[The research of liver failure in Banna miniature pigs caused by amanita exitialis]

Objective: To explore the characteristics of Banna miniature pig liver failure induced by amanita exitialis. Methods: From September to October 2020, a reverse high performance liquid chromatography (RP-HPLC) method was used to determine the toxin content of amanita exitialis solution, and 2.0 mg/kg amanita exitialis solution (α-amanitins+β-amanitins) was administered orally to Banna miniature pigs. Toxic symptoms, blood biochemical indexes and histopathological changes of liver, heart and kidney were observed at each time point. Results: All Banna miniature pigs died within 76 h of exposure, and different degrees of digestive tract symptoms such as nausea, vomiting and diarrhea appeared between 6 and 36 h. The biochemical indexes of alanine aminotransferase, aspartate aminotransferase, total bilirubin, lactate dehydrogenase, myoglobin, creatine kinase isoenzyme, blood urea nitrogen and creatinine increased significantly at 52 h after exposure, and the differences were statistically significant compared with 0 h (P<0.05). The bleeding of liver and heart was obvious under macroscopic and microscopic observation, hepatocyte necrosis, renal tubule epithelial cell swelling. Conclusion: Large dose of amanita exitialis can cause acute liver failure of Banna miniature pigs, which is in line with the pathophysiological characteristics of acute liver failure, and lays a foundation for further research on the toxic mechanism and detoxification drugs of amanita exitialis induced liver failure.

[Investigation on a case of Amanita neoovoidea poisoning]

This paper reported a case of poisoning caused by ingestion of Amanita neoovoidea. The patient experienced nausea, vomiting, oliguria, acute renal function injury, and was discharged after symptomatic support treatment and blood purification treatment. Given the different toxicity of different mushrooms, species identification of poisonous mushrooms can help clinicians in diagnosis and treatment.

[Three cases of mushroom poisoning caused by lethal Amanita species]

Mushroom poisoning with amatoxins can cause liver dysfunction in patients, and death in severe cases. The amatoxins detection by enzyme-linked immunosorbent assay (ELISA) can help early clinical diagnosis. Three patients were identified as α-amatoxin containing mushroom poisoning by ELISA. The first symptoms of patients was gastrointestinal symptoms, and liver function damage occured later. One patient gave up treatment and died. After received supportive treatments such as adsorption of toxins, catharsis, fluid supplementation to promote toxin metabolism and liver protection, 2 patients were recovered and discharged.

P914 Changes of echocardiographic parameters in primary mitral regurgitation and determinants of symptom: an assessment from the Asian valve registry data

[Background]Clinicians often have a difficulty in determining the presence of mitral regurgitation (MR)-relatedsymptoms because of subjectivity.However, there are few actual measurement data for echocardiographic left ventricular (LV) and left atrial (LA) size related to the severity of MR and the relationship between MR-related symptoms and these echocardiographic parameters.

[Purpose] The purpose of this study was to clarify actual values for echocardiographic parameters related to severity of MR and determinant factors of MR-related symptoms.

[Methods] Among patients enrolled in the Asian Valve Registry, we investigated 778 consecutive patients with primary MR showing sinus rhythm. Symptoms were determined by NYHA (≤ II or ≥ III).

[Results]MR severity was mild in 106, moderate in 285, and severe in 387 patients. LA volume index, LV end-diastolic diameter, and LV mass index increased with increasing MR grade [LA volume index: 47.9 (mild), 56.2 (moderate), and 64.9 ml/m2(severe) (p &lt; 0.001), LV end-diastolic diameter: 51.2, 54.5, 58.1 mm (p &lt; 0.001), and LV mass index: 101, 109, 123 g/m2(p &lt; 0.001)]. Regarding moderate and severe MR, 70 patients (10.4%) were symptomatic. Table shows multivariable analysis for being symptomatic in moderate and severe MR patients. LV mass index (p = 0.040), ejection fraction (p &lt; 0.001), female gender (p = 0.004), and heart rate (p = 0.007) were independent factors for MR-related symptoms.

[Conclusions] LV and LA parameters on echocardiography worsened as MR severity progressed. Larger LV mass index and lower ejection fraction were independent determinant factors for MR-related symptoms. We should also pay attention to LV hypertrophy in patients with primary MR.

Determinant factors for mitral regurgita Model 1 Model 2 OR (95% CI) P-value OR (95% CI) P-value Age, per 1-y increment 1.03 (1.00-1.05) 0.035 1.02 (0.99-1.05) 0.053 Sex (female) 2.23 (1.20-4.16) 0.011 2.28 (1.31-3.98) 0.004 Hear rate, per 1 bpm increment 1.03 (1.00-1.05) 0.025 1.03 (1.01-1.05) 0.007 LVDs index, per 1 mm increment 0.99 (0.90-1.09) 0.90 EF, per 1% increment 0.95 (0.92-0.99) 0.019 0.96 (0.93-0.98) &lt;0.001 LV mass index, per 10 g/m2increment 1.12 (1.01-1.25) 0.033 1.09 (1.005-1.18) 0.040 LA volume index, per 10 mL/m2increment 0.96 (0.90-1.03) 0.23 E wave, per 1cm/s increment 1.81 (0.70-4.66) 0.23 TR pressure gradient &gt;40 mmHg 2.11 (0.97-4.57) 0.057 Hypertention 1.40 (0.75-2.63) 0.29

Wearable cuff-less PTT-based system for overnight blood pressure monitoring

A wearable cuff-less pulse transit time (PTT) based monitoring device is developed for ambulatory blood pressure (BP) monitoring. Ten healthy subjects (aged 27 ± 4 years old) underwent 24-hour ambulatory BP monitoring using 1) a standard brachial cuff-based oscillometric device as reference and 2) the proposed cuff-less PTT measuring system. Raw PTT and BP measurements were linearly interpolated and then smoothed by a low-pass filter to remove aliasing effect caused by the low sampling rate and synchronized. Resampled PTT and BP were assessed for correlation using correlation coefficients and Bland-Altman plots. Our study showed that PTT estimated systolic BP most accurately within 4.8 ± 4.3 mmHg on healthy young subjects during sleep time. We conclude from this study that the proposed cuff-less PTT-based BP monitoring system has potential to be a less intrusive alternative to standard oscillometric method for long-term overnight BP monitoring.

Initial antihypertensive prescription and switching: a 5 year cohort study from 250,851 patients

Purpose

Adverse effects of antihypertensive therapy incur substantial cost. We evaluated whether any major classes of antihypertensive drugs were significantly associated with switching as a proxy measure of medication side effects in a large Chinese population in Hong Kong.

Methods

From a clinical database, all adult patients newly prescribed an antihypertensive mono-therapy in Hong Kong between the years 2001–2003 and 2005 were included. Those who paid only one visit, died or stayed in the cohort for <180 days after the prescription, or prescribed more than one antihypertensive agent were excluded. The factors associated with switching at 180 days were evaluated by multivariate regression analyses. Age, gender, payment status, service type, district of residence, drug class, systolic and diastolic blood pressure levels were predictor variables.

Results

From 250,851 subjects, 159,813 patients were eligible. A total of 6,163 (3.9%) switched their medications within 180 days. Patients prescribed thiazide diuretics had the highest switching rate (5.6%), followed by ACEIs (4.5%), CCBs (4.4%) and beta-blockers (3.2%). When compared with ACEIs, patients on thiazide diuretics were significantly more likely to be switchers (adjusted odds ratio [AOR] 1.49, 95% C.I. 1.31–1.69, p<0.001), whilst patients prescribed CCBs and beta-blockers were similarly likely to have switching. Following these patients up for 5 years showed that thiazide had the most marked increase in switching rate.

Conclusions

The higher rates of switching among thiazide diuretics in this study might raise a probably greater incidence of their adverse effects in this Chinese population, yet other factors might also influence switching rates. Patients prescribed thiazide diuretics for longer term should be observed for their intolerability.

Drug adherence and the incidence of coronary heart disease- and stroke-specific mortality among 218,047 patients newly prescribed an antihypertensive medication: a five-year cohort study

Background

Randomized trials have shown that optimal adherence to antihypertensive agents could protect against cardiovascular diseases, but whether adherence reduces cardiovascular deaths in community settings has not been explored so fully. This study evaluates the association between antihypertensive adherence and cardiovascular (coronary heart disease and stroke) mortality in the primary care settings.

Methods

From a territory-wide database in Hong Kong, we included all patients who were prescribed their first-ever antihypertensive agents in the years between 2001 and 2005 from the public healthcare sector. All patients were followed up for five years, and assigned as having poor (Proportion of Days Covered [PDC] < 40%), intermediate (40–79%), and high (≥ 80%) adherence to antihypertensive agents. The association between antihypertensive adherence and cardiovascular mortality was evaluated by using the Cox proportional hazard models.

Results

From a total of 218,047 eligible patients, 3825 patients (1.75%) died of cardiovascular disease within five years after having received their first-ever antihypertensive agents. The proportions of patients having poor, intermediate, and high medication adherence were 32.9%, 12.1%, and 55.0%, respectively. Higher adherence levels at PDC 40%–79% (HR = 0.46, 95% C.I. 0.41–0.52, p < 0.001) and ≥ 80% (HR = 0.91, 95% C.I. 0.85–0.98, p = 0.012) were significantly less likely to be associated with mortality than the poor adherence (PDC0.040) group.

Conclusions

Better antihypertensive adherence was associated with lower cardiovascular mortality. This highlights the need to promote adherence through strategies which have been proved to be effective in clinical settings.

SLICC/ACR damage index independently associated with left ventricular diastolic dysfunction in patients with systemic lupus erythematosus

Left ventricular (LV) diastolic dysfunction has been reported in both active and inactive systemic lupus erythematosus (SLE) patients without clinical evidence of cardiovascular disease. However, the relationship between the long-term inflammatory burden reflected by the SLICC/ACR damage index and LV diastolic function has not been studied. Eighty-two SLE patients and 82 controls matched for age, sex, body mass index, blood pressure and heart rate underwent echocardiography with tissue Doppler imaging (TDI). LV diastolic function was estimated by the myocardial early diastolic velocity (E') at the lateral annulus. There were 51 patients (62.2%) with nephritis, 23 patients (28.0%) with hypertension, 21 patients (25.6%) with vasculitis, 16 patients (19.5%) with pulmonary hypertension, 4 patients (4.9%) with cerebrovascular disease and 2 patients (2.4%) with diabetes mellitus. Sixty-two patients (75.6%) were taking prednisone and 35 patients (42.7%) used a immunosuppressant. Forty-five patients (54.8%) had active disease and suffered from disease-related end-organ damage. Patients with SLICC/ACR damage index ≥1 had more evidence of LV diastolic dysfunction with lower lateral annulus E' (9.6 ± 3.4 vs 12.9 ± 3.5 cm/s, p < 0.001) than those without. In addition, the proportion of patients with abnormal LV myocardial relaxation (defined as lateral E' < 10.0 cm/s) (51.1% vs 16.2%, χ(2) = 10.8, p = 0.001) were significantly higher. Multivariate analysis showed that the SLICC/ACR damage index ≥1 was independently associated with LV diastolic dysfunction (OR = 3.80, 95%CI: 1.21-11.95, p = 0.023) after adjusting for hypertension, disease duration and medical therapy. This may suggest that the overall inflammatory burden in SLE, as reflected by SLICC/ACR damage index, is associated with the development of diastolic dysfunction in SLE patients.

Genotoxicity of fenpropathrin and fenitrothion on root tip cells of Vicia faba

The genotoxicity of fenpropathrin and fenitrothion on root tip cells of Vicia faba was studied. The symptoms were investigated about the mitotic index, the micronucleus frequency and chromosomal aberration frequency of root tip cells of Vicia faba which were induced by different concentrations of fenpropathrin and fenitrothion (1 × 10(-10)-1 × 10(-2) g L(-1)). Results showed that fenpropathrin and fenitrothion could induce the micronucleus of root tip cells of Vicia faba. It occurred in a dose-dependent manner. Peaks were observed at 1 × 10( -6) g L(-1) fenpropathrin and 1 × 10(-4) g L(-1) fenitrothion, and micronucleus frequency reached 14.587 ± 1.511‰ and 14.164 ± 1.623‰, respectively. From 1 × 10(-10) g L(-1) to 1 × 10( -6) g L(-1) fenpropathrin and 1 × 10(-4) g L(-1) fenitrothion, the micronucleus frequency increased with the increase of the concentrations, but beyond this range, the micronucleus frequency decreased with the further increase of the concentrations. A similar trend was observed for mitotic index. Moreover, fenpropathrin and fenitrothion could induce various types of chromosome aberration, such as lagging chromosomes, chromosome fragment, chromosome bridge, multipolar, nuclear buds, karyorrhexis, etc.

Increased arterial stiffness correlated with disease activity in systemic lupus erythematosus

To evaluate the relationships between arterial stiffness, disease activity and end-organ damage in systemic lupus erythematosus (SLE), non-invasive vascular assessments were made on 32 female SLE patients and 32 female normal controls. The patients had significantly increased brachial-ankle pulse wave velocity (PWV) (13.06 +/- 1.79 vs. 11.50 +/- 1.00 m/s; P < 0.001), heart-ankle PWV (8.98 +/- 1.16 vs. 7.88 +/- 0.73 m/s; P < 0.001), carotid augmentation index (AI) (21.6 +/- 17.2% vs. 5.4 +/- 14.0%; P = 0.001) and carotid intima-medial thickness (IMT) (0.753 +/- 0.132 vs. 0.644 +/- 0.092 mm; P = 0.002) when compared with controls. The disease activity and organ damage were evaluated by SLE disease activity index (SLEDAI) and systemic lupus international collaborating clinics (SLICC) damage index. Patients with active disease (SLEDAI > or = 3) had significantly higher carotid AI (34.4 +/- 9.7% vs. 17.8 +/- 17.3%, P < 0.05) than stable ones (SLEDAI < 3) and those with organ damage (SLICC > or = 1) had significantly higher heart-ankle PWV (9.69 +/- 1.13 vs. 8.61 +/- 1.02 m/s, P < 0.05) than those with SLICC = 0. After making adjustments for age, body mass index (BMI) and blood pressure, carotid AI was found to show correlation with SLEDAI and haPWV with SLICC. A carotid AI value of 33.3% identified SLEDAI > or = 3 with a sensitivity of 83% and a specificity of 80%, whereas a heart-ankle PWV value of 9.0 m/s identified SLICC > or = 1 with a sensitivity of 91% and a specificity of 67%. In conclusion, SLE was an independent risk factor of sub-clinical atherosclerosis and arterial stiffness may identify the presence of active disease.

Rationale and design of a prospective trial to assess the sensitivity and positive predictive value of implantable intrathoracic impedance monitoring in the prediction of heart failure hospitalizations: the SENSE-HF study

BACKGROUND

Intrathoracic impedance monitoring is a new diagnostic tool for patients with heart failure that may aid early identification of decompensation and pulmonary congestion.

METHODS AND RESULTS

The Sensitivity of the InSync Sentry feature for the Prediction of Heart Failure (ie, SENSE-HF) trial is a prospective multicenter international study designed to evaluate the sensitivity and positive predictive value (PPV) of the intrathoracic impedance diagnostic tool, OptiVol, present in Medtronic implantable devices. A total of 500 patients will be enrolled in the trial, with follow-up for up to 24 months. The study has 3 phases. Phase I is double-blind, and evaluates retrospectively the sensitivity and PPV of the intrathoracic impedance data for the prediction of hospitalization with the signs and/or symptoms of pulmonary congestion. At 6 months, the patient enters Phase II, which evaluates the clinical utility of the nominal "alarm" threshold value for identification of episodes of decompensation. The patient enters the final phase (Phase III) after an episode of decompensation correctly identified by the Fluid Trend data ("true" positive alarm), with data collection on how physicians use the Fluid Trend data to influence management. An end point committee adjudicates health care utilizations events (hospitalizations and doctor visits) for their association with signs and/or symptoms of pulmonary congestion.

CONCLUSIONS

The study completed recruitment during 2008.

Effect of verapamil on prevention of atrial fibrillation in patients implanted with an implantable atrial defibrillator

BACKGROUND

The role of verapamil in the prevention of atrial fibrillation (AF) in patients with recurrent AF is unknown.

HYPOTHESIS

The aim of this study was to evaluate the effect of verapamil on the prevention of AF in patients implanted with an implantable atrial defibrillator (IAD).

METHODS

The effects of verapamil (240 mg/day) on the total duration of AF, number of AF recurrences, and number of cardioversions were prospectively evaluated in a randomized, crossover fashion over an 8-week period in 11 patients (9 men, 2 women; mean age: 60 +/- 6 years) implanted with an IAD.

RESULTS

Implantable atrial defibrillators successfully converted 13 of 14 (93%) spontaneous episodes of AF. There was no significant difference in the efficacy of cardioversion (86 vs. 100%, p = 0.8), the total duration of AF (173 +/- 198 vs. 270 +/- 241 h, p = 0.5), the number of AF episodes (8.5 +/- 9.0 vs. 9.3 +/- 10.2, p = 0.3), and the number of cardioversions (1.7 +/- 2.4 vs. 1.8 +/- 2.1 p = 0.7) with or without treatment with verapamil.

CONCLUSIONS

The results of the present study suggest that treatment with verapamil has no significant effect on the prevention of AF in patients treated with an LAD.

Translation and validation of two Chinese health-related quality of life instruments in patients with coronary heart disease

1. The Chinese version of the 27-item MacNew health-related quality of life (HRQL) questionnaire is a valid, reliable and responsive core coronary heart disease (CHD)-specific HRQL measure. It can be used to compare the health outcomes, burdens of illness, and treatment effectiveness in pure or mixed populations of patients with myocardial infarction, angina, or heart failure in clinical trials and in routine clinical practice. 2. The Chinese version of the 35-item Myocardial Infarction Dimensional Assessment Scale (MIDAS) did not perform as well. Although four of the seven subscales, which cover the physical and psychosocial aspects of HRQL, are psychometrically sound when used to evaluate HRQL among CHD patients with different cardiac diagnostic categories, the remaining three subscales covering treatment-related aspects are not. The latter had only weak validity and responsiveness, which may be due to cultural differences. 3. To improve the overall performance of the Chinese version of the MIDAS, further effort is required to clarify the treatment-related impact of CHD on well-being from the patient's perspective.

Independence of restrictive filling pattern and LV ejection fraction with mortality in heart failure: an individual patient meta-analysis

BACKGROUND

The Doppler echocardiographic restrictive mitral filling pattern (RFP) is an important prognostic indicator in patients with heart failure (HF), but the interaction between RFP, left ventricular ejection fraction (LVEF) and filling pattern remains uncertain.

AIMS

To determine whether the RFP is predictive of mortality independently of LVEF in patients with HF.

METHODS

Online databases were searched to identify studies assessing the relationship between prognosis and LV filling pattern in patients with HF. Individual patient data from 18 studies (3540 patients) were extracted and collated at the MeRGE Coordinating Centre (The University of Auckland).

RESULTS

Overall, RFP was associated with higher all-cause mortality than the non-restrictive filling pattern: hazard ratio 2.42 (95% CI 2.06, 2.83). In multivariable analysis the RFP, LVEF, NYHA class and age were independent predictors of mortality. The prevalence of the RFP was inversely related to LVEF but remained a predictor of mortality even in those patients with preserved LVEF.

CONCLUSIONS

The restrictive mitral filling pattern is a powerful predictor of mortality, independent of LVEF and age, in patients with HF. Doppler-derived LV filling patterns are an accessible marker from echocardiography that can readily be incorporated in risk stratification of all patients with HF.

Independent prognostic importance of a restrictive left ventricular filling pattern after myocardial infarction: an individual patient meta-analysis: Meta-Analysis Research Group in Echocardiography acute myocardial infarction

BACKGROUND

Restrictive mitral filling pattern (RFP), the most severe form of diastolic dysfunction, is a predictor of outcome after acute myocardial infarction (AMI). Low power has precluded a definite conclusion on the independent importance of RFP, especially when overall systolic function is preserved. We undertook an individual patient meta-analysis to determine whether RFP is predictive of mortality independently of LV ejection fraction (LVEF), end-systolic volume index, and Killip class in patients after AMI.

METHODS AND RESULTS

Twelve prospective studies (3396 patients) assessing the relationship between prognosis and Doppler echocardiographic LV filling pattern in patients after AMI were included. Individual patient data from each study were extracted and collated into a single database for analysis. RFP was associated with higher all-cause mortality (hazard ratio, 2.67; 95% CI, 2.23 to 3.20; P<0.001) and remained an independent predictor in multivariate analysis with age, gender, and LVEF. The overall prevalence of RFP was 20% but was highest (36%) in the quartile of patients with lowest LVEF (<39%) and lowest (9%) in patients with the highest LVEF (>53%; P<0.0001). RFP remained significant within each quartile of LVEF, and no interaction was found for RFP and LVEF (P=0.42). RFP also predicted mortality in patients with above- and below-median end-systolic volume index (1575 patients) and in different Killip classes (1746 patients). Importantly, when diabetes, current medication, and prior AMI were included in the model, RFP remained an independent predictor of outcome.

CONCLUSIONS

Restrictive filling is an important independent predictor of mortality after AMI regardless of LVEF, end-systolic volume index, and Killip class.

Particle image velocimetry measurements of three proximal anastomosis models under a pulsatile flow condition

This study was designed to examine the effects of the anastomotic angle on the flow and haemodynamic parameter distribution patterns of the proximal anastomoses, with emphasis on identifying site-specific haemodynamic features that could reasonably be expected to trigger the initiation and further development of anastomotic intimal hyperplasia. Particle image velocimetry measurements were carried out with three simplified glass proximal models under a physiological flow condition. The results revealed that the disturbed flow and the induced shear stress patterns including low recirculation flow, stagnation point, high wall shear stress, high temporal wall shear stress gradient, low time-averaged wall shear stress (TAWSS), and high oscillating shear index (OSI) occurred around the anastomotic joints and the flow field at proximal anastomosis was strongly affected by the anastomotic angle. Among the three models investigated, the 45° backward anastomosis is found to have a smaller low-recirculation-flow region along the graft inner wall, non-stationary stagnation, and separation points, a higher TAWSS and smaller high-OSI low-TAWSS and low-OSI high-TAWSS regions.

Validation of the Chinese version of the MacNew heart disease health-related quality of life questionnaire

RATIONALE

Patient-reported outcomes such as health-related quality of life (HRQL) describe or characterize what patients have experienced as a result of their health care. However, treatment outcome comparisons among different pure or mixed populations of patients with myocardial infarction, angina or heart failure cannot be made using existing coronary heart disease (CHD)-specific HRQL instruments.

AIMS AND OBJECTIVES

The aim of this study was to evaluate the psychometric properties of the Chinese version of the MacNew in a cohort of Hong Kong patients diagnosed with CHD.

METHODS

Chinese translations of a CHD-specific HRQL instrument, the MacNew Heart Disease HRQL questionnaire (MacNew), the Short-form 36 Health Survey and the Hospital Anxiety and Depression Scale were administered to 365 Chinese-speaking patients with CHD at baseline and again 3 months later (n = 363). The Medical Outcomes Trust Scientific Advisory Committee criteria were used to examine the psychometric properties of the Chinese MacNew Heart Disease HRQL questionnaire.

RESULTS

The results warrant recommending the use of the MacNew as an outcome measure to enhance treatment evaluation in Chinese patients with CHD and a diagnosis of myocardial infarction, angina or heart failure, substantiating previous psychometric data on the MacNew in a number of different studies in patients speaking seven different languages.

CONCLUSION

The MacNew questionnaire may have value as a core CHD questionnaire for treatment outcome comparisons among pure or mixed populations of patients with myocardial infarction, angina or heart failure.

Left ventricular diastolic function during normal pregnancy: assessment by spectral tissue Doppler imaging

OBJECTIVE

Tissue Doppler imaging (TDI) is an echocardiographic technique for assessing the diastolic function that is relatively independent of preload. Since loading conditions change significantly during pregnancy, a load-independent technique will give a more accurate assessment of diastolic function in pregnant women. The aim of this study was to evaluate maternal diastolic function using tissue Doppler imaging.

METHODS

This was a prospective observational study on 35 healthy pregnant women. M-mode, transmitral inflow (peak transmitral flow velocities during early diastole (E wave) and atrial contraction (A wave)) and TDI studies (peak myocardial velocities during early diastole (Em wave), during atrial contraction (Am wave) and peak systole in ejection phase (Sm)) were performed in each trimester and postpartum. The differences in variables between trimesters were analyzed.

RESULTS

The peak transmitral inflow velocity during early diastole (E wave) was significantly decreased during the third trimester and postpartum. The peak flow velocity during atrial contraction (A wave) was increased in the second trimester, but decreased again in the third trimester and postpartum period. As a result, the E/A ratio progressively reduced as pregnancy advanced. TDI showed that peak myocardial velocities during early diastole (Em) tended to increase during the second trimester, and then decreased significantly in the third trimester or postpartum period. The peak myocardial velocities during atrial contraction (Am) increased significantly with advancing gestational age. As a consequence, both Em/Am and E/Em ratios decreased significantly throughout pregnancy.

CONCLUSIONS

This study demonstrates the changes in myocardial relaxation velocity throughout pregnancy. Because of its advantage of being relatively load-independent, TDI may be a useful non-invasive technique for monitoring maternal cardiac function in high-risk pregnancies to detect the early signs of cardiac failure and to prevent further deterioration with prompt interventions.

Use of silicone stents for the management of post-tuberculosis tracheobronchial stenosis

The role of bronchoscopic management in post-tuberculosis tracheobronchial stenosis is not well defined. To investigate the role of bronchoscopic intervention, including silicone stenting, in the management of post-tuberculosis tracheobronchial stenosis, the current retrospective study was conducted at a tertiary referral hospital. Under rigid bronchoscopy, 80 patients underwent ballooning, neodymium-yttrium aluminium garnet laser resection and/or bougienation as first-line methods of airway dilatation between January 2000 and December 2003 inclusive, and were followed for a median of 41 months. Silicone stents were required in 75 out of 80 (94%) patients to maintain airway patency. Bronchoscopic intervention provided immediate symptomatic relief and improved lung function in 88% of the patients. After airway stabilisation, stents were removed successfully in 49 out of 75 (65%) patients at a median of 14 months post-insertion. Three patients out of 75 (4%) eventually underwent surgical management. Acute complications included: excessive bleeding (n = 1); pneumothorax (n = 5); and pneumomediastinum without mortality (n = 2). Stent-related late complications, such as migration (51%), granuloma formation (49%), mucostasis (19%) and re-stenosis (40%), were controllable during a median follow-up of 41 months. In conclusion, bronchoscopic intervention, including silicone stenting, could be a useful and safe method for treating post-tuberculosis tracheobronchial stenosis.

Pulmonary TB and NTM lung disease: comparison of characteristics in patients with AFB smear-positive sputum

OBJECTIVE

To compare the clinical and radiographic features of pulmonary tuberculosis (PTB) and non-tuberculous mycobacteria (NTM) lung disease in patients with acid-fast bacilli (AFB) positive sputum specimens.

DESIGN

The initial clinical and radiographic features of 229 PTB patients were compared with those of 70 patients with NTM lung disease. The most commonly involved organisms in the NTM lung disease cases were Mycobacterium avium complex (n = 38, 54%) and M. abscessus (n = 26, 37%).

RESULTS

Clinical and radiographic findings that were more common in patients with NTM lung disease than in PTB patients were: older age (P < 0.001), non-smoker (P < 0.001), history of previous TB treatment (P < 0.001), absence of pleural effusion (P = 0.017), involvement of middle and/or lower lung zones (P = 0.007), and bilateral disease (P = 0.005). Multivariate analysis showed that older age (> or = 40 years), non-smoker, previous TB treatment, absence of pleural effusion and involvement of middle and/or lower lung zones were significant independent predictors for NTM lung disease.

CONCLUSIONS

There is considerable overlap in the clinical and radiographic appearances of PTB and NTM lung disease. The isolation and identification of causative organisms are mandatory for a correct diagnosis in patients with AFB-positive sputum specimens.

A review of the management of patients after percutaneous coronary intervention

The exponential increase in the numbers of percutaneous coronary interventions (PCIs) has led to many clinicians having to care for post-PCI patients. We review the management of early problems seen in post-PCI patients, such as vascular access site complications, contrast nephropathy, drug-induced thrombocytopaenia and chest pain. The management of possible restenosis and the use of stress testing are discussed. The complications from dual antiplatelet therapy are addressed. The prognosis of the post-PCI patient, the implications of co-existent heart failure and the newer technologies of implantable defibrillator and cardiac resynchronisation therapy are reviewed. We conclude by emphasising the importance of secondary prevention by risk factor modification as well as the communication between the clinician and the cardiologist.

Management of diastolic heart failure--a practical review of pathophysiology and treatment trial data

The lack of large randomised controlled trials to guide therapy in diastolic heart failure causes some difficulties for evidence-based medicine practising clinicians. Traditionally, treatments for systolic heart failure have been highjacked for diastolic heart failure without much proof of benefit. However, recent studies have began to provide some evidence base for our practice. Betablockers and angiotensin receptor antagonists have recently been shown to reduce hospitalisation in large randomised controlled trials. Diuretic based antihypertensive regimes have been shown to reduce heart failure by 50%. Left ventricular hypertrophy regression is likely to be a good surrogate endpoint for diastolic heart failure, although definitive proof for this is not yet available. Angiotensin receptor antagonists, ACEI, calcium channel blockers, diuretics and aldosterone blockers have all been shown to cause left ventricular hypertrophy regression. We recommend these drugs to achieve strict blood pressure control together with dietary and lifestyle modification for the treatment of diastolic heart failure. We emphasise the importance of rate control, as diastolic heart-failure patients tolerate tachycardia poorly. We further argue that the pathophysiology of diastolic heart failure is part of systolic heart failure and the two should not be thought of as separate entities. Therefore, our traditional practice of using systolic heart failure treatments for diastolic heart failure is theoretically sound and should not cause us undue anxiety.

Enhanced fusion of myoblasts with myofibers for efficient gene delivery induced by a partially purified protein fraction from rat muscle extract

The biggest challenge to gene therapy is how to efficiently deliver the desired therapeutic gene into a sufficient number of recipient cells to achieve significant clinical efficacy. Here, we identified a partially purified extract from rat muscle probably containing myoblast specific fusion factor(s) (MSF), which significantly enhanced fusion of donor myoblast with host muscle fibers. Once incorporated, the introduced genetic construct could instruct the machinery of the hybrid cells to express the desired protein(s). Rat satellite cells containing a plasmid carrying a marker bone morphogenetic protein-4 (BMP-4) coding sequence were used as foreign gene delivery vehicle. BrdU labeling of the MSF-pretreated satellite cells allowed tracing the fate of the genetically modified satellite cells in the host muscles. Immunohistochemistry using anti-BMP-4 antibody demonstrated the translation of the introduced gene construct. It was demonstrated that in the presence of MSF, numerous BrdU positive nuclei and the expression of BMP-4 polypeptides could be observed in host hybrid fibers, while in the control group using rat serum to replace MSF containing fraction, only a few BrdU positive signals were detected. The expression of osteocalcin and the elevated alkaline phosphatase activity detected in the hybrid fibers indicated the proper folding, secretion and, post-translational modification of the expressed foreign protein. This strategy of enhanced myoblast-mediated gene transfer would break the major barrier in current practice of normal or engineered myoblast transplantation in the management of genetic muscle diseases or systemic genetic disorders.

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.

Echocardiographic evaluation of cardiac dyssynchrony for predicting a favourable response to cardiac resynchronisation therapy

Cardiac resynchronisation therapy (CRT) is an established therapy for patients with heart failure with wide QRS duration. Recent studies observed that assessment of systolic dyssynchrony is an important diagnostic tool as the treatment involves the re-coordination of regional wall contraction within the left ventricle. Therefore, the effectiveness of CRT depends heavily on whether systolic dyssynchrony is present before the treatment. Echocardiography is a useful tool for quantitative measurement of the severity of dyssynchrony in these patients before and after CRT. A number of echocardiographic tools have been developed during the past three years for such purpose, include M mode measurement of septal-to-posterior wall delay, tissue Doppler imaging for septal-to-lateral wall delay, the measurement of standard deviation of peak contraction time over 12 left ventricular segments, delayed longitudinal contraction, and potentially three dimensional echocardiography. This review discusses the potential role of various echocardiographic techniques in the assessment of systolic dyssynchrony and their clinical applications.

Tissue Doppler imaging for predicting outcome in patients with cardiovascular disease

PURPOSE OF REVIEW

Tissue Doppler imaging is being increasingly used for assessing global ventricular function in systole and diastole, and for quantifying regional wall motion abnormalities both in systolic heart failure with mechanical dyssynchrony and ischemic heart disease. Its use as a predictive tool is recent and the authors review publications relating to this aspect.

RECENT FINDINGS

Peak early diastolic mitral annular velocity is a powerful predictor of outcome in a variety of cardiovascular conditions and adds incremental value to clinical parameters and standard mitral Doppler inflow velocities. Tissue Doppler imaging can also predict the development of hypertrophic cardiomyopathy in asymptomatic individuals carrying the genetic mutation even before the onset of overt left ventricular hypertrophy. In addition, the standard deviation of the time to peak systolic velocity is a good marker of mechanical asynchrony and can predict reverse remodeling. It may also be useful in identifying individuals with ischemic heart disease and regional wall motion abnormalities who have an adverse outcome.

SUMMARY

Tissue Doppler imaging is a powerful new echocardiographic tool that is now becoming the standard for assessing ventricular function in a variety of situations and diseases.

Breast milk substitutes in Hong Kong

OBJECTIVE

In 1981 the World Health Assembly (WHA) adopted the International Code of Marketing of Breast Milk Substitutes (the Code) to support breastfeeding. Despite improving trends, Hong Kong has low rates of breastfeeding compared to other developed countries.

METHODS

We surveyed companies marketing breast milk substitutes in Hong Kong to determine self-reported adherence to the Code. Companies were informed that individual responses would not be published and seven of nine companies responded to the questionnaire.

RESULTS

The majority of respondents promoted infant and follow-on formula in hospitals and provided free supplies of infant formula to hospitals. Follow-on formula and weaning foods were promoted in shops and to the general public and free samples were given to mothers reflecting a belief that, despite WHA resolutions, follow-on formula is not a breast milk substitute.

CONCLUSIONS

Transnational companies should follow the Code and subsequent WHA resolutions equally in all countries.