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U Mehlhorn

Publications and source records attributed to U Mehlhorn.

At least 37 records · Page 2Linked to original sources
PubMed2001

Impact of myocardial protection during coronary bypass surgery on patient outcome.

We have recently shown that continuous coronary perfusion with warm blood enriched with the ultra-short acting beta-blocker Esmolol (ES) improves functional and structural myocardial protection during coronary artery surgery as compared with conventional cardioplegia (CP). The purpose of the present study was to compare both myocardial protection techniques in terms of patient outcome. We retrospectively analyzed the charts of 150 consecutive patients subjected to coronary artery surgery using the ES-technique; 150 patients matched for age, gender, preoperative left ventricular function, history of renal failure, and history of neurological symptoms undergoing surgery with conventional CP during the same time period served as control group. There were no significant differences between both groups with respect to perioperative myocardial infarction rate, need for positive inotropic medication, need for mechanical circulatory support, duration of mechanical ventilation, duration of intensive care unit stay, time of mobilization, postoperative renal failure, cardiac arrhythmias, neurological symptoms, infections or in-hospital mortality. ES-patients were less frequently readmitted to the intensive care unit (ES: 3/150; 2.2% [95% confidence interval: 0-4.2%] vs. CP: 13/150; 8.7% [4.2-13.2%]; P=0.010) and total hospital stay was shorter (ES: 12.3+/-4.8 days [95% CI: 11.5-13.0] vs CP: 13.5+/-3.8 [12.9-14.1] days; P=0.0013), thus saving 159 patient days on the normal ward. Procedural costs were less for the ES-technique (US$ 60 per patient) as compared to the cardioplegia technique (US$ 120 per patient). These data suggest that myocardial protection using the ES-technique does not improve clinical outcome in patients subjected to routine coronary artery surgery, but may save costs.

Adrenergic beta-Antagonists↗
PubMed2001

Myocardial fluid balance.

Fluid accumulation in the cardiac interstitium or myocardial edema is a common manifestation of many clinical states. Specifically, cardiac surgery includes various interventions and pathophysiological conditions that cause or worsen myocardial edema including cardiopulmonary bypass and cardioplegic arrest. Myocardial edema should be a concern for clinicians as it has been demonstrated to produce cardiac dysfunction. This article will briefly discuss the factors governing myocardial fluid balance and review the evidence of myocardial edema in various pathological conditions. In particular, myocardial microvascular, interstitial, and lymphatic interactions relevant to the field of cardiac surgery will be emphasized.

Cardiopulmonary Bypass↗
PubMed2001

Nebivolol, bucindolol, metoprolol and carvedilol are devoid of intrinsic sympathomimetic activity in human myocardium.

1. The present study investigated whether or not there may be differences in the direct cardiac actions of the novel, highly beta(1)-selective adrenoceptor antagonist nebivolol (NEB) in comparison to metoprolol (MET), bisoprolol (BIS), carvedilol (CAR) and bucindolol (BUC) in human myocardium (n=9). 2. The rank order of beta(1)-selectivity as judged by competition experiments to (3)H-CGP 12.1777 in the presence of CGP 207.12 A (300 nmol l(-1), K(i)beta(2)) or ICI 118.551 (50 nmol l(-1), K(i)beta(1)) were NEB(K(i)beta(2)/K(i)beta(1): 40.7) > BIS(15.6) > MET(4.23) > CAR(0.73) > BUC(0.49). 3. The rank order of the negative inotropic potency of the beta-adrenoceptor antagonists measured in left ventricular trabeculae (dilated cardiomyopathy, DCM) as judged by the concentration needed to induce a 50% decrease in isoprenaline (1 micromol l(-1))-stimulated force (IC(50)) was: MET (0.6 micromol l(-1)) > CAR (4.1 micromol l(-1)) > NEB (7.0 micromol l(-1)). 4. NEB, BUC, MET and CAR did not not exert an intrinsic sympathomimetic activity (ISA) as determined by measurements of force development in forskolin (0.3 micromol l(-1)) pre-treated left ventricular trabeculae, nor by measuring adenylate cyclase activity in forskolin (0.3 micromol l(-1))-stimulated assays (crude membranes). This also holds true for radioligand binding assays with or without guanine nucleotide guanyl-5'-yl imidodiphosphate (Gpp(NH)p). 5. Although all studied beta-adrenoceptor antagonists lack intrinsic sympathomimetic activity (ISA), they differ in the beta(1)-selectivity as well as in their direct negative inotropic action. These differences as well as the mode of extracardiac action may have an impact on outcome of patients treated with beta-adrenoceptor antagonists.

Adrenergic beta-Antagonists↗
PubMed2001

Failure of autologous fresh frozen plasma to reduce blood loss and transfusion requirements in coronary artery bypass surgery.

BACKGROUND: Previous studies failed to demonstrate any benefit from prophylaxis with fresh frozen plasma (FFP) after cardiopulmonary bypass (CPB). The results, however, were limited by either retrospective study design or use of FFP in subtherapeutic doses (2-3 units). The authors evaluated whether a therapeutic dose (15 ml/kg) of FFP reduces blood loss and transfusion requirements in elective coronary artery bypass surgery. The risks of multiple allogeneic blood donor exposure were circumvented by using autologous plasma. METHODS: Sixty adult patients scheduled for elective primary coronary artery bypass grafting were randomized to receive, after CPB, an intravenous infusion of 15 ml/kg of either autologous FFP (30 patients) or 6% hydroxyethyl starch 450/0.7 (HES; 30 patients). Autologous plasma was obtained by platelet-poor plasmapheresis several weeks before surgery. Perioperative blood transfusions were administered per protocol. Postoperative blood loss was defined as the chest tube drainage during the first 24 h after surgery. RESULTS: The data from 56 patients (FFP group, 27 patients; HES group, 29 patients) who completed the study according to protocol were analyzed. Median postoperative blood loss was 630 ml (range, 450-1,840 ml) and 830 ml (range, 340-1,980 ml) in the FFP and HES groups, respectively (P = 0.08). Both postoperative (0-24 h) and total perioperative erythrocyte transfusion requirements did not differ significantly between the groups (P = 0.32 and 0.14, respectively). CONCLUSION: The prophylactic administration of a therapeutic dose (15 ml/kg) of autologous FFP after CPB failed to reduce blood loss and transfusion requirements in patients undergoing uncomplicated, elective, primary coronary artery bypass surgery.

Aged↗
PubMed2000

Cardiac surgery in patients with end-stage renal disease: 10-year experience.

BACKGROUND: End-stage renal disease is known to be an important risk factor complex for cardiac operations performed with cardiopulmonary bypass. METHODS: To investigate the influence of preoperative status on perioperative mortality and morbidity, we retrospectively analyzed data from 65 patients (20 women and 45 men with a mean age of 58.8+/-10.0 years [+/-standard deviation]) with end-stage renal disease who were on dialysis and who underwent a cardiac surgical procedure between 1988 and 1998. RESULTS: Fifty-one percent of the patients had isolated coronary artery bypass grafting, 35% had replacement or reconstruction of one valve or two valves, and 14% underwent combined coronary artery bypass grafting and valve replacement. The perioperative mortality rate was 13.8% with 78% (7 of 9) of deaths occurring in patients having a valve procedure. Six of the 9 patients who died had compromised left ventricular function preoperatively, and all 9 were in New York Heart Association class III or IV. Mean preoperative duration of dialysis was longer (80+/-70 months) in the 9 patients who died compared with that in the surviving 56 patients (45+/-49 months) (p = 0.05). We found dyspnea at rest, duration of dialysis of 60 months or more, combined procedures (coronary artery bypass grafting and valve operation), and New York Heart Association class IV to be associated with a higher relative risk for perioperative death. Neither angina pectoris nor isolated coronary artery bypass grafting was associated with increased relative risk for perioperative death. However, after a cardiac operation, mortality in patients with end-stage renal disease was substantially higher than in those with normal renal function. CONCLUSIONS: These data are comparable with those in the literature and possibly suggest that both indications and referral for surgical intervention have been delayed in patients who have end-stage renal disease combined with coronary artery disease, valve disease, or both. The delay may contribute to the relatively high perioperative mortality.

Adult↗
PubMed2000

Activation of myocardial constitutive nitric oxide synthase during coronary artery surgery.

OBJECTIVE: The role of nitric oxide (NO) in myocardial ischemia/reperfusion is controversial. While some studies have shown cardioprotective effects of NO, others suggested that increased myocardial NO release secondary to ischemia may contribute to reperfusion injury. However, the impact of cardioplegia-induced myocardial ischemia/reperfusion on the activity of the NO-producing enzyme constitutive NO-synthase (cNOS or NOS-III) has not been investigated. METHODS: Twenty elective CABG patients were randomized to receive myocardial protection using either intermittent cold blood cardioplegia with 'hot-shot' (CBC; n=10) or continuous warm blood enriched with the ultra-fast-acting beta-blocker esmolol (WBE; n=10). We collected transmural LV biopsies prior to cardiopulmonary bypass (CPB), at the end of the cross-clamp period, and at the end of CPB. Specimen were subjected to immunocytochemical staining against myocardial NOS-III and cGMP using polyclonal antibodies. NOS-III activity was determined using TV-densitometry (gray units) and cGMP content using a semiquantitative score. Global myocardial metabolism was assessed by arterio-coronary sinus lactate concentration difference (a-csD(LAC)). For LV function determination we measured the fractional area of contraction (FAC) using TEE. RESULTS: In CBC hearts a-csD(LAC) was significantly decreased following cross-clamp removal as compared to pre-CPB indicating global ischemia during cross-clamp. In contrast, a-csD(LAC) was unchanged in WBE hearts indicating absence of relevant ischemia in this group. In CBC hearts NOS-III activity did not change from pre-CPB (35.6+/-11.1 U) to the end of the cross-clamp period (38. 0+/-8.1 U; P=0.2), but increased significantly to 48.5+/-12.1 U at the end of CPB following initial warm blood reperfusion (P=0.026). In WBE hearts NOS-III activity remained unchanged throughout (29. 2+/-10.8, 35.1+/-11.8, and 32.2+/-14.7 U, respectively; 0.3). At the end of CPB, nine CBC hearts, but only one WBE heart showed increased cGMP content (P=0.002). Compared to pre-CPB, FAC in the CBC group was 109+/-25% following weaning off CPB (P=0.26), but was slightly decreased to 87+/-22% at 4 h post-CPB (P=0.03). In the WBE group FAC remained unchanged compared to pre-CPB throughout (103+/-21 and 96+/-37%, respectively; 0.5). CONCLUSIONS: Our data show that global myocardial ischemia and reperfusion induced by CBC is associated with myocardial NOS-III activation and increased cGMP content suggesting increased NO release. In contrast, avoidance of ischemia by use of WBE prevented NOS-III and c-GMP increase. As LV function was decreased at 4 h post-CPB in the CBC group, these data suggest that increased NO release secondary to NOS-III activation may have contributed to ischemia-reperfusion injury as has been shown experimentally.

Adrenergic beta-Antagonists↗
PubMed2000

Risk stratification in heart surgery: comparison of six score systems.

OBJECTIVE: Risk scores have become an important tool in patient assessment, as age, severity of heart disease, and comorbidity in patients undergoing heart surgery have considerably increased. Various risk scores have been developed to predict mortality after heart surgery. However, there are significant differences between scores with regard to score design and the initial patient population on which score development was based. It was the purpose of our study to compare six commonly used risk scores with regard to their validity in our patient population. METHODS: Between September 1, 1998 and February 28, 1999, all adult patients undergoing heart surgery with cardiopulmonary bypass in our institution were preoperatively scored using the initial Parsonnet, Cleveland Clinic, French, Euro, Pons, and Ontario Province Risk (OPR) scores. Postoperatively, we registered 30-day mortality, use of mechanical assist devices, renal failure requiring hemodialysis or hemofiltration, stroke, myocardial infarction, and duration of ventilation and intensive care stay. Score validity was assessed by calculating the area under the ROC curve. Odds ratios were calculated to investigate the predictive relevance of risk factors. RESULTS: Follow-up was able to be completed in 504 prospectively scored patients. Receiver operating characteristics (ROC) curve analysis for mortality showed the best predictive value for the Euro score. Predictive values for morbidity were considerably lower than predictive values for mortality in all of the investigated score systems. For most risk factors, odds ratios for mortality were substantially different from ratios for morbidity. CONCLUSIONS: Among the investigated scores, the Euro score yielded the highest predictive value in our patient population. For most risk factors, predictive values for morbidity were substantially different from predictive values for mortality. Therefore, development of specific morbidity risk scores may improve prediction of outcome and hospital cost. Due to the heterogeneity of morbidity events, future score systems may have to generate separate predictions for mortality and major morbidity events.

Adult↗
PubMed2000

Myocardial protection with high-dose beta-blockade in acute myocardial ischemia.

OBJECTIVE: The risk of postoperative cardiac dysfunction is markedly increased by emergency coronary artery bypass grafting in the presence of acute myocardial ischemia. High dose beta-blockade during continuous coronary perfusion has been suggested as an alternative to conventional cardioplegia and this technique has been applied successfully in high risk patients for coronary artery bypass grafting (CABG) surgery. This study compared high dose beta-blockade with esmolol to continuous warm blood cardioplegia in a clinically oriented model of acute left ventricular (LV) ischemia and reperfusion. METHODS: Twelve dogs were subjected to 60 min of regional LV ischemia by left anterior descending branch (LAD) ligation. Cardiopulmonary bypass (CPB) and aortic crossclamp were applied after 45 min of ischemia. Thereafter, high dose beta-blockade during continuous coronary perfusion (ESMO, n = 6) or antegrade continuous warm blood cardioplegia (WBC, n = 6) were maintained for 60 min. Myocardial water content (measured from endomyocardial biopsies using a microgravimetric technique), global LV function (preload recruitable stroke work: PRSW), and regional LV function (echocardiographic wall motion score) were determined at baseline and after weaning from CPB. RESULTS: During aortic crossclamp interstitial edema formation was significantly higher in the WBC group with an average water gain of 2.2 +/- 0.49 vs. 0.76 +/- 0.12% in the ESMO group. Thereafter, edema resolved in both groups, but myocardial water gain remained significantly higher in the WBC group at 60 and 120 min post CPB (0.98 +/- 0.19 and 1.13 +/- 0.32% vs. 0.07 +/- 0.25 and 0.04 +/- 0.08%). Global LV function was significantly higher in the ESMO group at 60 and 120 min post CPB (PRSW 103 +/- 6 and 94.7 +/- 4.6% of baseline vs. 85.3 +/- 4.9 and 74.7 +/- 7.6% of baseline). However, regional LV function showed no significant difference between groups. CONCLUSIONS: High-dose beta-blockade during continuous coronary perfusion may allow the surgeon to utilize the advantages of warm heart surgery, while avoiding the interstitial edema formation and temporary cardiac dysfunction associated with continuous warm blood cardioplegia. In high risk patients such as patients with unstable angina or after failed PTCA, high-dose beta-blockade may be an applicable alternative to cardioplegic arrest.

Acute Disease↗
PubMed2000

Surgical repair of right-atrial aneurysm.

Atrial fibrillation and embolic events are the most common clinical symptoms of congenital right- or left-atrial aneurysms. We report an a case of righ-atrial aneurysm, in a patient with typical history of atrial fibrillation and history of stroke. The aneurysm was resected, but the patient suffered from acute embolic occlusion of the left anterior descending coronary artery on the fourth postoperative day despite of systemic heparinization with 300 IU/kg bw per 24 hours.

Anticoagulants↗
PubMed2000

Single-channel activity and expression of atrial L-type Ca(2+) channels in patients with latent hyperthyroidism.

Patients with "latent hyperthyroidism" (suppressed thyroid-stimulating hormone and normal circulating thyroid hormones) are at risk to develop atrial fibrillation. In animal models, hyperthyroidism is associated with increased cardiac L-type Ca(2+) current. Therefore, we assessed L-type channel function and expression in right atria from patients undergoing cardiac surgery. Single L-type channels were studied in the cell-attached condition. Voltage dependence of gating was similar in patients with and without latent hyperthyroidism. With use of a pulse protocol leading to maximum channel availability, single-channel activity was further analyzed. Average peak current was significantly enhanced in latent hyperthyroidism, mainly because of an increased channel availability (P < 0.05). Protein expression was analyzed by Western blot. In latent hyperthyroidism, expression of Ca(2+) channel alpha(1)-subunits was increased more than threefold (P < 0.01). In contrast, sarco(endo)plasmic reticulum Ca(2+)-ATPase and phospholamban levels were not significantly changed. We only observed a trend toward increased sarco(endo)plasmic reticulum Ca(2+)-ATPase expression (P = 0.085). Function and expression of human atrial L-type Ca(2+) channels are increased in latent hyperthyroidism. These endocrine effects on the heart may be clinically relevant.

Blotting, Western↗
PubMed2000

SERCA2a activity correlates with the force-frequency relationship in human myocardium.

The present investigation addresses whether protein expression and function of sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA2a) and phospholamban (PLB) correlate in failing and nonfailing human myocardium. SERCA2a activity and protein expression, PLB phosphorylation, and the force-frequency relationship (FFR) have been determined in right atrium (RA) and left ventricle (LV) from nonfailing (NF, n = 12) and terminally failing [dilated cardiomyopathy (DCM), n = 12] human hearts. Only in LV of DCM hearts was SERCA2a activity significantly decreased [maximal turnover rate (V(max)) = 196 +/- 11 and 396 +/- 30 nmol. mg(-1). min(-1) in LV and RA, respectively], whereas protein expression of SERCA2a in the different chambers was unchanged in NF (3.9 +/- 0.3 and 3.2 +/- 0.4 densitometric units in LV and RA, respectively) and DCM hearts (4.8 +/- 0.8 and 3.4 +/- 0.1 densitometric units in LV and RA, respectively). Phosphorylation of PLB was higher in LV than in RA in NF (Ser(16): 180.5 +/- 19.0 vs. 56.8 +/- 6.0 densitometric units; Thr(17): 174.6 +/- 11.2 vs. 37.4 +/- 8.9 densitometric units) and DCM hearts (Ser(16): 132.0 +/- 5.4 vs. 22.4 +/- 3.5 densitometric units; Thr(17): 131.2 +/- 10.9 vs. 9.2 +/- 2.4 densitometric units). SERCA2a function, but not protein expression, correlated well with the functional parameters of the FFR in DCM and NF human hearts. Regulation of SERCA2a function depends on the phosphorylation of PLB at Ser(16) and Thr(17). However, direct SERCA2a regulation might also be affected by an unknown mechanism.

Adult↗
PubMed2000

Effects of myocardial edema on the development of myocardial interstitial fibrosis.

OBJECTIVE: The mechanism by which chronic myocardial edema causes cardiac dysfunction is poorly understood. We hypothesized that myocardial edema triggers cardiac fibrosis development resulting in cardiac dysfunction. Since collagen is the most abundant constituent of the interstitial matrix, we examined the effects of edema development on cardiac collagen metabolism. METHODS: We utilized a chronic pulmonary artery banded rat model that produces right ventricular hypertrophy with myocardial edema and left ventricular edema without hypertrophy or hyperplasia. Wet to dry ratios (index of edema), collagen type I and III concentrations, prolyl 4-hydroxylase (P4-H) and collagen type I and III mRNA levels, collagenase activity and transforming growth factor-beta were measured in both ventricles. RESULTS: Right and left ventricular wet to dry ratios were significantly elevated from 1 to 28 days after pulmonary artery banding compared to sham rats. Right and left ventricular collagen types I and III and P4-H mRNA levels increased significantly at 3 days followed by significant increases in right and left ventricular collagen concentration 7 days after pulmonary artery banding. Right ventricular collagenase activity increased at 3 days while left ventricular collagenase activity decreased 7 days after PA banding. CONCLUSIONS: We conclude that myocardial edema preceded the observed increase in collagen deposition and that edema may have triggered increased collagen synthesis by fibroblasts. leading to fibrosis development.

Animals↗
PubMed2000

Different effect of the Ca(2+) sensitizers EMD 57033 and CGP 48506 on cross-bridge cycling in human myocardium.

Ca(2+) sensitizers may be advantageous for treatment in human heart failure by increasing cardiac force without increasing the Ca(2+) transient or energy consumption. To study the mode of action of the Ca(2+) sensitizers EMD 57033 (EMD) and CGP 48506 (CGP), their influence on butanedione monoxime (BDM)-mediated depression of cross-bridge cycling was analyzed in human myocardium (explanted hearts, dilated cardiomyopathy, n = 19). In Triton X (1%)-skinned fiber preparations of left ventricular myocardium from patients suffering from dilated cardiomyopathy, troponin I was extracted by vanadate (10 mM) treatment, resulting in a Ca(2+)-independent contraction. In troponin I-depleted fibers BDM (5-50 mM) was applied in the absence and presence of EMD (10 microM) or CGP (10 microM). To analyze the influence on cross-bridge kinetics, tension cost (ratio of ATPase activity and tension development) was studied. BDM exerted a dose-dependent force inhibition in troponin I-depleted fibers (IC(50) = 7.22 mM), which was antagonized by EMD (IC(50) of BDM + EMD = 19.97 mM) and CGP (IC(50) of BDM + CGP = 15.30 mM). EMD increased Ca(2+) sensitivity of force and maximal force in Triton X-skinned fibers. The Ca(2+)-sensitizing effect of CGP was accompanied by an increased Ca(2+) sensitivity of myosin-ATPase activity, an increased slope of the Ca(2+) force and Ca(2+) ATPase curve, as well as a reduced maximal myosin ATPase activity. CGP and EMD reduced tension cost. In conclusion, EMD and CGP antagonize the BDM-mediated relaxation in troponin I-depleted cardiac muscle fibers. The Ca(2+)-sensitizing effect of CGP seems to be dependent on an improvement of the myofilament cooperativity, whereas EMD seems to operate by increasing the force per cross-bridge.

Adult↗
PubMed2000

Structural myocardial changes after coronary artery surgery.

BACKGROUND: Postoperative contractile dysfunction or 'myocardial stunning' has been described after coronary artery bypass grafting (CABG). In the present study we sought to determine if and to what extent clinical, structural and histochemical evidence of myocardial changes associated with stunning could be found in patients after CABG and cold crystalloid cardioplegia. MATERIALS AND METHODS: Left ventricular (LV) biopsies were obtained from CABG patients (n = 10) prior to and at the end of cardiopulmonary bypass (CPB). These biopsies were immunostained for the inducible heat-shock protein 70 (HSP-70i), intercellular adhesion molecule-1 (ICAM-1) and actin. ATP was measured by bioluminescence. RESULTS: Biopsies pre-CPB showed no evidence of myocardial damage as HSP-70i was absent and a regular actin cross-striation pattern and only constitutive ICAM-1-expression were present. After CPB we found significantly increased HSP-70i and ICAM-1 levels as well as a deranged actin cross-striation pattern with a widening of actin bands. ATP levels declined from 10 mmol L-1 pre-CPB to 4.9 mmol L-1 after CPB. Correspondingly, coronary sinus effluent showed a significant lactate production. Although, cardiac function determined by transoesophageal echocardiography did not deteriorate, significant inotropic support was necessary to maintain cardiac output. CONCLUSIONS: Our results present clinical and structural evidence of 'myocardial stunning' after CABG and cold crystalloid cardioplegia. Increased HSP-70i and ICAM-1 expression, as well as a deranged actin cross-striation pattern, might be structural markers to determine 'myocardial stunning' in clinical settings.

Actins↗
PubMed1999

Variation in tau, the time constant for isovolumic relaxation, along the left ventricular base-to-apex axis.

Tau (tau), the time constant for isovolumic relaxation, is often used as a measure of cardiac diastolic function. However, several methods of calculating tau have been published which may produce different results and, thereby, different conclusions. The purpose of this study was to determine if the method of tau calculation effects the results when left ventricular pressure (LVP) is measured at different positions along the base-to-apex axis. In 16 dogs, we measured LVP at 6 positions along the base-to-apex axis. We calculated tau using three different methods: 1) a monoexponential model (P(t) = [P0-Pasym]eAt + Pasym, where t = time, P0 = LVP at t = 0, Pasym is asymptotic pressure as t-->infinity, A is -1/tau) with a zero asymptote 2) a monoexponential model with a variable asymptote in which the monoexponential decay equation is differentiated with respect to time and substituted into the original equation so that dP/dt vs. LVP is A (-1/tau), and 3) a monoexponential decay model with variable asymptote in which Pasym and A are varied until the best fit line is reached by minimizing the residual sum of squares. When tau is calculated using method 1, tau measured at the LV base is 98.01% +/- 8.85% of tau at the apex. If calculated using method 2, tau measured at the LV base was 75.46 +/- 39.4% of tau measured at the apex. When method 3 is used for tau calculations, base tau increases to 117.76 +/- 4.91% of the apical tau. We conclude: 1) the method used to calculate tau will effect the results and, thus, conclusions drawn from tau data. 2) When using Method 3, which appears to be the best method for tau calculation, tau increases at the LV base compared to the apex.

Animals↗
PubMed1999

Cardiac myocytes of hearts from patients with end-stage dilated cardiomyopathy do not contain Borrelia burgdorferi DNA.

OBJECTIVE: To determine if end-stage dilated cardiomyopathy (DCM) is associated with the presence of Lyme disease causing spirochete Borrelia burgdorferi in the myocardium, we used nested polymerase chain reaction to detect B burgdorferi DNA in myocardial samples from explanted hearts of patients with end-stage DCM. Patients originated from endemic areas for Lyme disease (Bavaria, Lower Saxony, Germany). METHODS AND RESULTS: This was a retrospective study. Polymerase chain reaction was used to detect the specific B burgdorferi recombinant outer surface protein A (OspA) gene in myocardial tissue from 68 patients with end-stage DCM who had undergone heart transplantation. The clinical history of Lyme disease, the presence of Borrelia burgdorferi OspA, and antibodies against OspA in myocardial tissue and serum were investigated. B burgdorferi DNA was not detected in any of the 68 human hearts. Immunoglobulin G antibodies against specific B burgdorferi antigens were observed in 3 (12.5%) of 24 patients. In contrast, 4 hearts from rats experimentally infected with B burgdorferi were all positive for OspA DNA as measured by polymerase chain reaction. CONCLUSION: Our data show that cardiac myocytes of hearts obtained from subjects with end-stage DCM did not contain B burgdorferi DNA as investigated by polymerase chain reaction. However, B burgdorferi shows a high affinity for myocardial tissue as shown by the animal studies, indicating that myocardial infections are nevertheless possible.

Animals↗