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M Kochs

Publications and source records attributed to M Kochs.

At least 19 recordsLinked to original sources
PubMed2006

Comparison of the slow-release polymer-based paclitaxel-eluting Taxus-Express stent with the bare-metal Express stent for saphenous vein graft interventions.

BACKGROUND: The paclitaxel-eluting Taxus-Express stent is superior regarding angiographic and clinical outcome compared with its bare-metal platform for lesions in native coronary arteries. We studied the potential impact of the Taxus-Express stent in comparison with its bare-metal counterpart for treatment of lesions in saphenous vein grafts (SVGs). Furthermore, a meta-analysis was performed regarding use of drug-eluting (DES) vs bare-metal stents (BMS) in SVG lesions. METHODS: We analyzed 13 consecutive patients who underwent percutaneous revascularization in SVG lesions using the slow-release, paclitaxel-eluting Taxus-Express stent. These lesions were balanced with 26 patients with SVG lesions treated with the bare-metal Express stent (BMS) in the preceding period. Angiographic follow-up was performed after 6 months, clinical follow-up after 6 and 12 months. RESULTS: There were no statistically significant differences regarding clinical, procedural and angiographic parameters pre and post intervention. Binary restenoses occurred significantly less in the Taxus group compared with the BMS group (0% vs 34.6%; p=0.016). This translated into a significantly lower occurrence of major adverse cardiac events (death, Q-wave myocardial infarction, repeat target vessel revascularization) in the Taxus group compared with the BMS group at the 6-month (0% vs 26.9%, p=0.039) and 12-month follow-up (7.7% vs 38.5%, p=0.045). Multivariate predictors for freedom of binary restenosis were the reference diameter pre intervention and treatment with Taxus stents. Meta-analysis including 280 DES and 256 BMS patients revealed an odds ratio of 0.34 (95% confidence interval 0.21-0.54) for MACE and 0.26 (95% confidence interval 0.16-0.44) for target vessel revascularizations, both favoring DES. CONCLUSIONS: We conclude that the use of the slow-release Taxus-Express stent has the potential to be superior regarding angiographic and clinical outcome compared with its bare-metal counterpart for treatment of SVG lesions within a 12-month follow-up. A large, randomized trial including a long follow-up period is now required to prove the results of the meta-analysis.

Aged↗
PubMed2004

Assessment of left ventricular function with steady-state-free-precession magnetic resonance imaging. Reference values and a comparison to left ventriculography.

UNLABELLED: Ejection fraction (EF) and end-diastolic and end-systolic volume index (EDVI/ ESVI) derived from ventriculography are important prognostic parameters. Cine magnetic resonance imaging (MRI) using a steady-state, free-precession sequence (SSFP) offers excellent delineation of the endocardial borders and highly reproducible and accurate results for cardiac volumes. We evaluated MRI volumetry against routine x-ray ventriculography. In 200 patients EF, EDVI and ESVI were measured with MRI volumetry and x-ray ventriculography. The same MRI protocol was applied to 102 healthy persons in order to establish reference values. In healthy subjects mean EF was 68.8% +/- 5.4% (range 59-84%), mean EDVI 69 +/- 10 (43-90) and mean ESVI 22 +/- 5.8 (10-35 ml). In the patients, overall correlation (Spearman's R) of MRI with ventriculography was 0.86 for EF, 0.77 for EDVI and 0.88 for ESVI. For postextrasystolic beats (38% of the measurements), R was 0.73/0.65/0.73 for EF/EDVI/ESVI. MRI correlated best with biplane ventriculography during sinus rhythm (0.96/0.85/0.93); the worst correlation (0.78/0.81/0.83) resulted from patients with wall motion abnormalities in comparison to monoplane x-ray ventriculography. CONCLUSION: Contemporary MRI volumetry compares well to invasive data obtained under optimal conditions. In view of the known limitations of single plane ventriculography, MRI seems to allow exact volumetry independent from regional wall motion abnormalities.

Cardiac Catheterization↗
PubMed2004

Value of the proximal flow convergence method for quantification of the regurgitant volume in mitral regurgitation Influence of the mechanism of regurgitation, the imaging of the flow convergence region, and different calculation modalities.

UNLABELLED: The purpose of this study was to evaluate whether the underlying mechanism of mitral regurgitation influences the reliability of the proximal flow con- vergence method to assess the regurgitant volume. Furthermore, the mode of imaging the flow convergence region and different correction algorithms for calculation of the regurgitant volume were compared. METHODS: Regurgitant volume was assessed in 45 patients (age 61+/-13 years) with organic (n=19) and functional (n=26) mitral regurgitation by the proximal flow convergence method for aliasing velocities between 14 and 64 cm/s using two-dimensional color Doppler imaging. Different correction and calculation algorithms were compared. In addition, regurgitant volume was determined using color Doppler M-mode for an aliasing velocity of 28 cm/s. The quantitative Doppler method was used as reference. RESULTS: In organic mitral regurgitation correlation coefficients (mean differences) between the proximal flow convergence method and the reference method were 0.25-0.43/ 0.58-0.67 (46-111 ml/15-17 ml) before/after geometric correction of the regurgitant volume for the aliasing velocities investigated. The correlation coefficient (mean difference) using color Doppler M-mode imaging was 0.68 (85 ml). The corresponding values in functional mitral regurgitation were 0.74-0.88/0.74-0.88 (-5-8 ml/-7-5 ml) for two-dimensional color Doppler and 0.88 (-1 ml) for M-mode imaging. CONCLUSIONS: The regurgitant volume was overestimated by the proximal flow convergence method in organic mitral regurgitation irrespective of the application of different correction algorithms or the use of color Doppler M-mode. A sufficiently reliable determination of the regurgitant volume by the proximal flow convergence method was possible in functional mitral regurgitation. In that case a simplified calculation of the regurgitant volume based on the proximal flow convergence method was feasible.

Adult↗
PubMed2003

[Effect of molsidomine on rheological parameters and the incidence of cardiovascular events].

BACKGROUND AND OBJECTIVE: In-vitro studies revealed that nitric oxide (NO) may affect rheological parameters. We studied the effect of highly-dosed NO-donor molsidomine on blood rheology and the impact of rheological parameters on the incidence of severe cardiovascular events. PATIENTS AND METHODS: In this randomized, placebo-controlled and double-blind trial 166 patients (60 +/- 10 years) with stable angina pectoris and coronary intervention received molsidomine 3 x 8 mg t. i. d. (controlled release tablets) or placebo for 6 months. Patients with inflammatory/neoplastic disorders or elevated values of C-reactive protein were excluded from analysis. A rheological profile (plasma viscosity, blood viscosity, aggregation and flexibility of erythrocytes, filtrability of leukocytes, fibrinogen levels) was done initially and after 6 months. Adverse cardiovascular events (death, myocardial infarction, stroke, coronary/peripheral revascularization) were recorded during 12 months. Furthermore, the impact of rheological parameters regarding the occurrence of severe cardiovascular events (death, myocardial infarction, stroke) was evaluated during a follow-up of median 38 months. RESULTS: The data of 137 patients (n = 71 placebo, n = 66 molsidomine) were analysed. The difference of rheological parameters between the two measurements did not vary between the two groups. Analysis of event-free survival with Kaplan-Meier technique revealed no difference between the two groups. Multivariate Cox regression analysis with adjustment for diabetes mellitus, smoking and therapy with statin showed a significant association of fibrinogen and plasma viscosity with the occurrence of severe cardiovascular events. CONCLUSION: Treatment with molsidomine 3 x 8 mg/day for 6 months does not improve blood rheology or reduce cardiovascular events. But elevated levels of fibrinogen and plasma viscosity were associated with the occurrence of severe cardiovascular events.

Blood Viscosity↗
PubMed2003

Syncope in the elderly.

Syncope is defined as a self-limited loss of consciousness, usually combined with falling due to the inability to maintain postural tone. The underlying mechanism is a transient global cerebral hypoperfusion. The aetiology essentially includes cardiac disorders (structured heart disease or arrhythmias), neurally-mediated reflex syndromes, orthostatic hypotension and carotid sinus syndrome. History and physical examination will lead to the diagnosis in up to 50%. The most important step is to differentiate patients with heart disease from others, since the mortality of these patients is doubled. Echocardiography, Holter-monitoring and electrophysiological study are useful to approach this population. In patients with suspected neurally-mediated syncope (vasovagal syncope) tilt testing is indicated. Treatment depends on the aetiology. The diagnostic work-up and the therapeutic approach of patients with syncope are outlined. For patients with vasovagal syncope conventional therapeutic strategies include an increased salt/fluid intake, moderate exercise training, tilt-sleeping or tilt-training. Beta-blockers failed to show efficacy in a number of randomised trials. Recently, pacemaker implantation in selected patients with recurrent vasovagal syncopical episodes showed a significant increase in syncope-free survival, compared to no therapy and compared to beta-blocker therapy. In contrast to the increased mortality risk for patients with cardiac syncope, patients with vasovagal syncope have a benign prognosis.

Accidental Falls↗
PubMed2003

Pulmonary hemodynamics in obstructive sleep apnea: frequency and causes of pulmonary hypertension.

The association between nocturnal apneas and transient pulmonary hypertension (PHT) has been well documented. However, there is controversy over the frequency and pathophysiological mechanisms of daytime pulmonary hypertension in patients with obstructive sleep apnea (OSAS). The present study sought to evaluate frequency and mechanisms of pulmonary hypertension in patients with OSAS. It included 49 consecutive patients with polysomnographically proven OSAS without pathological lung function testing. All patients performed daytime measurements of pulmonary hemodynamics at rest and during exercise (50-75W). Six patients (12%) had resting PHT mean pulmonary of artery pressure (PAPM) of >20 mmHg), whereas 39 patients (80%) showed PHT during exercise (PAPM >30 mmHg). Multiple regression analysis revealed 3 independent contributing factors for mean pulmonary artery pressure during exercise (PAPMmax): body mass index, age and total lung capacity % of predicted. Twenty-five of the 39 patients with pathologically high PAPMmax (64%) showed elevated pulmonary capillary wedge pressures (PCWPmax > 20 mmHg), whereas no patient had elevated pulmonary vascular resistance (PVRmax > 120 dynes x s x cm(-5)). In conclusion, daytime PHT during exercise is frequently seen in patients with OSAS and normal lung function testing and is mainly caused by abnormally high PCWP, whereas PVR seems to play a minor role.

Adult↗
PubMed2001

Comparison of the heparin coated vs the uncoated Jostent--no influence on restenosis or clinical outcome.

AIMS: Heparin coating of stents is thought to reduce stent thrombosis and restenosis rates. However, clinical data comparing coated and uncoated stents of the same model are lacking. We compared the heparin coated (C) and the uncoated (U) version of the Jostent stent with regard to the clinical and angiographic outcome after 6 months. METHODS AND RESULTS: Provisional stenting was done in 277 patients and 306 lesions; only 40 were Benestent-II like lesions. Delivery success rate was 98.4%. Both groups (C/U: n=156/150 lesions) were comparable in clinical and procedural data. Post stenting, reference diameter (C/U: 2.68+/-0.56/2.66+/-0.53 mm) and minimal lumen diameter did not differ (C/U: 2.48+/-0.47/2.48+/-0.52 mm). During follow-up the rate of subacute stent thrombosis (C/U: 1.9%/1.3%) and myocardial infarction did not differ. Angiography at the 6-month follow-up (79.4%) revealed no difference in restenosis rate (C/U: 33.1%/30.3%). Risk factors for restenosis were a type B2/C lesion (P<0.02), a stented segment longer than 16 mm (P<0.006) and a stent inflation pressure <14 bar (P<0.0063). CONCLUSION: Corline heparin coating of the Jostent has no impact on the in-hospital complication rate, stent thrombosis or restenosis. The Jostent design gives a high procedural success rate and satisfying result at 6 months in an everyday patient population undergoing provisional stenting.

Anticoagulants↗
PubMed2000

Intracoronary beta-irradiation with a liquid (188)re-filled balloon: six-month results from a clinical safety and feasibility study.

BACKGROUND: Coronary irradiation is a new concept to reduce restenosis. We evaluated the feasibility and safety of intracoronary irradiation with a balloon catheter filled with (188)Re, a liquid, high-energy beta-emitter. METHODS AND RESULTS: Irradiation with 15 Gy at 0.5-mm tissue depth was performed in 28 lesions after balloon dilation (n=9) or stenting (n=19). Lesions included 19 de novo stenoses, 4 occlusions, and 5 restenoses. Irradiation time was 515+/-199 seconds in 1 to 4 fractions. There were no procedural complications. One patient died of noncardiac causes at day 23. One asymptomatic patient refused 6-month angiography. Quantitative angiography after intervention showed a reference diameter of 2. 77+/-0.35 mm and a minimal lumen diameter of 2.36+/-0.43 mm. At 6-month follow-up, minimal lumen diameter was 1.45+/-0.88 mm (late loss index 0.57). Target lesion restenosis rate (>50% in diameter) was low (12%; 3 of 26). In addition, we observed 9 stenoses at the proximal or distal end of the irradiation zone, potentially caused by the short irradiation segment and the decreasing irradiation dose at its borders ("edge" stenoses). The total restenosis rate was 46% and was significantly lower (29% vs 70%, P=0.042) when the length of the irradiated segment was more than twice the lesion length. CONCLUSIONS: Coronary irradiation with a (188)Re-filled balloon is technically feasible and safe, requiring only standard percutaneous transluminal coronary angioplasty techniques. The target lesion restenosis rate was low. The observed edge stenoses appear to be avoidable by increasing the length of the irradiated segment.

Adolescent↗
PubMed2000

Elevation of vascular endothelial growth factor-A serum levels following acute myocardial infarction. Evidence for its origin and functional significance.

Following the onset of acute myocardial infarction (AMI), a number of serum parameters show well-defined changes reflecting myocardial injury. During the consecutive repair phase, compensatory processes are initiated including the formation of a collateral circulation on the basis of angiogenesis and arteriogenesis. An important angiogenic factor is vascular endothelial growth factor-A (VEGF-A), shown to be upregulated in the ischemic myocardium. It is unclear, however, whether acute myocardial ischemia leads to a detectable elevation of VEGF-A serum concentrations. With the use of an immunoradiometric assay, we measured the levels of VEGF-A in the serum of patients after AMI at defined time intervals, of patients with unstable angina pectoris (UAP) and of healthy individuals. In addition, in a small group of patients with subacute myocardial infarction VEGF-A concentrations were measured in coronary sinus blood. The data are given as median followed by the 25th and 75th percentiles. In the group with AMI serum VEGF-A measured 105 [78; 176] pg/ml on day 1 and 114 pg/ml [72; 163] pg/ml on day 3 after onset of AMI. Serum levels of VEGF-A significantly increased on day 7 after AMI to 189 [119; 373] pg/ml (P=0.0103) and on day 10 to 255 [162; 371] pg/ml (P=0.0007). The VEGF-A serum level in healthy controls and in patients with UAP measured 98 [75; 137] pg/ml and 116 [57; 140] pg/ml, respectively. Serum at day 10 after AMI contained VEGF-A at a biologically relevant concentration capable of stimulating proliferation of endothelial cells. Surprisingly, VEGF-A serum levels were similar in samples taken from the coronary sinus with 61 [43; 83] pg/ml. Therefore the main source for VEGF-A in the blood stream is not the infarcted myocardium. However, the number of platelets, a rich source of VEGF-A, is significantly increased after myocardial infarction, i.e. 284 [252; 363] x 10(9)/litre v 220 [177; 250] x 10(9)/litre. In conclusion, the time course of VEGF-A elevation following AMI strongly suggests that VEGF-A plays a role as an endogenous activator of coronary collateral formation in the human heart. The most likely source of the elevated VEGF-A are platelets, rather than the infarcted myocardium.

Acute Disease↗
PubMed2000

[Risk stratification after myocardial infarct].

In industrialized countries the rate of sudden cardiac death remains unchanged. The most frequently encountered structural heart disease in these patients is coronary artery disease. Despite the era of thrombolytic therapy of acute myocardial infarction patients carry an increased risk of sudden cardiac arrhythmogenic death within a time period of one to two years following the acute event. Therefore, risk stratification post-MI before patient discharge is furthermore mandatory. The spectrum of non-invasive techniques for risk stratification includes the clinical risk profile, measurement of left ventricular global function (LV ejection fraction), the resting ECG (QT dispersion), an ECG stress test (detection and severity of myocardial ischemia), ambulatory ECG monitoring (number and type of ventricular arrhythmias), surface high resolution ECG (detection of ventricular late potentials), measurement of T wave alternans (TWA, alternans ratio), and measurements of the activity and balance of the autonomous nervous system (heart rate variability, baroreflex sensitivity = BRS). Programmed ventricular stimulation (PVS) serves as an invasive risk stratification technique (detection of an arrhythmogenic substrate). The prognostic power of the non-invasive techniques is limited; in general, the prognostic value of a negative test is reasonably high (90 to 100% depending on the test used), whereas the prognostic value of a positive test is rather low (4 to 42% depending on the test used). Combining several non-invasive tests may significantly improve the positive predictive value above 50%, but this goes along with a significant decreases of sensitivity below 50%. Therefore, a combination of several non-invasive tests (detection and exclusion of a large number of low-risk individuals) with the invasive method of PVS (detection of an arrhythmogenic substrate, i.e. a high-risk patient) seems reasonable, as has been convincingly shown by several smaller prognostic studies.

Arrhythmias, Cardiac↗
PubMed1999

Aortic regurgitant flow by color Doppler measurement of the local velocity 7 mm above the leak orifice--Part 2: Comparison with cardiac catheterization.

AIMS: An in vitro study of the flow convergence region in aortic regurgitation has shown that regurgitant flow rate can be derived from the local velocity V(7 mm) at 7 mm distance above the leak orifice. This clinical study was performed to test this method in patients. METHODS AND RESULTS: In 67 patients with aortic regurgitation, the flow convergence region was imaged by color Doppler. By analogy with the afore mentioned in vitro study, velocity profiles of the acceleration across the flow convergence region were read from the color maps. The profiles were fitted by using a multiplicative regression model. The V(7 mm) was read from the regression curve, and instantaneous regurgitant flow Q was derived from the V(7 mm) with the equation developed in vitro (Q = V(7 mm).cm2/0.28). Q showed a close association with the angiographic grade. Q-derived regurgitant stroke volume correlated significantly with invasive measurements by the angio-Fick method (r = 0.897, SEE = 19.9 ml, y = 0.88x + 5.9 ml). CONCLUSIONS: Within the color Doppler flow convergence region of aortic regurgitation, the local velocity at 7 mm distance to the leak reflects regurgitant flow rate.

Adult↗
PubMed1999

A randomized trial of elective stenting after balloon recanalization of chronic total occlusions.

OBJECTIVES: The aim of this study was to assess the role of Wiktor stent implantation after recanalization of chronic total coronary occlusions with regard to the clinical and angiographic outcome after six months. BACKGROUND: Beside the common use of stents in clinical practice, the number of stent indications proven by randomized trials is still limited. METHODS: Eighty-five patients with a thrombolysis in myocardial infarction grade 0 chronic coronary occlusion were examined. After standard balloon angioplasty, the patients were randomly assigned to stent implantation, or percutaneous transluminal coronary angioplasty (PTCA) alone (no further intervention). Quantitative coronary angiography was performed at baseline and after six months. RESULTS: The minimal lumen diameter did not differ immediately after recanalization (stent group 1.61 +/- 0.30 mm vs. PTCA group 1.65 +/- 0.36 mm), and increased after stent implantation to 2.51 +/- 0.41 mm. After six months, the stent group still had a significantly greater lumen (1.57 +/- 0.59 vs. 1.06 +/- 0.90 mm; p < 0.01) and a significantly lower restenosis and reocclusion rate (32% and 3%) compared with the PTCA group (64% and 24%); restenosis analysis according to treatment was 72% (PTCA) versus 29% (stent, p < 0.01). Late loss was equal in both groups. At follow-up, the stent patients had a better angina class (p < 0.01), and fewer cardiac events (p < 0.03). A meta-analysis including this trial and three other controlled trials with the Palmaz-Schatz stent showed concordant results. CONCLUSIONS: Stent implantation after reopening of a chronic total occlusion provides a better angiographic result, corresponding to a better clinical outcome with fewer recurrence of symptoms and reinterventions after six months.

Adult↗
PubMed1998

Quantification of mitral and tricuspid regurgitation by the proximal flow convergence method using two-dimensional colour Doppler and colour Doppler M-mode: influence of the mechanism of regurgitation.

In patients with mitral (n=77: organic=49, functional=28) and tricuspid regurgitation (n=55: functional=54) quantified by angiography, the temporal variation of the proximal flow convergence region throughout systole was assessed by colour Doppler M-Mode, and peak and mean radius of the proximal isovelocity surface area for 28 cm/s blood flow velocity were measured. Additionally, the peak radius derived from two-dimensional colour Doppler was obtained. About 50% of the patients with mitral and tricuspid regurgitation showed a typical temporal variation of the flow convergence region related to the mechanism of regurgitation. The different proximal isovelocity surface area radii were similarly correlated to the angiographic grade in mitral and tricuspid regurgitation (rank correlation coefficients 0.55-0.89) and they differentiated mild to moderate (grade < or =II) from severe (grade > or =III) mitral and tricuspid regurgitation with comparable accuracy (82-96%). However, moderate mitral regurgitation due to leaflet prolapse in two patients was correctly classified by the mean M-mode radius and overestimated by both peak radii. Only half of the patients showed a typical variation of the flow convergence region related to the mechanism of regurgitation. The different proximal isovelocity surface area radii were suitable to quantify mitral and tricuspid regurgitation in most patients. However, in mitral regurgitation due to leaflet prolapse the use of the mean M-mode radius may avoid overestimation.

Adult↗
PubMed1998

Heart-rate variability for discrimination of different types of neuropathy in patients with insulin-dependent diabetes mellitus.

It has been shown that patients with insulin-dependent diabetes mellitus (IDDM) may reveal abnormal alterations in heart-rate variability (HRV) due to autonomic neuropathy. This study was performed to prove whether heart-rate variability can be used to stratify diabetic patients with different types of neuropathy. 48 patients with IDDM (age 17-64 yr) underwent standard function tests to assess autonomic and peripheral neuropathy. According to the results of these tests they were divided into 4 groups: Group 1: 18 patients without autonomic or peripheral neuropathy. Group 2: 13 patients with peripheral neuropathy. Group 3: 7 patients with autonomic neuropathy. Group 4: 9 patients with autonomic and peripheral neuropathy. HRV was measured by continuous 24-hours monitoring and time domain parameters were calculated. The results were compared with sex and age-matched healthy controls according to the individual characteristics of the groups and among each subgroup. Our results showed that in Group 1 there was a significant difference of time domain parameters indicative of parasympathetic influence, i.e. rMSSD and pNN50 in comparison to the control subjects (p = 0.002, p = 0.008). These results depended on the duration of diabetes; a subgroup of patients with a duration of IDDM of less than 2 years had no significant differences of HRV values. Group 2 showed the same significant differences. Group 3 and 4 showed significant differences in all measured time domain variables (SDNN, SDANN, SDNN index, rMSSD and pNN50) in comparison to the control subjects (p < 0.04). A comparison of group 1 with group 2 offered significant differences in rMSSD and pNN50 (p = 0.004, p = 0.003). Comparing group 1 with group 3 and 4, all HRV parameters showed significant differences (p < 0.03). In conclusion, HRV is able to distinguish between patients with different types of neuropathy depending on the involvement of parasympathetic or more sympathetic influenced parameters. Furthermore, this method is able to unmask early manifestations of neurological disorders prior to their detection by neurological function tests.

Adolescent↗
PubMed1998

Time-dependent changes of heart rate variability after percutaneous transluminal angioplasty.

OBJECTIVES: It is not known whether the improvement of myocardial perfusion by percutaneous transluminal coronary angioplasty (PTCA) is followed by a response of the autonomic nervous system depending on the recovery of the myocardium. In this study we investigated changes of heart rate variability parameters in patients before and after PTCA at different time intervals. METHODS: In 42 patients with coronary artery disease documented on angiography, before and after PTCA 24-hour measurements of heart rate variability (HRV) were performed from Holter tapes. The time elapsed between the two measurements was 3 to 4 days in 26 patients and 6 to 8 months in 16 patients. Time domain parameters of HRV were calculated. RESULTS: Comparison of the two recordings showed that the parameters rMSSD, pNN50, and SDNN index decreased, whereas SDNN and SDANN increased. These changes were not statistically significant. A subgroup analysis revealed different results for patients with and without previous myocardial infarction: the parasympathetically and more sympathetically influenced parameters revealed different changes in these groups. Other variables such as ejection fraction or severity of coronary artery disease did not influence the HRV results. Although no statistically significant difference was seen on comparison of the patients with different recording intervals, patients with a longer interval between the two measurement periods showed higher values of all HRV parameters closer to normalized values. This observation may be explained by a delayed recovery of myocardial function after successful revascularization by PTCA.

Adult↗
PubMed1998

Comparison of the proximal flow convergence method and the jet area method for the assessment of the severity of tricuspid regurgitation.

AIMS: To compare the value of the proximal flow convergence method and the jet area method for the determination of the severity of tricuspid regurgitation. METHODS AND RESULTS: The proximal isovelocity surface area radius and the jet area/length were measured in 71 consecutive patients with angiographically graded (grade 0/I-III) tricuspid regurgitation. Rank correlation coefficients with the angiographic grade were 0.71 (P < 0.001) for the proximal isovelocity surface area radius (aliasing border of 28 cm.s-1), 0.66 (P < 0.001) for the jet area, and 0.63 (P < 0.001) for the jet length. The proximal isovelocity surface area radius was significantly correlated with the jet area/length (correlation coefficients 0.82/0.77, P < 0.001). Correct differentiation between mild to moderate (grade I-II) and severe (grade III) tricuspid regurgitation was achieved in 62 of 71 patients (87%) by means of the proximal isovelocity surface area radius, in 61 of 71 (86%) by the jet area, and in 62 of 71 (87%) by the jet length. Grade III tricuspid regurgitation was not identified in five of 21 patients (24%) by means of the proximal isovelocity surface area radius, in six of 21 (29%) by the jet area, and in seven of 21 (33%) by the jet length. CONCLUSION: The flow convergence method and the jet area method are of similar value for the determination of the severity of tricuspid regurgitation. Both methods differentiated mild to moderate from severe tricuspid regurgitation in most patients. However, underestimation of severe tricuspid regurgitation in 20-30% of the cases represents a serious limitation of both methods.

Adult↗
PubMed1998

Direct enzyme immunometric measurement of plasma big endothelin-I concentrations and correlation with indicators of left ventricular function.

Recent studies have suggested that the plasma concentrations of endothelin-1, a potent vasoconstrictive peptide, are increased in patients with congestive heart failure. This study aimed to evaluate a new direct ELISA for big endothelin-1 (the precursor of endothelin-1), in comparison with a big endothelin-1 ELISA using plasma sample extraction, and to investigate whether plasma big endothelin-1 concentrations correlate with indicators of left ventricular function. The direct ELISA yielded significantly (P < 0.001) lower results than the assay with extracted samples (0.9 +/- 0.5 pmol/L vs 2.7 +/- 1.9 pmol/L; n = 90); however, the results of the two assays were closely correlated (r = 0.86, P < 0.001). Plasma big endothelin-1 concentrations exhibited a significant (P < 0.001) negative correlation (r = -0.46, r = -0.40) with the left ventricular ejection fraction and a significant positive correlation (r = 0.40, P < 0.001; r = 0.36, P < 0.01) with the left ventricular end-diastolic pressure and the left ventricular end-diastolic (r = 0.42, r = 0.38, P < 0.001) and end-systolic (r = 0.52, r = 0.47, P < 0.001) volume indices. Plasma big endothelin-1 concentrations were notably greater in patients with New York Heart Association (NYHA) class II-IV symptoms than in patients without cardiac disease or in patients categorized to NYHA class I. These data suggest that plasma big endothelin-1 concentrations, measured by a direct ELISA, correlate with hemodynamic indicators and symptoms of left ventricular dysfunction.

Adult↗