Prospective multicentre clinical study on inter- and intrapatient genetic variability for antimicrobial resistance of Helicobacter pylori.

OBJECTIVES: We report on a large prospective, multicentre clinical investigation on inter- and intrapatient genetic variability for antimicrobial resistance of Helicobacter pylori. METHODS: Therapy-naive patients (n = 2004) who had undergone routine diagnostic gastroscopy were prospectively included from all geographic regions of Austria. Gastric biopsy samples were collected separately from antrum and corpus. Samples were analysed by histopathology and real-time PCR for genotypic resistance to clarithromycin and quinolones. Clinical and demographic information was analysed in relation to resistance patterns. RESULTS: H. pylori infection was detected in 514 (26%) of 2004 patients by histopathology and confirmed in 465 (90%) of 514 patients by real-time PCR. PCR results were discordant for antrum and corpus in 27 (5%) of 514 patients, indicating inhomogeneous infections. Clarithromycin resistance rates were 17% (77/448) and 19% (84/455), and quinolone resistance rates were 12% (37/310) and 10% (32/334) in antrum and corpus samples, respectively. Combination of test results per patient yielded resistance rates of 21% (98/465) and 13% (50/383) for clarithromycin and quinolones, respectively. Overall, infection with both sensitive and resistant H. pylori was detected in 65 (14%) of 465 patients. CONCLUSIONS: Anatomically inhomogeneous infection with different, multiple H. pylori strains is common. Prospective clinical study design, collection of samples from multiple sites and microbiologic methods that allow the detection of coinfections are mandatory for collection of reliable data on antimicrobial resistance patterns in representative patient populations. (ClinicalTrials.gov identifier: NCT02925091).

Increased neopterin in patients with chronic and acute coronary syndromes.

OBJECTIVES: The aim of our study was to determine neopterin levels in patients with chronic and acute coronary syndromes. BACKGROUND: In chronic and acute coronary syndromes the release of different cytokines activates cellular defense. Infiltration of neutrophils and monocytes/macrophages is detected in the vessel wall as well as in the myocardium. Neopterin, which is a by-product of the guanosine triphosphate-biopterin pathway, is a marker for those activated macrophages. METHODS: We studied 123 subjects: 1) 21 consecutive patients (17 men, 4 women; mean age +/- SD 66 +/- 15 years, range 31 to 87) with acute myocardial infarction (AMI); 2) 62 consecutive patients (50 men, 12 women; mean age 61 +/- 8 years, range 43 to 81) with signs and symptoms of clinically stable coronary artery disease (CAD); and 3) 40 healthy blood donors (28 men, 12 women; mean age 35 +/- 13 years). Neopterin levels were determined with a commercially available enzyme-linked immunosorbent assay method. RESULTS: In patients with AMI before thrombolytic therapy, neopterin levels were significantly higher than levels in patients with CAD and control subjects (13.7 vs. 8.6 and vs. 6.8 nmol/liter, p < 0.0001). Values also differed significantly between patients with CAD and control subjects (p < 0.0001). Neopterin levels in patients with AMI were measured seven times during a 72-h period. Within-group comparison showed significant differences over this period (p < 0.00001). The lowest value (11.4 nmol/liter) was observed after 4 h and differed significantly from the initial value and values after 24 and 72 h (p < 0.05). After 72 h, neopterin increased to 14.9 nmol/liter, a value significantly different from all values other than the initial one. There was no correlation between neopterin and creatine kinase (CK); CK, MB isoenzyme; or lactate dehydrogenase as markers for the extent of the myocardial infarction during the observation period. CONCLUSIONS: Our data support the hypothesis of an activation of monocytes and macrophages in patients with an acute or chronic coronary syndrome. Neopterin as a marker for macrophage activation is significantly increased in patients with chronic CAD and more pronounced in patients with AMI shortly after the onset of symptoms.

Binding of endothelin to plasma proteins and tissue receptors: effects on endothelin determination, vasoactivity, and tissue kinetics.

In vitro binding of (3-[125I]Tyr)-endothelin-1 ([125I]ET-1) and (3-[125I]Tyr)-big ET-1(1-38) ([125I]big ET-1) to plasma proteins of healthy humans, cardiac patients and normotensive and hypertensive rats was investigated by equilibrium dialysis. Binding of both tracers was similar in plasma from healthy humans, patients with congestive heart failure, and following myocardial infarction (approximately 60%), and marginally higher in rat plasmas (approximately 70%). Binding of [125I]ET-1 to human plasma could be explained by binding to human serum albumin. Endogenous plasma ET-1 levels were approximately 9 pg/ml in healthy humans, and approximately 12-16 pg/ml in cardiac patients; big ET-1 concentrations were approximately two- to threefold higher. ET-1 bound to plasma protein was partly lost in column extraction. In rat isolated perfused hearts, the coronary dilator and constrictor potency of exogenous free and albumin-bound ET-1 was similar, whereas the kinetics of endogenous ET-1 was impeded by tight binding to ET receptors. The data indicate that binding of ET-1 to plasma proteins is without effect on peptide vasoactivity, but binding to tissue receptors greatly impedes its tissue kinetics.

Comparison of wrist blood pressure measurement with conventional sphygmomanometry at a cardiology outpatient clinic.

OBJECTIVE: Oscillometric measurement of blood pressure at the wrist is becoming a widely used method for detection of hypertension and its control by treatment. The objective of the present study was to evaluate accuracy and suitability of wrist measurement in a clinical routine setting. PATIENTS AND METHODS: A series of 333 consecutive patients admitted to our cardiology outpatient clinic were included. Blood pressure was measured at both upper arms according to World Health Organization-International Society of Hypertension guidelines. Oscillometric measurement was performed at the contralateral wrist simultaneously. Blood pressure readings were taken by an oscillometric device applied at the wrist ('Klock'; Industrielle Entwicklung Medizintechnik, Stolberg, Germany) and a conventional mercury sphygmomanometer applied at the upper arm. RESULTS: Seventy-eight patients were excluded due to differences in blood pressure > 5 mmHg between both upper arms or due to 'error' messages of the wrist device. The data of the remaining 255 patients (149 males; mean age, 65 +/- 13 years; range, 18-95 years) are presented. Mean conventional blood pressure was significantly lower compared with the wrist device (137 +/- 20/80 +/- 11 mmHg versus 153 +/- 28/87 +/- 18 mmHg; P < 0.001 and P < 0.001). The mean difference was 16 +/- 25/6 +/- 17 mmHg. In clinical terms, differences in blood pressure exceeding +/-20/+/-10 mmHg reflecting classification of hypertension are considered important. Measurements of 101 (40%) patients were within these limits. Systolic readings of 110 (43%) and diastolic readings of 117 patients (46%) were beyond this scope. CONCLUSION: Due to low reliability of wrist blood pressure measurement, it cannot compete with the upper arm standard procedure. If ever, it should only be used if test readings in an individual comparing wrist and upper arm measurement show differences within a range of +/-20/+/-10 mmHg.

Pulmonary hypertension. Response of vasoactive peptides to a nonionic contrast medium in patients undergoing pulmonary angiography.

RATIONALE AND OBJECTIVES: The degree to which pulmonary angiography may contribute to serious complications in patients with pulmonary hypertension has not been clarified and remains a matter of debate. Accordingly, this study was designed (1) to detect the potential release of vasoactive peptides and (2) to investigate the hemodynamic response after administration of a nonionic contrast medium in patients with pulmonary hypertension undergoing pulmonary angiography. Allergy-mediating substances also were measured to monitor for possible anaphylactoid reactions. METHODS: Pulmonary digital subtraction angiography was performed in 20 patients with pulmonary hypertension (mean pulmonary arterial pressure more than 20 mm Hg). Iopromide was administered as a total of 100 mL via a 7F catheter inserted from the right femoral vein. The injected volume and duration of injection (15 to 20 mL/sec) were kept constant. Hemodynamic parameters were continuously monitored, including electrocardiogram, heart rate, phasic and mean pulmonary arterial and peripheral arterial pressures. Blood samples were obtained before and after administration of contrast media to assay for the concentration of the following vasoactive peptides using radioimmunoassay techniques: renin, angiotensin-I-converting enzyme, angiotensin II, aldosterone, atrial natriuretic peptide, antidiuretic hormone, cyclic-guanosine monophosphate, and myoglobin, as well as allergy-mediating substances such as tryptase, eosinophil protein X, and eosinophil cationic protein. RESULTS: Administration of iopromide caused significant increases in atrial natriuretic peptide (from 61.3 +/- 11.8 to 94.0 +/- 16.7) and antidiuretic hormone (from 6.6 +/- 1.9 to 12.3 +/- 3.1), whereas renin significantly decreased (from 3.0 +/- 0.6 to 1.3 +/- 0.5). After administration of contrast media, there were no significant changes in the other measured vasoactive peptides, allergy-mediating substances, and monitored cardiovascular parameters. CONCLUSION: Administration of iopromide for pulmonary angiography in patients with pulmonary hypertension resulted in no appreciable hemodynamic alterations associated with the observed changes in atrial natriuretic peptide, antidiuretic hormone, and renin. No allergy-mediated reactions were observed in these patients.

Effects of iopromide on vasoactive peptides and allergy-mediated substances in healthy volunteers.

RATIONALE AND OBJECTIVES: Little information is available about the direct action of angiographic contrast media on vasoactive peptides and allergy-mediated substances in humans. This study defined the acute effects of iopromide, a nonionic contrast medium (370 mg/mL iodine), on vasoactive peptides, allergy-mediated substances, and hemodynamic parameters in healthy volunteers. METHODS: Pulmonary digital subtraction angiography was performed in seven healthy volunteers with no cardiovascular or pulmonary disease. Iopromide was administered as a total volume of 100 mL through a 7-Fr catheter inserted in the right femoral vein. The injected volumes and duration of injection (15-20 mL/second) were kept constant. The following hemodynamic parameters were monitored continuously: results of electrocardiogram, heart rate, and phasic and mean pulmonary arterial and peripheral arterial pressures. Blood samples were obtained before and 3 to 5 minutes after injection of contrast media to determine the concentrations of the following vasoactive peptides: renin, angiotensin I-converting enzyme, angiotensin II, aldosterone, atrial natriuretic peptide, antidiuretic hormone, cyclic guanosine monophosphate, and myoglobin; and to allergy-mediated substances such as tryptase, eosinophil protein X, and eosinophil cationic protein, using radioimmunoassay techniques. RESULTS: Iopromide substantially increased atrial natriuretic peptide (48.8 +/- 8.9 to 85.8 +/- 13.0) and antidiuretic hormone (3.4 +/- 0.3 to 4.6 +/- 0.5) levels, whereas renin decreased (0.9 +/- 0.1 to 0.8 +/- 0.2) slightly but not significantly. Iopromide did not induce substantial changes in the other vasoactive peptides or in allergy-mediated substances after the contrast medium was injected. Similarly, cardiovascular parameters (heart rate, pulmonary and systemic blood pressures, and results of electrocardiogram) also remained unchanged after contrast injection. CONCLUSION: Iopromide caused no appreciable hemodynamic alterations associated with the changes in atrial natriuretic peptide and antidiuretic hormone and no evidence of allergy-mediated reactions in all volunteers.

Differing beta-blocking effects of carvedilol and metoprolol.

BACKGROUND: Metoprolol is a beta(1)-selective beta-adrenergic antagonist while carvedilol is a non-selective beta-blocker with additional blockades of alpha(1)-adrenoceptors. Administration of metoprolol has been shown to cause up-regulation of beta-adrenoceptor density and to decrease nocturnal melatonin release, whereas carvedilol lacks these typical effects of beta-blocking drugs. AIMS: To compare beta-blocking effects of metoprolol and carvedilol when applied orally in healthy subjects. METHODS: We investigated the effects of single oral doses of clinically recommended amounts of metoprolol (50, 100 and 200 mg) and carvedilol (25, 50 and 100 mg) to those of a placebo in a randomised, double-blind, cross-over study in 12 healthy male volunteers. Two hours after oral administration of the drugs heart rate and blood pressure were measured at rest, after 10 min of exercise, and after 15 min of recovery. RESULTS: Metoprolol tended to decrease heart rate during exercise (-21%, -25% and -24%) to a greater extent than carvedilol (-16%, -16% and -18%). At rest, increasing doses of metoprolol caused decreasing heart rates (62, 60 and 58 beats/min) whereas increasing doses of carvedilol caused increasing heart rates (62, 66 and 69 beats/min), 50 and 100 mg carvedilol failed to differ significantly from the placebo (71 beats/min). CONCLUSIONS: We conclude that clinically recommended doses of carvedilol cause a clinically relevant beta-blockade in humans predominantly during exercise where it appears to be slightly (although not significantly) less effective than metoprolol. On the other hand, the effects of carvedilol on heart rate at rest appear rather weak, particularly in subjects with a low sympathetic tone. This might be caused by a reflex increase on sympathetic drive secondary to peripheral vasodilation resulting from the alpha-blocking effects of the drug. These results might be helpful in explaining why carvedilol, in contrast to metoprolol, may fail to cause up-regulation of beta-adrenoceptor density and does not decrease nocturnal melatonin release. This, in turn, may be a reason for the weak side-effects of carvedilol resulting from the beta-blockade. In addition, our data might be of interest in the interpretation of the forthcoming results of the COMET trial, although it has to be emphasised that they were derived from healthy subjects and, therefore, cannot be directly extrapolated to patients with heart failure.

Plasma antioxidants and cognitive performance in middle-aged and older adults: results of the Austrian Stroke Prevention Study.

OBJECTIVES: To study the association between cognitive status and plasma concentrations of various antioxidants in middle-aged and older individuals without neuropsychiatric disease. DESIGN: Evaluation of cross-sectional data from a cohort study. SETTING: The Austrian Stroke Prevention Study. PARTICIPANTS: A total of 1769 subjects aged 50 to 75 years, with no history or signs of neuropsychiatric disease, selected randomly from the community register. MEASUREMENTS: The score on the Mattis Dementia Rating Scale (MDRS) was dichotomized according to age-and education-specific lowest quartile cut-off points. Reversed-phase high performance liquid chromatography measurements of the plasma concentrations of lutein/zeaxanthin, cryptoxanthin, canthaxanthin, lycopene, alpha-carotene, beta-carotene, retinol, gamma-tocopherol, alpha-tocopherol, and ascorbate were measured. RESULTS: Individuals with MDRS results below the lowest quartile cut-off point had lower levels of beta-carotene and alpha-tocopherol than their counterparts with test performance above this limit (0.44+/-.33 micromol/L vs 0.51+/-.48 micromol/L, P < .001; and 29.50+/-7.98 micromol/L vs 30.93+/-11.10 micromol/L, P < .001, respectively). Only alphatocopherol remained significantly associated with cognitive functioning when logistic regression analysis was used to adjust for possible confounders including age, sex, month of blood sampling, years of education, smoking, lipid status, and major risk factors for stroke (P = .019). CONCLUSION: These observations are compatible with the view that some dietary antioxidants may protect against cognitive impairment in older people.

MR contrast media for myocardial viability, microvascular integrity and perfusion.

Cardiovascular imaging requires an appreciation of rapidly evolving MR imaging sequences as well as careful utilization of intravascular, extracellular and intracellular MR contrast media. At the present time, clinical studies are restricted to the use of extracellular MR contrast media. MR imaging has the potential to noninvasively measure multiple parameters of the cardiovascular system in a single imaging session. Recent advances in fast and ultrafast MR imaging have considerably enhanced the capability of this technique, beyond the assessment of left ventricular wall motion and morphology into visualization of the coronary arteries and measurement of blood flow. During the course of the last several years, multiple strategies for imaging viable myocardium have been developed and validated using MR contrast media. Contrast enhanced dynamic MR imaging provides information regarding microvascular integrity and perfusion. Because these information can be provided noninvasively by MR imaging, repeated measurements can be performed in longitudinal studies to monitor the progression or regression of myocardial injury. Similar studies are needed to examine the effects of newly developed cardioprotective therapeutics. Development of suitable intravascular MR contrast medium may be essential for visualization of the coronary arteries and interventional therapies. MR imaging may emerge as one-stop-shop for evaluating the heart and coronary system. This capability will make MR imaging cost-effective in the first decade of this millennium.

Trace elements in coronary heart disease: Impact of intensified lifestyle modification.

Concentrations of 14 trace elements (Bi, Cd, Co, Cs, Cu, Hg, Mn, Pb, Rb, Sb, Sn, Sr, Tl, and Zn) were determined by inductively coupled plasma mass spectrometry (ICP-MS) in 120 whole-blood and 121 plasma samples of 56 patients with angiographically documented coronary heart disease (CHD). One serum and two whole-blood reference materials were analyzed for quality control. At baseline, patients had elevated Co plasma as well as diminished Cu blood concentrations compared to healthy adults. The Zn concentrations in whole blood were below or at the lower end of the normal range, but the concentrations in plasma were elevated. All other trace elements were within the normal concentration ranges for healthy adults. After initial investigations, patients were randomly assigned to an experimental group (N = 27) and to a usual care group (N = 29). Experimental group patients were prescribed a lifestyle program that included a low-fat diet and a weekly moderate exercise. Patients were examined at baseline, after 6 and 12 mo for clinical assessment and fasting venous blood samples. No significant time-course changes in concentrations of trace elements in blood and plasma during the clinical treatment in both groups of patients could be observed. The experimental group patients lost weight and had lower blood pressure after 12 mo compared to baseline. The interventional therapy reduced the need for further revascularization procedures.

[Diagnostic accuracy of contrast-enhanced 64-row MSCT coronary angiography in patients with severe coronary calcification in the clinical routine]. / Diagnostische Wertigkeit der kontrastverstärkten MSCT-Koronarangiografie bei Patienten mit hochgradiger Koronarverkalkung im klinischen Alltag.

PURPOSE: Our aim was to evaluate the diagnostic accuracy of contrast-enhanced 64-MSCT coronary angiography (MSCT-CA) in patients with severe coronary calcification. MATERIALS AND METHODS: 110 patients with an Agatston score > 400 were included in this retrospective analysis. Each patient underwent both conventional coronary angiography and MSCT-CA. No patient was excluded from the study because of coronary artery bypass grafting or coronary stenting. The results of MSCT-CA were compared with those of conventional coronary angiography and the diagnostic accuracy for detecting a hemodynamically significant stenosis was determined for coronary segments, vessels and patients. RESULTS: The average Agatston score for the study population was 1368 ± 1105. At least one significant stenosis was detected in 97 patients (88%) during conventional coronary angiography defining the gold standard. The sensitivity, specificity, positive and negative predictive values of MSCT-CA for detecting a significant stenosis were 54%, 83%, 52% and 85% for coronary segments (n = 1384), 80%, 70%, 74% and 77% for coronary vessels (n = 440), and 100%, 31%, 92% and 100% for patients (n = 110), respectively. No significant correlation could be observed between the degree of coronary calcification and the number of misclassified coronary segments. CONCLUSION: Artifacts caused by severe coronary calcification decrease the diagnostic accuracy of MSCT-CA. Performing MSCT-CA in patients with an Agatston score > 400 with the drawbacks of contrast media application and radiation exposure should be critically questioned and this decision should be made on an individual basis.

[Diagnosis of heart failure]. / Diagnostik der Herzinsuffizienz.

Heart failure is a clinical syndrome caused by various etiologic factors. The physician should undertake every effort to identify potentially reversible causes that lead to heart failure. Therefore one should go through various non-invasive as well as invasive diagnostic procedures. The diagnostic tests can be helpful in identifying patients with a poor prognosis.

[Drug therapy of chronic heart failure]. / Medikamentöse Therapie der chronischen Herzinsuffizienz.

Prevention of disease leading to cardiac dysfunction, improvement of quality of life and reduction of mortality are the primary objectives in the treatment of chronic heart failure. The therapeutic possibilities are various, including general advices, pharmacological therapy and surgical interventions. Standard medical treatment of systolic cardiac dysfunction contains ACE inhibitors, diuretics and cardiac glycosides. Beta-blocking agents, oral anticoagulation and antiarhythmic drugs can be used in addition. A therapeutic management of chronic heart failure tailored to the individual patient has nowadays become available due to multiple treatment options.

[Dilated cardiomyopathy--diagnosis and conservative therapy]. / Die dilatative Kardiomyopathie--Diagnostik und konservative Therapie.

Diagnosis of dilated cardiomyopathy (IDC) is a diagnosis of exclusion. Physical examination of the patient, non-invasive tests and invasive tests have to be done to exclude secondary dilated cardiomyopathies. Treatment can be divided into baseline therapy, established treatment, e.g. ACE-inhibitors, digitalis and diuretics and optional treatment including betablocker, anticoagulation and an natural course of IDC for an individual patient is not clear although there are several prognostic parameters for this disease.

[The extent of diastolic dysfunction and its correlation with subjective impairment of physical capacity in dilated cardiomyopathy]. / Das Ausmass der diastolischen Dysfunktion und dessen Korrelation zur subjektiven Leistungseinschränkung bei dilativer Kardiomyopathie.

OBJECTIVE: To find out whether in patients with dilated cardiomyopathy (DCM) there is a correlation between subjective reduction in physical capacity and the transmitral Doppler profile as a measure of left ventricular (LV) filling. PATIENTS AND METHODS: 30 consecutive patients (24 men, six women; average age 55 +/- 2 years) with chronic primary DCM were examined by Doppler echocardiography to determine possible differences in LV filling pattern, in correlation with subjective impairment of physical capacity graded according to the New York Heart Association (NYHA) classification. RESULTS: Mean LV ejection fraction was 34 +/- 1%. All patients were in sinus rhythm. Eight patients, in NYHA class I had nearly normal LV filling (E wave 79 m/s, A wave 0.76 m/s); 11 patients in class II had impaired relaxation (E wave 0.77 m/s. A wave 0.82 m/s) and 11 in class III/V had a restricted filling pattern (E wave 0.98 m/s. A wave 0.57 m/s). There was a significant difference between class II and class III/IV patients with regard to E wave deceleration time (0.15 and 0.11 s, respectively; P < 0.05), as well as between class I and class III/IV patients (0.18 and 0.11 s, respectively; P < 0.05). The A wave deceleration time was clearly shorter in class III/IV than class II (0.08 s and 0.11 s; P < 0.05) and class I patients (0.08 s and 0.10 s; P < 0.05). CONCLUSIONS: The extent of LV diastolic dysfunction correlated with subjective physical capacity. The more the LV filling pattern had changed from normal towards restricted, the greater the patient's symptoms.

Syncope in dilated cardiomyopathy is a predictor of sudden cardiac death.

Fifty percent of patients with dilated cardiomyopathy die within 5 years of diagnosis. Syncope is known to be a predictor of poor outcome in patients with advanced heart failure. To assess the risk of patients with dilated cardiomyopathy with a history of syncope during standard medical treatment we compared this group to similar patients without syncope. Twenty-three patients with angiographically proven dilated cardiomyopathy and syncope were followed prospectively and compared to 201 patients without history of syncope. All patients showed a left-ventricular ejection fraction of less than 45%. Both groups did not differ in left-ventricular ejection fraction at baseline (30 +/- 7% in the syncope group, 30 +/- 8% in the no syncope group). Mean follow-up was 2.6 years in the syncope group and 2.4 years in the no syncope group. At baseline, syncope patients used more often amiodarone (p < 0.04), while there was no statistically significant difference between the two groups regarding the intake of digitalis, diuretics and angiotensin-converting enzyme inhibitors. Twenty-six percent of patients in the syncope group and 20% in the no syncope group died during follow-up (non significant). The striking difference, however, was the type of death: 5 out of 6 patients in the syncope group died suddenly compared to 13 of 41 patients in the no syncope group (p < 0.025). Patients with dilated cardiomyopathy and a history of syncope are at high risk of sudden death.

[Survival after poisoning due to intake of ten-times lethal dose of acetone]. / Uberlebte Vergiftung nach Einnahme der zehnfachen Letaldosis von Aceton.

HISTORY AND ADMISSION FINDINGS: A 42-year-old man was found unconscious, having swallowed 800 ml of an unknown liquid with suicidal intent. On admission, when his breath smelled strongly of acetone, he was intubated and ventilated, and several gastric lavages were performed. INVESTIGATION: The serum acetone concentration was 2000 mg/l, that in urine 2300 mg/l. The residue of the liquid in the bottle from which he had drunk was pure acetone. DIAGNOSIS, TREATMENT AND COURSE: Acetone poisoning having been established he was carefully hyperventilated, haemofiltration was performed over 16 hours and forced diuresis with high fluid intake was undertaken. His condition quickly improved and he was extubated after 14 hours. There was no subsequent evidence of organ damage. Repeated measurements of acetone in blood and urine indicated its elimination with a half-life of 11 hours. Literature search revealed that this was the second highest concentration of acetone in blood and urine followed by survival. CONCLUSION: This case demonstrates that, after acute acetone poisoning with an amount ten times the lethal dose, intensive care and rapid elimination of acetone can achieve sequelae-free survival.

Myocardial viability: magnetic resonance assessment of functional reserve and tissue characterization.

The determination of myocardial viability is crucial in patients with left ventricular dysfunction resulting from acute myocardial ischemia or chronic coronary artery disease. Viable myocardium will most likely benefit from revascularization procedures. However, the revascularization of scar tissue will not lead to improvement of ventricularfunction andfurthermore bears unnecessary riskfor the patient. Currently, echocardiographic and radionuclide techniques are the most established methods for the assessment of presence and extent of viable myocardium. Magnetic resonance imaging (MRI) also provides multiple approaches for determining viability of acute ischemically injured and hibernating myocardium. MRI can assess contractile reserve in a manner similar to echocardiography. Additionally, contrast-enhanced MRI can characterize myocardial ischemic injury, including the ability to discriminate viable from nonviable zones. Several new contrast media have been introduced for this purpose. This review addresses the progress toward the goal of defining myocardial viability based on MR techniques and focuses on the current and future role of MR in the assessment of viable myocardium.