PubMed Health⌕ Search

Biomedical subjects

Karl-Heinz Kuck

Publications and source records attributed to Karl-Heinz Kuck.

At least 19 recordsLinked to original sources
PubMed2007

Remote-controlled catheter ablation of accessory pathways: results from the magnetic laboratory.

AIMS: This study evaluates feasibility, safety, and efficacy of magnetic remote-controlled accessory pathway (AP) ablation. METHODS AND RESULTS: The novel magnetic navigation system (MNS) (Niobe, Stereotaxis) creates a steerable magnetic field (0.08 T) controlling the distal magnetic tip of an ablation catheter. In conjunction with a catheter advancer system (Cardiodrive, Stereotaxis) remote catheter ablation is enabled. Conventional electrophysiology study identified AP conduction in 59 patients (37 males, 36+/-14 years, 60 APs). First generation 1-magnet tip (1-M) (group I, n=18), second generation bipolar 3-magnet tip (3-M) (group II, n=27), and third generation quadripolar 3-magnet tip catheters (3-M quad.) (group III, n=14) were used for magnetic remote-controlled ablation. Successful AP ablation was achieved in 67% (group I), 85% (group II), and 92% (group III). A significant decrease of median [IQR: Q1-Q3] fluoroscopy time and dosage was observed: 21.2 [12.1-33.8] min, 1110 [395-3234] microGym2 (group I); 6.5 [4.4-15.4] min, 290 [129-489] microGym2 (group II), and 4.9 [3.4-8.0] min, 129 [74-270] microGym2 (group III). Mean procedure time (217+/-67 min; 182+/-68 min, and 172+/-90 min) significantly decreased in group III. Median number [Q1-Q3] of radiofrequency current applications in groups I, II, and III was 4 [2-9], 4 [2-6], and 2 [2-4], respectively. No complications occurred. CONCLUSION: Remote AP ablation is safe and feasible using the novel MNS. Introduction of the 3-magnet quadripolar ablation catheter significantly improved the efficacy of the procedure.

Adult↗
PubMed2006

Tako-Tsubo cardiomyopathy (apical ballooning) with parvovirus B19 genome in endomyocardial biopsy.

The phenomenon of transient apical ballooning is a rare underlying cause of severe left ventricular dysfunction and has been described as Tako-Tsubo-like cardiomyopathy. Acute myocarditis has been reported to masquerade as acute myocardial infarction or vice versa and is considered as differential diagnosis in this phenomenon. We present here a case of an adult female who was admitted to our cardiology department with chest pain, electrocardiographic and echocardiographic features, suggestive of an acute anterior myocardial infarction, preceded by physical and emotional stress. Coronary angiography demonstrated coronary arteries without relevant atherosclerotic lesions; left ventriculography showed a severe anteroapical dysfunction. Right ventricular endomyocardial biopsy showed normal cardiac tissue, but was positive for Parvovirus B19. Follow-up (2 months later) showed complete regression of regional wall motion abnormalities in transthoracic echocardiography.

Aged↗
PubMed2006

Remote-controlled magnetic ablation of a right anterolateral accessory pathway - the superior caval vein approach.

OBJECTIVE: An 18-year old male patient with recurrent supraventricular tachycardias was admitted for catheter ablation. Baseline ECG was consistent with right anterolateral accessory pathway (AP) conduction. MATERIALS AND METHODS: The novel magnetic navigation system (MNS, Niobe Stereotaxis) in combination with a catheter advancer unit (Cardiodrive, Stereotaxis) allows a complete remote-controlled electrophysiologic study and ablation. RESULTS: Despite accurate identification of the AP insertion site using the MNS, a stable catheter position was not achieved from the inferior caval vein. Therefore, the venous access was switched to the superior caval vein approach using the left subclavian vein. The same magnetic field vector now resulted in a perfectly stable catheter position, and application of radiofrequency current immediately blocked AP conduction. CONCLUSION: This case demonstrates feasibility and safety of a complete remote-controlled ablation of a right-sided anterolateral accessory pathway using the superior approach in conjunction with the novel magnetic navigation system Niobe.

Adolescent↗
PubMed2006

A single pulmonary vein as electrophysiological substrate of paroxysmal atrial fibrillation.

INTRODUCTION: It has been demonstrated that pulmonary veins (PVs) play an important role in initiation and maintenance of paroxysmal atrial fibrillation (AF). However, it is not clearly known whether a single PV acts as electrophysiological substrate for paroxysmal AF. METHODS AND RESULTS: This study included five patients with paroxysmal AF. All patients underwent complete PV isolation with continuous circular lesions (CCLs) around the ipsilateral PVs guided by a three-dimensional mapping system. Irrigated radiofrequency (RF) delivery was performed during AF on the right-sided CCLs in two patients and on the left-sided CCLs in three patients. The incomplete CCLs resulted in a change from AF to atrial tachycardia (AT), which presented with an identical atrial activation sequence and P wave morphology. Complete CCLs resulted in AF termination with persistent PV tachyarrhythmias within the isolated PV in all five patients. PV tachyarrhythmia within the isolated PV was PV fibrillation from the left common PV (LCPV) in two patients, PV tachycardia from the right superior PV (RSPV) in two patients, and from the left superior PV in one patient. All sustained PV tachyarrhythmias persisted for more than 30 minutes, needed external cardioversion for termination in four patients and a focal ablation in one patient. After the initial procedure, an AT from the RSPV occurred in a patient with PV fibrillation within the LCPV, and was successfully ablated. CONCLUSION: In patients with paroxysmal AF, sustained PV tachyarrhythmias from a single PV can perpetuate AF. Complete isolation of all PV may provide good clinical outcome during long-term follow-up.

Adult↗
PubMed2006

Ablation of atrial fibrillation in humans using a balloon-based ablation system: identification of the site of phrenic nerve damage using pacing maneuvers and CARTO.

Injury of the phrenic nerve during pulmonary vein isolation for the treatment of atrial fibrillation is a well-recognized complication, especially when performing ostial ablations or using balloon-based technologies. This report describes the exact anatomical location of phrenic nerve injury during an attempt of right superior pulmonary vein isolation using a balloon that delivered high intensity focused ultrasound. Electroanatomical three-dimensional CARTO (Biosense Webster, Diamond Bar, CA, USA) mapping of the superior caval vein, the right and left atrium, as well as the right superior pulmonary vein was performed in conjunction with meticulous phrenic nerve pacing maneuvers before and after ablation and showed that the nerve was damaged at the level of the antero-inferior ostium of the right superior pulmonary vein. Diaphragmatic denervation occurred despite using an oversized balloon fluoroscopically placed at the atrial side of the pulmonary vein ostium.

Atrial Fibrillation↗
PubMed2006

Randomized, double-blind, multicenter study of the Endeavor zotarolimus-eluting phosphorylcholine-encapsulated stent for treatment of native coronary artery lesions: clinical and angiographic results of the ENDEAVOR II trial.

BACKGROUND: The use of the Endeavor stent might reduce restenosis and stent thrombosis at 9 months. METHODS AND RESULTS: Patients (n = 1197) treated for single coronary artery stenosis were enrolled in a prospective, randomized, double-blind study and randomly assigned to receive the Endeavor zotarolimus-eluting phosphorylcholine polymer-coated stent (n = 598) or the same bare metal stent but without the drug or the polymer coating (n = 599). The 2 groups were well matched in baseline characteristics. Diabetes was present in 20.1% of patients; the mean reference vessel diameter was 2.75 mm; and the mean lesion length was 14.2 mm. The primary end point of target vessel failure at 9 months was reduced from 15.1% with the bare metal stent to 7.9% with the Endeavor (P = 0.0001), and the rate of major adverse cardiac events was reduced from 14.4% with the bare metal stent to 7.3% with the Endeavor (P = 0.0001). Target lesion revascularization was 4.6% with Endeavor compared with 11.8% with the bare metal stent (P = 0.0001). The rate of stent thrombosis was 0.5% with the Endeavor, which was not significantly different from 1.2% with the bare metal stent. In 531 patients submitted to angiographic follow-up, late loss was reduced from 1.03 +/- 0.58 to 0.61 +/- 0.46 (P < 0.001) in stent and from 0.72 +/- 0.61 to 0.36 +/- 0.46 (P < 0.001) in segment. The rate of in-segment restenosis was reduced from 35.0% to 13.2% with Endeavor (P < 0.0001). There was no excessive edge stenosis, aneurysm formation, or late acquired malapposition by intravascular ultrasound imaging. Differences in clinical outcome were maintained at 12 and 24 months (P < 0.0001). CONCLUSIONS: Compared with bare metal stents, the Endeavor stent is safe and reduces the rates of clinical and angiographic restenosis at 9, 12, and 24 months.

Aged↗
PubMed2006

Focal atrial tachycardia originating from the non-coronary aortic sinus: electrophysiological characteristics and catheter ablation.

OBJECTIVES: We sought to investigate electrophysiological characteristics and catheter ablation in patients with focal atrial tachycardia (AT) originating from the non-coronary aortic sinus (AS). BACKGROUND: In patients with failed ablation of focal AT near the His bundle (HB) region, an origin from the non-coronary AS should be considered because of the close anatomical relationship. METHODS: This study included 9 patients with focal AT, in 6 of whom attempted radiofrequency (RF) ablation had previously failed. Activation mapping was performed during tachycardia to identify an earliest activation in the atria and the AS. The aortic root angiography was performed to identify the origin in the AS before RF ablation. RESULTS: Focal AT was reproducibly induced by atrial pacing. Mapping in atria demonstrated that the earliest atrial activation was located at the HB region, whereas mapping in the non-coronary AS demonstrated that an earliest atrial activation preceded the atrial activation at the HB by 12.2 +/- 6.9 ms and was anatomically located superoposterior to the HB in all 9 patients. Also, His potentials were not found at the successful site in the non-coronary AS in all 9 patients. The focal AT was terminated in <8 s in all 9 patients. Junctional beats and PR prolongation did not occur during RF application in all 9 patients. No complications occurred in any of the nine patients. All 9 patients were free of arrhythmias without antiarrhythmic drugs during a follow-up of 9 +/- 3 months. CONCLUSIONS: In patients with focal AT near the HB region, mapping in the non-coronary AS can improve clinical outcome.

Adult↗
PubMed2006

ICD therapy: 'the sickest benefit the most...': what about the less sick?

Implantable cardioverter defibrillators (ICDs) have been proven to be highly efficacious in protecting very high-risk cardiac patients from sudden cardiac death and hence enhancing their overall survival. Furthermore, several post hoc sub-study analyses seem to indicate that ICD benefit is predominant in the patients with the highest risk, particularly with depressed left ventricular function. This, in turn, has led some clinicians to question the benefit of ICD therapy in relatively healthy, i.e. 'less sick', patients. As these interpretations come entirely from the sub-group analyses of the completed ICD prospective studies, it is important to examine more profoundly the study design, length of follow-up, and outcomes of these studies. Such analysis identifies three primary reasons why the conclusion that 'less sick' patients benefit less from ICD therapy may be erroneous: (i) the relatively short follow-up time of the studies (ended as soon as ICD therapy benefit became manifest); (ii) high 'crossover rate' from control to ICD therapy; and (iii) predominance of study endpoints (deaths) in the 'sickest' patients. The results of several studies, including the most recent and largest ICD study-SCD-Heft-and sub-group analyses of 'healthier' patient cohorts in several studies, support the benefit of ICDs in this group of patients, provided the follow-up time is sufficiently long.

Clinical Trials as Topic↗
PubMed2006

Transesophageal echocardiography: a screening method for pulmonary vein stenosis after catheter ablation of atrial fibrillation.

AIMS: Pulmonary vein (PV) stenosis has been described as a complication after catheter ablation of atrial fibrillation. The aim of the study was to investigate the diagnostic role of transesophageal echocardiography (TEE) in the assessment of PV stenosis. METHODS: Ninety-one patients (71 men, mean age 57+/-16years), initially treated by catheter ablation of atrial fibrillation, underwent re-ablation because of arrhythmia recurrences. PV angiograms and TEE were performed before the first and second ablation. PVs were analysed in an intraindividual comparison by measurements of mean and peak flow velocity and of velocity time integrals and diameters. PV angiograms served as standard for assessment of PV stenosis. RESULTS: Sixteen of 91 patients developed PV stenoses as a consequence of the first ablation (13 mild PV stenoses, 4 moderate PV stenoses). All patients with PV stenosis were asymptomatic. In moderate PV stenosis (50-70%) a significant increase of blood flow parameters, reduction of vessel diameter, inhomogeneous blood flow and aliasing were demonstrated by TEE. Using quantitative TEE criteria moderate PV stenosis could be identified with a sensitivity of 84% and specificity of 98%. Detection of mild PV stenosis (30-50%) is challenging (sensitivity of 48% and specificity of 75%). CONCLUSIONS: TEE identifies significant PV stenosis by assessment of flow characteristics and vessel diameter and can thereby be used as a follow-up tool after catheter ablation of atrial fibrillation.

Aged↗
PubMed2006

Percutaneous endocardial injection of erythropoietin: assessment of cardioprotection by electromechanical mapping.

BACKGROUND: Apart from its well-known stimulation of erythropoiesis, erythropoietin (EPO) exhibits angiogenic and anti-apoptotic effects. These cellular protective effects have also been described in experimental acute myocardial infarction models. We investigated the effects of EPO in a porcine model of chronic progressive myocardial ischaemia. METHODS: At weeks 2 and 6 after implantation of a circumflex ameroid constrictor, endocardial electromechanical NOGA system (Biosense Webster, Inc., California, USA) mapping of the left ventricle, coronary and ventricular angiography, as well as echocardiography were performed. Two weeks after ameroid placement, 13 pigs were randomized with 7 pigs receiving 10.000 U EPO and 6 pigs receiving placebo into the ischaemic region using a NOGA guided percutaneous transendocardial injection catheter, MYOSTAR. After 6 weeks, histology (Masson's Trichrome) was analyzed. RESULTS: Endocardial electromechanical mapping showed an increase of mean unipolar voltage (UV) amplitude in the ischaemic myocardial segments in the EPO-treated animals (8.5 mV pre and 10.6 mV post treatment) and a significantly reduced ischaemic surface area compared to the control group (19% vs. 41%) suggesting a decline in ischaemic injury. Echocardiography revealed 2,2 hypokinetic segments of the lateral wall in the EPO group vs. 3,3 in the control groups. The mean ejection fraction was 64% in the EPO group and 55% in the placebo group. Quantitative histological analysis of the ischaemic regions revealed a reduction of myocardial fibrosis (8% vs. 28%) in the EPO group. CONCLUSION: Endocardial EPO injection may induce cardioprotective effects in hibernating myocardium and may attenuate the progression of ischaemic tissue damage.

Animals↗
PubMed2006

[Sudden cardiac death, ICD and resynchronization therapy].

The guidelines for the implantation of cardioverter defibrillators recommend the primary prevention of sudden cardiac death based on the results of MADIT II, Companion and SCD-HeFT. The main risk factors for ventricular arrhythmias are previous myocardial infarction, depressed left ventricular function, and chronic heart failure. The presented case reports demonstrate the indication for a defibrillator or biventricular defibrillator as a basis of clinical pathways.

Aged↗
PubMed2006

Spontaneous retraction of an intramyocardial dissecting hemorrhage and multiple left ventricular thrombus formations in subacute myocardial infarction and antiphospholipid syndrome: a case report with long-term follow-up.

This report describes a 68-year-old patient with a subacute myocardial infarction and antiphosholipid syndrome. He developed an intramyocardial dissecting hemorrhage involving the left ventricular apex and multiple left ventricular thrombus formations, documented by contrast echocardiography and magnetic resonance imaging. By use of transthoracic echocardiography, spontaneous retraction of the dissecting hemorrhage could be detected. Severe coronary 3-vessel disease was successfully treated by coronary artery bypass grafting. During follow-up of 16 months, the dissecting hematoma could not been detected. Under initiation of anticoagulant treatment with Coumadin, the patient was in stable clinical condition and improved in New York Heart Association class from III to II. The pathophysiology, diagnosis, and management of this potentially highly lethal complication is reviewed.

Aged↗
PubMed2006

Substrate mapping vs. tachycardia mapping using CARTO in patients with coronary artery disease and ventricular tachycardia: impact on outcome of catheter ablation.

AIMS: For ablation of ventricular tachycardia (VT) in patients after myocardial infarction, a three-dimensional mapping system is often used. We report on our overall success rate of VT ablation using CARTO in 47 patients, with a subgroup analysis comparing VT mapping with the results of mapping that had to be performed during sinus rhythm or pacing (substrate mapping). METHODS AND RESULTS: A CARTO map was performed and VT ablation attempted using two strategies: Patients in the VT-mapping group had incessant VT (four patients) or inducible stable VT (18 patients) such that the circuit of the clinical VT could be reconstructed using CARTO. During VT, the critical area of slow conduction was identified using diastolic potentials and conventional concealed entrainment pacing. In contrast, patients in the substrate-mapping group had initially inducible VT. However, a complete VT map was not possible because of catheter-induced mechanical block (six patients) or because haemodynamics deteriorated during the ongoing VT (19 patients). Therefore, pathological myocardium was identified by fragmented, late- and/or low-amplitude (<1.5 mV) bipolar potentials during sinus rhythm or pacing, and the ablation site was primarily determined by pace mapping inside or at the border of this pathological myocardium. Acute ablation success in all patients with regard to non-inducibility of the clinical VT or any slower VT was 79% after a single ablation procedure, but increased to 95% after a mean of 1.2 ablation procedures. However, chronic success was 75%, when it was defined as freedom from any ventricular tachyarrhythmia (VT or VF) during a follow-up of 25+/-13 months. In the subgroup analysis, patients in the VT-mapping group were not significantly different from patients in the substrate-mapping group with regard to age (65+/-7 vs. 65+/-9 years), ejection fraction (30+/-7 vs. 30+/-8%), VT cycle length (448+/-81 vs. 429+/-82 ms), number of radiofrequency applications (17+/-9 vs. 14+/-6 applications), use of an irrigated tip catheter (23 vs. 32%), and ablation results. CONCLUSION: When using a CARTO-guided approach for VT ablation in patients with coronary artery disease, the freedom from any ventricular arrhythmia is high (75%), but leaves the patient at a 23% risk of developing fast VT/VF during follow-up. Mapping during sinus rhythm or pacing is as successful as mapping during VT.

Aged↗
PubMed2006

External and endoluminal analysis of left atrial anatomy and the pulmonary veins in three-dimensional reconstructions of magnetic resonance angiography: the full insight from inside.

INTRODUCTION: The detailed knowledge of the individual pulmonary vein (PV) anatomy may help to prevent serious complications during PV isolation (PVI). The purpose of this study was to determine the geometry of the PV ostia and their spatial relation to adjacent structures in external (ex 3D) and endoluminal (en 3D) three-dimensional reconstructions of magnetic resonance angiographies (MRAs). METHODS AND RESULTS: Ex 3D and en 3D of the left atrium (LA) and the PVs of 28 patients were calculated. Diameters and the shape of PV ostia were assessed. In addition, the distances between ipsilateral PV ostia, the LA isthmus line, the roof line and the distance between the left PV and the LA appendage (LAA) were measured. Both ex 3D and en 3D are useful tools to determine the dimensions and the geometry of PVs. En 3D facilitates the identification of common PV ostia (15/28 patients). In en 3D, ipsilateral PV ostia are separated by a narrow myocardial ridge of less than 4 mm in 19/38 PVs (mean 4.3 +/- 1 mm; 4.6 +/- 2 mm with ex 3D). LAA and the LPV ostia are separated by a ridge of less than 4 mm in 12/28 PVs measured with en 3D (4.8 +/- 2 mm; 6.4 +/- 2 mm with ex 3D). CONCLUSIONS: Both ex 3D and en 3D reconstructions of MRA precisely visualize the complex LA anatomy. Exact determination of PV ostial geometry is facilitated with en 3D and provides important anatomical information for the PVI strategy. According to our data, individual encircling of every PV is strongly discouraged.

Aged↗
PubMed2005

Transient left ventricular apical ballooning in a community hospital in Germany.

INTRODUCTION: Tako-tsubo cardiomyopathy represents an intermittent left ventricular dysfunction with a ballooning of the left ventricular apical myocardium without significant coronary artery disease. Precise epidemiological data are not yet available. METHODS AND RESULTS: We retrospectively reviewed 16,989 cases with diagnostic angiographies in our catheter laboratory from January 2001 until December 2004 for intermittent left ventricular apical ballooning. Thirty-two (0.2%) patients were included (50% of all cases presented in 2004, 50% of all cases during the summer months). Twenty-nine (91%) were female, median age was 67.5 years. Fourteen patients (44%) were known to have chronic obstructive pulmonary disease or asthma. Thirteen patients (41%) reported an acute stressful event prior to onset of symptoms. Twenty-five (78%) of the patients presented with clinical signs of an acute coronary syndrome with positive troponin T in 20 (63%) patients. Median left ventricular ejection fraction was 42.5%. Follow-up data of 30 patients (94%) could be obtained; median follow-up time is 6 months. Two patients died during follow-up (malignancy; unknown cause). Echocardiography was performed in 26 (81%) patients; median ejection fraction was 70%. CONCLUSION: Tako-tsubo-like cardiomyopathy might be considered a differential diagnosis for acute coronary syndrome especially in elderly women. Chronic pulmonary diseases may be associated with a higher risk. The reason for the increasing number of cases during the last year is not clear; however, the tendency for early angiography in acute coronary syndrome may have contributed. The reason for the accumulation of cases during the summer months is also not yet understood.

Aged↗
PubMed2005

Electrophysiological findings during ablation of persistent atrial fibrillation with electroanatomic mapping and double Lasso catheter technique.

BACKGROUND: Pulmonary veins (PVs) can be completely isolated with continuous circular lesions (CCLs) around the ipsilateral PVs. However, electrophysiological findings have not been described in detail during ablation of persistent atrial fibrillation (AF). METHODS AND RESULTS: Forty patients with symptomatic persistent AF underwent complete isolation of the right-sided and left-sided ipsilateral PVs guided by 3D mapping and double Lasso technique during AF. Irrigated ablation was initially performed in the right-sided CCLs and subsequently in the left-sided CCLs. After complete isolation of both lateral PVs, stable sinus rhythm was achieved after AF termination in 12 patients; AF persisted and required cardioversion in 18 patients. In the remaining 10 patients, AF changed to left macroreentrant atrial tachycardia in 6 and common-type atrial flutter in 4 patients. All atrial tachycardias were successfully terminated during the procedure. Atrial tachyarrhythmias recurred in 15 of 40 patients at a median of 4 days after the initial ablation. A repeat ablation was performed at a median of 35 days after the initial procedure in 14 patients. During the repeat study, recovered PV conduction was found in 13 patients and successfully abolished by focal ablation of the conduction gap of the previous CCLs. After a mean of 8+/-2 months of follow-up, 38 (95%) of the 40 patients were free of AF. CONCLUSIONS: In patients with persistent AF, CCLs can result in either AF termination or conversion to macroreentrant atrial tachycardia in 55% of the patients. In addition, recovered PV conduction after the initial procedure is a dominant finding in recurrent atrial tachyarrhythmias and can be successfully abolished.

Adult↗
PubMed2005

Tissue velocity imaging during dobutamine stimulation for assessment of myocardial viability: segmental analysis in patients after myocardial infarction.

BACKGROUND: Dobutamine stress echocardiography (DSE) is an established method for the detection of viable myocardium, but evaluation of this method is subjective. Tissue velocity Imaging (TVI) allows quantitative analysis of regional myocardial wall motion by assessment of systolic myocardial velocities. The aim of this study was to evaluate the diagnostic value of DSE and TVI for detection of viable myocardium. METHODS: In 56 patients (58+/-12 years) with previous myocardial infarction (130+/-42 days, mean ejection fraction 42+/-15%) low-dose DSE was combined with analysis of peak systolic myocardial velocities (Vpeak) by TVI for assessment of myocardial viability. As reference served a follow-up echocardiography after successful revascularization (mean 91+/-3 days). RESULTS: Of a total of 896 segments 200 showed abnormal wall motion (31 mildly hypokinetic, 50 severely hypokinetic, 115 akinetic, 4 dyskinetic). In 125 of these 200 segments regional improvement of regional wall motion was observed (62.5% viable). An increase of Vpeak>1 cm/s during dobutamine stimulation allowed the identification of viable myocardium with a sensitivity of 82% and a specificity 82% (DSE: 77% and 80%). By receiver operating characteristic (ROC) curve analysis, a cut-off value of 1.0 cm/s was the best parameter to differ viable from nonviable myocardium (area under the curve 0.85; p<0.01; 95% CI 0.79 to 0.90). Improvement of global ejection fraction after revascularization (47+/-13%, p=0.11) corresponded with three TVI viable segments with a sensitivity of 92% and a specificity of 89% (p=0.012). CONCLUSIONS: TVI allows the identification of viable myocardium during dobutamine stimulation and enables a quantitative interpretation of DSE.

Cardiotonic Agents↗