Cardiac rehabilitation in patients with severe ischemic left ventricular dysfunction

Twenty patients who had had a myocardial infarction and who had a resting left ventricular ejection fraction of 25% or less participated in an 8-week outpatient supervised exercise and education program. No morbidity or mortality occurred during the program, and most patients achieved a substantial improvement in exercise capacity. During a follow-up interval of a mean of 29.7 +/- 13.0 months, four patients died, an annualized mortality of 8 +/- 4%. The outcome of cardiac rehabilitation was assessed 19.1 +/- 4.4 months after completion of the supervised program. Of the 16 survivors, all of whom had been fully employed before their most recent myocardial infarction, 9 (56%) had returned to full-time work, 6 (38%) were medically disabled, and 1 was retired (age 73 years) but fully active. Of the 16 survivors, 13 (81%) completed a questionnaire about their perceptions of their current quality of life. Of the 13 patients, 12 (92%) had continued to exercise regularly. Four patients (31%) reported the ability to perform all desired activities without symptoms, whereas nine patients (69%) noted some impairment in their functional capacity. Thus, in this group of patients with profound left ventricular dysfunction, the rehabilitation potential, as evidenced by return to productive employment and the ability to perform desired activities-including exercise training-was generally favorable.     

Preventing sudden cardiac death in post myocardial infarction patients with left ventricular dysfunction

Cardiovascular nurses play a key role in caring for the post myocardial infarction (MI) patient. That role includes reducing the risk of MI recurrence and the progression to heart failure. Equally important is evaluating for the risk of sudden cardiac death (SCD). Although drugs such as beta blockers and angiotensin converting enzyme (ACE) inhibitors are typically indicated to help reduce the risk of SCD, data continue to show that using implantable cardioverter defibrillators (ICDs) saves lives compared with using medications alone. This article focuses on the problem of SCD, the findings of recent clinical trials, the implant criteria for defibrillators, new Centers for Medicare & Medicaid Services (CMS) decisions regarding reimbursement, and postoperative care for the defibrillator patient. Included are 2 case studies demonstrating the nurses' role in identifying asymptomatic patients who are indicated for ICD therapy. It is critical that cardiovascular nurses be aware of the latest scientific evidence showing improved outcomes for post-MI patients, particularly those with left ventricular dysfunction.     

Long-term prognostic value of stress-redistribution-reinjection Tl-201 imaging in patients with severe left ventricular dysfunction and coronary artery bypass surgery

Objectives: This study sought to evaluate the long-term prognostic significance of stress–redistribution–reinjection Tl-201 imaging in patients with severe left ventricular (LV) dysfunction and coronary artery bypass surgery. Background: Preoperative stress–redistribution–reinjection Tl-201 imaging detects viable but asynergic segments which show functional improvement postoperatively and is considered as a valuable noninvasive method in selection of patients with severe LV dysfunction for revascularization. The long-term prognostic value of the reinjection technique remains unclear. Methods: Fifty-two patients with severe LV dysfunction (mean ejection fraction (EF) 0.32 ± 0.03) who underwent coronary artery bypass surgery in 1993–1994 were included in the study. Patients had follow-up 49 ± 12 months. LV function was assessed by two-dimensional echocardiography. Perfusion was assessed by Tl-201 SPECT imaging and was graded on a four-point scale (0 = normal, 3 = absent uptake) using the 20 segment model. Perfusion index was derived by adding the score of all segments and dividing these by 20. Patients were divided into two groups. Group A comprised patients with seven and more dysfunctional viable myocardial segments. Group B included patients with less than seven dysfunctional but viable segments. Results: Mean EF increased from 0.32 ± 0.03 to 0.46 ± 0.04. Mean perfusion index did not show a significant difference as a whole during follow-up compared to the early postoperative values (0.9 ± 0.4 and 1.1 ± 0.4, p = NS). When adequacy of revascularization was considered, the predictive value of a positive preoperative viability test for functional improvement was 82%. Nineteen cardiac events occurred in group B patients and six in group A patients: six deaths (four from cardiac and two from noncardiac causes), 13 myocardial infarctions (MI). Multivariate Cox survival analysis identified the number of viable segments detected preoperatively (² = 7.2, p = 0.002), postoperative improvement in Tl-uptake (² = 6.6, p = 0.01) and functional improvement (² = 5.3, p = 0.03) postoperatively as independent predictors of cardiac events. Preoperative EF and functional capacity were not associated with cardiac events in long-term prognosis. Conclusion: These data suggest that preoperative stress–redistribution–reinjection Tl-201 imaging, specifically the number of viable segments detected preoperatively and postoperative improvement in Tl-201 uptake provide important long-term prognostic information in patients with severe LV dysfunction who had coronary artery bypass surgery.     

Pulmonary hypertension and right ventricular dysfunction in patients with left to right shunt coronary artery fistula: evaluation with cardiac CT

In this study, we aimed to evaluate whether patients with left to right shunt coronary artery fistula (LRSCAF) are predisposed to developing pulmonary hypertension and right ventricular dysfunction compared with healthy individuals. The value of cardiac CT findings in determining the necessity of intervention for these patients was investigated. We retrospectively studied 19 patients with LRSCAF and 19 healthy patients. Several parameters were observed on cardiac CT by two radiologists, including pulmonary trunk diameter (PA diameter), right ventricular diameter (RVD), left ventricular diameter (LVD), RVD/LVD ratio, septal bowing and CT score of right ventricular dysfunction (CSRVD). Data from both groups were compared. The inter- and intra-observer variabilities and correlations were examined. The disease group was further divided into intervention (n = 9) and non-intervention (n = 10) groups, and their data were compared. All cardiac CT findings showed significant intra- and inter-observer correlation without significant variability. Mann–Whitney U tests and χ² analysis showed that PA diameter, RVD/LVD ratio acquired from two observers, and CSRVD were higher in the disease group than in the control group (all P values < 0.05 for χ² and almost all P values < 0.05 for Mann–Whitney U). The RVD/LVD ratio and CSRVD were higher in the intervention group than in the non-intervention group (all P values < 0.05). Receiver operating curve analysis identified RVD/LVD = 1.036 and CSRVD = 3.5 as the best cut-off values to determine the necessity of further intervention. Patients with LRSCAF are more predisposed to pulmonary hypertension and right ventricular dysfunction compared with the normal population. RVD/LVD > 1.0 and CSRVD ≥ 4.0 may determine the necessity of intervention for patients with LRSCAF.     

Normal cardiac output during beta blockade with timolol in hypertensive patients.

Data published by this laboratory indicated that the beta adrenergic blocking drugs timolol and propranolol exerted equivalent beta blocking and antihypertensive actions in patients with mild essential hypertension, but that whereas cardiac output fell acutely with both drugs, it returned to normal after 5 wk of treatment with timolol, but remained depressed after propranolol. This preliminary observation needed further confirmation in a larger series of patients. In this study, 11 patients with initial diastolic blood pressures between 90 and 125 mm Hg were given timolol for 5 wk. Hemodynamic measurements were made before and at the end of treatment. Mean heart rate fell from 76.8 to 64.3 bpm (p less than 0.001), and blood pressure was reduced from 179.4/99 mm Hg to 167.4/93.3 mm Hg (less than 0.02). Cardiac output averaged 6.29 L/min before timolol, and fell to 5.95 L/min (NS) after treatment. Stroke volume increased significantly, while total peripheral resistance was unchanged. These results confirm our earlier observations that timolol is an effective beta adrenergic blocking drug with antihypertensive action that does not reduce cardiac output significantly when given chronically. This drug merits further evaluation in other cardiovascular disorders since it may have advantages over other beta adrenergic blocking drugs.     

Exaggerated increase of exercise-induced pulmonary artery pressure in systemic sclerosis patients predominantly results from left ventricular diastolic dysfunction

Objective

High prevalence of exaggerated pulmonary artery pressure response to exercise (EPAPR) was reported in patients with systemic sclerosis (SSc). However, pathophysiology of this phenomenon has not been well defined. Therefore, we evaluated the frequency and potential aetiology of EPAPR in SSc patients.

Methods

We included 85 patients (79 female, 6 male, mean age 54.3 ± 13.9 years) with SSc. Transthoracic echocardiography followed by exercise Doppler echocardiography (EDE) were performed. A positive EDE was defined when at least 20 mmHg increase of tricuspid regurgitation peak gradient (TRPG) was recorded. Right heart catheterization (RHC) with exercise was performed in positive EDE patients and in subjects with resting TRPG >31 mmHg.

Results

Resting TRPG >31 mmHg and/or positive EDE was found in 30 patients and they were referred to RHC. Finally, RHC was performed in 20 patients (16 pts resting TRPG >31 mmHg and 4 others normal resting TRPG and positive EDE). In 12 (60 %) of them an EPAPR with elevated pulmonary capillary wedge pressure (PCWP) was observed. Interestingly, mean left atrium (LA) diameter was greater in an EPAPR with elevated PCWP patients than in subjects with normal exercise response (39.36 ± 5.6 vs. 35.53 ± 3.48, p = 0.03). In EPAPR with elevated PCWP group greater mean value of E/E′ of mitral lateral annulus was observed (7.98 ± 3.35 vs. 6.27 ± 1.94, p = 0.03). In the univariate logistic regression analysis increased LA diameter was significant predictor of EPAPR with elevated PCWP (OR 1.199, 95 % CI 1.029–1.396, p = 0.019).

Conclusions

Despite very well-known risk of PAH in systemic sclerosis patients, the excessive increase of PAP during exercise is more commonly caused by left ventricular diastolic dysfunction than pulmonary arterial vasculopathy.     

Comparison of pulmonary artery and arterial thermodilution cardiac output in critically ill patients

Objective: We studied the agreement between cardiac output measurements via pulmonary artery thermodilution [CO(PA)], regarded as the current clinical gold standard, and aortic transpulmonary thermodilution [CO(AORTA)]. Design: Prospective clinical study. Setting: Surgical intensive care unit of a university hospital. Patients: 37 patients with sepsis or septic shock (n = 34) and subarachnoid haemorrhage (n = 3). Measurements and results: We analysed 449 simultaneous cardiac output measurements. All patients were deeply sedated and mechanically ventilated in a pressure controlled mode. Each patient received a 7.5-F five-lumen pulmonary artery catheter and a 4-F aortic catheter with an integrated thermistor. The thermistors of the two different catheters were connected to one computer system (COLD-Z021, Pulsion Medical Systems, Munich, Germany). Linear regression analysis revealed: CO(AORTA) = 0.96 · CO(PA) + 1.02 (l/min) (r = 0.97, p < 0.0001). CO(AORTA) was consistently higher than CO(PA) with a bias of 0.68 (l/min) and a standard deviation of 0.62 (l/min). Conclusion: Cardiac output derived from aortic transpulmonary thermodilution is suitable for measurement in the intensive care unit. Measurements of CO(AORTA) are consistent with, but slightly higher than, those obtained from pulmonary artery thermodilution. Received: 8 February 1999 Final revision received: 26 May 1999 Accepted: 28 May 1999     

超声斑点追踪成像评价心功能不全患者收缩期心肌扭转的初步研究

目的 应用超声斑点追踪成像技术评价心功能不全患者收缩期左室心肌旋转及扭转运动变化.方法 32例正常对照者和24例心功能不全患者,显示左室标准短轴观图像,分别测量并比较两组患者各短轴观图像在标化时间点处的左室旋转及扭转角度、收缩期左室旋转及扭转峰值与相应达峰时间,观察左室旋转值及扭转值随时间变化的关系.结果 心功能不全患者左室各短轴观收缩期左室旋转及扭转峰值均显著低于对照组(P<0.05);与对照组比较,心功能不全组左室扭转达峰时间明显延长(P<0.05),达峰点出现在舒张期,左室心尖水平顺时针旋转达峰时间长于对照组(P<0.05),延长至射血期.结论 心功能不全患者左室扭转运动减低,左室心底、心尖相对旋转不同步,旋转角度减低.     

Effect of indecainide in patients with left ventricular dysfunction

Indecainide, a new antiarrhythmic agent classified as type Ic was evaluated in 11 patients with heart disease who had greater than or equal to 30 ventricular premature complexes/hour, moderate-to-marked left ventricular dysfunction, and mean ejection fraction 34% +/- 8%. Patients received indecainide, 50 mg by mouth, every 6 hours and the dose was increased until greater than or equal to 80% suppression was noted, adverse effects occurred, or a maximum dose of 100 mg indecainide was given every 6 hours. Ventricular premature complexes were suppressed greater than or equal to 80% in nine patients (p less than 0.05) and ventricular tachycardia episodes were completely suppressed in five of eight patients. The effective or maximal mean daily indecainide dose was 191 +/- 32 mg; half of the responders achieved achieved efficacy at serum drug concentration greater than or equal to 600 ng/ml. Serum drug concentration was directly related to gender (r = 0.78, p less than 0.04) and inversely related to creatinine clearance (r = 0.74, p less than 0.05) and ejection fraction (r = 0.71, p less than 0.02). Indecainide prolonged mean PR and QRS intervals (p less than 0.05) but not QT or QTc. There was a linear relation between percent change in PR (r = 0.80, p less than 0.001) and QRS (r = 0.66, p less than 0.001) intervals and serum drug concentration. After starting or increasing the dose, careful observation of patients with decreased renal function or reduced ejection fraction should be exercised because they attain higher drug concentration than normal subjects.     

Left ventricular filling patterns and pulmonary artery pressures in patients aged 90 to 100 years with normal echocardiography results.

Left ventricular filling and pulmonary artery pressure (PAP) have not been well described in patients > or = 90 years old. We reviewed our database to obtain echocardiograms with normal findings in this age group. The peak early and late mitral filling velocities, the early and late velocity-time integral (VTI), the mitral deceleration time, and the atrial filling fraction (late VTI/total VTI) were measured. PAP was obtained from the peak tricuspid regurgitation velocity. Of 252 echocardiograms performed on patients > or = 90 years old, 47 (19%) were normal. The mean +/- SD values were: ratio of peak early and late mitral filling velocities, 0.69 +/- 0.16; deceleration time, 240 milliseconds +/- 31; ratio of early and late VTI, 1.0 +/- 0.3; atrial filling fraction, 47% +/- 7; and PAP, 31 mm Hg +/- 6. Left ventricular filling in patients aged 90 to 100 years demonstrates increasingly impaired left ventricular relaxation from patients in their eighth and ninth decades. PAP continues to increase with age and PAP < or = 40 mm Hg in the elderly could be considered normal.     

Transesophageal Doppler reliably tracks changes in cardiac output in comparison with intermittent pulmonary artery thermodilution in cardiac surgery patients

In this study a comparison of cardiac output (CO) measurements obtained with CardioQ transesophageal Doppler (TED) and pulmonary artery catheter (PAC) thermodilution (TD) technique was done in a systematic set-up, with induced changes in preload, afterload and heart rate. Twenty-five patients completed the study. Each patient were placed in the following successive positions: (1) supine, (2) head-down tilt, (3) head-up tilt, (4) supine, (5) supine with phenylephrine administration, (6) pace heart rate 80 beats per minute (bpm), (7) pace heart rate 110 bpm. The agreement of compared data was investigated by Bland–Altman plots, and to assess trending ability a four quadrants plot and a polar plot were constructed. Both methods showed an acceptable precision 6.4 % (PAC TD) and 12.8 % (TED). In comparison with PAC TD, the TED was associated with a mean bias in supine position of ?0.30 l min^?1 (95 % CI ?0.88; 0.27), wide limits of agreement, a percentage error of 69.5 %, and a trending ability with a concordance rate of 92 %, angular bias of 1.1° and a radial sector size of 40.0° corresponding to an acceptable trending ability. In comparison with PAC TD, the CardioQ TED showed a low mean bias, wide limits of agreement and a larger percentage error than should be expected from the precision of the two methods. However, an acceptable trending ability was found. Thus, the CardioQ TED should not replace CO measurements done by PAC TD, but could be a valuable tool in guiding therapy.     

Characteristics and prevalence of various types of left ventricular myocardial dysfunction in patients with chronic cardiac failure

Prevalence of systolic and diastolic myocardial dysfunctions of the left ventricle (SDLV, DDLV) was studied in 223 patients with chronic cardiac failure (CCF) arising in the presence of arterial hypertension (AH), coronary heart disease (CHD) and their combination. The diagnosis was made in outpatient diagnostic center and included patients free of distinct clinical symptoms of CHD. DDLV was rather prevalent in a functional class (FC) I of CCF, in AH patients with SDLV FC III and CHD patients. Mean duration of cardiovascular diseases (CVD) before CCF onset with various types of left ventricular dysfunction was determined. Echocardiographic, including Dopplerographic, criteria of SDLV and DDLV were studied and their significance depending on FC and etiology of CCF was ascertained. The study elicited regularities of CCF formation in patients with various cardiovascular diseases, impact of the latter on myocardial dysfunction, echocardiographic features of CCF by systolic and diastolic type.     

The management of patients with aortic regurgitation and severe left ventricular dysfunction: a systematic review

A systematic search of Medline, EMBASE and CINAHL electronic databases was performed. Original research articles reporting all-cause mortality following surgery in patients with aortic regurgitation and severe left ventricular systolic dysfunction (LVSD) were identified. Nine of the 10 eligible studies were observational, single-center, retrospective analyses. Survival ranged from 86 to 100% at 30 days; 81 to 100% at 1 year and 68 to 84% at 5 years. Three studies described an improvement in mean left ventricular ejection fraction (LVEF) following aortic valve replacement (AVR) of 5–14%; a fourth study reported an increase in mean left ventricular ejection fraction (LVEF) of 9% in patients undergoing isolated AVR but not when AVR was combined with coronary artery bypass graft and/or mitral valve surgery. Three studies demonstrated improvements in functional New York Heart Association (NYHA) class following AVR. Additional studies are needed to clarify the benefits of AVR in patients with more extreme degrees of left ventricular systolic dysfunction (LVSD) and the potential roles of cardiac transplantation and transaortic valve implantation.     

Effect of the 30 degree lateral recumbent position on pulmonary artery and pulmonary artery wedge pressures in critically ill adult cardiac surgery patients.

BACKGROUND: Despite demonstrated benefits of lateral positioning, critically ill patients may require prolonged supine positioning to obtain reproducible hemodynamic measurements. OBJECTIVES: TO determine the effect of 30 degree right and left lateral positions on pulmonary artery and pulmonary artery wedge pressures after cardiac surgery in critically ill adult patients. METHODS: An experimental repeated-measures design was used to study 35 patients with stable hemodynamics after cardiac surgery. Subjects were randomly assigned to 1 of 2 position sequences. Pulmonary artery and pulmonary artery wedge pressures were measured in each position. RESULTS: Measurements obtained from patients in the 30 degree left lateral position differed significantly (all Ps < .05) from measurements obtained from patients in the supine position for pulmonary artery systolic, end-diastolic, and mean pressures. Pulmonary artery wedge pressures did not differ significantly; however, data were available from only 17 subjects. The largest mean difference in pressures between the 2 positions was 2.0 +/- 2.1 mm Hg for pulmonary artery systolic pressures, whereas maximum differences for end-diastolic and pulmonary artery wedge pressures were 1.4 +/- 2.7 mm Hg and 1.6 +/- 2.4 mm Hg, respectively. Clinically significant position-related changes in pressure occurred in 12 (2.1%) of 581 pressure pairs. Clinically significant changes occurred in end-diastolic pressure in 2 subjects and in pulmonary artery wedge pressure in 1 subject. CONCLUSiONS: In patients with stable hemodynamics during the first 12 to 24 hours after cardiac surgery, measurements of pulmonary artery and pulmonary artery wedge pressures obtained in the 30 degree lateral and supine positions are clinically interchangeable.     

左心室功能不全冠心病患者支架术与冠状动脉旁路移植术的对比研究

目的 比较左心室功能不全的冠心病患者经皮冠状动脉介入治疗(PCI)支架术与冠状动脉旁路移植术(CABG)对住院与临床随访结果的影响.方法 147例左心室功能不全的冠心病患者,根据血运重建方式的不同将其分为PCI组(60例)和CABG组(87例),记录其,临床与冠状动脉造影特征、血运重建情况和住院,临床结果等资料,并进行临床随访.主要观察终点为住院与随访主要不良心脑血管事件(MACCE)(包括全因死亡、新发心肌梗死、卒中和再次血运重建).所有资料采用SPSS 13.0软件进行统计分析,以P＜0.05为差异有统计学意义.结果 PCI组和CABG组相比,院内MACCE发生率差异无统计学意义(1.7%与9.2%,P＞0.05);院内病死率差异无统计学意义(1.7%与8.0%,P＞o.05).多因素Logistic回归分析表明,院内MACCE风险相当(OR=3.03,95%C/0.27～34.48,P＞0.05).平均随访22个月(中位数时间668 d)显示,2组MACCE发生率差异无统计学意义(16.0%与13.8%,P＞0.05),再次血运重建差异均无统计学意义(8.0%与1.7%,P＞0.05).多因素Cox回归分析显蟊,2组随访MACCE风险基本相当(HR=1.35,95%CI 0.44～4.13,P＞0.05).结论 合并左心室功能不全的冠心病患者,PCI支架术与CABG的住院及随访MACCE发生率均相当.随着药物洗脱支架的广泛应用,PCI术的远期效果有望进一步提高.