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Jeffrey W H Fung

Publications and source records attributed to Jeffrey W H Fung.

15 recordsLinked to original sources
PubMed2006

Prognostic value of renal function in patients with cardiac resynchronization therapy.

BACKGROUND: Renal insufficiency is prevalent in patients with heart failure and indicates poor prognosis. We examine (i) the relationship between left ventricular (LV) reverse remodeling (RR) and renal function and (ii) the prognostic value of renal function in patients receiving cardiac resynchronization therapy (CRT). METHODS: The relationship between LV-RR, defined as a 10% reduction in LV end-systolic volume, and renal function was examined in 85 consecutive patients receiving CRT. Echocardiographic assessment and renal function tests were performed before and 3 months after CRT. All-cause mortality and the composite of mortality or heart failure hospitalization between those with preserved or deteriorated renal function at 3 months were assessed by Kaplan Meier analysis. RESULTS: There was a slight improvement in glomerular filtration rate (GFR) in those with LV-RR (n=44; 51.7+/-20.4 vs. 54.2+/-19.1 ml/min/1.73 m2; p=0.024) while a significant deterioration (n=41; 61.9+/-17 vs. 48.8+/-13.0 ml/min/1.73 m2; p<0.001) was observed in those without LV-RR. The change (Delta) in GFR was significantly correlated with DeltaLV end-systolic/diastolic volumes and DeltaLV ejection fraction. After follow up of 856.4+/-576.8 days, patients with preserved renal function had significant lower all-cause mortality (log rank chi2=4.82, p=0.029) and the composite endpoints (log rank chi2=5.04, p=0.025). CONCLUSION: Preservation of renal function was observed in patients with systolic heart failure and renal insufficiency responding to CRT and provided prognostic information. A rapid decline in renal function after CRT was associated with worse clinical outcomes.

Aged↗
PubMed2006

Effect of cardiac resynchronization therapy in patients with moderate left ventricular systolic dysfunction and wide QRS complex: a prospective study.

BACKGROUND: We sought to investigate the effect of cardiac resynchronization therapy (CRT) on disease progression in patients with moderate left ventricular (LV) systolic dysfunction. METHODS AND RESULTS: This is a prospective study to explore the effect of CRT in 15 optimally treated patients (age: 66.1 +/- 12.8 years; male = 13) with New York Heart Association (NYHA) class III, LV ejection fraction >35% and <45% and QRS duration >120 msec. Echocardiographic examination and standard heart failure assessment was performed before and 3 months after CRT implantation. The magnitude of echocardiographic remodeling measurements was compared with 30 age, sex, NYHA class, and heart failure etiology matched patients with conventional CRT indication. There were significant reductions in LV end-systolic (86.2 +/- 24.1 to 69.7 +/- 22.2 mL, P < 0.01)/end-diastolic (135.5 +/- 36.8 to 120.5 +/- 34.6 mL, P < 0.01) volumes, improvement in LV ejection fraction (39.1 +/- 2.2 to 44.2 +/- 5.5%, P = 0.01), and NYHA class (3.0 +/- 0.0 to 2.07 +/- 0.46, P < 0.001). There was no difference in changes in LV volumes, ejection fraction, NYHA class, and exercise capacity before and after CRT between the study and conventional groups except for greater improvement in the quality of life score in the conventional group. CONCLUSION: In this prospective study, significant LV reverse remodeling by CRT in those with a wide QRS complex and moderate LV systolic dysfunction was observed. Further studies to explore the benefit of CRT in patients with less severe heart failure are recommended.

Aged↗
PubMed2006

Atrial strain rate echocardiography can predict success or failure of cardioversion for atrial fibrillation: a combined transthoracic tissue Doppler and transoesophageal imaging study.

AIMS: The purpose of this study was to assess the feasibility of measuring left atrial dysfunction with tissue Doppler imaging derived strain rate and to explore its role in predicting the maintenance of sinus rhythm after cardioversion for atrial fibrillation. METHODS AND RESULTS: Strain rate (SR) and tissue Doppler imaging (TDI) were performed with offline analysis of the basal left atrial wall (LA). SR detected a systolic (Ssr) and early diastolic (Esr) deformation induced by ventricular motion. LA dimensions and volume were measured. Left atrial appendage emptying (LAA_EV) and filling (LAA_FV) velocities were also obtained by transesophageal echocardiography. 27 healthy age-matched controls and 42 patients with AF before cardioversion were studied. Patients were grouped into (1): those who remained in sinus rhythm (group S, n=12) and (2) those who either failed cardioversion or reverted to AF within 4 weeks (group F, n=30). LA dimensions were significantly larger and atrial Esr was significantly lower in group F than group S (all p<0.01). LAA_EV and LAA_FV were not different between groups S and F. Multivariate regression analysis showed that a lower Esr and larger transverse LA diameter (LADtr) were independent predictors of failure of cardioversion (HR, 95% CI: 0.36, 0.14-0.88 and 2.85, 1.33-6.10, respectively). Esr combined with LADtr improved the sensitivity and specificity for predicting successful cardioversion. CONCLUSIONS: SR can be measured in the basal LA wall in atrial fibrillation and the magnitude of the early diastolic SR could predict the success of cardioversion and the likelihood of maintenance of sinus rhythm.

Adult↗
PubMed2006

Suboptimal medical therapy in patients with systolic heart failure is associated with less improvement by cardiac resynchronization therapy.

BACKGROUND: Proven medical therapy is under-prescribed in heart failure (HF) for various reasons. Cardiac resynchronization therapy (CRT) is of proven value in selected patients with HF; however, the degree of benefit in those without the optimal therapy is not clear. METHODS: This is a retrospective study comparing the effect of CRT in 30 patients without optimal combination therapy (group 1; 10 (33%) without ACEi or equivalent and 25 (83%) without beta-blockers) to an age, sex, ejection fraction (EF) and New York Heart Association (NYHA) class matched control but with the combination (group 2; n=30) at baseline. All patients were in NYHA class III or IV with EF < or = 35% and QRS interval > or = 120 ms. Echocardiographic examination and N-terminal pro-brain natriuretic peptide (NT pro-BNP) levels before and 3 months after CRT were compared between the two groups. The composite endpoints of HF hospitalization or death during follow-up were compared by Kaplan-Meier analysis. RESULTS: There were significantly less improvement in EF (+4.0+/-2.5% vs +10.1+/-3.2%; p<0.05) and degree of reverse remodeling in group 1 after 3 months. Patients in group 1 had significantly higher level of NT pro-BNP levels at 3 months (2221+/-2001 pg/mL vs 1038+/-905 pg/mL; p<0.001) and higher rates of HF hospitalization or death (53.3% vs 23.3%; Log rank chi2 5.52; p=0.019). CONCLUSION: Patients receiving CRT but without optimal medical therapy were associated with less echocardiographic and clinical improvement. Optimal medical therapy, if tolerated, before CRT is necessary.

Aged↗
PubMed2005

Cardiac resynchronization therapy: Part 1--issues before device implantation.

Cardiac resynchronization therapy (CRT) has been used extensively over the last years in the therapeutic management of patients with end-stage heart failure. Data from 4,017 patients have been published in eight large, randomized trials on CRT. Improvement in clinical end points (symptoms, exercise capacity, quality of life) and echocardiographic end points (systolic function, left ventricular size, mitral regurgitation) have been reported after CRT, with a reduction in hospitalizations for decompensated heart failure and an improvement in survival. However, individual results vary, and 20% to 30% of patients do not respond to CRT. At present, the selection criteria include severe heart failure (New York Heart Association functional class III or IV), left ventricular ejection fraction <35%, and wide QRS complex (>120 ms). Assessment of inter- and particularly intraventricular dyssynchrony as provided by echocardiography (predominantly tissue Doppler imaging techniques) may allow improved identification of potential responders to CRT. In this review a summary of the clinical and echocardiographic results of the large, randomized trials is provided, followed by an extensive overview on the currently available echocardiographic techniques for assessment of LV dyssynchrony. In addition, the value of LV scar tissue and venous anatomy for the selection of potential candidates for CRT are discussed.

Cardiac Output, Low↗
PubMed2005

Cardiac resynchronization therapy: Part 2--issues during and after device implantation and unresolved questions.

Encouraged by the clinical success of cardiac resynchronization therapy (CRT), the implantation rate has increased exponentially, although several limitations and unresolved issues of CRT have been identified. This review concerns issues that are encountered during implantation of CRT devices, including the role of electroanatomical mapping, whether CRT implantation should be accompanied by simultaneous atrioventricular nodal ablation in patients with atrial fibrillation, procedural complications, and when to consider surgical left ventricular lead positioning. Furthermore, (echocardiographic) CRT optimization and assessment of CRT benefits after implantation are highlighted. Also, controversial issues such as the potential value of CRT in patients with mild heart failure or narrow QRS complex are addressed. Finally, open questions concerning when to combine CRT with implantable cardioverter-defibrillator therapy and the cost-effectiveness of CRT are discussed.

Atrial Fibrillation↗
PubMed2005

Strain rate imaging differentiates transmural from non-transmural myocardial infarction: a validation study using delayed-enhancement magnetic resonance imaging.

OBJECTIVES: The aim of this study was to determine if strain rate imaging (SRI) correlates with the transmural extent of myocardial infarction (MI) measured by contrast-enhanced magnetic resonance imaging (Ce-MRI). BACKGROUND: Identification of the transmural extent of myocardial necrosis and degree of non-viability after acute MI is clinically important. METHODS: Tissue Doppler echocardiography with SRI and Ce-MRI were performed in 47 consecutive patients with a first acute MI between days 2 and 6 and compared to 60 age-matched healthy volunteers. Peak myocardial velocities and peak myocardial deformation strain rates were measured. Location and size of the infarct zone was confirmed by Ce-MRI using the delayed enhancement technique with a 16-segment model. RESULTS: Contrast-enhanced MRI identified transmural infarction in 21 patients, non-transmural infarction in 15 (mean transmurality of infarct 72.3 +/- 10.6%), and another 11 patients with subendocardial infarction (<50% transmural extent of the left ventricular wall). Peak systolic strain rate (SRs) of the transmural infarction segments was significantly lower compared to normal myocardium or with non-transmural infarction segments (both p < 0.0005). A cutoff value of SRs >-0.59 s(-1) detected a transmural infarction with high sensitivity (90.9%) and high specificity (96.4%), and -0.98 s(-1) >SRs >-1.26 s(-1) distinguished subendocardial infarction from normal myocardium with a sensitivity of 81.3% and a specificity of 83.3%. CONCLUSIONS: Peak myocardial deformation by SRI can differentiate transmural from non-transmural MI, and it allows noninvasive determination of transmurality of the scar after MI and thereby the extent of non-viable myocardium.

Acute Disease↗
PubMed2005

Do metoprolol and carvedilol have equivalent effects on diurnal heart rate in patients with chronic heart failure?

BACKGROUND: Carvedilol exerted a greater reduction in mortality than metoprolol tartrate in the Carvedilol or Metoprolol European Trial (COMET). However, it is unclear if the degree and time course of beta1-blockade during a 24-h period was similar with each agent at the doses used. Therefore we analyzed 24-h ECG Holter recordings from a study which compared the long-term clinical efficacy of metoprolol tartrate to carvedilol in chronic heart failure patients using the same dosing regimen as in COMET. METHODS AND RESULTS: Fifty-one patients with chronic heart failure with a mean LVEF 26+/-1.8% were randomized in a double-blind fashion to receive metoprolol tartrate 50 mg bid or carvedilol 25 mg bid. 24-h ECG monitoring (Holter) was performed at baseline, 12 weeks and 1 year. Adequate quality recordings for analysis were obtained from 43 subjects at baseline, 42 at 12 weeks and 29 subjects at 1 year. Both drugs produced a fall in average 24-h heart rate from baseline at 12 weeks and at 1 year: metoprolol 88+/-3 to 71+/-2 and 69+/-3 bpm; carvedilol 83+/-3 to 70+/-2 and 70+/-3 bpm respectively (all p<0.001). The pattern of suppression of heart rate during the 24-h period was similar for both drugs. CONCLUSION: Metoprolol tartrate 50 mg bid and carvedilol 25 mg bid had similar effects on 24-h heart rate. This result suggests that the degree of beta1-blockade produced by these two drugs in these doses is comparable and the superior survival effect of carvedilol compared to metoprolol seen in COMET is likely to be due to actions of carvedilol other than beta1-blockade.

Adrenergic beta-Antagonists↗
PubMed2004

Effect of N-acetylcysteine for prevention of contrast nephropathy in patients with moderate to severe renal insufficiency: a randomized trial.

BACKGROUND: The effect of N-acetylcysteine (NAC) to prevent contrast nephropathy (CN) in patients with moderate to severe renal insufficiency undergoing coronary angiography or interventions is not clear. METHODS: This is a prospective, open-label, randomized, controlled trial. Ninety-one consecutive patients with a serum creatinine level of 1.69 to 4.52 mg/dL (149 to 400 micromol/L) undergoing coronary procedures were recruited and randomly assigned to administration of either oral NAC, 400 mg, thrice daily the day before and day of the contrast procedure (the NAC group) or no drug (the control group). Serum creatinine was measured before and 48 hours after contrast exposure. The primary end point of this study was the development of CN, defined as an increase in serum creatinine concentration of 0.5 mg/dL or greater (> or =44 micromol/L) or a reduction in estimated glomerular filtration rate (GFR) of 25% or greater of the baseline value 48 hours after the procedure. RESULTS: There were no significant differences between the 2 groups (46 patients, NAC group; 45 patients, control group) in baseline characteristics or mean volume of contrast agent administered. Six patients (13.3%) in the control group and 8 patients (17.4%) in the NAC group developed CN (P = 0.8). Serum creatinine levels increased from 2.27 +/- 0.54 to 2.45 +/- 0.65 mg/dL (201 +/- 48 to 217 +/- 57 micromol/L; P = 0.003) in the NAC group and 2.37 +/- 0.61 to 2.40 +/- 0.70 mg/dL (210 +/- 54 to 212 +/- 62 micromol/L; P = 0.6) in the control group. The increase in serum creatinine levels between the 2 groups had no difference (P = 0.7). Estimated GFR decreased from 30.3 +/- 8.4 to 28.1 +/- 8.4 mL/min (P = 0.01) in the NAC group and 28.4 +/- 8.6 to 27.5 +/- 8.8 mL/min (P = 0.3) in the control group. The decline in estimated GFR between the 2 groups had no difference (P = 0.7). CONCLUSION: In the current study, oral NAC had no effect on the prevention of CN in patents with moderate to severe renal insufficiency undergoing coronary angiography or interventions. However, the sample size of our present study is small. Our findings highlight the need for a large-scale, randomized, controlled trial to determine the exact beneficial effect of NAC.

Acetylcysteine↗
PubMed2003

Effect of beta blockade (carvedilol or metoprolol) on activation of the renin-angiotensin-aldosterone system and natriuretic peptides in chronic heart failure.

Beta blockers are known to suppress renin release in hypertension and in patients taking angiotensin-converting enzyme (ACE) inhibitors. This study sought to explore the effect of additional beta blockade on neurohumoral modulation in patients with severe heart failure (HF) who received ACE inhibitors. Forty-nine patients with chronic HF who received ACE inhibitors were given metoprolol 50 mg or carvedilol 25 mg twice daily after a 4-week dose titration period in addition to standard therapy in a prospective trial. Samples of plasma renin activity (PRA), aldosterone, aminoterminal B-type natriuretic peptide (N-BNP), and atrial natriuretic peptide (ANP) were taken at baseline and at 4, 12, and 52 weeks after starting therapy. Treatment with either beta blocker significantly lowered PRA at 4 weeks compared with baseline (-2.0 +/- 0.6 nmol/L/hour, p = 0.006), but at 12 weeks, PRA had reduced to -1.1 +/- 0.6 nmol/L/hour (p = 0.08), but at 52 weeks, it was not significantly different from baseline (+1.05 +/- 0.6 nmol/L/hour, p = 0.13). Aldosterone levels did not change significantly from baseline at 4 or 12 weeks, although there was a nonsignificant trend for lower levels at 52 weeks (baseline 232 +/- 154 pmol/L, 52 weeks 192 +/- 100 pmol/L, p = 0.09). There was significant reduction in N-BNP and ANP together with an improvement in symptom and left ventricular systolic function at 1-year follow-up. These results indicate that the suppressive effect of beta blockers on PRA in patients with HF taking ACE inhibitors is temporary, and that there is no significant effect on serum aldosterone levels.

Adrenergic beta-Antagonists↗
PubMed2003

Role of beta-blocker therapy in heart failure and atrial fibrillation.

Heart failure is a serious disorder associated with substantial morbidity and mortality. Approximately 15-30% patients with systolic heart failure are in atrial fibrillation and the proportion increases with severity of heart failure. Patients with heart failure and atrial fibrillation have worse outcome than those in sinus rhythm. Beta-blockers, together with angiotensin-converting enzymes inhibitors, are the standard therapy in patients with chronic heart failure. Retrospective studies have suggested that despite the improvement in left ventricular systolic function after treatment with beta-blockers, the exercise capacity and symptoms in those heart failure patients with atrial fibrillation was not improved as much as those in sinus rhythm. Moreover, the use of bisoprolol in the Cardiac Insufficiency Bisoprolol Study II, unlike those in sinus rhythm, failed to produce any survival benefit in patients with poor systolic function and atrial fibrillation. It seems that those patients with heart failure and atrial fibrillation may have different response to beta-blocker therapy. Prospective trials to clarify the impact of beta-blocker therapy and the optimal therapeutic strategy in this high-risk group of patients are warranted.

Adrenergic beta-Antagonists↗
PubMed2003

Ablation of nonsustained or hemodynamically unstable ventricular arrhythmia originating from the right ventricular outflow tract guided by noncontact mapping.

Conventional activation or pacemapping is effective in guiding ablation of ventricular tachyarrhythmia originating from right ventricular outflow tract (RVOT). However, in selected patients with hemodynamically unstable or nonsustained tachycardia, noncontact mapping may be an effective alternative method to guide ablation in RVOT. Five patients with symptomatic hypotension during ventricular tachycardia (VT) or nonsustained tachyarrhythmia originating from the RVOT had radiofrequency ablation guided by noncontact mapping. All patients had a history of syncope and the tachyarrhythmias were refractory to antiarrhythmic therapy. Four patients had spontaneous sustained VT of a cycle length from 250 to 300 ms and one had symptomatic ventricular ectopic beats. Two patients were diagnosed to have arrhythmogenic right ventricular cardiomyopathy (ARVC). Sustained VT with hypotension was induced in two patients and nonsustained VT in three patients. Isopotential color maps were used to locate the earliest activation site of the tachyarrhythmia in RVOT. Three patients had tachyarrhythmia exit sites at the septal region and two at lateral region of RVOT. Low voltage area and diastolic activity were detected in the two patients with ARVC. Radiofrequency ablation guided by noncontact mapping was performed during sinus rhythm in all patients. The number of ablation attempts ranged from 1 to 14. After follow-up for 12 +/- 5.8 months, there was no recurrence of tachyarrhythmia and syncope in all five patients. Noncontact mapping is a safe and effective alternative method to guide ablation of hemodynamically unstable or nonsustained ventricular arrhythmia originating from RVOT.

Adult↗
PubMed2002

Is beta-blockade useful in heart failure patients with atrial fibrillation? An analysis of data from two previously completed prospective trials.

BACKGROUND: Beta-adrenergic blockade is of proven value in chronic heart failure. It is uncertain, however, if beta-blockade provides a similar degree of clinical benefit for heart failure patients with atrial fibrillation (AF) as those in sinus rhythm (SR). AIMS: To compare the effectiveness of beta blockade in patients with heart failure and AF. METHODS: Patients with chronic heart failure were randomized to treatment (double blind) with metoprolol 50 mg twice daily or carvedilol 25 mg twice daily in addition to standard therapy. Response was assessed after 12 weeks by a quality of life questionnaire, New York Heart Association class, exercise capacity (6-min walk test), radionucleotide ventriculography for LVEF, 2-D echocardiography measurement of left ventricular (LV) dimensions and diastolic filling and 24-h electrocardiograph monitoring to assess heart rate changes. RESULTS: Both beta-blockers produced significant improvements in LVEF in both the SR group: (+6+/-10% at 12-week, P<0.001) and the AF group: (+11+/-9% at 12-week, P<0.05). However, significant improvement in symptoms (P<0.001) and exercise capacity (P<0.001) were observed only in the SR group but not in the AF group despite a significant improvement in LVEF. CONCLUSION: Beta-blockers were effective in improving LV ejection fraction in chronic heart failure patients in either SR or AF but had less effect on symptoms and exercise capacity in those with AF.

Adrenergic beta-Antagonists↗
PubMed2002

Severe obstructive sleep apnea is associated with left ventricular diastolic dysfunction.

INTRODUCTION: Hypertension is common in patients with obstructive sleep apnea (OSA). However, the effect of OSA on ventricular function, especially diastolic function, is not clear. Therefore, we have assessed the prevalence of diastolic dysfunction in patients with OSA and the relationship between diastolic parameters and severity of OSA. METHODS: Sixty-eight consecutive patients with OSA confirmed by polysomnography underwent echocardiography. Diastolic function of the left ventricle was determined by transmitral valve pulse-wave Doppler echocardiography. Various baseline characteristics, severity of OSA, and echocardiographic parameters were compared between patients with and without diastolic dysfunction. RESULTS: There were 61 male and 7 female patients with a mean age of 48.1 +/- 11.1 years, body mass index of 28.5 +/- 4.3 kg/m(2), and apnea/hypopnea index (AHI) of 44.3 +/- 23.2/h (mean +/- SD). An abnormal relaxation pattern (ARP) in diastole was noted in 25 patients (36.8%). Older age (52.7 +/- 8.9 years vs 45.1 +/- 11.3 years, p = 0.005), hypertension (56% vs 20%, p = 0.002), and a lower minimum pulse oximetric saturation (SpO(2)) during sleep (70.5 +/- 17.9% vs 78.8 +/- 12.9%, respectively; p = 0.049) were more common in patients with ARP. By multivariate analysis, minimum SpO(2) < 70% was an independent predictor of ARP (odds ratio, 4.34; 95% confidence interval, 1.23 to 15.25; p = 0.02) irrespective of age and hypertension. Patients with AHI > or = 40/h had significantly longer isovolumic relaxation times than those with AHI < 40/h (106 +/- 19 ms vs 93 +/- 17 ms, respectively; p = 0.005). CONCLUSION: Diastolic dysfunction with ARP was common in patients with OSA. More severe sleep apnea was associated with a higher degree of left ventricular diastolic dysfunction in this study.

Diastole↗