Molecular Genetics of Congestive Heart Failure

The manifestation of congestive heart failure occurs secondary to a great variety of cardiac or systemic disorders that share a temporal or permanent loss of cardiac function. In order to enhance our knowledge about the genetics of heart failure it is mandatory to analyse the aetiologic factors of these underlying disorders separately. Monogenic forms of congestive heart failure have initially been described by observant physicians in consecutive generations of affected families. Molecular genetic analyses of these families subsequently allowed us to localise and identify some of the genes that cause hypertrophic, dilative, or restrictive cardiomyopathies, congenital heart disease, as well as a number of inborn errors of metabolism. However, the great majority of patients develops heart failure as a final consequence of multifactorial conditions such as hypertension, cardiac hypertrophy, or coronary artery disease. Each of these conditions may be the product of a complex equation that includes environmental and genetic factors. Indeed, some of these factors may be harmful, others protective and for most it takes decades before a phenotype will be clinically detectable. Given this complex scenario it was not unexpected that early studies on candidate genes came up with partially controversial information. This review aims to summarize and to comment on the principal findings of this work.     

Refractory Congestive Heart Failure and Modest Renal Failure: II

A 47-year-old male was admitted to the hospital because of progressive dyspnea leading to orthopnea. He had a history of insulin-dependent diabetes mellitus for 23 years with nephropathy and mild renal insufficiency for two years. The patient had undergone triple vessel coronary artery bypass surgery five years prior. Ischemic cardiomyopathy was diagnosed two years previously when heart failure led to multiple hospital admissions. During the past year, congestive heart failure (CHF) was treated with increasing doses of furosemide (maximum 160 mg) and metolazone (10 mg), intermittent intravenous dobutamine, and amrinone infusions. A short trial of an angiotensin converting enzyme (ACE) inhibitor (captopril 12.5–50 mg/day) resulted in hyperkalemia and deterioration of renal function. On admission to the hospital, physical examination revealed a well-developed and well-nourished male in respiratory distress. Supine blood pressure was 90/60 mmHg. Jugular veins were distended up to the jaw. Heart rate was 90/min, regular. Heart sounds were distant but an S3 gallop was heard. Wet rales were heard bilaterally over the lungs. Liver was enlarged below the costal margin and was tender to touch. Pitting edema was present in both lower extremities up to the knees. Laboratory data: serum sodium was 130 mEq/l, potassium 5.7 mEq/l, blood urea nitrogen (BUN) 59 mg%, serum creatinine 4.9 mg%, hemoglobin 11.2 gm%. Chest X ray revealed cardiomegaly and pulmonary vascular congestion. EKG showed a normal sinus rhythm with first degree heart block and a left bundle branch block. Echocardiogram revealed moderate left ventricular dilation, moderate global hypokinesia, estimated left ventricular ejection fraction of 20%, mild right ventricular dilation, mild right atrial dilation, mitral regurgitation, and no pericardial effusion. The patient exercised for 4 min and 22 sec in a modified Naughton protocol. Heart response to exercise was accentuated and blood pressure response was flat. The patient received 200 mg of IV furosemide and 5 mg of metolazone with an increase in urine output of only 200 cc over a 2-hr period. In a 24-hr urine, output was only 950 cc. Urine sodium was 18 mEq/l, potassium 39 mEq/l, and osmolality 310 mOsm/kg. Because of the continued dyspnea and an arterial oxygen saturation of 68% despite 100% oxygen via face mask, the patient was subjected to 3 hr of isolated ultrafiltration using a femoral Quinton catheter. Three liters of fluid were removed with a drop in pulmonary wedge pressure to 20 from 27 mmHg. Subjectively, the patient started breathing better. Oxygen saturation improved. However, no increase in urine output was observed during the next 48 hr. The symptoms of CHF recurred. Isolated ultrafiltration was repeated with good result. Over the next week, it became apparent that the patient was dependent on ultrafiltration to maintain a symptom-free status. It was decided to put the patient on chronic dialysis because of chronic renal failure and chronic heart failure. Following multiple discussions with the dialysis educator, the patient chose continuous ambulatory peritoneal dialysis (CAPD) as the form of chronic renal replacement therapy.     

A Perspective on the Surgical Management of Congestive Heart Failure

Surgical treatment of patients with congestive heart failure (CHF) has steadily advanced from rescue procedures such as aneurysmectomy, rupture repair, ventricular assist devices (VADs), and transplantation to procedures that can prevent or delay the progression of cardiac dysfunction and failure. The latter include operations such as coronary artery bypass grafting (CABG) and mitral valve repair for patients with ischemic cardiomyopathy (ICMP) and mitral annular dilatation, ventricular restoration and remodeling, and cardiac resynchronization therapy. As the number of heart transplants reported worldwide continues to decline over the past decade (by over 30%), newer surgical therapies have emerged. A need arises for clinical registries such as the NIH-sponsored LVAD registry and registries for biventricular pacing and AICD implantation, for total artificial heart implants, and for mitral valve repair in patients with ICMP. Prospective trials comparing sole ventricular restoration therapy (SVR) to SVR with concomitant CABG/MVR, coronary sinus versus epicardial LV pacing for ventricular resynchronization therapy, trials comparing LVAD as destination therapy to AICD implants, mitral valve repair versus chordal-sparing valve replacement for ischemic and valvular cardiomyopathy, and off-pump versus on-pump CABG for patients with ICMP are urgently needed. Future research should also be directed toward drugs targeting “B-cell mediated” humeral vascular rejection—the Achilles heel of cardiac transplantation, xenotransplantation, permanently implantable VADs, gene therapy, and myocardial cell regeneration therapy.     

Clinical Consequences of the Autonomic Imbalance in Hypertension and Congestive Heart Failure

The reduction of coronary mortality is not as large as one would expect from the observed blood pressure lowering in trials of antihypertensive medications. This is not surprising; hypertension is a complex disease where the high blood pressure is only one of numerous coronary risk factors. Sympathetic overactivity in hypertension, independent of the blood pressure, may be conducive to premature atherosclerosis by inducing insulin resistance and dyslipidemia. Through its trophic effect on blood vessels, sympathetic overactivity potentiates vasoconstriction. This, in turn, accelerates hypertension and the metabolic syndrome. The hypertrophy of small coronary arterioles decreases the coronary reserve and enhances coronary spasms. Tachycardia, which is due to increased sympathetic tone and a decreased parasympathetic tone, favors arrhythmias and sudden death in congestive heart failure and hypertension. Increased hematocrit is frequently found in male patients with hypertension, and high hematocrit is a predictor of coronary heart disease/thrombosis. The increase of hematocrit is in part due to an alpha adrenergic postcapillary venoconstriction. Enhanced sympathetic drive, insulin resistance and dyslipidemia have been demonstrated also in congestive heart failure, but the clinical importance of these findings is not fully understood.     

双心室同步起搏治疗充血性心力衰竭患者的观察及护理

目的 探讨双心室同步起搏治疗充血性心力衰竭的观察及护理方法。方法 观察患者术前、术后用药的最大剂量及临床表现，并结合治疗采取有效的护理措施。结果 治疗后患者用药剂量明显减少，生命体征、卧位明显改善（均P〈0.01）。结论 双心室同步起搏治疗充血性心力衰竭，能明显提高患者的生活质量。术前做好纠正心功能的护理；术后密切心电监护，进行功能锻炼指导及健康教育是其护理要点。     

双心室同步起搏治疗充血性心力衰竭患者的观察及护理

目的探讨双心室同步起搏治疗充血性心力衰竭的观察及护理方法.方法观察患者术前、术后用药的最大剂量及临床表现,并结合治疗采取有效的护理措施.结果治疗后患者用药剂量明显减少,生命体征、卧位明显改善(均P<0.01).结论双心室同步起搏治疗充血性心力衰竭,能明显提高患者的生活质量.术前做好纠正心功能的护理;术后密切心电监护,进行功能锻炼指导及健康教育是其护理要点.     

The Assessment of Allostatic Overload in Patients with Congestive Heart Failure by Clinimetric Criteria

The precipitating role of emotional stress in the development of congestive heart failure (CHF) is a long‐standing clinical observation. We employed new clinimetric criteria for the assessment of allostatic overload (AO) in a sample of CHF patients, with regard to its associations with psychological distress and health status. Allostatic overload was assessed by a semi‐structured interview based on clinimetric criteria in 70 consecutive outpatients with CHF. One observer‐rated scale and two self‐rating questionnaires for psychological distress were administered. Cardiac variables were also collected at intake. Twenty‐three patients (32.9%) were classified as having AO according to clinimetric criteria. Significant differences were found with regard to gender, with women being more likely to report AO than men (23.5% versus 57.9%). Patients with AO presented significantly higher levels of psychological distress (based on scales administered) compared with those who did not. Among cardiac risk factors, hyperglycaemia was found to be significantly associated with the presence of AO. The use of the clinimetric criteria provides a global index for identifying distress that might adversely influence the course and progression of CHF. It may be of use in clinical practice, leading to therapeutic suggestions such as lifestyle modifications and psychotherapy to help patients deal with their difficulties. Copyright © 2014 John Wiley & Sons, Ltd.     

心力衰竭病人健康教育无效原因分析及对策

对部分慢性充血性心力衰竭(CHF)病人在住院期间健康教育无效的原因进行分析,认为①病人及家属方面：老年病人接受能力差及长期形成的不良习惯难以改变;反复住院使病人对治疗失去信心;住院时间短,健康教育不充分;病人家属未积极参与;病人对护士缺乏信任。②护士方面：健康教育缺乏连续性;健康教育流于形式。提出需针对老年病人特点采取多样化形式进行健康教育;教育病人控制情绪,指导家属积极参与;指导其遵医行为;其做好出院指导,避免诱发因素;加强护理人员素质培养和技能训练。     

Contribution of Renal Function Impairment to Unexplained Troponin T Elevations in Congestive Heart Failure

Background. Patients with severe congestive heart failure (CHF) often have unexplained elevations in serum concentrations of troponin T (TnT), and it is proposed that this is due to cardiac TnT release because of underlying cardiac disease. We investigated whether impaired renal function is an additional underlying phenomenon contributing to increased TnT levels in patients with CHF. Methods. Sixty-two patients with nonischemic CHF, New York Heart Association (NYHA) class III–IV, with normal coronary angiogram and normal serum creatinine were included in the study. Baseline glomerular filtration rate (GFR) was calculated using the Cockcroft Gault equation. Results. Although mean creatinine level was normal (0.92 ± 0.17 mg/dL), mean GFR was low (56 ± 16 mL/min) in the cohort. Elevated (≥0.02 >g/L) TnT was measured in 33 patients (53%). Compared with patients with normal (<0.02 >g/L) TnT levels, patients with elevated TnT had significantly higher NYHA class (p = 0.02), longer duration of disease (p = 0.02), lower GFR (p = 0.0001), and lower LVEF (p = 0.0001). There were significant associations between TnT levels and duration of disease (r = 0.29, p = 0.01), creatinine (r = 0.30, p = 0.01), GFR (r = ?0.55, p < 0.0001), and LVEF (r = ?0.39, p = 0.001). Independence of these associations was evaluated in multiple linear regression analysis, and serum TnT was independently and negatively associated only with GFR (p = 0.005). Conclusions. Renal function (GFR) correlated significantly and more strongly than cardiac function (LVEF) with the serum TnT levels in patients with CHF. This supports our hypothesis that impaired renal function causes the accumulation of troponin and is very likely the cause of unexplained elevations of serum TnT in patients severe CHF.