Effects of retail style or food service style packaging type and storage time on sensory characteristics of bacon manufactured from commercially sourced pork bellies.

UNLABELLED: Objectives were to characterize differences in pork bellies that were stored frozen for different durations prior to processing and characterize sensory properties of the bacon derived from those bellies when stored in either retail or food service style packaging. Bellies (n = 102) were collected from 4 different time periods, fresh bellies (never frozen) and bellies frozen for 2, 5, or 7 mo, and manufactured into bacon under commercial conditions. Food service bacon was packaged in oxygen-permeable polyvinyl lined boxes layered on wax-covered lined paper and blast frozen (-33 °C) for 45 or 90 d after slicing. Retail bacon was vacuum-packaged in retail packages and refrigerated (2 °C) in the dark for 60 or 120 d after slicing. At the end of respective storage times after slicing, bacon was analyzed for sensory attributes and lipid oxidation. Off-flavor and oxidized odor of bacon increased (P < 0.01) with increasing storage time in both packaging types. Lipid oxidation increased (P < 0.01) as storage time increased from day 0 to day 45 in food service packaged bacon from frozen bellies, but was unchanged (P ≥ 0.07) with time in food service packaged bacon from fresh bellies. Lipid oxidation was also unchanged (P ≥ 0.21) over time in retail packaged bacon, with the exception of bellies frozen for 5 mo, which was increased from day 0 to day 90. Overall, off-flavor, oxidized odor, and lipid oxidation increased as storage time after processing increased. Freezing bellies before processing may exacerbate lipid oxidation as storage time after processing was extended. PRACTICAL APPLICATION: Bacon can be packaged and managed several different ways before it reaches the consumer. This research simulated food service (frozen) and retail packaged (refrigerated) bacon over a range of storage times after slicing. Off-flavor and oxidized odor increased as storage time after processing increased in both packaging types. Lipid oxidation increased as storage time after slicing increased to a greater extent in food service packaging.

Varying the temperature of the liquid used for high-pressure processing of prerigor pork: effects on fresh pork quality, myofibrillar protein solubility, and frankfurter textural properties.

UNLABELLED: The objective was to evaluate high-pressure processing (HPP) with varying liquid (water) temperatures on pork quality and textural properties of frankfurters. HPP pressurization liquid temperatures were 15.5 °C (HPP Low) and 29.4 °C (HPP Med). Analyses were conducted using paired boneless loins and paired boneless hams. Loins were evaluated for pH, purge loss, objective color, subjective color, firmness; and changes in color after a bloom period. Eight independent batches (2 batches each of HPP Low, paired untreated, HPP Med, and paired untreated) of frankfurters were manufactured from the outside portion of the ham and the knuckle. Both HPP treatments resulted in higher (P < 0.05) ultimate pH and less (P < 0.05) purge loss of the loin. Loin tenderness was not different among either HPP treatment temperature groups when compared to untreated controls except HPP Med chops were more tender (P = 0.02) than untreated controls. Salt-soluble protein extractability of inside ham muscles was lower (P < 0.05) for both HPP treatment levels when compared to untreated controls, but was not different between the 2 HPP treatment levels. Textural properties of frankfurters were not different for either HPP treatment group when compared to its respective untreated control for any parameter except springiness. HPP Low frankfurters had lower (P = 0.10) springiness values than untreated controls. Fracturability of HPP Med samples was lower (P = 0.12) than untreated controls. Overall, HPP caused higher ultimate pH and increased water-holding capacity, but did not affect tenderness of fresh meat or textural properties of frankfurters. PRACTICAL APPLICATION: HPP can be used on prerigor pork as means to improve fresh pork quality. Loins from HPP-treated pork sides had higher ultimate pH values and less package purge loss. Tenderness values were not affected positively or negatively by HPP treatment. The high pH and water-holding capabilities of treated samples have positive implications for further processing applications. Frankfurter textural properties suggest emulsified products can be made with pressurized pork without sacrifice to the textural profile.

Comparison of varying doses and durations of ractopamine hydrochloride on late-finishing pig carcass characteristics and meat quality.

The objective was to investigate the effect of various doses and durations of ractopamine hydrochloride (RAC) on pig HCW, cutting yields, and meat quality. Late-finishing pigs (approximately 93 kg) were allotted to 12 treatments 35 d before slaughter. Treatments consisted of negative control (NEG; 13.1% CP, 0.64 TID Lys), positive control (POS; 17.8% CP, 0.94 TID Lys), and 2 RAC doses (5 and 7.4 mg/kg) with 5 different feeding durations for each dose (7, 14, 21, 28, or 35 d). Pigs on ractopamine-duration diets were fed NEG until incorporation of RAC, and then the diet was switched to POS to comply with label requirements. A subset of 240 pigs was utilized to determine the effects of RAC on carcass cutting yields. This subset was selected by taking the 5 pigs closest to the average pen weight from 4 complete replicates. Differences in response to RAC between 5 and 7.4 mg/kg were not significant. Therefore, RAC dosages were pooled, resulting in an average dose of 6.2 mg/kg, which was then compared with NEG and POS diets. Ractopamine increased (P < 0.05) HCW by 2.5 and 2.3 kg compared with the NEG and POS diets, respectively. Hot carcass weight also increased linearly (P=0.003) as RAC duration increased. Indicators of carcass leanness increased with RAC compared with NEG. Estimated carcass lean percentage increased (P=0.010) 1 percentage unit from 54.79 to 55.79%, carcass cut yield increased (P<0.001) 1.23 percentage units from 50.61 to 51.84%, and (P=0.006) boneless lean cut yield increased 1.27 percentage units from 36.71 to 37.98%. Ractopamine decreased (P=0.002) subjective marbling scores 0.49 units from the NEG value of 3.0, but RAC did not differ (P=0.203) from POS. Subjective color values and shear force aging curves for RAC were not significantly different from NEG or POS. Overall, RAC had greater responses in carcass weight and cut yield than NEG, and had minimal effects on meat quality.

The effect of processing techniques and brine formulations on the development of surface sheen in enhanced beef strip loin steaks.

The surface sheen phenomenon in enhanced beef steaks, packaged under modified atmosphere, was studied using various combinations of processing techniques and brine formulations. There was no effect (P > 0.05) of time between enhancement and when steaks were cut on surface sheen. Beef temperature less than 0 °C prior to enhancement, resulted in less (P ≤ 0.05) sheen and less retained pump (P ≤ 0.05) than beef greater than 2 °C. Removal of phosphate from the brine resulted in lower (P ≤ 0.05) sheen, and the addition of lactate decreased (P ≤ 0.05) sheen but resulted in less (P ≤ 0.05) retained pump. Sheen was correlated (P ≤ 0.05) with pump uptake (r = 0.58) and pH (r = -0.29). Results indicate that surface sheen can be significantly affected by ingredients used, but caution must be taken as retained brine and pH can also be affected, causing secondary influences on instrumental and visual traits.

Fresh meat and further processing characteristics of ham muscles from finishing pigs fed ractopamine hydrochloride.

Ractopamine hydrochloride (RAC) has consistently led to an advantage in carcass cutting yields of finishing pigs and remains a common feed additive in US finishing pig diets. Less is known about the effect of RAC on further processing characteristics. Some researchers have reported advantages in ultimate pH of the LM in pigs fed RAC. If a greater ultimate pH was also observed in hams, the increased pH could affect further processing characteristics and lead to better protein interaction and improved textural properties. The objective of this experiment was to determine if RAC-fed pigs yielded hams with a greater ultimate pH, and if so, whether or not that advantage improves textural properties and water retention of further processed hams. Two hundred hams from barrows and gilts fed RAC or control diets were selected based on HCW. Hams were fabricated into 5 separate pieces to determine cutting yields, and 6 muscles were evaluated for ultimate pH. Hams were processed to make cured and smoked hams. Ractopamine increased cutting yields of the whole ham (P < 0.0001), inside (P < 0.01), outside (P < 0.01), and knuckle (P < 0.01) when expressed as a percentage of chilled side weight. Ultimate pH of the rectus femoris, vastus lateralis, and semitendinosus were all 0.06 pH units greater (P < 0.05), the biceps femoris was 0.04 pH units greater (P = 0.02), and the semimembranosus and adductor muscles were 0.03 pH units greater in pigs fed 7.4 mg/kg of RAC when compared with control pigs. Cured hams from RAC-fed pigs were heavier at all stages of production. No differences were detected in binding strengths (P = 0.88) or protein fat-free values (P = 0.13) between RAC (9.06 kg and 20.37) and control hams (9.01 kg and 20.13). Ractopamine increased cutting yields, total weight of cured hams, and ultimate muscle pH. Ractopamine can be fed to pigs to achieve the desired growth characteristic advantages and cutting yields without affecting further processed ham characteristics.

The effects of high pressure processing on pork quality, palatability, and further processed products.

The objective was to evaluate high pressure processing (HPP) on postmortem metabolism and pork quality. Six pigs were randomly selected immediately after slaughter. After splitting, one side was randomly designated for HPP of 215 MPa for 15 s with water temperature at 33 °C and the other side (non-pressure treated) served as the control. Chilled sides were fabricated into loins, boneless picnic, boneless Boston butt, and ham. Samples were cut from the loin, inside portion of the ham and cushion (M. triceps brachii). Pork quality, lipid oxidation, connective tissue solubility, protein functionality, sensory analysis, and processed characteristics of restructured hams were evaluated. HPP partially inhibits postmortem metabolism, indicated by lower muscle lactate levels and higher ultimate pH values. Cook and drip loss were both reduced in HPP treated muscles compared to controls. HPP treated sides were more tender than controls. Collagen content was not different between HPP and control groups.

The effect of zilpaterol hydrochloride on meat quality of calf-fed Holstein steers.

The objective of these studies was to evaluate the effects of zilpaterol hydrochloride (ZH), fed for 0, 20, or 30 d, on meat quality attributes of calf-fed Holstein steers. Steers were slaughtered at a commercial facility, and carcasses were selected by HCW to represent the pen mean. Further carcass selection was based on quality grade (Choice and Select) and yield grade. Proximate composition, measures of water holding capacity, and tenderness using Warner-Bratzler shear force after 7, 14, or 21 d postmortem were evaluated on the shoulder clod (triceps brachii), top butt (gluteus medius), and strip loin (longissimus lumborum). Percentage of purge for the 3 subprimals was not different (P > 0.05) among ZH treatments. Steers fed ZH for 20 d or 30 d had decreased (P < 0.05) percentages of fat in the triceps brachii, compared with 0-d ZH. Percentage of fat was less (P < 0.05) in the gluteus medius and longissimus lumborum when steers were fed ZH for 30 d compared with those steers fed ZH for 0 d. Percentage of fat was greater in Choice triceps brachii (P < 0.05) and longissimus lumborum (P < 0.10) compared with Select. Thaw loss was not different (P > 0.05) for any muscle due to ZH treatment. Only longissimus had a greater (P < 0.05) cooking loss with ZH treatment. Cooking loss was not different (P > 0.05) for the gluteus medius or longissimus lumborum due to quality grade or aging day. At each aging day, the 20- and 30-d ZH longissimus lumborum had greater (P < 0.05) shear force values than 0 d; however, 20- and 30-d ZH had a greater absolute change in shear force from 7 to 21 d than that of 0 d ZH. Triceps brachii steaks were less tender (P < 0.05) after ZH treatment, but gluteus medius steaks were not different (P > 0.05). There was no difference (P > 0.05) in shear force due to quality grade. Results illustrate the use of ZH in calf-fed Holstein steers will have minimal effects on purge, thaw, or cooking loss. Percentage of intramuscular fat will decrease, especially when fed for longer durations. Steaks from ZH treated steers were tougher than steaks from control animals at all aging times, but ZH steaks became more tender with postmortem aging.

Effects of feeding zilpaterol hydrochloride for twenty to forty days on carcass cutability and subprimal yield of calf-fed Holstein steers.

Zilpaterol hydrochloride (ZH) is designed to increase carcass leanness, chilled side weight (CSW), and percent saleable yield. The objective of this study was to evaluate the effect of a single dose of ZH on cutability and subprimal yield of calf-fed Holstein steers when fed for increasing durations. Two hundred forty steers were fed 8.3 mg/kg of ZH on a DM basis for 0, 20, 30, or 40 d, with a 3-d withdrawal before slaughter. After slaughter, steers were fabricated into 4 pieces (round, loin/flank, rib/plate, and chuck), packaged in combos, shipped to 2 locations, and further fabricated into subprimal pieces and trim. Trim was collected from each primal and separated into groups based on composition of 90, 80, and 50% lean. Zilpaterol hydrochloride increased (P = 0.01) CSW by 6.22 kg and saleable yield by 6.4 kg when included in the diet for 20 d. Furthermore, saleable yield as a percentage of CSW was increased (P = 0.03) 1.18 percentage units when included in the diet for 20 d. Steers fed ZH for 20 d had heavier strip loins (4.47 vs. 4.12 kg, P = 0.02), tenderloins (2.75 vs. 2.49 kg, P = 0.02), and ribeye rolls (5.74 vs. 5.30 kg, P = 0.01) than steers not fed ZH. These advantages are further demonstrated as a percentage of CSW. Strip loins (P = 0.06), tenderloins (P = 0.04), and ribeye rolls (P = 0.04) of ZH-fed steers had a greater percentage of CSW than controls. Zilpaterol hydrochloride also increased the percentage of CSW of the 3 primary components of the round when fed for 20 d. The knuckle was 0.10 percentage units heavier (P = 0.11), the top round was 0.24 percentage units heavier (P = 0.04), and the bottom round was 0.22 percentage units heavier (P = 0.03) in ZH-fed steers when compared with steers not fed ZH. Based on these data, it can be concluded that ZH significantly increased subprimal cutting weights, yields, and percentage saleable yield of calf-fed Holstein steers when fed for at least 20 d before slaughter. Zilpaterol hydrochloride increased percentage of CSW of subprimal cuts from Holstein steers in the round and to a lesser degree in the loin.

Sodium citrate as a replacement for sodium chloride in a brine solution when evaluated in cows of different backfat thickness.

The objective of this study was to evaluate seven muscles from cow forequarters, which were selected based on backfat thickness; an indicator of supplemental feed before slaughter: Moderate cover (Moderate ⩾ 0.76cm) and Thin cover (Thin ⩽ 0.51cm). In addition, enhancement with a brine solution containing either Sodium Chloride or Sodium Citrate was evaluated for differences in shelf-life and meat quality. Moderate carcasses had increased carcass weight, increased fat cover and a lower yield for some of the muscles compared to Thin. However, there were minimal differences for palatability and shelf-life compared to Thin. Trained panelists detected minimal differences between Citrate and Chloride for palatability. Citrate resulted in visually darker steaks, but less discoloration during the display period. Results indicate that while selection of cow carcasses based upon backfat thickness results in minimal quality differences; compared to enhancement with Chloride, Citrate minimally impacts palatability and will extend product shelf-life by reducing discoloration.

Characterization of striping in fresh, enhanced pork loins.

To investigate the striping phenomenon in fresh, enhanced pork, a series of experiments were undertaken to identify possible causes of the problem. No one factor (individual brine components, brine pH, ingredient concentration, enhancement pressure, meat and brine pH, or enhancement level) was specifically identified, which could be used to reduce the severity of the striping problem. Furthermore, tumbling the product for 2h, did not reduce the amount of striping, indicating once striping has occurred, it is permanent. Evaluation of the striping pattern indicates that the stripes are formed not only at the needle injection site, but also follow the muscle fiber orientation. The use of darker pork provided more of a contrast when evaluating striping, thus exacerbating the perceived level of striping.

The effect of pH on shelf-life of pork during aging and simulated retail display.

The pork industry uses pH to differentiate product of varying quality; thus, the effect of pH on shelf-life is important as time during transport is extended. The objective was to develop regression equations to predict shelf-life over a range of ultimate pH (5.42-6.26). Shelf-life was evaluated after vacuum aging pork loin sections 0, 7, 14, 21, or 28d and during 3d of simulated retail display (4.5°C) for pork loin chops. Correlation coefficients indicated a strong relationship between pH and quality measurements. Regression analysis with Aging Day and pH was able to explain 87% of the variation in aerobic plate counts for pork. After 28d of vacuum aging, loin sections from the upper end of the pH distribution had about a 3log(1000X) greater aerobic plate count than did the lower end pH product. An increase in pH resulted in pork with lower L*, a*, b* and R(630)-R(580) values and as Aging Day increased, instrumental measurements of color increased slightly. Although higher pH is associated with improved pork quality, higher pH and longer aging periods will result in increased microbial proliferation and decreased shelf-life. Thus, an intermediate pH may provide the most desirable combination of quality and shelf-life when extensive aging is used.

The influence of early post-mortem enhancement and accelerated chilling on pork quality.

To improve pork quality, the effectiveness of early post-mortem enhancement and accelerated chilling were investigated. The four treatments evaluated were: Enhancement with Accelerated Chilling (ENAC), Accelerated Chilling Only (ACO), Enhancement with Conventional Chilling (ENCC), and Conventional Chilling Only (CCO). ENAC had a higher (P<0.05) pH than all other treatments. CCO resulted in the highest (lightest; P<0.05) L(∗), while ENAC had the lowest L(∗) value (darkest; P<0.05). Subjective color and striping did not differ (P>0.05) between ENAC and ENCC, although ENAC was numerically higher for both parameters. Sensory analysis for juiciness and tenderness were not different (P>0.05) between ENAC and ENCC, but both were higher (P<0.05) than ACO and CCO. Enhancement early post-mortem coupled with accelerated chilling may be used to improve instrumental color and pH over conventional processing methods.

Mechanisms of regional wall motion abnormalities in contrast-enhanced dobutamine stress echocardiography.

BACKGROUND: In the diagnosis of coronary artery disease (CAD) with Dobutamine Stress Echocardiography (DSE), regional wall motion abnormalities (RWMA) are assumed to indicate a perfusion deficit. METHODS AND RESULTS: For a more particular examination of RWMAs, we compared simultaneous echo-contrast (Optisone)-enhanced DSE (0-40 microg/kg Dobutamine, 16-segment- model) and MiBi-SPECT in a prospective double-blinded study design in 69 non-selected consecutive patients (44 male, 25 female, age 64+/-12 years). Additionally, all patients were examined by coronary-angiography. The prevalence of significant CAD (stenosis >50% lumen diameter) was 52%. DSE had a sensitivity of 78% and a specificity of 66% for the detection of significant CAD with a positive and negative predictive value of 72 and 73%, respectively. Among 28 patients with significant CAD and positive DSE study (true positive), 78% displayed a corresponding perfusion deficit in MiBi-SPECT. Among 11 patients with a positive DSE study but no current significant coronary stenosis (false positive), 82% showed stress-induced RWMAs in the inferior/posterior region, 73% displayed left ventricular hypertrophy, 54% resting-ECG abnormalities and 45% resting-RWMA (3 previous MI, 2 previous CABG surgery). Among 8 patients with negative DSE study but significant coronary stenosis (false negative), 75% had a stenosis of the LCX, 63% displayed resting- WMA, 63% displayed left bundle branch block or ST-segment depression, 50% displayed only peripheral coronary stenosis, and DSE visualization was suboptimal in 38%. CONCLUSION: This prospective study in non-selected patients shows that the majority of RWMAs in DSE are matched to a perfusion deficit detectable by nuclear imaging. Nevertheless, pre-existing cardiac abnormalities may also lead to stress-induced RWMA not associated with a perfusion deficit or mask a perfusion deficit upon DSE. Particularly in patients with LV hypertrophy, resting-RWMA, bundle branch block or ST segment depression, the predictive value of DSE may, therefore, be limited.

Cardiovascular phenotypes and functional parameters in the general population--results of the MONICA/KORA studies.

The MONICA/KORA surveys are characterized by a careful and broad investigation of multiple cardiovascular phenotypes. Particularly, repeated blinded measurements of blood pressure, comprehensive echocardiographic and electrocardiographic evaluations as well as differentiation between fat and fat-free body mass have led to manifold innovative observations. Specifically, genetic and serological markers of the renin angiotensin system could be associated with high blood pressure and left ventricular hypertrophy. The same applies to the importance of parameters of body composition as obesity and muscular mass. Moreover, the prevalence of heart failure in the general population could be determined for the first time in Germany. Additionally, the prevalence of left ventricular systolic and diastolic dysfunction could be obtained in the region of the survey, exemplarily for the Federal Republic of Germany. Finally, the surveys of the population random sample were used to define normal serum levels of natriuretic peptides. In summary, the evaluation of cardiovascular phenotypes in the MONICA/KORA surveys resulted in a -- in the European region unique -- documentation of cardiovascular functional parameters in the general population. Moreover, multiple epidemiological observations as to pathophysiologically relevant topics of heart and vascular diseases could be studied in extraordinary details.

Failure to achieve recommended LDL cholesterol levels by suboptimal statin therapy relates to elevated cardiac event rates.

OBJECTIVES: The majority of patients with myocardial infarction (MI) and hypercholesterolaemia does not achieve guideline recommended low-density lipoprotein cholesterol (LDL) levels. Suboptimal dosages of statins explain this dilemma in most patients. DESIGN AND SETTING: We evaluated the relationship between statin treatment quality (optimal: LDL<115 mg/dl, suboptimal: LDL>/=115 mg/dl, no statin therapy despite hypercholesterolaemia) and the subsequent incidence of coronary events (coronary death, nonfatal MI, bypass surgery) over a 30 months follow-up in a large cohort of post MI patients with hypercholesterolaemia (n=2045). Analysis was performed in a nested case-control manner comparing 173 cases with a coronary event and 346 matched controls. RESULTS: Patients who developed a coronary event were treated optimally in 11.0%, suboptimally in 43.4% (p<0.05 vs. optimal treatment) and were untreated in 45.7% (p<0.001 vs. optimal treatment). Respective numbers in event-free patients were 21.4%, 47.7%, and 30.9%. After adjustment for most potential confounders, including all cardiovascular risk factors and medication, the relative risk of future non-fatal MI and coronary death associated with a suboptimal statin treatment was 2.02 (95% CI 1.04 to 4.18) compared to optimal statin treatment. Moreover, the statin equivalent dose in optimally treated individuals was significantly higher than in suboptimally treated individuals (0.85+/-0.03 vs. 0.78+/-0.02, p<0.05). CONCLUSION: In this community-based study, a lipid lowering therapy with statins into the recommended target range of LDL levels may be associated with decreased cardiovascular risk compared to a statin therapy without titrating the LDL level below 115 mg/dl. Thus, the quality of statin treatment was identified as an independent predictor of coronary events in post MI patients.

NT-proBNP and the diagnosis of heart failure: a pooled analysis of three European epidemiological studies.

Many studies have shown that the B-type natriuretic peptides (BNP and NT-proBNP) are proven diagnostic markers for heart failure due to left ventricular systolic dysfunction. The manner in which they are to be used is still being unravelled; most single centre studies have chosen the best concentration of the peptide on ROC analysis as their cut-point resulting in numerous different values for both BNP and NT-proBNP appearing in the literature. We report a different approach of defining an age and sex corrected abnormal concentration for NT-proBNP, derived from normal individuals within a large sample of 3051 subjects pooled from three European epidemiology studies and applying that to the entire population to detect HF and LVD. Three thousand and fifty one subjects were studied. Of these 10% (305) had significant LVD and 3.1% (94) had HF. The median concentrations of NT-proBNP (IQR) in normals, those with LVD and in heart failure subjects were 20 pg/ml (10.30), 117.3 pg/ml (28.145) and 269.6 pg/ml (54.323), P<0.001, respectively. The area under the ROC curve for NT-proBNP for the detection of 'heart failure' was 0.85 and 0.69 for LVD. NT-proBNP was an independent predictor of the presence of HF on multivariate analysis. An abnormal NT-proBNP was defined as being >95th centile for normals, age and sex corrected, and diagnosed HF with a sensitivity of 75% and a negative predictive value of 99%. In an additional analysis in a breathless subgroup of our population, in 30% a raised NT-proBNP concentration could be explained by HF due to LVD, in another 64% the high BNP level was associated with some other structural of functional cardiac abnormality or renal impairment. We were unable to assign a possible cause to the high NT-proBNP values in 5.9% of this breathless subgroup of the population. An abnormal NT-proBNP concentration is an accurate diagnostic test both for the exclusion of HF in the population and in ruling out LVD in breathless subjects. An elevated NT-proBNP merely indicates the presence of 'cardio-renal distress' and should prompt referral for further investigation.

KCNJ11 polymorphisms and sudden cardiac death in patients with acute myocardial infarction.

PURPOSE: Patients with an acute myocardial infarction (AMI) are of high risk to develop ischemia-induced ventricular arrhythmias, leading to sudden cardiac death (SCD) in about one third of all AMI patients. The individual susceptibility to ischemia-induced arrhythmias may be modified by polymorphisms in genes encoding ion channels. The cardiac ATP-dependent potassium channel (K(ATP)) current is generated by ion channels encoded by the KCNJ11 gene and the SUR2a gene. Opening of the K(ATP) channel during ischemia results in action potential shortening in various studies and may therefore influence the outcome of AMI patients. METHODS: Using a three-primer strategy, we sequenced the complete coding and adjacent 5' and 3' sequences of the intronless KCNJ11 gene (1.3 kb) prospectively in two groups. Patients of group 1 (n = 84) survived three or more transmyocardial infarctions without developing any ventricular arrhythmias. Patients of group 2 died suddenly from their first myocardial infarction (n = 86), most of them witnessed SCDs. RESULTS: We identified a total of six known polymorphisms (K23E, A190A, L267V, L270V, I337V, and K281K) and two new polymorphisms (L267L, 3'UTR +62 G/A). The allele, genotype, and haplotype frequencies did not differ between the two groups. All polymorphisms were found to be in Hardy-Weinberg equilibrium. In addition, we identified two novel missense mutations in a highly conserved region of the gene in two patients of group 2 (P266T and R371H) with yet unknown functional consequences. CONCLUSION: In this study of AMI patients, SCD was not related to polymorphisms in the KCNJ11 gene.

[Epidemiology of left ventricular systolic dysfunction in the general population of Germany: results of an echocardiographic study of a large population-based sample]. / Epidemiologie der linksventrikulären systolischen Dysfunktion in der Allgemeinbevölkerung Deutschlands. Ergebnisse echokardiografischer Untersuchungen einer grossen Bevölkerungsstichprobe.

The prevalence of left ventricular systolic dysfunction (LVSD) in the general population is poorly defined. Specifically, the number of asymptomatic individuals with LVSD and, thus, the most appropriate strategy to identify and treat such subjects is still unknown. Therefore, the aim of this study was to document LV dysfunction in a middle-aged (25 to 75 years, mean 51.8+/-13.8) population - based sample in Germany (MONICA Augsburg, n=1678; echocardiography technically adequate n=1418) by M-mode and 2D-echocardiography and to analyze the importance of predisposing contributors. The overall prevalence of an ejection fraction (EF) less than 48% (mean minus 2 SD=LVSD) was 2.3% (n=33), with a slightly higher rate in men than in women (2.8% vs 1.9%, n.s.). LVSD rate increased with age: from 1.5% in individuals younger than 40 years to 4.0% among those older than 60 years of age (p<0.05). Of 33 participants with reduced left ventricular systolic function, 20 presented with at least one cardiovascular disease. The most frequent diagnoses were arterial hypertension, obesity and coronary heart disease. Only 13 subjects (0.9%) of the study population were asymptomatic without a history of cardiovascular disease. Furthermore, only 6 subjects (0.4%, 4 male) in this population presented with a moderate impairment of LV function (EF of 30 to 40%) and only 1 subject (0.07%, male) had severe LVSD (EF less than 30%). Almost all subjects with an EF less than 40% (6 of 7 individuals) had a known history of cardiovascular disease. In conclusion, LVSD is a relatively common finding in the general population. However, severe LVSD is rare in subjects without any concomitant cardiovascular disease. Thus, echocardiographic screening cannot be recommended in the unselected, middle-aged population to identify such patients.

Prevalence of left ventricular diastolic dysfunction in the community. Results from a Doppler echocardiographic-based survey of a population sample.

AIMS: The prevalence of left ventricular diastolic abnormalities in the general population is largely unclear. Thus, the aim of this study was, firstly, to identify abnormal diastolic function by echocardiography in an age-stratified population-based European sample (MONICA Augsburg, n=1274, 25 to 75 years, mean 51+/-14) and, secondly, to analyse clinical and anthropometric parameters associated with diastolic abnormalities. METHODS AND RESULTS: The overall prevalence of diastolic abnormalities, as defined by the European Study Group on Diastolic Heart Failure (i.e. age dependent isovolumic relaxation time (92-105 ms) and early (E-wave) and late (A-wave) left ventricular filling (E/A-ratio, 1-0.5)) was 11.1%. When only subjects treated with diuretics or with left atrial enlargement were considered (suggesting diastolic dysfunction) the prevalence was 3.1%. The prevalence of diastolic abnormalities varied according to age: from 2.8% in individuals aged 25-35 years to 15.8% among those older than 65 years (P<0.01). Significantly higher rates of diastolic abnormalities were observed in men as compared to women (13.8% vs 8.6%, P<0.01). Independent predictors of diastolic abnormalities were arterial hypertension, evidence of left ventricular (LV) hypertrophy, and coronary artery disease. Interestingly, in the absence of these predisposing conditions, diastolic abnormalities (4.3%) or diastolic dysfunction (1.1%) were rare, even in subjects older than 50 years of age (4.6%) and (1.2%), respectively. In addition to these factors, diastolic dysfunction was related to high body mass index, high body fat mass, and diabetes mellitus. CONCLUSION: The prevalences of diastolic abnormalities and diastolic dysfunction are higher than that of systolic dysfunction and are increased (despite age-dependent diagnostic criteria) in the elderly. However, in the absence of risk factors for diastolic abnormalities or diastolic dysfunction, namely LV hypertrophy, arterial hypertension, coronary artery disease, obesity and diabetes the condition is rare even in elderly subjects. These data allow speculation on whether diastolic heart failure may be prevented by improved implementation of measures directed against predisposing conditions.