,而IL 1β在Ⅳ级时才显著升高。不同病因的CHF之间差异无统计学意义 ,恶病质组及非恶病质组之间差异也无统计学意义。血清TNF α与IL 6呈正相关 (r =0 .5 82 9,P <0 .0 1)。结论 :血清IL 6、IL 1β、TNF α、NO水平与CHF的严重程度密切相关 ,可作为判断CHF严重程度的指标 ;IL 6、IL 1β、TNF α在CHF的发生发展中可能起重要作用     

Cheyne-Stokes respiration in patients with congestive heart failure

Cheyne-Stokes Respiration (CSR) is a breathing pattern characterised by rhythmic oscillation of tidal volume with regularly recurring periods of hyperpnoea, hypopnoea and apnoea. CSR is no longer solely regarded as a symptom of severe congestive heart failure (CHF), but has been recognised as an independent risk factor for worsening heart failure and reduced survival in patients with CHF. CSR is associated with frequent awakening that fragment sleep and with concomitant sympathetic activation both of which may worsen CHF. Cheyne-Stokes Respiration is very common in patients with severe CHF and its prevalence may have been underestimated in the past due to technical limitations that precluded respiratory monitoring outside sleep laboratories. Since treatment of CSR appears to be beneficial and safe, patients at risk should be promptly diagnosed and treated. Treatment of CSR has been demonstrated to improve left ventricular ejection fraction and potentially prolongs survival in patients with severe CHF. This article briefly summarises the current knowledge of the patho-physiology, prevalence and therapy of Cheyne-Stokes respiration.     

Hormonal profile in patients with congestive heart failure

BACKGROUND: Recent progress has been made in the understanding of the cellular and molecular mechanisms of growth hormone action and of its effects on cardiac tissue. The aim of this study was to measure growth hormone concentrations, along with various other hormones, in patients with stable chronic congestive heart failure due to idiopathic dilated cardiomyopathy. METHODS: The study included 23 ambulatory men, 51.2+/-9.3 years of age, on standard medical therapy for heart failure due to idiopathic dilated cardiomyopathy. All patients underwent clinical and laboratory evaluations, including echocardiogram, radionuclide ventriculography, right heart catheterization, coronary angiography, and right ventricular endomyocardial biopsy. Serum or plasma concentrations of growth, thyroid, sex and adrenal hormones were measured in all patients and compared with those found in 20 age-matched healthy men. RESULTS: Growth hormone, insulin-like growth factor I, and free testosterone values in patients with idiopathic dilated cardiomyopathy and heart failure were 0.37+/-0.2 ng/ml, 123.7+/-50 ng/ml and 48.6+/-23.8 pmol/l, respectively, versus 0.5+/-0.4 ng/ml (P<0.01), 236.3+/-66.4 ng/ml (P<0.001) and 105+/-17 pmol/l (P<0.01), respectively, in the healthy age-matched individuals. All other hormone concentrations were comparable in both groups. CONCLUSIONS: Chronic heart failure due to idiopathic dilated cardiomyopathy is associated with a significant decrease in growth hormone, insulin-like growth factor I, and testosterone concentrations, probably due to chronic disease.     

慢性心力衰竭患者补体激活的临床研究

目的　探讨慢性心力衰竭 (心衰 )患者是否存在补体激活以及补体激活与心衰患者预后的关系。方法　检测 4 4例心衰患者 (心衰组 )和 16例性别、年龄匹配的健康人 (对照组 )血浆补体经典激活途径产物C4d、替代激活途径产物Bb、终末共同途径产物C3bc和补体激活终末复合物C5b 9浓度。心衰组平均随访 (13± 3)个月 ,观察患者是否因心功能恶化而住院治疗或因心功能恶化死亡。结果　 (1)心衰组血浆C4d、Bb、C3bc和C5b 9浓度均显著高于对照组 ;(2 )心衰组中 ,血浆C5b 9浓度低于中位数的心衰患者与血浆C5b 9浓度高于中位数的心衰患者相比 ,后者心功能较差 ,因心功能恶化住院和死亡的例数较多。结论　心衰患者补体系统被激活 ,血浆C5b 9浓度显著提高与心衰患者心功能和预后较差有关 ,提示补体可能成为治疗慢性心衰的一个新的靶点。     

Prostacyclin therapy in patients with congestive heart failure

The acute hemodynamic effects of intravenous prostacyclin (PGI₂), in doses of 22 ± 11 ng/kg per min were studied in nine patients with severe congestive heart failure refractory to digitalis and diuretic drugs. After prostacyclin infusion, mean (±standard deviation) pulmonary capillary wedge pressure decreased from 21.0 ± 7.9 to 15.0 ± 6.6 mm Hg (p < 0.001), mean arterial pressure from 98.9 ± 12.8 to 76.2 ± 7.0 mm Hg (p < 0.001), systemic vascular resistance from 2,574 ± 384 to > 1,368 ± 283 dynes s cm^?5 (p < 0.001), pulmonary vascular resistance from 1,008 ± 451 to 443 ± 135 dynes s cm^?5 (p < 0.001) and pulmonary arteriolar resistance from 330 ± 111 to 189 ± 73 dynes s cm^?5 (p < 0.001). Heart rate increased from 78 ± 21 to 82 ± 24 beats/min (p = not significant [NS]), cardiac index from 2.0 ± 0.37 to 3.2 ± 0.59 liters/min per m² (p < 0.001) and stroke index from 27.6 ± 8.69 to 42.0 ± 0.62 cc/m² (p < 0.001). With prostacyclin, moreover, coldness of the limbs and face disappeared, and patients felt warmth and mild flushing of the face. After prostacyclin, plasma norepinephrine levels, renin activity and aldosterone concentrations rose from 824 ± 375 to 880 ± 468 pg/ml (NS), 0.68 ± 1.36 to 0.95 ± 1.21 ng/ml per h (NS), and 6.64 ± 2.50 to 6.38 ± 2.88 ng/dl (NS), respectively, while plasma epinephrine increased from 140 ± 80 to 250 ± 154 pg/ml (p < 0.025).     

老年人慢性充血性心力衰竭稳定期的睡眠呼吸障碍

目的　了解稳定期、已得到良好治疗的老年慢性充血性心力衰竭患者睡眠呼吸障碍的发生情况及其对心力衰竭的影响。　方法　应用多导睡眠监护仪对 42例老年稳定期充血性心力衰竭患者进行监测。以呼吸紊乱指数 (AHI) 15作为界值 ,AHI >15者为睡眠呼吸障碍组 ,19例 ;AHI≤ 15者为对照组 ,2 3例。　结果　睡眠呼吸障碍组AHI为 18 3～ 84 1,平均 48 6± 16 3,其中阻塞性者AHI为 10 7± 9 2 ,而中枢性者AHI为 37 9± 10 5。与对照组比较 ,睡眠呼吸障碍组有着显著高的醒觉指数 (分别为 17 6± 12 1和 37 3± 2 2 4 )。同时 ,有着更低的睡眠中最低血氧饱和度〔分别为(81 2± 6 8) %和 (6 7 8± 8 2 ) %〕、更低的左心室射血分数〔(32 4± 10 3) %和 (2 4 5± 8 6 ) %〕。　结论　老年稳定期慢性充血性心力衰竭患者有着很高的睡眠呼吸障碍的发生率 ,主要为伴中枢性睡眠呼吸暂停的周期性呼吸 (陈 施呼吸 )。睡眠呼吸障碍的发生与严重的夜间氧合血红蛋白的脱饱和过多的醒觉有关。严重的未经治疗的睡眠呼吸障碍可能影响左心室功能 ,并能加剧老年充血性心力衰竭患者的死亡。     

Functional capacity in patients with congestive heart failure

BACKGROUND: Six-minute walk distance (6MWd) is related to activities of daily living and is also an independent predictor of prognosis in patients with congestive heart failure (CHF). Therefore, it is important to determine factors that contribute to the variability of this test. METHODS AND RESULTS: We assessed the relationship between 6MWd and peak aerobic capacity (VO2) and dynamic muscle strength in 180 patients with CHF (age, 66+/-10 years; 146 men, 34 women; ejection fraction, .29+/-0.08). We also hypothesized that a measure of work performed during the walk test (6MWw) would be a better indicator of exercise capacity than 6MWd. The 6MWd had weak to moderate correlations with dynamic muscle strength (r = 0.33 to 0.41) and peak VO2 (r = 0.48). However, 6MWw was strongly related to dynamic muscle strength (r = 0.63 to 0.70) and peak VO2 (r = 0.77). Multivariate analysis indicated that a model combining dynamic muscle strength and peak VO2 explained 69% of the variance in 6MWw, more than with peak VO2 alone (R2 = 0.59). CONCLUSIONS: Compared with 6MWd, 6MWw correlates significantly better with peak VO2 and dynamic muscle strength, suggesting that 6MWw may be a better reflection of a patient's exercise capacity. Furthermore, these results suggest that an exercise program combining both aerobic and strength training in patients with CHF may improve 6MWw and therefore 6MWd.     

Sleep disordered breathing and its treatment in congestive heart failure

Sleep disordered breathing (SDB) is a common problem with adverse cardiorespiratory, endocrinological, and endothelial effects. Recent studies demonstrate an even higher prevalence of SDB in congestive heart failure (CHF) than in a randomly selected population, with up to 40% and 11% having Cheyne Stokes respiration-central sleep apnoea and obstructive sleep apnoea-hypopnoea syndromes, respectively. Randomised controlled trials of nocturnal respiratory support for SDB associated with CHF for up to three months demonstrate significant benefits in terms of improvements in left ventricular ejection fraction, markers of sympathetic system activity, and quality of life. Further randomised controlled trials of larger scale and longer duration are required to establish the role and benefit of this intervention for the treatment of this debilitating condition. The evidence for the higher prevalence of SDB in CHF, its pathogenesis, its pathophysiological consequences, and the emerging benefits of respiratory support are reviewed.     

Sleep disturbances in caregivers of patients with end-stage congestive heart failure: Part II--assess and intervene

Sleep disturbances in caregivers of patients with congestive heart failure is common. The consequences of sleep disturbances are dire and have potential to seriously impact caregiver health and patient outcomes. Therefore, it is imperative that the health care team, especially nurses, assess and intervene. Basic assessment of caregiver sleep disturbance can be quick and simple and can be performed while assessing the congestive heart failure patient's health. If a more complex sleep disorder is suspected, other assessments can be conducted if time and money permit. The benefits to properly assessing sleep disturbance and subsequent treatment far outweigh the minimal time spent by the health care team or caregiver.     

Echocardiography-based optimization of cardiac resynchronization therapy in patients with congestive heart failure and conduction disorders

Resynchronization of segmental left ventricular mechanics as well as re-coordination of both atrio-ventricular and inter-ventricular contraction are potential mechanisms responsible for the clinical benefit observed in patients with advanced congestive heart failure treated by cardiac resynchronization therapy (CRT). Initially electrical conduction problems, in the majority of cases a left bundle branch block (LBBB), were considered the target for CRT. However, growing experience with CRT in different patient populations including those with milder degrees of conduction disturbance, and improved cardiac imaging utilizing the tissue Doppler approach, have shown the complexity of CRT and the usefulness of sophisticated echocardiographic imaging techniques for therapeutic decision making and optimization of CRT device settings.     

卡维地洛治疗充血性心力衰竭的临床研究

目的:探讨卡维地洛对充血性心力衰竭(CHF)患者心功能的影响。方法:45例CHF患者被随机分成2组.对照组(B组)用利尿剂、强心甙、硝酸酯类等药进行治疗,治疗组(A组)在B组治疗基础上加用卡维地洛,起始剂量3.125mg,2次/d,每2周加量1倍,至最大剂量25mg,2次/d。结果:治疗16周后,两组的心功能分级均有明显改善.与对照组比较,治疗组LVEF增加更加显著(P<0.05)。结论:卡维地洛对CHF有较好的疗效。     

充血性心力衰竭患者窦性心率震荡现象及其临床意义

目的观察心率震荡(HRT)现象在慢性充血性心力衰竭(CHF)患者中的变化,并探讨其临床意义。方法选择66例CHF患者和30例室性期前收缩者(对照组)。其中CHF患者按纽约心功能分级(NYHA)分为轻度CHF组(NYHAⅡ级,29例)和重度CHF组(NYHAⅢ～Ⅳ级,37例);又根据预后不同分为死亡组(11例)和生存组(55例)。所有研究对象经超声心动图测量左心室射血分数(LVEF)和左心室舒张末期内径(LVEDD),并行动态心电图(Holter)检查,获取震荡初始(TO)和震荡斜率(TS)。结果 CHF患者HRT现象明显减弱,CHF组TO和LVEDD明显大于对照组[1.65%±1.49%比-1.02%±0.76%;(59.85±4.46)mm比(47.64±4.96)mm,均为P<0.01],TS和LVEF明显小于对照组[(4.13±2.07)ms/RR比(7.86±3.02)ms/RR;53.34%±11.00%比69.46%±12.75%,均为P<0.01]。重度CHF组TO高于轻度CHF组,但差异无统计学意义。重度CHF组Ts和LVEF则明显低于轻度CHF组[(3.22±1.52)ms/RR比(5.28±2.12)ms/RR;46.34%±6.88%比62.20%±8.59%,均为P<0.01],LVEDD明显大于轻度CHF组[(59.53±4.91)mm比(55.27±3.91)mm,P<0.01]。死亡组TS和LVEF明显低于生存组[(1.92±0.79)ms/RR比(4.34±1.97)ms/RR,44.27%±7.50%比55.09%±10.75%,均为P<0.01],LVEDD和TO明显大于生存组[(58.45±5.11)mm比(55.35±4.19)mm,2.75%±1.75%比1.43%±1.35%,均为P<0.05]。HRT 0级:生存组患者多于死亡组[8例(14.5%)比0(0),P>0.05],HRT 1级:生存组患者明显多于死亡组[39例(70.9%)比3例(27.3%),P<0.05],HRT 2级:生存组患者明显少于死亡组[8例(14.5%)比8例(72.7%),P<0.01]。死亡与TO、HRT 2级和LVEDD呈正相关(均为P<0.05),与TS和LVEF呈负相关(P<0.01)。结论重度CHF患者心率震荡现象明显减弱,HRT可作为CHF患者危险性评估的指标。     

Effects of dichloroacetate in patients with congestive heart failure

Background: Conventional approaches to management of congestive heart failure (CHF) rely on drugs that increase myocardial contractility or reduce ventricular afterload. These approaches often improve cardiac symptoms and survival, but may be associated with significant deleterious effects. An alternative approach is to enhance myocardial energy production. Dichloroacetate (DCA) stimulates pyruvate dehydrogenase activity and accelerates aerobic glucose, pyruvate, and lactate metabolism in myocardial cells. These alterations would be expected to improve myocardial function. Hypothesis: The purpose of the investigation was to assess the efficacy of DCA in patients with left ventricular systolic dysfunction and to examine the mechanism by which improvement occurs. Methods: A total of 25 patients (16 men, 9 women; age range 31-72 years, mean 59) with CHF and ejection fraction ≤40% received an intravenous infusion of 50 mg/kg DCA over 15 min. Indices of systolic and diastolic function were obtained by two-dimensional and Doppler echocardiography performed at baseline, 30 min, and 60 min following completion of DCA infusion. Results: Baseline ventricular ejection fraction was 27.3 ± 9.1%; 17 patients (68%) had nonischemic cardiomyopathy. Heart rate increased after DCA infusion from 73.9 ± 14.5 to 79.2 ± 14.9 beats/min at 60 min; p = 0.02. Left ventricular diastolic and systolic volumes increased at 30 min compared with baseline (248.7 ± 98.1 vs. 259.6 ± 99.6; p = 0.04, and 180.1 ± 80.4 vs. 192.2 ± 84.9; p = 0.002, respectively), but stroke volume (49.2 ± 19.1 vs. 48.9 ± 18.1; p = 0.9) and ejection fraction (27.3 ± 9.1 vs. 25.7 ± 9.8; p = 0.2) were un changed. Indices of diastolic function were also unchanged. Conclusion: Dichloroacetate infusion in patients with CHF is not associated with improvement in noninvasively assesse left ventricular function.     

Treatment of arrhythmias in patients with congestive heart failure

Both ventricular and atrial arrhythmias are commonly encountered in patients with ventricular dysfunction. In fact, roughly half of the deaths occurring in patients with ventricular dysfunction are caused by ventricular arrhythmias. Atrial arrhythmias in this patient population compromise left ventricular filling and if uncontrolled can exacerbate (and in some cases cause) the underlying myopathic process. Consequently, the diagnosis and treatment of these complex, and often life-threatening, arrhythmias is a critical component in the management of congestive heart failure (CHF). As the complexity of pharmacologic and nonpharmacologic antiarrhythmic therapy evolves, it has become increasingly important to understand the potential benefits and limitations of the various treatment modalities in the setting of patients with CHF. The management of arrhythmias in patients with CHF includes conventional drug therapies, as well as therapies directed specifically at treating the arrhythmias that are encountered. The treatment of atrial arrhythmias may include anticoagulation, drugs for rate control, rhythm control, or radiofrequency ablation. The treatment of ventricular arrhythmias, conversely, uses the implantable cardioverter-defibrillator to prevent sudden death, with adjuvant drug therapy or ablation for refractory ventricular tachycardia. This article provides an overview of the current state-of-the-art arrhythmia management in patients with CHF.     

Central sleep apnea in patients with congestive heart failure

Central apnea during sleep represents a manifestation of breathing instability in many clinical conditions of varied etiologies. Central apnea is the result of transient cessation of ventilatory motor output, which represents that inhibitory influences favoring instability predominate over excitatory influence favoring stable breathing. This article will review the determinants of central apnea, the specific features of CHF-related central apnea, and outline a management approach     

Learning needs of patients with congestive heart failure

BACKGROUND: It is suggested that more effective and efficient educational intervention can be created by matching the program to patient learning needs. Previous attempts to determine the learning needs of patients with congestive heart failure (CHF) find all types of information endorsed as very important to learn. OBJECTIVES: To increase differentiation between patients' ratings of information needs by modifying the CHF Patient Learning Needs Inventory (CHFPLNI) and examined predictors of learning needs. METHODS: Thirty-four inpatients with CHF from the Toronto General Hospital, Toronto, Ontario completed the modified CHFPLNI and rank ordered the perceived importance of eight categories of CHF knowledge measured by the CHFPLNI. Patients also completed measures of emotional distress, fatigue, health beliefs, locus of control and current CHF knowledge. RESULTS: Ratings across all information categories were similar (M=4.4-5.3/7) and highly correlated (r=0.52-0.87). Patients indicated information on medication, cardiovascular anatomy and physiology, and treatment were the most important to learn on both the CHFPLNI and by rank ordering. Higher fatigue was correlated with information needs on diet (r=0.37), activity (r=0.37), psychological (r=0.38) and risk (r=0.37) factors. No other variables consistently predicted learning needs. CONCLUSIONS: Changing the format of the CHFPLNI did not increase the differentiation of patients' ratings across information categories. The assessment of patients' learning needs using extensive questionnaires does not appear warranted because simple rank ordering obtained similar information. Individuals who are more fatigued wanted more information on those aspects of care that they managed on a day-to-day basis.