The effect of beta-blockade on heart rate recovery following exercise stress echocardiography

The purpose of this study was to determine the effects of beta-blockers (BBs) on heart rate recovery (HRR) following exercise stress testing. HRR is a predictor of mortality following exercise stress testing and is thought to be due to reinstitution of vagal tone. Exercise testing in the presence of BBs should have no effect on reinstitution of vagal tone and therefore no effect on HRR. One published study contradicts this understanding. The authors performed a retrospective analysis of the University of California, Davis, treadmill database and found 334 patients who underwent exercise stress echocardiography (ESE) with complete data. Patients undergoing ESE without a BB were compared with patients who were receiving a BB. HRR was not affected by BB use in patients without stress-induced echocardiographic abnormalities (negative ESE result). In patients with stress-induced echocardiographic abnormalities (positive ESE result), HRR was delayed compared with patients with negative ESE. BB use improved HRR in patients with positive ESE. BBs do not affect HRR in patients with a negative ESE result, and HRR can be used for mortality prediction. In patients with a positive ESE result, HRR is improved in the presence of a BB.     

Frequency and significance of acute heart failure following liver transplantation

Reversible cardiomyopathy has been reported in patients after liver transplantation. However, there are few data on the incidence, risk factors, and prognosis of this condition. Liver transplantation recipients who underwent preoperative right- and left-sided cardiac catheterization as well as preoperative transthoracic echocardiography from 2001 to 2005 were identified. Eighty-six patients met the outlined criteria and were included in the study. The incidence of severe heart failure (HF) after transplantation in this population was 6 of 86 (approximately 7%). Patients who developed HF were slightly older (mean age 61.2 +/- 8.9 vs 55.4 +/- 9.2 years, p = 0.08) but had similar preoperative ejection fractions (60 +/- 5% vs 57 +/- 8%, p = 0.22) and comparable systemic arterial blood pressure (116 +/- 22/62 +/- 11 vs 127 +/- 9/66 +/- 9, p >0.1). In addition, the severity of liver disease as measured by the model for end-stage liver disease score was not different between the 2 groups (23.9 +/- 9.7 vs 26 +/- 10.7, p = 0.5). There was also no significant difference in the preoperative cardiac index (3.8 +/- 1 vs 3.6 +/- 1.5 L/min/m2, p = 0.9) or pulmonary artery wedge pressure (13.6 +/- 5.8 vs 15.3 +/- 2.8 mm Hg, p = 0.42). The incidence of alcohol use as the presumed cause of liver failure was equivalent in the 2 groups (33% vs 25%, p = 0.65). The patients who developed HF did have significantly higher preoperative mean pulmonary arterial systolic pressures (43 +/- 10 vs 30 +/- 9 mm Hg, p = 0.02) and right ventricular systolic pressures (44 +/- 13 vs 34 +/- 8 mm Hg, p = 0.05). In conclusion, severe systolic HF may occur after liver transplantation in patients without traditional risk factors for HF. This study suggests that those patients with preoperative elevated right-sided cardiac pressures, as well as older patients, may be at excess risk for developing HF after transplantation.     

Restrictive-type hemodynamics following valve surgery for rheumatic heart disease

Over a six-year period three patients with rheumatic valvular disease presented with congestive heart failure due to abnormalities in myocardial diastolic function. Each patient previously had been operated for mitral stenosis; one patient had additional aortic valve replacement for aortic insufficiency. The mean time for the development of symptoms following surgery was 4.7 years. In all patients, left ventricular systolic function was normal (radionuclide or angiographic ejection fraction greater than 0.50). Abnormalities in diastolic function involved the left ventricle in all patients. Biopsy material from right (one patient) and left (one patient) ventricles was nonspecific in its histologic appearance. Other disease processes, such as constrictive pericarditis and diabetic cardiomyopathy were considered to be clinically unimportant in these patients. Restrictive-type hemodynamics in patients with postoperative rheumatic heart disease may comprise a newly recognized entity.     

Questioning the clinical significance of upper gastrointestinal cytomegalovirus disease following heart transplantation

We performed a retrospective review of patients who underwent esophagogastroduodenoscopy after heart transplantation to determine the clinical setting in which upper gastrointestinal cytomegalovirus disease is identified. No gastrointestinal cytomegalovirus disease was found prior to transplant 51 and this period (from transplant 1 to 50) corresponded to a time when significantly fewer esophagogastroduodenoscopies included biopsy. Patients in whom cytomegalovirus was identified were more likely to have been CMV seronegative and to have received a heart from a seropositive donor (60% vs 20%,P=0.029). In addition, patients with cytomegalovirus used aspirin more commonly (90% vs 31%,P=0.001), and underwent esophagogastroduodenoscopy earlier after transplantation (123d vs 652d,P=0.029). We conclude that factors that increase the use of esophagogastroduodenoscopy and biopsy in the early transplant period increase the likelihood of identifying cytomegalovirus in gastrointestinal tissue. However, the clinical course and significance of cytomegalovirus identified in the upper gastrointestinal tract in heart transplant patients may be difficult to discern.     

Malignomas following heart transplantation

Up to 30% of patients with an organ transplantation develop precancerous lesions and malignant tumors, especially of the skin. All 241 patients who underwent heart transplantation from 1990 to 2000 were evaluated with regard to the development of neoplasias. Those alive in September 1999 were referred for a standardized dermatological exam (n=156) which detected malignancy in 28 patients being transplanted for 4.98 years on average. The skin was the organ most frequently involved (64%, n=18). 18% (n=5) of tumors were found in the urinary and genital tract, 7% (n=2) each in the respiratory and gastrointestinal tract, and 4% (n=1 ) in the breasts. The average age of patients who developed tumors was significantly higher as compared to the overall mean age (59.5+/-5 vs 49.8+/-14.7 years, p=0.00027). There was no correlation between development of malignancy and HLA matching, immunosuppressive drugs used, dosage and serum levels of immunosuppressive medication, and episodes of transplant rejection. Our study shows that the risk to develop tumors is at least doubled after heart transplantation. Due to the high incidence of skin tumors, transplant patients should undergo dermatological examinations on a regular basis.     

Home inotrope treatment for intractable heart failure following heart transplantation

A 49 year old man developed intractable heart failure three years after undergoing heart transplantation. Coronary angiography showed no evidence of graft vascular disease. An initial cardiac biopsy identified one episode of rejection which responded to augmented immunosuppressive treatment. The patient became inotrope dependent and has now survived at home for 22 months using an ambulatory delivery system for intravenous adrenaline (epinephrine), without significant complications. There has been a noticeable improvement in symptoms and left ventricular systolic performance, both clinically and as seen through echocardiographic and radiographic examination. This improvement was substantiated by the results of cardiac catheterisation, which showed a return to normal left ventricular filling pressure and cardiac output. The case is noteworthy because this treatment has allowed a patient who otherwise would have been hospital bound to return to the community. With the current shortage of organs, he would have been unlikely to receive a second transplant. The clinical features and outcome, and social, medicolegal, and financial issues are discussed.     

心率对心力衰竭患者预后的影响

心力衰竭作为很多心血管疾病的最终恶化趋势,对于其相关的临床诊疗近年来有了很大进步.近年的临床研究也显示,快速心率对于心力衰竭患者的病情发生、发展及预后有着重要的影响,当心率控制在适当范围内可明显改善心功能不全的预后.对心率的严密监控能够有效地指导临床诊疗,并且通过指数差异预测心力衰竭的预后,从而有效地判断治疗效果.心率...     

心率震荡现象及其临床意义

心率震荡(heart rate turbulence，HRT)是指心脏在发生室性早搏(室早)后，出现短期的心率波动的现象，由Schmidt于1999年最早提出。心率震荡是自主神经对单发室早后出现动脉血压波动的反应，与压力反射的敏感性密切相关。心率震荡这一概念提出后，引起了医学界广泛的关注，进行了几个大样本的临床实验，提出了一些新的评价指标和观点。     

Levosimendan for postoperative ventricular dysfunction following heart transplantation

The development of postoperative ventricular dysfunction immediately after heart transplantation is a serious complication that leads to low-output syndrome and which necessitates circulatory support. It is one of the most common causes of early morbidity and mortality. We present our experience with 6 heart transplant patients who were treated with intravenous levosimendan, a calcium sensitizer with inodilator properties, after regular hemodynamic therapy with sympathomimetic amines failed to result in a satisfactory hemodynamic status. Use of this drug was well tolerated and brought about hemodynamic improvements that were sufficient to enable patients to be weaned from inotropic support with amines and which led to clinical recovery, with 5 of the 6 patients being discharged from the intensive care unit.     

Prognostic significance of early short-term measurements of heart rate variability following acute myocardial infarction

This study of 164 subjects demonstrates that short-term (5-minute) recordings of heart rate variability, performed within 48 hours of admission, identify those who survive acute myocardial infarction but have an adverse prognosis.     

L-arginine reduces heart rate and improves hemodynamics in severe congestive heart failure

BACKGROUND: Stimulated endothelium-derived relaxing factor-mediated vasodilation and conduit artery distensibility are impaired in congestive heart failure (CHF). L-arginine could have a potentially beneficial role in CHF, acting through the nitric oxide (NO)-L-arginine pathway or by growth hormone increment. HYPOTHESIS: This study was undertaken to investigate the effects of L-arginine on heart rate, hemodynamics, and left ventricular (LV) function in CHF. METHODS: In seven patients (aged 39 +/- 8 years) with CHF, we obtained the following parameters using echocardiography and an LV Millar Mikro-Tip catheter simultaneously under four conditions: basal, during NO inhalation (40 ppm), in basal condition before L-arginine infusion, and after L-arginine intravenous infusion (mean dose 30.4 +/- 1.9 g). RESULTS: Nitric oxide inhalation increased pulmonary capillary wedge pressure from 25 +/- 9 to 31 +/- 7 mmHg (p < 0.05), but did not change echocardiographic variables or LV contractility by elastance determination. L-arginine decreased heart rate (from 88 +/- 15 to 80 +/- 16 beats/min, p<0.005), mean systemic arterial pressure (from 84 +/- 17 to 70 +/- 18 mmHg, p < 0.007), and systemic vascular resistance (from 24 +/- 8 to 15 +/- 6 Wood units, p<0.003). L-arginine increased right atrial pressure (from 7 +/- 2 to 10 +/- 3 mmHg, p<0.04), cardiac output (from 3.4 +/- 0.7 to 4.1 +/- 0.8 l/min, p < 0.009), and stroke volume (from 40 +/- 9 to 54 +/- 14 ml, p < 0.008). The ratios of pulmonary vascular resistance to systemic vascular resistance at baseline and during NO inhalation were 0.09 and 0.075, respectively, and with L-arginine this increased from 0.09 to 0.12. CONCLUSION: L-arginine exerted no effect on contractility; however, by acting on systemic vascular resistance it improved cardiac performance. L-arginine showed a negative chronotropic effect. The possible beneficial effect of L-arginine on reversing endothelial dysfunction in CHF without changing LV contractility should be the subject of further investigations.     

心率震荡现象与心力衰竭

恶性心律失常和心源性猝死是心力衰竭患者死亡的重要原因.心率震荡(HRT)是对心脏室性早搏内源性刺激的反应,不仅反映自主神经功能的变化,也反映在一次室性早搏后心室压力变化所导致的主动脉弓颈动脉窦压力反射调节机制的变化.HRT有望成为预测心力衰竭高危患者的有效预测指标.     

Cardiac isoenzymes following heart transplantation.

Creatine phosphokinase (CPK) isoenzymes are commonly obtained after heart transplantation (HT) to assess myocardial injury of the donor heart. This investigation retrospectively evaluated the utility of this practice. Fifty-six recipients of orthotopic heart transplants had at least two daily CPK-MB studies following HT. All patients were followed up for at least one year (or until death). Nineteen patients had entirely negative CPK-MB determinations (NEG). Eighteen patients had a single positive CPK-MB determination, and were considered to be equivocal (EQUIV). Nineteen patients had more than one daily positive CPK-MB determination (POS). To evaluate the influence of positive CPK-MB determinations on the outcome of HT, we compared the results in the NEG and POS groups. There was no difference in the donor organ ischemic times between the two groups. The duration of follow-up for the two groups was also similar (1,192 days vs 1,020 days). The NEG and POS groups had no significant difference in: 1 year survival (84 percent vs 74 percent); freedom from treated rejection episodes in 3 months (39 percent vs 42 percent); and freedom from coronary artery disease (CAD) at 3 years (83 percent vs 86 percent). Additionally, the ejection fractions of the donor hearts were similar at 1 year post-transplant for the 2 groups (64 percent vs 59 percent). We conclude that myocardial injury, as reflected by post-transplant CPK-MB levels, does not predict one-year mortality, predisposition to rejection, predisposition to coronary artery disease, or ultimate graft dysfunction. In an effort to perform HT more economically, we no longer obtain CPK-MB levels following HT.     

心脏移植术后肾功能不全患者不同免疫抑制方案的临床研究

目的:回顾性分析心脏移植后出现肾功能不全的患者,进行不同的免疫制方案调整策略的结果。方法:34例在心脏移植1年后随访期出现肾功能不全的患者,以诊断标准分类,进行3种不同的免疫抑制方案调整:①、降低环孢素A剂量,记为Lo-C组;②、转换为低剂量他克莫司,记为Lo-F组;③、转换为西罗莫司,记为S组。观察各组方案调整后的血肌酐(Scr)及肾小球滤过率(GFR)变化趋势、血压、血脂、血糖变化情况及全部随访期的排斥反应发生情况。结果:33例患者存活并完成1年随访,1例死亡。排斥反应发生率分别为16.7%(2/12)vs.5.9%(1/17)vs.20%(1/5)。各组Scr及GFR在免疫抑制方案替换后均有所改善,其中Lo-C组在替换后6个月和12个月时,Scr值比较替换前差异有统计学意义(P<0.05);Lo-F组在替换后3个月、6个月和12个月时Scr及GFR比较替换前差异均有统计学意义(P<0.05);S组在替换后3个月、6个月和12个月时Scr及GFR比较替换前差异均有统计学意义(P<0.05)。各组患者高血压、糖尿病及高脂血症罹患情况,Lo-C组在替换前后无变化;Lo-F组在替换后6个月较替换前糖尿病明显增多,而高脂血症减少;S组在替换后6个月较替换前高脂血症明显增多。结论:心脏移植术后出现肾功能不全的患者,低剂量的钙调素抑制剂(CNI)或替换为西罗莫司(SLR)可改善肾功能,但相应排斥反应和代谢并发症的风险会加大,免疫抑制方案的调整仍须谨慎,并考虑个体情况和加强监测。     

Infectious endocarditis following orthotopic heart transplantation

Infection remains a major problem in the early phase after heart transplantation. Immunosuppressive therapy is the most important predisposing factor. It may also reactivate preexisting latent endogenous infections. Unspecific symptoms and a chronic clinical course, as described in this report, may suggest infective endocarditis of the cardiac allograft. From this case, we do not suggest a general antibiotic prophylaxis for heart transplant recipients; however, special precaution should be considered in heart transplant patients with a history of endocarditis.