Biomedical subjects

Cheuk-Man Yu

Publications and source records attributed to Cheuk-Man Yu.

At least 37 records · Page 2Linked to original sources

PubMed2005

Intrathoracic impedance monitoring in patients with heart failure: correlation with fluid status and feasibility of early warning preceding hospitalization.

BACKGROUND: Patients with heart failure are frequently hospitalized for fluid overload. A reliable method for chronic monitoring of fluid status is therefore desirable. We evaluated an implantable system capable of measuring intrathoracic impedance to identify potential fluid overload before heart failure hospitalization and to determine the correlation between intrathoracic impedance and standard measures of fluid status during hospitalization. METHODS AND RESULTS: Thirty-three patients with NYHA class III and IV heart failure were implanted with a special pacemaker in the left pectoral region and a defibrillation lead in the right ventricle. Intrathoracic impedance was regularly measured and recorded between the lead and the pacemaker case. During hospitalizations, pulmonary capillary wedge pressure and fluid status were monitored. Ten patients were hospitalized for fluid overload 25 times over 20.7+/-8.4 months. Intrathoracic impedance decreased before each admission by an average of 12.3+/-5.3% (P<0.001) over an average of 18.3+/-10.1 days. Impedance reduction began 15.3+/-10.6 days (P<0.001) before the onset of worsening symptoms. There was an inverse correlation between intrathoracic impedance and pulmonary capillary wedge pressure (r=-0.61, P<0.001) and between intrathoracic impedance and net fluid loss (r=-0.70, P<0.001) during hospitalization. Automated detection of impedance decreases was 76.9% sensitive in detecting hospitalization for fluid overload, with 1.5 false-positive (threshold crossing without hospitalization) detections per patient-year of follow-up. CONCLUSIONS: Intrathoracic impedance is inversely correlated with pulmonary capillary wedge pressure and fluid balance and decreased before the onset of patient symptoms and before hospital admission for fluid overload. Regular monitoring of impedance may provide early warning of impending decompensation and diagnostic information for titration of medication.

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PubMed2005

A novel tool to assess systolic asynchrony and identify responders of cardiac resynchronization therapy by tissue synchronization imaging.

OBJECTIVES: This study was designed to investigate if tissue synchronization imaging (TSI) is useful to identify regional wall delay and predict left ventricular (LV) reverse remodeling after cardiac resynchronization therapy (CRT). BACKGROUND: Echocardiographic assessment of systolic asynchrony is helpful to predict a positive response to CRT. Tissue synchronization imaging is a new imaging technique that allows quick evaluation of regional systolic delay. METHODS: Tissue synchronization imaging was performed in 56 heart failure patients at baseline and three months after CRT. Regional wall delay was identified on TSI images and the time to regional peak systolic velocity (Ts) in LV was measured by the six-basal-six-mid-segmental model. Eight TSI parameters of systolic asynchrony were computed when Ts was measured in ejection phase or also included postsystolic shortening. RESULTS: Severe lateral wall delay occurred in 17 patients, which predicted LV reverse remodeling (chi-square = 8.13, p = 0.004). Among the eight quantitative parameters of asynchrony, the predictive values were higher for parameters that measured Ts in ejection phase than in postsystolic shortening. The standard deviation of Ts of 12 LV segments in ejection phase (Ts-SD-12-ejection) was most powerful to predict reverse remodeling (r = -0.61, p < 0.001) and gain in ejection fraction (r = 0.53, p < 0.001). The area of the receiver-operating characteristic (ROC) curve was the largest for Ts-SD-12-ejection (0.90, p < 0.001), with a sensitivity of 87% and specificity of 81% at a cutoff of 34.4 ms. The combination of lateral wall delay with Ts-SD-12-ejection gave a sensitivity and specificity of 82% and 87%. CONCLUSIONS: Tissue synchronization imaging allows quick evaluation of regional wall delay, and combined with Ts-SD-12-ejection provides a reliable way of predicting reverse remodeling after CRT.

Aged↗

PubMed2005

Independent and incremental prognostic value of early mitral annulus velocity in patients with impaired left ventricular systolic function.

OBJECTIVES: This study sought to investigate the incremental prognostic value of non-invasive measures of early myocardial relaxation and left ventricular diastolic pressure (LVDP) in patients with impaired left ventricular (LV) systolic function. BACKGROUND: The early diastolic mitral annulus velocity (Em) reflects myocardial relaxation, and the combined ratio of the early transmitral flow velocity (E) to Em (E/Em) >15 correlates well with elevated mean LVDP. It is unknown if these new indexes will predict poorer survival in patients with LV systolic dysfunction. METHODS: Echocardiograms were prospectively obtained in 182 patients with impaired LV systolic function, defined as an LV ejection fraction <0.50. The end point was cardiac mortality. The majority of this patient sample (80%) has been reported on in a previous publication. RESULTS: After a median 48 months' follow-up, Em emerged as an independent predictor of survival (hazard ratio 0.61, 95% confidence interval 0.45 to 0.82). An Em <3 cm/s was associated with a significantly excess mortality (log-rank statistic 9.36, p = 0.002), and this measurement added incremental prognostic value to standard indexes of systolic or diastolic function, including a deceleration time <140 ms and an E/Em >15 (p = 0.038). CONCLUSIONS: Early diastolic mitral annulus velocity is a powerful predictor of cardiac mortality in patients with LV systolic impairment; Em <3 cm/s emerged as the best prognosticator in long-term follow-up, incremental to other clinical or echocardiographic variables, including the ratio E/Em.

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PubMed2005

Assessment of the effect of cardiac resynchronization therapy on intraventricular mechanical synchronicity by regional volumetric changes.

A new echocardiographic technology, the timing of regional volumetric changes by 3-dimensional echocardiography, was applied to assess intraventricular mechanical synchronicity in 13 patients who had received cardiac resynchronization therapy (CRT). When biventricular pacing was withheld, left ventricular (LV) asynchrony occurred as reflected by these echocardiographic parameters, whereas LV volume increased and the ejection fraction decreased. Further studies are needed to explore whether this novel method can be used to select suitable candidates for CRT and to predict a favorable response.

Cardiac Pacing, Artificial↗

PubMed2005

Left ventricular systolic asynchrony after acute myocardial infarction in patients with narrow QRS complexes.

BACKGROUND: The aim of the study was to assess the degree of left ventricular (LV) asynchrony after myocardial infarction (MI) in patients with a narrow QRS complex using tissue Doppler imaging (TDI) and correlate this with the site and extent of the infarction measured by contrast-enhanced magnetic resonance imaging (Ce-MRI). METHODS: Echocardiography with TDI and Ce-MRI was performed within 6 days of acute MI in 47 patients and compared with 69 age-matched healthy volunteers. Regional myocardial velocities were assessed in 12 segments, and the corresponding systolic velocity (Sm), early diastolic velocity (Em), as well as the time to peak Sm (Ts) and time to peak Em (Te) were measured. To assess LV synchronicity, SDs of Ts (Ts-SD) and Te (Te-SD) of all 12 segments were computed. Location and size of infarct were confirmed by Ce-MRI with a 16-segment model. RESULTS: All the patients had a normal QRS complex duration. The Ts-SD was significantly prolonged in the MI group when compared with controls (42.2 +/- 13.7 vs 18.0 +/- 7.0 milliseconds, P < .001). The Ts-SD was longer in patients with anterior than inferior MI (46.8 +/- 13.9 vs 34.6 +/- 8.5 milliseconds, P = .002). Stepwise multiple regression analysis revealed that infarct size was the main independent predictor of systolic asynchrony ( B = 0.79, 95% CI 0.75-1.23, P < .001). Asynchrony was not related to the transmurality of the infarction. CONCLUSIONS: Myocardial infarction has a significant impact on LV synchronicity even in those with a narrow QRS complex. The degree of LV systolic asynchrony is mainly determined by the infarct size and not transmurality.

Contrast Media↗

PubMed2005

Predictors of response to cardiac resynchronization therapy (PROSPECT)--study design.

BACKGROUND: Cardiac resynchronization therapy (CRT) is currently indicated in patients with moderate to severe heart failure, a wide QRS complex and significant left ventricular dysfunction despite optimal medical therapy. Adoption of these criteria for CRT results in a favorable response in only two thirds of candidates. METHODS: "Predictors of response to cardiac resynchronization therapy (PROSPECT)," a prospective, multicenter, nonrandomized study, aims to identify echocardiographic measures of dyssynchrony and evaluate their ability to predict response to CRT. PROSPECT will enroll approximately 300 patients in up to 75 centers in the United States, Asia, and Europe with clinical follow-up for 6 months. We will prospectively and individually test a variety of conventional echocardiographic and tissue Doppler imaging parameters against measures of clinical response. The primary response criteria are improvement in the heart failure Clinical Composite Score and left ventricular reverse remodeling. Enrollment began in March 2004 and is expected to conclude early 2005.

Asia↗

PubMed2005

Improvement of serum NT-ProBNP predicts improvement in cardiac function and favorable prognosis after cardiac resynchronization therapy for heart failure.

BACKGROUND: Cardiac resynchronization therapy (CRT) is now an established therapy for patients with advanced heart failure with electromechanical delay, although nonresponders have been observed. Because natriuretic peptides are relevant markers to reflect the severity of heart failure and filling pressure of cardiac chambers, it may be helpful to assess the efficacy of CRT. METHODS AND RESULTS: Forty-two patients with heart failure with QRS of >120 msec were recruited; their serial N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were measured at baseline and at 1 and 3 months after CRT. There was a reduction in NT-proBNP level 1 month after CRT (2655 +/- 2242 pg/mL vs 2149 +/- 2033 pg/mL; P = .03), which was further reduced at 3 months (1473 +/- 1786 pg/mL; P < .001 vs baseline). The reduction of NT-proBNP correlated with the change of left ventricular (LV) end-systolic volume (r = 0.53; P = .001) or LV ejection fraction ( r = -0.49; P = .002) and with improvement in exercise capacity after CRT for 3 months (r = 0.50; P = .002). The patients were classified by the degree of reduction in NT-proBNP as group 1 (reduction of > or =50% vs baseline; n = 19) and group 2 (reduction of <50% vs baseline; n = 23). The degree of LV reverse remodeling (-31.8 +/- 24.7 mL vs -12.6 +/- 19.2 mL; P = .007) and gain in LV ejection fraction (+12.5% +/- 8.8% vs +4.6% +/- 5.8%; P = .002) were significantly better in group 1 than group 2. Both the all-cause mortality rate (Log-rank chi 2 = 4.01; P = .04) and the composite end-point of mortality rate or hospitalization rate for cardiovascular causes (Log-rank chi 2 = 4.31; P = .02) were significantly lower in group 1 than in group 2. CONCLUSION: Serial monitoring of NT-proBNP may be helpful to predict a favorable outcome after CRT. Those who had a reduction of NT-proBNP level of >/=50% were more likely to exhibit a favorable response.

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PubMed2005

Endothelial dysfunction in normotensive Chinese with a family history of essential hypertension.

Endothelial dysfunction is seen in patients with essential hypertension. However, it is still debated whether impaired endothelial function occurs before the development of hypertension. The aim of our study was to investigate whether endothelial dysfunction occurs in genetically vulnerable normotensive Chinese, and whether the endothelial dysfunction is worse as essential hypertension progresses. Endothelial function was assessed by high-resolution vascular ultrasound (7.5 MHz). The diameters of brachial arteries were measured at rest, during reactive hyperemia, and after sublingual administration of nitroglycerine (GTN) in 58 subjects with a mean age of 46.7 +/- 10.1 years. Among them, 18 patients had essential hypertension (Group 2), 20 normotensive subjects had a family history of hypertension (Group 3), and 20 normotensive subjects without a family history of cardiovascular diseases served as controls (Group 1). There was no difference in age among the three groups (Group 1: 46.5 +/- 10.5 versus Group 2: 46.7 +/- 9.5 versus Group 3: 44.50 +/- 11.21 years, P = NS). Flow-mediated dilatation of brachial arteries was significantly reduced in Group 2 and 3 as compared with Group 1 (Group 1: 13.2 +/- 5.9% versus Group 2: 8.0 +/- 3.6 versus Group 3: 4.86 +/- 3.5, both p < .01). On the other hand, nonflow mediated vasodilatation in response to GTN did not differ among the three groups. Endothelium-dependent vasodilatation is impaired not only in normotensive subjects with a family history of hypertension, but also becomes worse in the hypertensive patients.

Adult↗

PubMed2005

Tissue Doppler imaging provides incremental prognostic value in patients with systemic hypertension and left ventricular hypertrophy.

OBJECTIVES: We sought to determine the prognostic value of left ventricular (LV) mitral annular velocities measured by tissue Doppler imaging (TDI) in hypertensive patients with echocardiographic evidence of LV hypertrophy. BACKGROUND: Echo LV hypertrophy and LV geometry provide additional predictive value of all-cause mortality beyond traditional cardiovascular risk factors. Limited data exist regarding the predictive value of TDI velocities for cardiovascular risk stratification in treated hypertensive patients. METHODS: Two-dimensional and Doppler echocardiograms were obtained in 252 consecutive subjects, including 174 subjects with systemic hypertension and 78 age-matched normal subjects. The end point was cardiac death in subsequent median follow-up of 19 months. RESULTS: Nineteen patients (7.54%) died of cardiac causes. The TDI mitral annulus systolic velocity and the early diastolic mitral annular velocity (Em) were significantly lower in the non-survivors (all P < 0.001). The pseudonormal (PN) or restrictive filling pattern (RFP) was associated with cardiac mortality. The other parameters associated with cardiac mortality were LV ejection fraction, LV mass index, inter-ventricular septal wall thickness in diastole and the ratio of early mitral inflow to early myocardial velocity. In multivariate analysis, Em, inter-ventricular septal wall thickness in diastole and either PN or RFP were the strongest predictors. The addition of Em < 3.5 cm/s significantly improved the outcome of a model that contained clinical risk factors, inter-ventricular septal wall thickness in diastole > 1.4 cm and either PN or RFP (P = 0.043). CONCLUSIONS: Early diastolic mitral annulus velocity measured by TDI provides prognostic information, incremental to clinical data and standard echocardiographic variables, for risk stratification of hypertensive patients under treatment.

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PubMed2005

Understanding nonresponders of cardiac resynchronization therapy--current and future perspectives.

INTRODUCTION: Cardiac resynchronization therapy (CRT) is now an established nonpharmacologic therapy for advanced heart failure with electromechanical delay. Despite compelling evidence of the benefits of CRT, one troubling issue is the lack of a favorable response in about one-third of patients. METHODS AND RESULTS: Currently, there is no unifying definition of responders, and published data were based on acute hemodynamic changes, chronic left ventricular reverse remodeling, as well as the intermediate or long-term clinical response. The lack of improvement with CRT can be due to many factors including the placement of the left ventricular pacing lead in an inappropriate location, the absence of electrical conduction delay or mechanical dyssynchrony despite wide QRS complexes, and possibly failure to optimize the CRT settings after device implantation. In acute hemodynamic studies, placing the left ventricular leads at the free wall region has been suggested to generate the best pulse pressure and positive dp/dt. The degree of mechanical dyssynchrony has recently been assessed noninvasively in CRT patients by echocardiography and in particular by tissue Doppler imaging. These studies suggested that responders of left ventricular reverse remodeling or systolic function had more severe systolic dyssynchrony. However, further studies are needed to examine the clinical utility of these parameters when applied to the standardized anatomic or functional endpoints. Optimization of atrioventricular and interventricular pacing intervals may also reduce the number of nonresponders, though newer methods, especially interventricular pacing intervals, are still under clinical investigation. CONCLUSION: With the adjunctive use of imaging technology, physicians are able to characterize the response to CRT objectively, and cardiac imaging is an important clinical tool for determining more precisely the presence and degree of mechanical dyssynchrony.

Cardiac Pacing, Artificial↗

PubMed2004

Tissue Doppler imaging is superior to strain rate imaging and postsystolic shortening on the prediction of reverse remodeling in both ischemic and nonischemic heart failure after cardiac resynchronization therapy.

BACKGROUND: A number of noninvasive techniques have been used to predict the effectiveness of cardiac resynchronization therapy (CRT) in heart failure patients, in particular left ventricular (LV) reverse remodeling. This study compared the relative predictive values of tissue Doppler imaging (TDI) and strain-rate imaging (SRI) parameters for LV reverse remodeling in patients who received CRT and examined for potential differences in ischemic (n=22) and nonischemic (n=32) heart failure. METHODS AND RESULTS: TDI and SRI were performed at baseline and 3-month follow-up. Eighteen parameters of intraventricular and interventricular asynchrony based on the time to peak myocardial contraction (Ts) and time to peak strain rate (Tsr) were compared, along with postsystolic shortening (PSS). Reverse remodeling with reduction of LV end-diastolic and end-systolic volumes and gain in ejection fraction (all P<0.001) was observed in the whole study population. The standard deviation of Ts of 12 LV segments (Ts-SD) is the most powerful predictor of reverse remodeling in both the ischemic (r=-0.65, P<0.001) and nonischemic (r=-0.79, P<0.001) groups. The PSS of 12 LV segments was a good predictor only for the nonischemic (r=-0.64, P<0.001) but not the ischemic (r=0.32, P=NS) group. However, parameters of SRI and interventricular asynchrony failed to predict reverse remodeling. By multiple regression analysis, independent parameters included Ts-SD in both groups (P<0.005) and PSS of 12 LV segments in the nonischemic group (P=0.03). The area of the receiver operating characteristic curve was largest for Ts-SD (0.94; CI=0.88 to 1.00). CONCLUSIONS: Ts-SD is the most powerful predictor of LV reverse remodeling and was consistently useful for ischemic and nonischemic heart failure. However, PSS is useful only for nonischemic pathogenesis, whereas the role of SRI parameters was not supported by the present study.

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PubMed2004

Effect of a cardiac rehabilitation program on left ventricular diastolic function and its relationship to exercise capacity in patients with coronary heart disease: experience from a randomized, controlled study.

BACKGROUND: A cardiac rehabilitation and prevention program (CRPP) is a recognized nonpharmacological modality in the management of coronary heart disease (CHD). However, the effect of a CRPP on systolic function of the heart is controversial, and no data exists on diastolic function in CHD. A randomized, controlled study was conducted to address these issues. METHODS: Patients (n = 269) with recent acute myocardial infarction (n = 193) or after percutaneous coronary intervention (PCI) (n = 76) were randomized to either CRPP (2-hour twice-weekly exercise program for 8 weeks) or conventional therapy (control group). Serial treadmill exercise testing and at-rest echocardiography were performed during phases 1 (baseline), 2 (post-exercise training), and 3 (8-month follow up). RESULTS: The prevalence of left ventricular (LV) abnormal relaxation pattern (ARP) of diastolic dysfunction was increased in the control group only in phase 3 (65% vs 88%, chi2 = 7.6, P <.01). Significant improvement of individual LV diastolic parameters towards less severe delayed relaxation was also observed in the CRPP group, especially in those with recent acute myocardial infarction or ARP. The gain in exercise capacity was faster and more substantial in the CRPP than the control group (P <.001 for phase 2, P <.05 for phase 3), and was significantly correlated with LV diastolic indices in those with ARP. Exercise training had neutral effects on LV systolic function and rate-pressure product. CONCLUSIONS: In patients with CHD, CRPP prevented the progression of resting LV diastolic dysfunction, without affecting systolic function. In those with ARP, the improvement of diastolic function predicted the gain in exercise capacity.

Adult↗

PubMed2004

A short course of cardiac rehabilitation program is highly cost effective in improving long-term quality of life in patients with recent myocardial infarction or percutaneous coronary intervention.

OBJECTIVE: To evaluate the long-term effect of a cardiac rehabilitation and prevention program (CRPP) on quality of life (QOL) and its cost effectiveness. DESIGN: Prospective, randomized controlled trial. SETTING: University-affiliated outpatient cardiac rehabilitation and prevention center. PARTICIPANTS: A total of 269 patients (76% men; mean age, 64+/-11 y) with recent acute myocardial infarction (AMI; n=193) or after elective percutaneous coronary intervention (PCI; n=76) were randomized in a ratio of 2 to 1. INTERVENTION: Patients received either CRPP (an 8-wk exercise and education class in phase 2) or conventional therapy without exercise program (control group). They were followed until they had completed all 4 phases of the program (ie, 2 y). MAIN OUTCOME MEASURES: QOL assessments, by using the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and Symptoms Questionnaire, were performed at the end of each phase. Direct health care cost was calculated, whereas cost utility was estimated as money spent (in US dollars) per quality-adjusted life-year (QALY) gained. RESULTS: In the CRPP group, 6 of the 8 SF-36 dimensions improved significantly by phase 2 and were maintained throughout the study period. Patients were less anxious and depressed, and felt more relaxed and contented. In the control group, none of the SF-36 dimensions were improved by phase 2, and bodily pain was increased. In phase 4, only 4 dimensions were improved. Symptoms were unchanged except for increased hostility score. There was a significant gain in net time trade-off in the CRPP group after phase 2. The direct health care expenses in the CRPP and control groups were 15,292 dollars and 15,707 dollars per patient, respectively. Therefore, the cost utility calculated was 640 dollars saved per QALY gained. Savings attributable to CRPP were primarily explained by the lower rate (13% vs 26% of patients, chi2 test=3.9, P <.05) and cost of subsequent PCI (P =.01). CONCLUSIONS: In an era of managing patients with coronary heart disease, a short-course CRPP was highly cost effective in providing better QOL to patients with recent AMI or after elective PCI. In addition, the improvement of QOL was quick and sustained for at least 2 years after CRPP.

Angioplasty, Balloon, Coronary↗

PubMed2004

Normalization of renal aquaporin-2 water channel expression by fosinopril, valsartan, and combination therapy in congestive heart failure: a new mechanism of action.

This study investigated the effect of fosinopril (Fos), valsartan (Val), and combination of both drugs (Fos + Val) on the cardiac and renal expression of aquaporin-1 (AQP1) and aquaporin-2 (AQP2) in congestive heart failure (CHF). A rat model of CHF was created by ligating the left anterior descending coronary artery to induce acute myocardial infarction (AMI). Rats were treated by Fos, Val, or Fos + Val for 4 weeks. In renal medulla and cortex, AMI was associated with 2.2- and 1.8-fold increase in AQP2 mRNA expression when compared with Sham-operated rats (medulla: 23.6 +/- 2.8 vs. 52.3 +/- 8.7%; P<0.001; cortex: 19.4 +/- 3.9 vs. 35.5 +/- 7.1%; P<0.05). All the treatment regimens were able to normalize AQP2 transcription in the renal medulla (Fos, 19.9 +/- 4.9%; Val, 22.8 +/- 4.9%; Fos + Val, 20.1 +/- 5.1%; P=NS vs. Sham) and in the cortex (Fos, 21.2 +/- 6.7%; Val, 20.4 +/- 6.0%; Fos + Val, 18.9 +/- 7.5%; P=NS vs. Sham). Similarly, the AQP2 protein expression increased by 2.1-fold after CHF (P<0.05), and was normalized by the treatment regimens (Sham, 0.57 +/- 0.19%; CHF, 1.22 +/- 0.45%; Fos, 0.39 +/- 0.36%; Val, 0.46 +/- 0.34%; Fos + Val, 0.36 +/- 0.15%; all P<0.05 vs. CHF). These treatment regimens also prevented the increase in body weight as found in untreated CHF rats (analysis of variance P<0.05). The renal and cardiac AQP1 gene and protein expressions were unaltered in CHF or by medical therapy. There was no observed cardiac AQP2 expression in all the study groups. Treatment with Fos, Val, or combination therapy was effective in preventing the upregulation of renal AQP2 gene and protein expressions in CHF rats caused by AMI.

Administration, Oral↗

PubMed2004

Comparison of efficacy of reverse remodeling and clinical improvement for relatively narrow and wide QRS complexes after cardiac resynchronization therapy for heart failure.

INTRODUCTION: Cardiac resynchronization therapy (CRT) has been shown to reverse left ventricular (LV) remodeling and improve symptoms in heart failure patients with wide QRS complexes; however, its role in patients with mildly prolonged QRS complexes is unclear. This study investigated if CRT benefited patients with mildly prolonged QRS complexes >120 to 150 ms and explored if the severity of systolic asynchrony determined such a response. METHODS AND RESULTS: Fifty-eight patients (age 66 +/- 11 years, 66% male) who had undergone CRT were studied prospectively. Of these patients, 27 had QRS duration between 120 and 150 ms (group A), and 31 had QRS duration >150 ms (group B). Tissue Doppler echocardiography and clinical assessment were performed at baseline and 3 months after CRT. Both groups had significant reduction of LV volume and increased ejection fraction, +dP/dt, and sphericity index (all P < 0.05). These improvements were greater in group B and were explained by the higher prevalence of systolic intraventricular asynchrony. Significant reverse remodeling (reduction of LV end-systolic volume >15%) was evident in 46% of group A patients and 68% of group B patients. Improvement in clinical endpoints was observed in both groups (all P < 0.01), although the changes in metabolic equivalent and New York Heart Association functional class were greater in group B. In both groups, systolic asynchrony index (TS-SD) was the most important predictor of reverse remodeling (r =-0.78, P < 0.001) and was the only independent predictor in the multivariate model (beta=-1.80, confidence interval =-2.18 to -1.42, P < 0.001); QRS duration was not. A predefined TS-SD value >32.6 ms had a sensitivity of 94% and specificity of 83% to predict reverse remodeling. Improvement of intraventricular asynchrony after CRT was evident only in responders (P = 0.01). CONCLUSION: Improvement of LV remodeling and clinical status is evident after CRT in heart failure patients with QRS duration >120 to 150 ms. These responders are closely predicted by the severity of prepacing intraventricular asynchrony but not QRS duration.

Aged↗

PubMed2004

Update in the management of diastolic heart failure.

Diastolic heart failure (DHF) is characterized by the clinical presentation of heart failure in the setting of preserved left ventricular systolic function and evidence of diastolic dysfunction. It is estimated to be present in at least one-third of patients, who represent the signs and symptoms of heart failure, and is especially prevalent among the elderly population. Despite an increasing understanding of the pathophysiology of this disease and the improvement of diagnostic and prognostic assessment, the management of DHF remains to be established. Medical therapy consists of the cautious use of diuretics, and some studies suggested the beneficial role of beta-blockers and calcium antagonists. The rationale of current therapy is largely dependent on understanding the pathophysiology of DHF and observations from clinical trials that included relatively small numbers of patients. Large, multicenter, randomized, controlled studies are needed to define the role of various therapeutic agents in DHF, and whether the prognosis of the disease will be altered. The SWEDIC trial observed that carvedilol treatment in patients with DHF was associated with an improvement in diastolic indices measured by Doppler echocardiography. The CHARM-Preserved trial reported a non-significant reduction of cardiovascular death or admission for heart failure. Other studies which are underway include PEP-CHF and the Hong Kong Diastolic Heart Failure study. They will play a pivotal role in ascertaining the therapeutic efficacy of various agents and will help experts to set up treatment guidelines for this common condition.

Adrenergic beta-Antagonists↗

PubMed2003

Quality of life in patients with coronary heart disease-I: assessment tools.

Health-related quality of life (HRQL) assessment is an important measure of the impact of the disease, effect of treatment and other variables affecting people's lives. The review focused on the assessment of HRQL in patient with coronary heart disease (CHD) by appropriate tools. Although no consensus exists about the precise definition of HRQL, a plethora of instruments have been developed to assess it. Two broad types - generic and disease-specific - have been developed but there is some debate about their relative merits. There is a wide selection of instruments available but choice should be based on a careful consideration of an instrument's psychometric properties, the breadth and depth with which it addresses relevant health domains and the specific clinical or research purpose for which it is intended.

Coronary Disease↗

PubMed2003

Predictors of left ventricular reverse remodeling after cardiac resynchronization therapy for heart failure secondary to idiopathic dilated or ischemic cardiomyopathy.

Biventricular pacing results in left ventricular (LV) reverse remodeling in heart failure patients with wide QRS complexes. This study examines potential predictors of reverse remodeling. Echocardiography with tissue Doppler imaging was performed at baseline and 3 months after biventricular pacing in 30 patients (21 men and 9 women, mean age 62 +/- 14 years). There were 17 responders to reverse remodeling (defined as a reduction in LV end-systolic volume by >15%) and 13 nonresponders. Responders had significant improvement in 6-minute hall-walking distance (p = 0.006), metabolic equivalents (p = 0.02), peak oxygen uptake (p = 0.02), New York Heart Association functional class (p <0.001), and quality of life (p <0.001); an increase in the sphericity index (p = 0.007), ejection fraction (p <0.001), and diastolic filling time (p = 0.03); a decrease in myocardial performance index (p = 0.02), isovolumic relaxation time (p = 0.004), and mitral regurgitation (p = 0.007); and an improvement in systolic dyssynchrony (SD of the time to peak myocardial systolic contraction of the 12 LV segments as dyssynchrony index) (45.0 +/- 8.3 vs 32.5 +/- 14.5 ms, p = 0.003). In contrast, nonresponders only had a small degree of clinical improvement in New York Heart Association class (p = 0.03) and quality-of-life scores (p = 0.03), without any change in cardiac function, and worsening of systolic dyssynchrony (24.8 +/- 4.5 vs 34.1 +/- 13.5 ms, p = 0.02). When all the above factors were put into univariate and multivariate analyses models, systolic dyssynchrony was the only independent predictor of reverse remodeling (r = -0.76, p <0.001) (beta = -1.54, p = 0.007). A preimplant dyssynchrony index of 32.6 ms (+2 SDs from mean of 88 normal controls) was able to totally segregate responders from nonresponders of biventricular pacing. Thus, responders of LV reverse remodeling were associated with improvement in clinical status, cardiac function, and systolic synchronicity. Direct assessment of systolic synchronicity by tissue Doppler imaging is highly accurate in predicting responders to therapy.

Aged↗