Introduction
Mortality and morbidity have remained constantly high among the end-stage renal disease patients despite advances in dialysis therapy. For example, the annual mortality rate of ESRD patients has remained at about 20% with mortality rates associated with cardiac disorders reaching 10 to 20 times higher among patients under dialysis than in the ordinary population. In fact only 16% of reported dialysis patients indicate a normal cardiac anatomy according to echocardiography, while 41% indicated concentric LVH and 16% systolic insufficiency (Walsh et al. 2).
Dialysis is usually a treatment intervention for kidney failure arising from Chronic Kidney Disease (CKD). Cardiovascular disease (CVD) is also another common condition secondary to CKD. Mortality for patients of CVD with underlying CKD is high compared to the risk for developing kidney failure (Samak, et al. 1)..
The National Kidney Task Force on Cardiovascular Disease reported a high prevalence of cardiovascular disease in patients with chronic kidney disease (Levey, Beto, Coronado, et al. 853 qtd in Samak et al., 3). CVD is highly prevalent in patients with CKD, and mortality rates for CVD patients under dialysis surpass those of the general population by 10 to 30 times (Samak et al., 3).
Dialyzed patients with Ischemic heart disease cannot necessarily present large-vessel coronary abnormality. In a certain study 50% of non-diabetic dialysis patients, indicating symptoms of myocardial ischemia devoid of large-vessel coronary artery disease. It was then speculated that such patients suffer ischemia as an outcome of coupled consequences of left ventricular hypertrophy (LVH) and volume overload, which account for increased oxygen requirement, and small vessel coronary disease, which attributes for insufficient oxygen supply (Samak et al., 6).
The prevalence of Left ventricular hypertrophy LVH are remarkably high in hemodialysis patients. The prevalence of LVH in reported hemodialysis patients has been found to be remarkably high. For instance, a Cohort Study of reported dialysis patients indicated a 74% LVH occurrence at baseline, 44% concentric LVH occurrence, 30% hypertrophy associated with left ventricular enlargement, and 15% occurrence of systolic malfunction (Samak et al. 7).
Cardiovascular Disease
High blood pressure exacerbates cardiovascular disorders and as such, alleviating blood pressure is important in the management of cardiovascular disease. Although decreasing blood pressure (BP) is beneficial for cardiovascular heart disease, conventional therapy cannot reduce the predisposition of cardiovascular disorders in patients with high blood pressure (Devereux; Wachtell; Gerdts; et al., 4).
Certain advancement has been made in predicting the occurrence of hypertension through analyzing the preclinical cardiovascular disease. Left ventricular hypertrophy (LVH) distinctively predetermines adverse result in hypertensive population among others. Such evidence supports the hypothesis that left ventricular pathological growth and treatment by mass deduction may depict self-sufficient attributes of disease development or restraint (Devereux; Wachtell; Gerdts; et al., 7).
Echocardiographic research findings have correlated the sustenance of typical left ventricular mass or degeneration of Left Ventricular Hypertrophy with decreased CV occurrence. Already, a correlation between inferior left ventricular mass and the effect of hypertension treatment have been established by study (Devereux; Wachtell; Gerdts; et al., 12).
Pathophysiology of Left Ventricular Hypertrophy
Left Ventricular Hypertrophy is essentially an adaptive reaction to elevated cardiac workload that confers short-lasting beneficial outcome on cardiac activity while a long-term, adverse outcomes (Meeus et al. 140 qtd in Ayus et al. 2778). For a short term, left ventricular hypertrophy improve the working power of the heart, at the same time maintaining tensile stress, however with time lapse these compensatory response turn maladaptive.
The pathophysiology of LVH is an intricate process which encompasses various attribute. Primarily, pressure overload lead to synthesis of extra sarcomeres in alignment while conserving left ventricular dimension at the expense of mounting the wall depth; concentric hypertrophy. Volume overload on the other hand, induce compilation of sarcomeres in series producing enlargement of ventricular cavity (Meeus et al. 141 qtd in Ayus et al. 2778).
The characteristics of Left Ventricular Hypertrophy in ESDR patients include both of the processes (Meeus et al. 142 qtd in Ayus et al. 2778). The medical symptoms indicated in the onset of kidney disease and subsequent dialysis that are risk factors for onset of LVH, are pressure overload, volume overload, development of arteriovenous fistulae and anemia (Foley 111-). Pressure overload essentially integrates increase in both stiffness and after-load (Meeus et al. 143 qtd in Ayus et al. 2778). Collectively, LV hypertrophy is a complicated abnormality that can be accounted for by a range factors associated with ESDR and undesirable changes on cardiovascular outcomes.
Cardiovascular malfunctions are the primary attribute of mortality in patients with End-Stage Renal Disease (ESRD). Left ventricular hypertrophy and left ventricular dilation (LVD) has been shown by echocardiography to be a common attribute of ESDR and are self-sufficient predisposition for mortality. Such attributes establish during the initial stage of renal inadequacy and their prevalence increases consistently with aggravation of the renal failure, such that LVA indicates in 75% of kidney failure patients at the onset of dialysis. This anatomical change emerges due to the volume overload, persistent pressure, or both, coupled with various neurohumoral and metabolic malfunction (London et al., 1).
The primary hemodynamic elements that aggravate LVH and LV dilation in renal insufficiency patients include, anemia, and elevated systolic BP (SBP), while for those patients under emodialysis are, overhydration exacerbated volume overload, and arteriovenous shunts. Lateral Ventricular distortions tend to increase with time in big proportion of the patients. Recent studies have indicated that management of hypertension or anemia has partial reversible effect on Left Ventricular Dilation and Left Ventricular Hypertrophy, although this regression has not been substantially proven to increase the survival of the patients (London et al., 1).
Nocturnal hemodialysis versus conventional hemodialysis
According to Besarab et al. (584- ), randomized tests that were intended to proof decrease in mortality in ESRD patients requiring dialysis, have not been successful. Also those studies developed to control substitute endpoints, like normalization of Left ventricular hypertrophy or dilation have not been fruitful. Moreover, few approach to have been proven to alleviate the low health-related quality of life (HRQOL) evident in such group of people.
Such obstacles to enhancement of health outcomes may perhaps be an attribute of various intricate physiological and metabolic malfunctions associated with ESRD. In this regard, the typical hemodialysis (CvHD) is not sufficient to correct most of these malfunctions, and affords a low proportion micro molecular weight electrolyte clearance relative to the natural kidney clearance (Gotch 10- ). In order to compensate for this insufficiency and enhance urea clearance and the subsequent clinical results, nocturnal hemodialysis (NHD) was invented in the 1970s and has presently attracted afresh interest. Under NHD, dialysis is undertaken at home 5 to 6 times on weekly basis (Walsh et al. 2).
Cohort studies and case control indicate that hemodialysis may stimulate renormalization of left ventricular hypertrophy, alleviate HRQOL, and enhance blood pressure restraint to name but a few such benefits. Nevertheless, data collected from observation may direct to conclusions completely opposed by randomized clinical trials (RCT). Because of instability connected with observed consequences and expenditures in non-randomized targeting nocturnal hemodialysis, it is paramount to consider superior quality information on NHD prior to widespread implementation of the new therapy (Walsh et al. 2)..
Past observational research study have depicted decreases in left ventricular mass attributed to the use of nocturnal hemodialysis. Because LV mass is a substitute indicator of cardiovascular disease and a sufficient risk factor of mortality due to cardiac disorder, this results have supported NHD as an absolute approach for dialysis patient(Walsh et al. 2)..
Further, studies based on observation have augmented the benefits of nocturnal hemodialysis therapy, including enhanced control of blood serum phosphate, and improved blood pressure regulation. Nevertheless, randomized controlled study to appraise NHD against CvHD has not yet been performed. Such study is important to establish credibility of NHD as a customary dialytic intervention may be relatively costly. Moreover, various approaches that produce enhanced health effects in studies of patients under dialysis have not attained the “gold standards” of reflecting similar development in randomized control studies (Walsh et al. 2).
A comparison trials between CvHD and NHD (Culleton et al. 1291- ), revealed a remarkable change in the LV mass outcome. It was shown that left ventricular mass decreased by23.0g in NHD patients and increased by 24.0g in CvHD dialysis group. Such alleviation of left ventricular mass induced a decrease in blood pressure and the subsequent decrease in antihypertensive therapy regimen, and decreased serum parathyroid hormone and phosphate levels (kliger 1331).
Nevertheless extracellular fluid (ECF) volume and the impact of NHD on its status were not assessed. The researchers were not able to establish if regressed LVH and blood pressure were an attribute of changes in volume regulation. The primary quality of life (QoL) status was consistent, although the QoL scores fell for patients put under a thrice per week hemodialysis but remained consistent in NHD patients. It was hard to understand these outcomes since the subjects were steady, long-term dialysis patients (placed under dialysis in the CvHD category for an average of 4.8 years) assessed for over six months period. However, this outcome was unreliable since a small sample size was not sufficient to detect clinically important changes in the quality of life status (Kliger 1332).
Nocturnal home hemodialysis
This refers to an intensive design of renal replacement therapy in which patients self-administer own dialysis 4 to 6 nights weekly at interval of 5 to 8 hours per a session. In other words, patients essentially undergo 30 to 40 hour therapy on weekly basis, which exceeds the 12 hour routine using the convention hemodialysis. The improved uremic clearance and prospect to attain normalized fluid balance have been the basis of interest for nocturnal home hemodialysis in the previous years (Pauly et al. 1846).
The constituent characteristics of a contemporary nocturnal home hemodialysis are long duration, home based, nightly administration and frequent treatments. NHD therapy combines these elements into one system. Uldall et al (1) pioneered the implementation of nocturnal hemodialysis in 1994, in which dialysis patients were put under home hemodialysis of 8 hour interval for 5 to 7 nights, on a weekly basis (Pauly et al. 1846).
Nocturnal home hemodialysis has attracted the interest of research for two major reasons. To begin with, past research have substantially proven the NHD superiority over other types of dialysis in reversing various physiological perturbations associated with uremia. Secondly, outcomes of conventional hemodialysis and peritoneal dialysis indicate their inadequacy and that comparatively minor change in minute uremic toxin clearance based on urea Kt/V, depicts that uremic clearance by CHD therapies is insufficient (Pauly et al. 1847).
Left ventricular hypertrophy and dilation in dialysis patient
The clinical indication of cardiac disease has been proven to be highly prevalent independent mortality risk factor for ESDR dialysis patients. Cardiovascular disease accounts for 40% of mortality in chronic dialysis patients. However, little knowledge about the risk factors for and the prognostic significance of various forms of cardiac disease association with ESDR patients are available (Foley et al. 2024).
Left ventricular hypertrophy is a common determinant of mortality in general cardiac disease patients especially in critical hypertensive patients. Later trials have revealed independent association of left ventricular dilation with increased risk for cardiovascular disease (Lauer 1180- ). LV hypertrophy relatively more prevalent in ESDR patients and is believed to an independent mortality risk factor (Silberberg 286 qtd in Foley et al. 2024; Foley 186- ). Left ventricular dilation is prevalent in dialysis patients on the account of various factors, including arteriovenous grafts and fistulae, anemia, and excretory malfunction (Foley 186-; London 973- ).
Echocardiographic anomalies, such as left ventricular hypertrophy and dilation, and systolic dysfunction, are commonly associated with end-stage renal disease patients initiating therapy (Greavea 245). LV dilation in patients subject to dialysis may attribute to factors such as chronic fluid overload, arteriovenous grafting, and anemia (London 973). Scientists believe that the extent of compensatory LV hypertrophy resulting from LV dilation is dulled in ESRD patients. Despite the insufficient proof of the prognostics outcomes of such abnormalities exist, there is proof that both Left Ventricular Hypertrophy (Silberberg qtd in Foley et al. 2024) and enlarge cardiomyopathy indicate inaccurate prognosis in patient under dialysis.
An escalated LV mass score is a chief cardiovascular predictor in the general population, in critical hypertensive patients, and in coronary disease patients. Asymptomatic LV dilation has been attributed to escalated risk of cardiovascular disease in adult men (Foley et al. 2026).
Patients with high LV mass, high LV mass-to-volume ratios, and average cavity volume, expressed inaccurate prognosis, while cavity volume was prognostically insignificant. LV geometry is the primary risk factor especially for asymptomatic cardiac disease dialysis patients. With regard to concentric hypertrophy, treatment focused towards the degeneration of LV hypertrophy may enhance chances of survival (Foley et al. 1995a, 2029).
Conclusively, LV dilation and hypertrophy are prevalent in patients embarking on ESDR treatment. Both Left Ventricular volume and mass are risk factors of subsequent mortality in ESDR patients under dialysis, although their prognosis are detached: wherein the LV mass connection with mortality is relevant only to typical cavity volume patient, while LV volume connection applies just for dilated cavity patients. Clearly, for both categories the LV mass-to-volume ratio seems to have prognostic importance, although in diametrically opposite perspective. From this view, Left Ventricular geometry is major risk factors for mortality and morbidity in end-stage renal disease (Foley et al. 1995b, 2031).
Left ventricular dysfunction in nocturnal haemodialysis
Cardiovascular disease is the major attribute of low quality of life and increased mortality in dialysis patients. In heamodialysis patients left ventricular dysfunction (LVDys) prevalence rate is 10 to 30 folds higher than in the general population (Jassal, Trpeski, Zhu et al. 1033- ). Diagnosis of congestive heart failure (CHF) in hemodialysis patients, associated with reduced left ventricular activity, correlates with the rate of mortality, proven by a 3-year survival rate of just 17% (5). LVDys is usually subsequent to left ventricular hypertrophy which in its own bears a low prognostic score for mortality in ESDR patients. Collectively LVDys or Left ventricular hypertrophy (LVDys precursor) and congestive heart failure confer a sufficiently high predictor of mortality and morbidity. Such connection provides the basis for the National Kidney Foundation guidelines to encourage regular echocardiographic and baseline follow-ups for patients embarking on hemodialysis (Sood, Pauly , Rigatto & Komenda 119).
Various documentation concerned with abnormalities of left ventricular (dys)function in hemodialysis provides inconsistent definitions of this issue, various aetielogies have beemn postulated as well as different techniques of are used, such that comparison of distinct research studies are hard to evaluate. However, (SOLVD Investigators 293-) defines left ventricular dysfunction as a LV ejection fraction below 40% or an endocardial LV shortening of less than 25%. Left Ventricular Hypertrophy is emphatically refers to left ventricular mass index (LVMI) of less than 131 g/m2 and 100 g/m2 in males and females respectively based on maximum standard in Framingham study (Levy et al. 956). LVMI is derived from the LV mass standardized to body surface area. Congestive Heart Failure is medical diagnosis based on evidence of pulmonary edema and dyspnoea that probably may associate with left ventricular dysfunction (Sood et al. 200).
Effect of hemodialysis on Left ventricular Hypertrophy
Persistent inaccurate prognosis associated with prolonged dialysis, has prompted researchers to approach this problem from different perspective particularly by alteration of customary hemodialysis regimens including increasing the dose, time and/or rate hemodialysis with possibility of improving the outcomes (Ayus et al. 2778).
Past cohort trials of physiologic approaches of hemodialysis, such as short daily hemodialysis and Nocturnal home hemodialysis have demonstrated prospect optimistic cardiovascular outcomes (Lindsay 85; Chan 1518-). Short daily hemodialysis; comprising of 6 weekly session of between 1.5 and 3.0 hr interval; focuses on enhanced solute and fluid clearance. In fact past controlled studies pertaining to short daily hemodialysis have revealed enhanced blood pressure restraint, reduced possibility of hospitalization, regeneration of LV hypertrophy, and increased hemoglobin index (Ayus et al. 2778).
Nocturnal home hemodialysis, employs increased time and rate of dialysis, so that it stimulate degeneration of left ventricular hypertrophy, it boost heart rate inconsistency during sleep, increase phosphorus control in specific patients, and alleviate nocturnal hypoxemia (low blood oxygen). Clearly, theses two modalities of dialysis are superior in regard of enhanced outcome of cardiovascular abnormalities (Ayus et al. 2778).
Current data indicated that short daily dialysis helps alleviate phosphorus regulation (Achinger S1-S5). Insufficient restraint of phosphorus in ESDR patients is a significant risk factor for cardiovascular disease, and hyperphosphatemia was recently associated with LV hypertrophy (Neves 2237- qtd in Ayus et al. 2779).
Chronic inflammation associated with chronic hemodialysis promotes undesirable cardiovascular outcomes (Zimmermann 648- qtd in Ayus et al. 2779) in patients subject to enduring hemodialysis. Two simple measures can alleviate inflammation, such as removal of contaminated AV grafts and of futile kidney allografts, although few therapeutic interventions to solve this problem exist. A drawback to short daily hemodialysis lies in its hypothetical potential to elevate status of inflammation a characteristics that can be accounted by frequent contact with extracorporeal circuit (Ayus et al. 2782).
Nevertheless, production of inflammatory cytokines is alleviated with adaption of enhanced biocompatible membranes (Memoli 266). Importantly, preceding researchers have discovered that C-reactive protein (CRP) levels do not automatically escalate in patients under nocturnal home hemodialysis (Klarenbach 57-).
Benefits of Nocturnal Hemodialysis
Current cohort and case-cohort have purported that nocturnal hemodialysis may be in a position to enhance clinical results in end-stage renal disease patients. In these findings patients who switch to nocturnal hemodialysis of 5 to 6 sessions a week, indicated improvement in left ventricular mass, health related quality of life (HRQOL), mineral metabolism, and systemic blood pressure (Culleton et al. 1292).
Studies by Culleton et al. (1296) proved that nocturnal hemodialysis was functionally superior in alleviating parathyroid hormone, calcium-phosphate metabolites, and serum phosphates, relative to conventional hemodialysis. Further, 37 patients were put on oral calcium-based phosphate binders while 12 patients were put on sevelamer either singly or combined with calcium based binders, at baseline. A decrease or withdrawal of oral phosphate binders were applied on 19 out 26 subjects in nocturnal hemodialysis category but just 3 out of 25 subjects in conventional hemodialysis. Consequently, elemental calcium intake o.d. was alleviated in nocturnal hemodialysis subjects but in subjects put on conventional hemodialysis.
Conclusion
According to the findings in the aforementioned studies, repeated nocturnal hemodialysis alleviates left ventricular mass, HRQOL, disturbance of mineral metabolism, and systemic blood pressure relative to the conventional hemodialysis of three sessions per week. However, anemic status was not impacted by nocturnal hemodialysis. Further, this research trial uphold various findings in previous nonrandomized trials, which revealed that embarking on nocturnal hemodialysis guarantees improvement in left ventricular mass and systemic blood pressure. Similarly, the findings help verify the indecisiveness surrounding the benefits of nocturnal hemodialysis on anemia control, HRQOL, and markers of mineral metabolism (Culleton et al. 1299).
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