Effectiveness of Enhanced External Counterpulsation Treatment on Symptom Burden, Medication Profile, Physical Capacity, Cardiac Anxiety, and Health-Related Quality of Life in Patients With Refractory Angina Pectoris.

BACKGROUND: Patients with refractory angina pectoris experience recurrent symptoms that limit their functional capacity, including psychological distress and impaired health-related quality of life (HRQoL), despite optimized medical therapy. Enhanced external counterpulsation (EECP) is an evidence-based alternative noninvasive treatment. Although physical well-being and mental well-being are equally important components of health, few studies have investigated the psychological effects of EECP in patients with refractory angina pectoris. OBJECTIVE: The aim of this study was to evaluate the effects of EECP treatment in patients with refractory angina pectoris regarding medication profile, physical capacity, cardiac anxiety, and HRQoL. METHODS: This quasi-experimental study with 1-group pretest-posttest design includes a 6-month follow-up of 50 patients (men, n = 37; mean age, 65.8 years) who had undergone 1 EECP course. The following pretreatment and posttreatment data were collected: medication use, 6-minute walk test results, functional class according to the Canadian Cardiovascular Society, and self-reported (ie, questionnaire data) cardiac anxiety and HRQoL. In addition, the questionnaires were also completed at a 6-month follow-up. RESULTS: After EECP treatment, patients used significantly less nitrates (P < .001), walking distance increased on average by 46 m (P < .001), and Canadian Cardiovascular Society class improved (P < .001). In addition, all but 1 subscale of cardiac anxiety and all HRQoL components improved significantly (P < .05). The positive effects for cardiac anxiety and HRQoL were maintained at the 6-month follow-up. CONCLUSIONS: Enhanced external counterpulsation treatment resulted in reduced symptom burden, improved physical capacity, and less cardiac anxiety, leading to increased physical activity and enhanced life satisfaction for patients with refractory angina pectoris. Enhanced external counterpulsation treatment should be considered to improve the life situation for these patients.

RheoStim: Development of an Adaptive Multi-Sensor to Prevent Venous Stasis.

Chronic venous insufficiency of the lower limbs is often underestimated and, in the absence of therapy, results in increasingly severe complications, including therapy-resistant tissue defects. Therefore, early diagnosis and adequate therapy is of particular importance. External counter pulsation (ECP) therapy is a method used to assist the venous system. The main principle of ECP is to squeeze the inner leg vessels by muscle contractions, which are evoked by functional electrical stimulation. A new adaptive trigger method is proposed, which improves and supplements the current therapeutic options by means of pulse synchronous electro-stimulation of the muscle pump. For this purpose, blood flow is determined by multi-sensor plethysmography. The hardware design and signal processing of this novel multi-sensor plethysmography device are introduced. The merged signal is used to determine the phase of the cardiac cycle, to ensure stimulation of the muscle pump during the filling phase of the heart. The pulse detection of the system is validated against a gold standard and provides a sensitivity of 98% and a false-negative rate of 2% after physical exertion. Furthermore, flow enhancement of the system has been validated by duplex ultrasonography. The results show a highly increased blood flow in the popliteal vein at the knee.

Alternative therapy for medically refractory angina: enhanced external counterpulsation and transmyocardial laser revascularization.

Medically refractory angina pectoris (RAP) is defined by presence of severe angina with objective evidence of ischemia and failure to relieve symptoms with coronary revascularization. Medication and invasive revascularization are the most common approaches for treating coronary artery disease (CAD). Although symptoms are eliminated or alleviated by these invasive approaches, the disease and its causes are present after treatment. New treatment approaches are needed to prevent the disease from progressing and symptoms from recurring. External enhanced counterpulsation therapy provides a treatment modality in the management of CAD and can complement invasive revascularization procedures. Data support that it should be considered a first-line treatment of RAP.

Enhanced external counterpulsation: a novel therapy for angina.

Improved pharmacological, invasive, and surgical therapies for cardiovascular diseases over the last few decades have led to an increase in life expectancy of individuals with angina. Despite treatment with multiple medications and invasive procedures, these patients remain symptomatic and functionally limited. Enhanced external counterpulsation (EECP) is a safe, noninvasive, well-tolerated, and clinically effective outpatient physical therapy for many patients with refractory angina. Numerous trials demonstrate positive clinical responses to EECP, including reductions in angina and nitrate use, increase in exercise tolerance, and enhanced quality of life. Several mechanisms are thought responsible for the clinical benefits of this therapy. Despite the marked success rates EECP achieves, the treatment remains largely unknown. This review will summarize the current evidence for the use of EECP and spark a better understanding of the potential role of this treatment.

External counterpulsation for acute ischaemic stroke.

BACKGROUND: External counterpulsation (ECP) may improve cerebral blood flow, and it has been proposed as a potential therapy for patients with ischaemic stroke. OBJECTIVES: To assess the efficacy and safety of ECP for acute ischaemic stroke. SEARCH METHODS: We searched the Cochrane Stroke Group Trials Register (June 2011), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2011 Issue 2), MEDLINE (1948 to June 2011), EMBASE (1980 to June 2011), CINAHL (1982 to June 2011), AMED (Allied and Complementary Medicine) (1985 to June 2011), China Biological Medicine Database (CBM) (1978 to June 2011), Chinese National Knowledge Infrastructure (CNKI) (1979 to June 2011), Chinese Science and Technique Journals Database (VIP) (1989 to June 2011) and Wanfang Data (1984 to June 2011). We also searched ongoing trials registers, reference lists and relevant conference proceedings and contacted authors and manufacturers of external counterpulsation devices. SELECTION CRITERIA: Randomised controlled trials (RCTs) in which ECP (started within seven days of stroke onset) was compared with sham treatment or no treatment, or ECP plus routine treatment was compared with routine treatment alone, in patients with acute ischaemic stroke. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and extracted data, checked for adverse events data and contacted trialists for missing information. MAIN RESULTS: We included two trials involving 160 patients. Numbers of death or dependent patients at the end of at least three months follow-up were not reported in either of the included trials. The outcome measure used in the included trials was only the number of participants with improvement of neurological impairment after treatment according to the Modified Edinburgh-Scandinavian Stroke Scale (MESSS) or self-making criteria. ECP was associated with a significant increase in the number of participants whose neurological impairment improved (risk ratio (RR) 1.75, 95% confidence interval (CI) 1.37 to 2.23). Only one trial reported no adverse events. AUTHORS' CONCLUSIONS: The methodological quality of the included studies was poor, and reliable conclusions could not be drawn from the present data. High-quality and large-scale RCTs are needed.

Enhanced external counterpulsation: mechanisms of action and clinical applications.

Symptomatic coronary artery disease (CAD) and heart failure (HF), either of ischaemic or nonischaemic aetiology, are common medical problems. Despite optimal medical treatment and improved revascularisation techniques, a significant number of patients are not successfully managed.Among the non-pharmacological, alternative, non-invasive treatments suggested for these patients, enhanced external counterpulsation (EECP) is considered the most effective one. EECP, administered in an outpatient setting, consists of three pneumatic cuffs applied to each of the patient's legs that are sequentially inflated and deflated synchronised with the cardiac cycle. Numerous clinical trials have shown that EECP is safe and effective in patients with ischaemic heart disease, with or without left ventricular dysfunction, improving their quality of life. EECP appears to be beneficial as an adjunctive therapy in patients with HF of any aetiology. Cardiac syndrome X has been shown to be effectively treated with EECP. Research in EECP expanded in its potential use for entities other than heart disease. More trials are necessary, including sham-controlled trials, to further establish EECP among medical society.

Metabolic supplementation with enhanced external counterpulsation improves myocardial function in acquired cardiomyopathy: a case report.

BACKGROUND: Cardiomyopathy is reflected in a deterioration of heart function, increased risk of developing arrhythmias, and the potential for sudden cardiac death. The use of enhanced external counterpulsation has been recommended for treating chronic stable angina in high-risk surgical patients. Furthermore, cells require adequate levels of adenosine triphosphate for the maintenance of integrity and function. Lower myocardial levels of adenosine triphosphate are commonly found with ischemia and heart failure. d-Ribose, a natural occurring carbohydrate, enhances the regeneration of adenosine triphosphate levels and improves diastolic function following ischemia. SUBJECT: We present a patient with cardiomyopathy and marked reduced cardiac function. CONCLUSIONS: This patient underwent enhanced external counterpulsation and metabolic supplementation, including d-ribose, and achieved a significant functional improvement.

Management options for angina refractory to maximal medical and surgical interventions.

Despite the seemingly daily advances in the primary, secondary, and tertiary prevention for coronary artery disease, many patients will ultimately experience progression of their disease and experience angina refractory to further active treatment. In these patients, disabling angina occurs at rest or during simple activities of daily living. When this occurs, symptom management, a predominant focus of nursing, becomes the goal of care. Several medical and surgical alternatives are available to patients with refractory angina. Enhanced external counterpulsation and transmyocardial laser revascularization are Food and Drug Administration approved therapies that can be used to attempt to restore the balance of supply and demand. Modulation of sympathetic tone via procedures such as stellate ganglion blocks has also been employed. Other methods to control the pain are techniques that alter pain perception such as spinal opioids, transcutaneous electrical nerve stimulation, and spinal cord stimulation. Too few patients with refractory angina are referred for any of these palliative therapies. Armed with knowledge regarding these therapies, nurses will be better prepared to provide anticipatory guidance to patients and their families and to support the patient's hope for relief as they cope with this devastating condition.

Current and future treatment strategies for refractory angina.

Patients with refractory angina are not candidates for revascularization and have both class III or IV angina and objective evidence of ischemia despite optimal medical therapy. An estimated 300,000 to 900,000 patients in the United States have refractory angina, and 25,000 to 75,000 new cases are diagnosed each year. This review focuses on treatment strategies for refractory angina and includes the mechanism of action and clinical trial data for each strategy. The pharmacological agents that have been used are ranolazine, ivabradine, nicorandil, L-arginine, testosterone, and estrogen; currently, only L-arginine, testosterone, and estrogen are approved by the Food and Drug Administration. Results with the noninvasive treatments of enhanced external counterpulsation and transcutaneous electrical nerve stimulation are provided. Invasive treatment strategies including spinal cord stimulation, transmyocardial revascularization, percutaneous myocardial revascularization, and gene therapy are also reviewed.

Enhanced external counterpulsation therapy: significant clinical improvement without electrophysiologic remodeling.

BACKGROUND: Enhanced external counterpulsation therapy (EECP), in addition to improving coronary flow and increasing the time to ischemia, noninvasively alters hemodynamics in patients with severe coronary artery disease (CAD). Other treatments that alter hemodynamics, for example, balloon valvuloplasty, left ventricular assist devices, and pharmacologic antagonism of the rennin-angiotensin system, promote electrophysiologic remodeling, as evidenced by alterations in the QT interval. METHODS: We studied 28 patients who completed a 7-week, 35-hour session of EECP to assess whether such therapy would also result in electrophysiologic remodeling. RESULTS: All patients had class II-III angina, imaging-proven ischemia, and severe, near-inoperable CAD. Of 28 patients, with a mean age 62 +/- 13 years (mean +/- SD), 78% were male, 46% diabetic, 82% hypertensive, 60% had undergone angioplasty, and 67% had undergone bypass surgery. The mean ejection fraction was 44% (range 25-60%). Following EECP, most patients (82%) had at least a one full class improvement in their anginal pattern. In most patients, there was substantial baseline conduction system disease present: a mean QRS of 105 +/- 19 ms. It is to be noted that there was no significant change in heart rate (HR), PR, QRS, or QT(c) intervals before and after EECP in either clinical responders or nonresponders. When analyzed by response to EECP, ejection fraction, or history of revascularization, there were still no detectable changes in ECG parameters (all P = NS). CONCLUSIONS: While EECP remains an effective treatment for severe CAD, it does not prompt early electrical remodeling of the heart.

[The hemodynamic and myostimulation regimens parallels of the extraaortic counterpulsation and skeletal ventricle in the experiment]. / Ekstraaortines kontrapulsacijos ir skeleto raumens skilvelio hemodinamikos bei miostimuliacijos rezimo paraleles eksperimente.

OBJECTIVE: Our investigation was aimed to evaluate the effect of extraaortic counterpulsation to central hemodynamics during the two modes of latissimus dorsi muscle electrostimulation. MATERIAL AND METHODS: Two groups of experimental dogs were divided into two subgroups and affected with continuous and work-rest regimens of stimulation. In one group latissimus dorsi muscle was mobilized and left in situ. The contraction force was measured before and during experiment, until it decreased till 50%. Recovery time needed to completely restore contraction force was calculated. In the second group latissimus dorsi muscle was stimulated just after aortomyoplasty and skeletal muscle ventricle by using LD PACE II electrostimulator (ventricle - muscle delay 290 ms). RESULTS: By using continuous stimulation in the first group the contraction force decreased till 50% of pre-assist level after 52+/-8 minutes and returned to baseline after 84+/-16 minutes of rest. Under the work-rest regimen this decrease lasted 105+/-8 minutes and returned to baseline after 25+/-6 minutes (p<0.05). After this regimen light microscopy did not revealed significant changes of muscle tissue. After continuous stimulation increased basophilic degeneration and wavy fibrils were revealed. Thoracic aortic counterpulsation by using continuous stimulation increased hemodynamic parameters from pre-assisted level in 40 minutes. The hemodynamic parameters during work-rest regimen became better after 20 minutes and lasted 100 minutes (p<0.05). When counterpulsation was completed, recovery time to baseline in case of continuous electrostimulation was 96+/-9 minutes; in case of work-rest electrostimulation, it was only 43+/-6 minutes. CONCLUSIONS: Work-rest regimen using LD PACE II electrostimulator may be used safely immediately post cardiac assist procedure.

Alternativas para o tratamento da angina do peito: novos agentes farmacológicos, contrapulsação externa, técnicas neuroanalgésicas, angiogênese terapêutica e revascularização transmiocárdica / Alternatives for the treatment of angina pectoris: new drugs, external counterpulsation, spinal-cord estimulation for analgesia, therapeutic angiogenesis, and transmyocardial revascularization

A terapêutica de pacientes com doença coronária e com angina do peito tem sido a mesma já há muitos anos, baseando-se nos nitratos, betabloqueadores e antagonistas de cálcio. Mais recentemente, e em função do crescente número de pacientes que têm angina do peito a despeito do tratamento habitual, novos fármacos têm sido desenvolvidos, alguns em estudo de fase III, incluindo trimetazidina, ranolazina, nicorandil e ivabradina. Quando a angina do peito não é controlada com a medicação, é realizado tratamento com angioplastia e com cirurgia, mas existem indivíduos que, a despeito desses tratamentos, persistem com angina sem perspectiva de resolução de seus sintomas. Para esses pacientes desenvolveram-se alternativas, desde o "laser" intramiocárdico até terapêutica com analgesia espinal, e, mais recentemente, a terapia gênica. Esta última está em fase de desenvolvimento, mas algumas alternativas já estão sendo avaliadas em estudo de fase III.

Long-term effects of dynamic aortomyoplasty.

Aortomyoplasty consists of wrapping the latissimus dorsi muscle (LDM) around the ascending aorta and electrostimulating it during diastole. The ascending aorta will act as an ectopic neo-ventricle compressed during diastole, thus reproducing the effects of long-term diastolic counterpulsation. In 5 goats, the right LDM was transferred to the thoracic cavity after removal of the second rib. The ascending aorta was enlarged by a pericardial patch and wrapped with the LDM. Postoperative electrostimulation was delivered in a counterpulsating manner. Hemodynamic studies were performed at 12 and 24 months postoperatively. Percent increase in the subendocardial viability index (diastolic pressure-time index/systolic tension-time index) was calculated using unassisted and assisted cardiac cycles with the stimulator off versus the stimulator on at a 1:1 ratio in the basal state and after acute heart failure was induced by the administration of high doses of propranolol hydrochloride. Diastolic counterpulsation of the ascending aorta resulted in significant improvement in the subendocardial viability index long term, both in basal state conditions and after induced cardiac failure. During heart failure, aortomyoplasty increased the cardiac output and decreased systemic vascular resistance. Histopathologic studies up to 24 months showed preservation of the histologic structure of the aortic wall and no evidence of thromboembolism. Tight adhesions developed between the aortic wall (including the pericardial patch) and the LDM. The diameters of the enlarged aortas showed no significant differences compared with diameters immediately postoperatively. In conclusion, aortomyoplasty produces chronic diastolic augmentation with preservation of aortic structure. After induction of heart failure, aortomyoplasty offers efficient circulatory support.

Metabolic analysis of latissimus dorsi coupled to a mock circulation.

A mock circulation system has been used to examine the metabolic and hemodynamic responses of untrained and trained latissimus dorsi muscle in a normal animal model. The metabolic response of untrained latissimus dorsi to differing stimulation regimes runs parallel to its mechanical performance. The ratio of power generated to oxidative capacity (a measure of metabolic efficiency) was maintained to a greater extent in muscle trained for 5 months subjected to specific fatigue tests, falling by only 20% (as opposed to 80% observed in untrained control muscle). This approach to studying metabolic and hemodynamic performance may have relevance when skeletal muscle is used for cardiac assistance.

The effect of skeletal muscle ventricle pouch pressure on muscle blood flow.

Skeletal muscle powered assist ventricles (SMV) are being investigated in animal studies as a treatment for heart failure. Muscle fatigue is almost always dependent upon muscle capillary blood flow. This study examined the relationship between SMV intrapouch pressure and blood flow to the circumferential muscle in a working SMV with a mock circulation. The unconditioned rectus abdominis muscle was used to create an in situ SMV in five dogs. Muscle blood flow was measured by both the radioactive microsphere and the electromagnetic flow probe method as the pouch pressure was varied between 10 and 70 mmHg and as the SMV was stimulated to contract at a rate of 20 min-1. The correlation coefficient for the two methods was 0.908. At pouch pressures of 10, 40, and 70 mmHg, the respective blood flow values were 22.60 +/- 2.50 (1 SEM), 12.20 +/- 2.10, and 4.40 +/- 0.74 ml min-1 (p less than 0.05). When they were corrected for muscle weight, the mean blood flow values at these same pouch pressures were 0.28 +/- 0.03, 0.15 +/- 0.03, and 0.05 +/- 0.01 ml min-1 g-1, respectively (p less than 0.05). SMV output was measured for each pouch pressure that was tested. Pouch output, expressed as ml min-1, was 458 +/- 20 (1 SEM) at an SMV diastolic pouch pressure of 10 mmHg, 309 +/- 22 at a pouch pressure of 40 mmHg, and 103 +/- 6 at a pouch pressure of 70 mmHg.(ABSTRACT TRUNCATED AT 250 WORDS)

Skeletal muscle ventricles: update after 18 months in circulation.

Skeletal muscle ventricles (SMVs) have been constructed from canine latissimus dorsi muscle and connected to the aorta as aortic diastolic counterpulsators. Presently one dog remains alive and well with an SMV that has been functioning continuously in circulation for 18 months, without evidence of thromboembolic complications. SMVs are able to perform cardiac-type work with an output equal to that of the left ventricle at physiologic preloads, when tested with a mock circulation device in our laboratory. SMVs have been used for right-sided cardiac assist. In acute experiments these ventricles have functioned effectively, bypassing the right side of the heart for up to 8 h. Most recently we have tested SMVs using them chronically to pump blood in the right-sided circulation, and at the time of writing they have been shown to function effectively in this configuration for up to 18 days. SMVs may be used in the future as a method of treating patients with left- or right-sided heart failure.