Early predictors of left ventricular function improvement late after myocardial infarction

BACKGROUND/AIM: Prognosis after acute myocardial infarction (AIM) depends on the extent of irreversibly damaged myocardium and viable tissue due to stunning or hibernation. The aim of the study was to assess the prognostic significance of early echocardiographic parameters of myocardial viability in prediction of late recovery of regional and global ventricular function. METHODS: The study prospectively included 40 patients after the first, uncomplicated univessel AIM treated with percutaneous coronary intervention (PCI). Low dose dobutamine echocardiography (LDDE) was preformed 7-10 days after AIM and follow-up resting echocardiography from 7 to 12 months later. RESULTS: The sensitivity and specificity for the prediction of post revascularisation regional, dys synergy improvement were 61.29% and 94.59% respectively. The positive and negative predicative values were 90.48% and 74.47% re spectively. The number of viable segments (p = 0.01) and extent of contractile reserve (p = 0.01) were univariate, independent predictors of improvement in ejection fraction (EF). From the multivariate stepwise regression analysis contractile reserve was selected as most powerful predictor of late recovery of left ventricular contractile function (p = 0.007). Receiving-operator characteristic curve (ROC) analysis demonstrated that three or more recovered segments were necessary for an improvement of left ventricular ejection fraction (LVEF) > or = 5% after the revascularisation, with the highest sensitivity, 100% and specificity 56% (p = 0.01). CONCLUSION: Low-dose dobutamine echocardiography is a powerful predictor of the regional dys synergy recovery late after AIM treated with PTCA with implantation stent. Late full functional improvement of the left ventricle is related to the extent of contractile reserve and amount of viable tissue. At least three recovered segments are necessary for a significant recovery of the global left ventricular contractility.     

曲美他嗪对慢性心力衰竭患者心功能及心率变异性的影响

目的探讨曲美他嗪对慢性心力衰竭（CHF）患者心功能及心率变异性（HRV）的影响。方法将60例CHF患者随机分为治疗组和对照组,每组30例,对照组给予常规治疗,治疗组在常规治疗的基础上加用曲美他嗪治疗6个月,观察两组患者治疗前后NYHA分级、左心室舒张末期内径（LVEDd）、左心室射血分数（LVEF）、N末端原脑利钠肽（NT-pro-BNP）及6min步行距离（6-MWD）的变化,采用12导联同步1-IOLTER检测系统检查,测定HRV时域指标（SDNN、SDANNindex MSDD、PNN50）。结果6个月后,治疗组患者的心功能明显改善,LVEDd及NT—pro—BNP与对照组相比明显降低,LVEF及6-MWD与对照组相比明显增加,HRV参数明显好转。结论曲美他嗪可以改善CHF患者的心功能及HRV。     

Age and heart rate variability after soccer games

To observe the effect of age on the changes in heart rate variability (HRV) of adult amateur athletes after playing a soccer game, 20 male were divided into two groups: middle-aged (n = 10, 35-55 years) and aged (n = 10, 56-75 years). Before and after 2-hour soccer games, HRV and blood pressure were recorded. In both groups heart rate increased greatly after exercise (73.1 ± 14.8 bpm vs 102.6 ± 16.2 bpm, p < 0.01 and 71.1 ± 8.6 bpm vs 89.9 ± 15.5 bpm, p < 0.01). In the middle-aged group, systolic blood pressure (SBP) did not change (124.0 ± 12.0 mmHg vs 118.9 ± 11.7 mmHg), while the mean standard deviation of the N-N intervals (SDNN), square root of the mean squared differences of successive N-N intervals (RMSSD), total power (TP), low frequency (LF) power, and high frequency (HF) power changed significantly (p < 0.05); in the aged group SBP decreased from 147.2 ± 23.7 mmHg to 127.7 ± 24.7 mmHg (p < 0.01), but SDNN, RMSSD, TP, LF, and HF did not change. It seems that in aged people the accommodation capability of the autonomic nervous system is different from that in middle-aged people.     

Characteristics of heart rate variability in war veterans with post-traumatic stress disorder after myocardial infarction

OBJECTIVE: The goal of the study was to evaluate differences in heart rate variability (HRV) among post-myocardial infarction (MI) patients, depending on their participation in the Croatian war and on established diagnoses of post-traumatic stress disorder (PTSD). METHODS: The study included 34 male war veterans with diagnosed PTSD who had suffered a first MI and 34 age-matched post-MI patients without PTSD. Cardiac autonomic balance was evaluated through HRV analysis. RESULTS: There were no differences in the mean R-R interval or overall HRV between the analyzed groups. Post-MI patients with PTSD had lower values for the square root of the mean of squared successive differences in R-R intervals (p = 0.02), the percentage of R-R intervals that were > or =50 milliseconds different from the previous interval (p = 0.03), and the high-frequency component (p = 0.03) but had higher values for the low-frequency component (p = 0.01) and the low-frequency/high-frequency ratio (p = 0.02), compared with post-MI patients without PTSD. CONCLUSION: Post-MI patients with PTSD have higher sympathetic and lower parasympathetic heart rate modulation activity, compared with patients with MI and no PTSD.     

急性心肌梗死患者心率变异性临床分析

对８４例急性心肌梗死患者进行心率变异性分析。应用２４ｈ磁带记录器。进行２４ｈＨｏｌｔｅｒ心电图记录，对记录磁带采用电子计算机分析，对急性心肌梗死的病变范围和程度及预后进行估计。     

高血压患者心率变异性及心率减速力变化

目的探讨高血压患者心率变异性(heart rate variability,HRV)及心率减速力(deceleration capacity of heart rate,DC)变化。方法选取80例健康体检和64例高血压患者进行24 h动态心电图监测,分析比较2组的HRV时域指标:全部窦性心搏R-R间期标准差(standard deviation of normal-to-normal intervals,SDNN)、R-R间期平均值的标准差(standard deviation of the average normal-to-normal intervals,SDANN)、相邻R-R间期差值的均方根(root mean square of successive differece,RMSSD)、相邻R-R间期差值>50 ms的百分比(proportion of number of pairs ofadjacent normal-to-normal intervals by more than 50 ms,PNN50)、三角指数和DC,探讨高血压患者HRV与DC的相关性,以及较健康体检者差异是否有统计学意义。结果高血压患者的SDNN、SDANN、三角指数、DC均较健康体检者减低,差异有统计学意义(P<0.01),RMSSD、PNN50差异无统计学意义。高血压组DC与SDNN、SDANN、RMSSD、PNN50均呈正相关,差异有统计学意义(P<0.01)。结论高血压患者HRV和DC减低,自主神经功能受损;高血压组DC与HRV时域指标呈正相关。     

T-wave and heart rate variability changes to assess training in world-class athletes

PURPOSE: A decrease of electrocardiographic T-wave voltage with increasing training loads has been reported in elite endurance athletes and ascribed to training-related adaptation in sympathetic activity to the ventricles. A switch from vagal to sympathetic predominance in sino-atrial node regulation on going from low to peak training load has been reported in world-class rowers. In this study on world-class endurance athletes, we tested the hypothesis that training-induced variations in T-wave amplitude at higher training loads are paralleled by changes in HR spectral profile. METHODS: We studied eight male rowers of the Italian national team in the season culminating with the Rowing World Championship. Athletes were evaluated at 50 and 100% of training load, approximately 20 d before the World Championship, and during the World Championship, when the intensity was markedly reduced. We assessed T-wave maximum amplitude in chest lead V6 and cardiac autonomic regulation by power spectral analysis of R-R interval variability. RESULTS: The increase in training load from 50 to 100% was accompanied by a significant decrease in high frequency and a significant increase in low-frequency R-R variability (in normalized units) with a concomitant significant decrease in T-wave amplitude (microV). Reduction in training load during the World Championship resulted in a return of spectral profile to the level observed at 50% training load and in a partial recovery of T-wave amplitude. HR did not change significantly. CONCLUSIONS: In high-performance world-class athletes, training load simultaneously affects both ventricular repolarization and HR variability patterns possibly through variations in cardiac sympathetic modulation to the ventricles and the sino-atrial node. Information on concomitant changes in ventricular repolarization and autonomic cardiac regulation might be employed to tailor training protocols of elite athletes.     

Intermittent pneumatic compression changes heart rate recovery and heart rate variability after short term submaximal exercise in collegiate basketball players: a cross-over study

Sport Sciences for Health - The aim of the study is to assess the effect of intermittent pneumatic compression (IPC) on heart rate recovery and heart rate variability (HRV) after submaximal aerobic...     

Changes in myocardial perfusion after catheter-based percutaneous laser revascularisation

This study investigated the effect of percutaneous laser revascularisation (PMR) on regional myocardial blood flow. PMR is a new therapeutic modality for patients suffering from angina pectoris due to coronary artery disease (CAD) that is not amenable to revascularisation. Initial clinical studies discovered reduced angina pectoris and increased exercise capacity after PMR. There are no previous clinical studies reporting the impact of PMR on perfusion. Thirty-six patients with end-stage CAD underwent thallium-201 single-photon emission tomography studies on four different occasions: immediately before PMR and 3, 6 and 12 months following PMR. Each study consisted of pharmacological stress and rest scintigraphy. Semiquantitative evaluation was performed by use of 14 standardised wall segments which were classified (a) according to the localisation of the PMR target region into treated segments, segments adjacent to the treated area and non-treated segments and (b) according to the pre-therapeutic local perfusion into four groups: no (0), slight (I), moderate (II) or severe (III) perfusion deficit. At stress in treated segments of groups II and III local scintigraphic count densities increased from 60.1% and 34.7% at baseline to 65.3% and 48.3% after 12 months (P<0.05) while they decreased in segments of group 0 from 94.2% to 85.7% (P<0.05). In rest studies no changes occurred. Thus, the local rest-stress differences within the target areas become smaller after PMR. In the PMR target area but not in the non-treated area an improvement in regional myocardial flow reserve occurs in wall segments with initially severely or moderately reduced stress perfusion. This effect is consistent with the clinical improvement after PMR.     

Changes in myocardial perfusion after catheter-based percutaneous laser revascularisation

This study investigated the effect of percutaneous laser revascularisation (PMR) on regional myocardial blood flow. PMR is a new therapeutic modality for patients suffering from angina pectoris due to coronary artery disease (CAD) that is not amenable to revascularisation. Initial clinical studies discovered reduced angina pectoris and increased exercise capacity after PMR. There are no previous clinical studies reporting the impact of PMR on perfusion. Thirty-six patients with end-stage CAD underwent thallium-201 single-photon emission tomography studies on four different occasions: immediately before PMR and 3, 6 and 12 months following PMR. Each study consisted of pharmacological stress and rest scintigraphy. Semiquantitative evaluation was performed by use of 14 standardised wall segments which were classified (a) according to the localisation of the PMR target region into treated segments, segments adjacent to the treated area and non-treated segments and (b) according to the pre-therapeutic local perfusion into four groups: no (0), slight (I), moderate (II) or severe (III) perfusion deficit. At stress in treated segments of groups II and III local scintigraphic count densities increased from 60.1% and 34.7% at baseline to 65.3% and 48.3% after 12 months (P<0.05) while they decreased in segments of group 0 from 94.2% to 85.7% (P<0.05). In rest studies no changes occurred. Thus, the local rest-stress differences within the target areas become smaller after PMR. In the PMR target area but not in the nontreated area an improvement in regional myocardial flow reserve occurs in wall segments with initially severely or moderately reduced stress perfusion. This effect is consistent with the clinical improvement after PMR.     

Early and late bone-marrow changes after irradiation: MR evaluation

Knowledge of the chronologic evolution of bone-marrow changes during and after radiation therapy is essential in differentiating normal postradiation changes from other marrow abnormalities. The appearance of the lumbar vertebral bone marrow was studied on 55 serial spin-echo and short-T1 inversion-recovery (STIR) MR images obtained in 14 patients receiving radiation therapy for Hodgkin disease, seminoma, or prostate carcinoma. Images were obtained before, at weekly intervals during, and at various monthly intervals up to 14 months after a 3- to 6-week course of fractionated paravertebral lymph-node irradiation of 1500-5000 rad (15-50 Gy). During the first 2 weeks of therapy, there was no definite change in the appearance of the marrow on spin-echo images; however, there was an increase in signal intensity on the STIR images, apparently reflecting early marrow edema and necrosis. Between weeks 3 and 6, the marrow showed an increasingly heterogenous signal and prominence of the signal from central marrow fat, shown best on T1-weighted images. Late marrow patterns (6 weeks to 14 months after therapy) varied and consisted of either homogenous fatty replacement or a band pattern of peripheral intermediate signal intensity, possibly representing hematopoietic marrow surrounding the central marrow fat. No focal marrow lesions or soft-tissue edema were identified during the course of radiation therapy; their presence should raise the possibility of the presence of a pathologic process other than radiation change. These data suggest that MR can detect radiation-induced marrow changes as early as 2 weeks after starting therapy, and that there are at least two distinct types of late marrow MR patterns.     

不明原因心悸患者动态心电图和心率变异性分析

 目的 分析不明原因心悸患者的心脏自主神经功能状态,探讨其发病机制。方法 选取不明原因心悸患者45例及健康对照组22例,进行24 h动态心电图检查并行心率变异性（HRV）分析,比较心悸组中动态心电图大致正常者与对照组24 h正常R-R间期标准差（SDNN）、每5 min正常R-R间期均值的标准差（SDANN）、相邻正常R-R间期差值的均方根（RMSSD）、SDNN＜100的例数、SDNN日夜比值以及LF/HF比值等指标。结果 不明原因心悸组与对照组平均心率无统计学差异。心悸组共检出室性心律失常8例（17.8%）,均为单源性室性期前收缩,平均（83.2±119.3）个/ h;窦性心动过缓3例（6.7%）;阵发性室上性心动过速6例（13.3%）;动态心电图大致正常28例（62.2%）。对照组动态心电图均大致正常（100%）。心悸组除了窦性心动过缓者外,其余各组SDNN、SDANN多小于对照组（P＜0.05或P＜0.01）,RMSSD各组间无显著差异。心悸组中动态心电图正常者的SDNN＜100为12例（42.9%）,对照组为0例（0.0%）,差异有统计学意义（χ²=12.4060,P＜0.05）。心悸组SDNN日夜比值及LF/HF比值增大,与对照组比较差异均有统计学意义（t=4.280、6.788,P＜0.01）。结论 不明原因心悸患者24 h动态心电图多数为大致正常,但心率变异性分析结果显示其心脏自主神经功能已有不同程度受损,主要表现为夜间迷走神经张力减低。     

Analysis of heart rate variability after a ranger training course

We studied the effects of prolonged physical activities on resting heart rate variability (HRV) during a training session attended by 23 cadets of the French military academy. This course lasts 1 month and is concluded by a 5-day field exercise simulation with physical and psychological stress. Data collection took place before (B) and immediately at the end (E) of the course. It included HRV recordings during a stand test (5 minutes lying down and 5 minutes standing), with a Polar R-R monitor, followed by blood sampling to assay plasma testosterone. The results (B and E) showed that the testosterone level fell by approximately 28.6 +/- 7%, indicating a high level of fatigue. During the stand test, the total power (TP) of the HRV spectrum increased in a supine position. The TP of B was 5,515.7 ms2 (SE, 718.4) and of E was 13018.9 ms2 (SE, 2,539.2; p < 0.001). High-frequency (HF) normalized values increased and low-frequency (LF) normalized values fell, regardless of position (HF normalized values and LF normalized values: supine, p < 0.01, p < 0.05; standing, p < 0.05, p < 0.01, respectively). LF:HF ratio fell 66.2 (SE, 12.9%; p < 0.01) in a lying position. During the time-domain analysis of HRV, differences between adjacent normal R-R intervals more than 50 milliseconds, expressed as a percentage, and differences between the coupling intervals of adjacent normal RR intervals increased in the lying position (p < 0.001). These results as a whole suggest that parasympathetic nervous system activity increases with fatigue.     

深呼吸对糖尿病患者心率变异性影响及意义

 目的分析糖尿病患者短程静息及深呼吸心率变异性(Heart rate variability,HRV)的动静变化,探讨深呼吸对自主神经损伤HRV的影响及意义.方法2型糖尿病患者64例分为:单纯糖尿病(SDM)组36例及糖尿病并发症(DMA)组28例,与健康者30例对照;全部施行HRV深呼吸试验(5 min静息态、5 min深呼吸态)检测,分析HRV每一指标的3个变量(静息态值、深呼吸态值、静息深呼差值).结果糖尿病各组深呼吸试验HRV各指标的3个变量值均较对照组有不同程度降低,DMA组较SDM组亦明显降低.结论深呼吸HRV随自主神经损伤程度不同而呈不同程度降低.短程HRV深呼吸试验可静动结合灵敏真实地反映自主神经损伤.     

肾脏病患者心率变异性的临床观察

目的 :用心率变异性 (HRV)分析技术观察肾脏病及肾功不全患者的HRV指标变化。方法 :用 2 4h动态心电图分析HRV的时域指标。观察肾功正常的肾病患者 2 6例 ,肾功不全患者 34例 ,正常对照 34例。结果 :肾功正常肾病组RRI 76 3.0 5±10 4.2 1、SD 12 2 .48± 39.82、SDAIDX 111.87± 40 .6 0 ,均显著低于正常组 ,P <0 .0 5 ;肾功不全组六项指标均明显低于正常对照组 ,SD 76 .0 9± 37.70 ,SDAIDX 6 7.74± 34.47,SDIDX 2 9.5 9± 15 .37,及rMSSD 17.85± 9.35显著低于肾功正常组。结论 :肾脏病患者在肾功正常期即有自主神经功能损伤 ,以交感神经活动受损为主 ,肾功不全患者交感神经及迷走神经功能均受损。     

Thoracic textilomas after myocardial revascularisation: typical CT findings

The objective of this work was to report the tomographic findings in five cases of intrathoracic textilomas. The CT scans of five patients presenting with textilomas after being submitted to thoracotomy for myocardial revascularisation were reviewed retrospectively. Two chest radiologists studied the scans independently, and decisions concerning the CT findings were made by consensus. In each of the five cases, the imaging findings were similar and showed lesions resembling an extrapulmonary mass and well-defined contours situated at the marginal posterior pleural surface. In four of the five cases, a low-density centre and peripheral rim-like enhancement were observed after administration of contrast media. The suspicion of textiloma should be raised when a patient with a history of previous myocardial revascularisation surgery presents with an extrapulmonary mass in close contact with the posterior pleural surface.Textiloma (also called gossypiboma) is a term used to describe a mass within the body composed of a cotton matrix, which usually refers to a retained surgical sponge or gauze, surrounded by a foreign body reaction [1, 2]. Most cases of textiloma reported in the literature have been connected to abdominal or orthopaedic surgery; very few have been linked with thoracic surgery [3]. It is also a rare complication of cardiac surgery [3, 4]. The aim of this work was to report the similar tomographic findings in five cases of intrathoracic textilomas, revealed by the presence of thoracic pain in the late post-operative period after successful myocardial revascularisation surgery. The pre-operative diagnosis was suspected by a combination of imaging findings and the historical context of previous cardiac surgery, and subsequently confirmed by surgical removal.     

Low whole-body insulin sensitivity in patients with ischaemic heart disease is associated with impaired myocardial glucose uptake predictive of poor outcome after revascularisation

We tested the hypothesis that low whole-body insulin sensitivity in patients with ischaemic heart disease and impaired left ventricular (LV) function is associated with abnormalities of insulin-mediated myocardial glucose uptake affecting outcome after coronary bypass surgery (CABG). We studied 29 patients with ischaemic heart disease and impaired LV ejection fraction (EF) and age-matched healthy volunteers ( n = 30). As assessed by euglycaemic glucose-insulin clamp, 15 patients had a low and 14 a normal whole-body insulin sensitivity. Using positron emission tomography, patterns of fluorine-18 fluorodeoxyglucose and nitrogen-13 ammonia uptake in addition to quantified glucose uptake, blood flow and hyperaemic blood flow were assessed before CABG in 16 myocardial segments of the left ventricle. Major adverse cardiac events and LVEF were evaluated 7 months after CABG. Glucose uptake in normokinetic PET-normal myocardium was found to be higher in patients with normal whole-body insulin sensitivity ( P < 0.001), whereas in patients with low whole-body insulin sensitivity more segments displayed a pattern of reduced glucose uptake in normoperfused myocardium (PET-reverse mismatch) ( P < 0.05). Hyperaemic blood flow was impaired in both patient groups. A major cardiac event after CABG could partly be predicted by the LV extent of normoperfused segments with PET-reverse mismatch. We conclude that low whole-body insulin sensitivity in patients with ischaemic heart disease and impaired LV function is associated with impaired insulin-mediated myocardial glucose uptake, which is partially predictive of a worse outcome after CABG.     

雷达作业人员昼夜不同作业班次心率和心率变异性的变化

Objective To investigate the circadian changes of heart rate (HR) and heart rate variability (HRV) on radar operators in day and night shifts. Methods Twenty-one military radar operators were selected as subject. Their HR was gotten from continually electrocardiogram recorded by a biomedical monitoring system in four different working shifts (morning, afternoon, early night and late night) and HRV was analyzed. In addition, each shift was divided into four phases and the average HR of different phases in same shift was compared. Results There was significant difference of average HR among four shifts (F=7. 287, P＜0.01). The average HR in late night was significantly lower than that in other three shifts. Comparing with morning and afternoon shifts, high frequency normalized unit (HFNU) in late night shift was significantly increased (P＜0.05). Low frequency normalized unit (LFNU) in late night shift was significantly decreased comparing with those in morning and afternoon shifts (P＜0. 05). The average HR in different phase of a shift showed significant differences among morning, afternoon and early night shifts (F= 5. 480, 3. 150, 3. 850,P＜0. 05 or P＜0. 01), and gradually decreased with working time. However, there was no significant difference of average HR in different working phase of late night shift. Conclusions Circadian change would significantly influence the HR and some HRV indices of military radar operators.     

雷达作业人员昼夜不同作业班次心率和心率变异性的变化

目的 观察雷达作业人员作业过程中心率和心率变异性的昼夜节律变化.方法 以某雷达部队21名男性雷达作业人员为对象,于昼夜不同作业班次（上午班、下午班、小夜班和大夜班）上班前佩带＂飞行员飞行生理参数记录检测仪＂,检测工作过程中动态心电图、心率等指标,分析有关心率变异性参数的变化.此外,将每一作业班次分为4个时段,比较同一班次不同时段平均心率的变化.结果 雷达作业过程中不同班次的平均心率有统计学差异（F=7.287,P＜0.01）,大夜班的平均心率较上午班、下午班、小夜班均明显降低（P＜0.01）;大夜班的标化低频功率较上午班、下午班明显降低（P＜0.05）,而标化高频功率较上午班、下午班显著增加（P＜0.05）.上午班、下午班和小夜班不同时段的平均心率均有统计学差异（F=5.480、3.150、3.850,P＜0.05或P＜0.01）,而且均呈现随着作业时间延长,平均心率逐渐降低的趋势;但大夜班中各时段间的平均心率无统计学差异.结论 生物节律的变化对雷达作业人员的心率和有关心率变异性指标产生明显影响.     

The effect of age and gender on heart rate variability after endurance training

PURPOSE: This research investigated the age and gender differences in cardiovascular adaptation to a standardized/quantified endurance-training program that included two taper periods. METHODS: The latter was analyzed from spectral analysis of electrocardiogram records of heart rate variability (HRV) at rest in groups of young (19-21 yr) and middle aged (40-45 yr), mixed gender groups (6 males and 6 females), pre- and poststandardized training. All subjects were recreational runners who completed the same 12-wk running program. Before, and subsequent to training, HRV was measured during supine rest and submaximal cycling. RESULTS: There was a significant decrease in heart rate both at rest (2.7 +/- 0.45 beats x min-1) and during submaximal exercise (8.1 +/- 0.67 beats x min-1) in both age groups after training. After training, total spectral power increased (560.7 +/- 308.9 ms2), as well as high-frequency power (362.3 +/- 405.5 ms2), in both age groups at rest. The young group showed a greater increase in total power (849.0 +/- 308.7 ms2) after the training program. CONCLUSION: It is concluded that a well-designed 12-wk endurance-training program will decrease resting and submaximal heart rate in both younger and older adults. The significant increase in HRV, total power, and high-frequency power in all groups after endurance training indicates that HRV measurement appears to provide an effective, noninvasive assessment of cardiovascular adaptation to aerobic training.