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Biomedical subjects

S Sack

Publications and source records attributed to S Sack.

At least 19 recordsLinked to original sources
PubMed2002

The reaction gammap-->pi0gamma'p and the magnetic dipole moment of the Delta+ 1232 resonance.

The reaction gammap-->pi(0)gamma'p has been measured with the TAPS calorimeter at the Mainz Microtron accelerator facility MAMI for energies between sqrt[s]=1221-1331 MeV. The cross section's differential in angle and energy have been determined for the photon gamma' in three bins of the excitation energy. This reaction channel provides access to the magnetic dipole moment of the Delta(+)(1232) resonance and, for the first time, a value of mu(Delta(+))=[2.7(+1.0)(-1.3)(stat)+/-1.5(syst)+/-3(theor)]mu(N) has been extracted.

Journal Article↗
PubMed2002

In-medium modifications of the pipi interaction in photon-induced reactions.

Differential cross sections of the reactions (gamma,pi(0)pi(0)) and (gamma,pi(0)pi(+/-)) have been measured for several nuclei (1H,12C, and (nat)Pb) at an incident-photon energy of E(gamma)=400-460 MeV at the tagged-photon facility at MAMI-B using the TAPS spectrometer. A significant nuclear-mass dependence of the pipi invariant-mass distribution is found in the pi(0)pi(0) channel. This dependence is not observed in the pi(0)pi(+/-) channel and is consistent with an in-medium modification of the pipi interaction in the I=J=0 channel. The data are compared to pi-induced measurements and to calculations within a chiral-unitary approach.

Journal Article↗
PubMed2001

Assessment of coronary morphology and flow in a patient with Guillain-Barré syndrome and ST-segment elevation.

Patients with Guillain-Barré syndrome often have cardiac disturbances as a manifestation of autonomic dysfunction. Such abnormalities consist of arrhythmias and disturbances of heart rate and blood pressure. We report a case of a patient with Guillain-Barré syndrome who developed ST-segment elevation in the inferolateral leads, suggestive of an acute coronary syndrome. Cardiac catheterization revealed angiographically normal coronary arteries. Intracoronary ultrasound was also normal. Intracoronary Doppler flow measurements revealed an elevated baseline coronary flow velocity of up to 41 cm/s and decreased coronary flow reserve, particularly in the left circumflex artery. Myopericarditis as cause of the electrocardiographic changes could be ruled out by echocardiography and endomyocardial biopsy. We postulate that the intracoronary Doppler findings are caused by autonomic dysfunction with decrease of coronary resistance and redistribution of the transmural myocardial blood flow.

Autonomic Nervous System Diseases↗
PubMed2001

Improved detection and analysis of sensed and paced events in dual chamber pacemakers with extended memory function. A prospective multicenter trial in 626 patients.

PATIENTS AND METHODS: This prospective study analyzed the incidence of atrial arrhythmias in a population of 626 patients in 173 medical centers of eleven European countries and Japan with indication for a dual chamber pacemaker system. The accuracy of the new Automatic Interpretation for Diagnosis Assistance (AIDA) program which is included in Chorus pacemakers was evaluated and the AIDA analysis was compared to and proven with Holter monitoring. Data stored in the pacemakers' memories for the first 24 hours (D1) were compared with simultaneously recorded 24-hour surface electrocardiograms, and data stored over the following 28 days (D28) were examined against reported intercurrent symptoms. RESULTS: At D1, atrial arrhythmias were detected by AIDA in 60 of 626 patients (12%), consisting of atrial fibrillation (n = 29), atrial flutter (n = 4), and miscellaneous arrhythmias (n = 17), and closely corroborated by Holter monitoring (sensitivity 93.7%, specificity 94.9%). At D28, 149 of 386 patients (49%) had had episodes of automatic mode switch prompted by atrial arrhythmias. Symptoms were reported by 81 patients (54%), 92 (62%) had no histories of atrial arrhythmias, and 57 patients (38%) were neither symptomatic nor had histories of atrial arrhythmias. An inverse relationship was found between the number of atrial paced events and the occurrence of atrial arrhythmias (p < 0.001). A history of atrial arrhythmias and older age were associated with a higher risk of atrial arrhythmias (p < 0.05). In contrast, gender, hypertension, concomitant heart disease, or type of atrial lead fixation system were not related with the occurrence of atrial arrhythmias. CONCLUSION: AIDA allowed to confirm, or disprove, the occurrence of atrial arrhythmias as a source of symptoms reported during long-term follow-up. It could also be used to examine the efficacy of antiarrhythmic therapy, and be of assistance when weighing the needs for anticoagulation in patients experiencing asymptomatic atrial arrhythmias.

Adult↗
PubMed2001

[Experiences with a new transvenous electrode for left ventricular stimulation].

BACKGROUND: Left ventricular and biventricular pacing has recently been introduced as a new therapy for chronic heart failure in selected patients. We report our initial experience with a new electrode for transvenous left epicardial pacing via tributaries of the coronary sinus. PATIENTS AND METHOD: Inclusion criteria were: chronic heart failure NYHA > or = II, QRS-duration > 120 ms, left ventricular ejection fraction < 35%. Dual chamber pacemakers (CPI Contak TR) or defibrillators (CPI Contak CD) designed for atrial triggered biventricular stimulation were implanted in conjunction with the CPI Easytrak-lead for left ventricular pacing in a coronary vein. Lead placement was achieved via a subclavian vein access and a preformed guiding catheter for coronary sinus insertion. RESULTS: In 13 of 16 patients (81%) the left ventricular lead was implanted successfully in a mid to distal posterior or anterolateral vein. Lead insertion could not be achieved in 2 patients with significant cardiomegaly and right atrial enlargement (12.5%), while 1 patient with a history of myocardial infarction and small anterior ventricular aneurysm had inacceptable high left ventricular pacing thresholds intraoperatively. The implantation was well tolerated by all patients without complications. There was no case of lead dysfunction (mean follow-up time: 142 +/- 126 days). Intraoperative electrode measurements and chronic parameters (> or = 3 months, n = 8) are given in Table 1. CONCLUSION: In the past left ventricular pacing has mainly been achieved by epicardially placed electrodes after thoracotomy with conventional electrodes. This new approach for chronic left ventricular pacing uses the familiar transvenous over-the-wire technique in combination with a newly developed guiding catheter and electrode for pacing in left epicardial veins. Lead placement was shown to be safe and success rate was higher than in previous reports with standard electrodes. We conclude that left epicardial lead placement with the over-the-wire technique and a preformed guiding catheter for coronary sinus access presents as a safe and maybe more efficient method for left ventricular pacing.

Cardiac Pacing, Artificial↗
PubMed2001

[Cardiac resynchronization therapy in terminal heart failure: current status and prospects].

BACKGROUND: With regard to epidemiological aspects, heart failure has been shown an increasing incidence in constrast to coronary artery disease which counts decreasingly due to secondary and primary prevention. The present data show an incidence for heart failure of 2% per year. 4-5 million people are newly affected by the disease. The prognosis is limited after diagnosis is confirmed. According to the US Framingham study, the median life expectancy is 3.2 and 5.4 after diagnosis for male and female, respectively. For patients in an advanced stage of the disease the mortality rate is 27% within 3 years. AV SEQUENTIAL PACING: The introduction of AV sequential pacing by the Austrian group of Margarete Hochleitner in 1992 showed an improved left ventricular systolic function, an improved clinical benefit in terms of NYHA classification, an enhanced left ventricular ejection fraction, an improved systolic and diastolic blood pressure, a reduction of the heart-chest relationship as well as a reduction of the resting hart rate and the echocardiographic dimension parameters. STUDIES: First experimental approach for biventricular stimulation, which means the simultaneous activation of the right and the left chamber, relied on the observation of a distorted ventricular activation due to the presence of a bundle branch block. The bundle branch block is a result of the dilatation of the myocardial fibers, death of myocardial cells which are replaced by fibrous tissue. Resynchronization of both ventricles was associated with an improved left ventricular function and improved diastolic relaxation. Clinical studies of patients with heart failure, severe left ventricular systolic dysfunction, and left bundle branch block have shown that systolic function can be improved by electrically stimulating the site of late activation. The magnitude of the improvement seems to be associated with the duration of the intrinsic surface QRS complex and whether the ventricle ipsilateral with the conduction defect is stimulated. The effect of ventricular resynchronization therapy was optimized by timing of atrioventricular activation associated with a decrease in both systolic and diastolic mitral regurgitation. CONCLUSION: The prognosis of patients with end-stage heart failure is limited by two determinants: myocardial pump failure and sudden (arrhythmogenic) cardiac death. Due to the fact that the incidence for sudden cardiac death is considerably high in patients with end-stage heart failure it is reasonable to include the implantation of cardioverters/defibrillaters (ICD) in the concept of biventricular stimulation.

Blood Pressure↗
PubMed2001

Changes in QRS voltage in cardiac tamponade and pericardial effusion: reversibility after pericardiocentesis and after anti-inflammatory drug treatment.

OBJECTIVES: The goal of this study was to define the association between low QRS voltage and cardiac tamponade or pericardial effusion and to assess the reversibility of low QRS voltage after therapeutic procedures. BACKGROUND: It is unclear whether low QRS voltage is a sign of cardiac tamponade or whether it is a sign of pericardial effusion per se. METHODS: In a prospective study design, we recorded consecutive 12-lead electrocardiograms and echocardiograms in 43 patients who were referred to our institution for evaluation and therapy of a significant pericardial effusion. Cardiac tamponade was present in 23 patients (53%). Low QRS voltage (defined as maximum QRS amplitude <0.5 mV in the limb leads) was found in 14 of these 23 subjects (61%). Nine of these 14 patients were treated by pericardiocentesis (group A). Five patients received anti-inflammatory medication (group B). Group C consisted of nine patients with pericarditis and significant pericardial effusion who had no clinical evidence of tamponade. RESULTS: In group A, low QRS voltage remained largely unchanged immediately after successful pericardiocentesis (0.36 +/- 0.17 mV before vs. 0.42 +/- 0.21 mV after, p = NS), but QRS amplitude recovered within a week (0.78 +/- 0.33 mV, p < 0.001). In group B, the maximum QRS amplitude increased from 0.40 +/- 0.20 mV to 0.80 +/- 0.36 mV (p < 0.001) within six days. In group C, all patients had a normal QRS amplitude initially (1.09 +/- 0.55 mV) and during a seven-day follow-up (1.10 +/- 0.56 mV, p = NS). CONCLUSIONS: Low QRS voltage is a feature of cardiac tamponade but not of pericardial effusion per se. Our findings indicate that the presence and severity of cardiac tamponade, in addition to inflammatory mechanisms, may contribute to the development of low QRS voltage in patients with large pericardial effusions.

Aged↗
PubMed2001

Impact of cardiac resynchronization therapy using hemodynamically optimized pacing on left ventricular remodeling in patients with congestive heart failure and ventricular conduction disturbances.

OBJECTIVES: We sought to investigate the impact of six months of cardiac resynchronization therapy (CRT) on echocardiographic variables of left ventricular (LV) function. BACKGROUND: Cardiac resynchronization therapy has recently been introduced as a new therapeutic modality in patients with advanced heart failure (HF) and conduction abnormalities. However, most studies have only investigated the early hemodynamic effects of CRT. METHODS: Twenty-five patients (12 women and 13 men; 59.8 +/- 5.1 years old) with advanced HF caused by ischemic (n = 7) or idiopathic dilated cardiomyopathy (n = 18) and a prolonged QRS complex were analyzed. All patients underwent early hemodynamic testing with a randomized testing protocol; echocardiographic measurements were compared before implantation and after six months of CRT. RESULTS: Left ventricular end-diastolic and end-systolic diameters (LVEDD and LVESD, respectively) were significantly reduced after six months (LVEDD from 71 +/- 10 to 68 +/- 11 mm, p = 0.027; LVESD from 63 +/- 11 to 58 +/- 11 mm, p = 0.007), as were LV end-diastolic and end-systolic volumes (LVEDV from 253 +/- 83 to 227 +/- 112 ml, p = 0.017; LVESV from 202 +/- 79 to 174 +/- 101 ml, p = 0.009). Ejection fraction was significantly increased (from 22 +/- 7% to 26 +/- 9%, p = 0.03). "Nonresponders," with regard to LV volume reduction, had significantly higher baseline LVEDV, compared with "responders" (351 +/- 52 vs. 234 +/- 74 ml, p = 0.018). Overall, there was only mild mitral regurgitation at baseline, with a minor reduction by semiquantitative analysis. The results of early hemodynamic testing did not predict the volume response. CONCLUSIONS: Cardiac resynchronization therapy may lead to a reduction in LV volumes in patients with advanced HF and conduction disturbances. Volume nonresponders have significantly higher baseline LVEDV.

Aged↗
PubMed2001

Stimulation of the left ventricle through the coronary sinus with a newly developed 'over the wire' lead system--early experiences with lead handling and positioning.

AIMS: This report describes the initial clinical results with a newly designed guiding catheter and an 'over the wire' pacing lead based on angiolasty technology to stimulate the left ventricle using the transvenous route via the coronary sinus (OTW-CV lead). METHODS AND RESULTS: In 75% of the 15 patients (6 males, 9 females, mean age of 53 +/- 9 years) with congestive heart failure, access to coronary sinus required less than 2 min; in one patient. the attempt failed. Mean R wave amplitudes plus or minus the standard deviation, measured at apical, mid-ventricular and basal positions the anterior (11.4 +/- 9.2, 10.8 +/- 6.2, 9.3 +/- 6.3 mV) and lateral or posterior veins (10.1 +/- 10.7, 8.6 +/- 6.4, 7.7 +/- 4.3 mV) showed a trend favouring the apex without statistical significance. Pacing impedance, measured at the same sites and vein tributaries, ranged from 670 +/- 191 to 915 +/- 145 ohms. Pacing thresholds measured at apical and mid ventricular sites were significantly lower than at the base in the anterior vein 2.5 +/- 2.8 and 2.8 +/- 1.8 vs 5.6 +/- 2.7 V at 0.5 ms, P<0.001). Thresholds in the lateral/posterior veins showed a similar trend but did not reach statistical significance (3.0 +/- 1.7, 3.6 +/- 1.4 +/- 1.8 V at 0.5 ms). In patients, in whom thresholds were determined in more than one vein, the 'best' mean threshold was 1.6 +/- 0.7 V. CONCLUSION: The new 'over the wire' lead and guiding catheter system allows uncomplicated access to the coronary sinus and the depth of the coronary vein tributaries. Left ventricular sensing and pacing thresholds are acceptable for chronic use in implanted cardiac rhythm management systems.

Adult↗
PubMed2001

Somatic comorbidity of addicts: does hospitalization yield relevant findings?

The aim of this prospective study was to examine the severity and character of somatic comorbidity when addicted patients were admitted to hospital for detoxification. The study was conducted at a university-based psychiatric clinic. Somatic comorbidity was registered by laboratory, radiological and electrocardiographic parameters and by the amount of non-psychiatric consultations. Besides the number of patients with dual diagnosis interpreted as combination of addictive and psychiatric diseases was registered. A total of 111 consecutive patients (32 women) was divided into patients with alcohol dependence and patients with other addictive diseases including polydrug abuse and opiate dependence. Patients with alcohol dependence were characterized by an elevated heart rate and higher values for gamma-glutamyltransferase. No significant differences between groups could be found for the rate corrected QT interval and cardiothoracic ratio. Although viral liver disease was diagnosed in both groups patients with a history of injecting drug use were at greatest risk for hepatitis C. About one-third of all patients required consultant non-psychiatric treatment. Concomitant heart and pulmonary diseases were more pronounced in the alcohol dependence group. The findings emphasize that hospitalization of addicted patients yields relevant somatic morbidity which has an impact on cost and requires medically supervised detoxification programs.

Adult↗
PubMed2000

Echocardiographic evidence of hemodynamic and clinical improvement in patients paced for heart failure.

Dilated cardiomyopathy is frequently associated with electrical conduction disturbances. Development of left bundle-branch block with discoordinated ventricular contraction pattern further contributes to impaired hemodynamic performance. Biventricular pacing has evolved as a new treatment option for patients with dilated cardiomyopathy and conduction disturbances. The "electrical" approach aims to normalize the disturbed contraction pattern, thereby improving hemodynamic function by simultaneous stimulation at different ventricular sites. Acute hemodynamic improvement with biventricular pacing has been demonstrated in patients with depressed left ventricular function and delayed intraventricular conduction. Due to the variations in optimal pacing site and atrioventricular delay, individual optimization to achieve optimal hemodynamic benefit is necessary. Echocardiography has the potential to provide hemodynamic data by Doppler techniques and combine these with geometric information about ventricular volumes, ejection fraction, and contraction patterns. This article focuses on the use of echocardiographic techniques for noninvasive optimization in cardiac pacing and presents preliminary experience from the initial trials on multisite pacing in heart failure.

Arrhythmias, Cardiac↗
PubMed2000

Pacing Therapies in Congestive Heart Failure II study.

Ventricular resynchronization therapy (VRT) by left or biventricular stimulation is gaining increasing acceptance as a new therapy in addition to drugs in patients with advanced heart failure and intraventricular conduction disturbances. Several studies have demonstrated acute hemodynamic benefit of VRT in these patients, although there are only limited long-term data in small patient cohorts. Many open questions remain: whether to pace both ventricles or the left ventricle alone, the optimal left ventricular pacing site, the criteria used to identify the optimal candidate for VRT (e.g., QRS width), and the importance of an integrated defibrillator function in a VRT device. The Pacing Therapy in Congestive Heart Failure (PATH-CHF) II study is a prospective, randomized, cross-over study currently investigating the potential benefit of VRT in a population with advanced heart failure, with or without an accepted indication for an implantable defibrillator. It focuses on the effects of optimized univentricular pacing in these patients, and both acute hemodynamic and chronic functional effects are assessed. Acute hemodynamic testing mainly investigates the impact of different left ventricular pacing sites, alone or combined with right ventricular sites, on hemodynamic performance. Primary endpoint of the study is an improvement in functional capacity as assessed by cardiopulmonary exercise testing and 6-minute walk distance; secondary endpoints include improvement in quality of life (assessed by Minnesota quality of life score, New York Heart Association (NYHA) functional class, and hospitalization frequency), and improvements in prognostic and hemodynamic parameters. The trial aims to enroll 64 patients with full datum sets (separately in 2 groups with a QRS of < or = 150 or > 150 msec, respectively) in 9 European centers. The enrollment began September 1998, and is expected to conclude in summer 2000 to reach the number of necessary datum sets.

Arrhythmias, Cardiac↗
PubMed2000

[Heart failure as a cardiac symptom of sarcoidosis. Successful treatment of heart failure with steroids, digitalis and an angiotensin-1-receptor antagonist in sarcoidosis].

BACKGROUND: Sarcoidosis is a multisystemic disorder that may involve every organ. A symptomatic manifestation of the myocardium is possible, in these cases arrhythmias are the most common symptoms. CASE REPORT: This case report presents a 26-year-old female with the recurrence of Boeck's sarcoid. Fever, chill and a severe reduction in stress tolerance were the first symptoms. At the time of admission she complained of Grade III dyspnea according to the NYHA classification. The echocardiogram showed a severe impairment of the global and left ventricular function. The left ventricular ejection fraction was reduced to 30% and the Tei index was elevated to 1.0. A specimen taken from a mediastinal tumor confirmed the hypothesis of the recurrence of the sarcoidosis. Myocardial perfusion scintigraphy showed typical lesions for myocardial sarcoidosis. There were signs of an old anteroseptal infarction in the resting ECG without evidence of myocardial ischemia during a stress test. Repeated Holter-ECGs were without signs of severe arrhythmias whereas ventricular late potentials were positive. After the combined therapy with steroids, digitalis and an angiotensin-1 receptor antagonist, mediastinal mass and Tei index were reduced and the ejection fraction moved to 56%. Dyspnoea was classified with Grade II according to the NYHA classification. CONCLUSION: Treatment of asymptomatic sarcoidosis is still controversial, whereas the treatment of life-threatening sarcoidosis, eye involvement or severe hypercalcemia is accepted. This case report presents the successful treatment of severe heart failure with prednisone, glycosides and an angiotensin-1 receptor antagonist. With this combined therapy an improvement of subjective and objective parameters was possible.

Adult↗
PubMed2000

Assessment of coronary calcification by electron-beam computed tomography in symptomatic patients with normal, abnormal or equivocal exercise stress test.

AIMS: Exercise stress testing is often used as the initial non-invasive diagnostic test in symptomatic patients with suspected obstructive coronary artery disease. Positive standard ECG criteria are quite specific for obstructive coronary artery disease, but there may be a substantial number of false negative tests, including patients with severe coronary artery disease. Also, exercise stress tests frequently yield equivocal results. Instead of detecting the functional consequences, electron-beam computed tomography visualized atherosclerotic plaque disease directly, but its relationship to functional testing has not been clearly delineated. It was the aim of the current study to examine electron-beam computed tomography for the identification of obstructive coronary artery disease in patients with a normal, abnormal, or equivocal exercise stress test. METHODS AND RESULTS: Symptomatic patients referred for coronary angiography were prospectively included in a consecutive manner if they had no prior diagnosis of coronary artery disease and an unremarkable resting ECG. All patients underwent both exercise stress test and electron-beam computed tomography on the day before coronary angiography. Standard protocols and ECG criteria to diagnose inducible ischaemia were used for the exercise stress test. The electron-beam computed tomography-derived total calcium score was computed according to standard Agatston criteria. Of the 323 patients (mean age, 55+/-11 years; 77% male), 179 (55%) had obstructive coronary artery disease, defined angiographically as luminal diameter narrowing >/=50%. A normal exercise stress test was documented in 105 patients (32.5%), an abnormal exercise stress test ('diagnostic for ischaemia') in 113 (35%), and an equivocal exercise stress test ('inadequate exercise or non-diagnostic ECG-changes') in 105 (32.5%). Multivariate analysis indicated that exercise stress test and electron-beam computed tomography yielded independent information for predicting obstructive coronary artery disease. Sensitivity, specificity and overall accuracy of the exercise stress test were 71%, 75% and 73%, respectively, if equivocal tests were not included, and 50%, 84% and 65% if they were included. Irrespective of the cutpoint regarded as 'positive', the overall accuracy of the electron-beam computed tomography-derived calcium score remained approximately 80% in patients with a normal, abnormal or equivocal exercise stress test. In patients with an equivocal and - to a lesser degree - with a normal exercise stress test, electron-beam computed tomography was able to significantly improve classification regarding obstructive coronary artery disease. Electron-beam computed tomography added no incremental predictive value in patients with an abnormal exercise stress test. CONCLUSION: In patients who are judged to have an intermediate post-test probability of disease after exercise stress test, electron-beam computed tomography scanning may be a meaningful strategy for further stratification regarding the likelihood of obstructive coronary artery disease.

Calcinosis↗
PubMed2000

Safety of intracoronary Doppler flow measurement.

BACKGROUND: With the introduction of Doppler-tipped guide wires, intracoronary Doppler flow measurement has been increasingly accepted as an additional diagnostic approach in the catheterization laboratory. However, the safety of intracoronary Doppler flow measurement has not been well-investigated. The purpose of our study was to evaluate the safety of intracoronary Doppler flow measurement using the Doppler FloWire (Cardiometrics, Mountain View, Calif). METHODS AND RESULTS: A total of 906 patients were examined by intracoronary Doppler with a 0.014-inch or an 0.018-inch Doppler FloWire. For coronary flow reserve measurement, intracoronary injection of adenosine or papaverine was used. Of the patients studied, 77 were cardiac transplant recipients and 829 were patients who had not received a transplant, of whom 617 had undergone diagnostic coronary procedures and 212 had coronary interventions. In 27 (2.98%) of 906 patients adverse cardiac events were observed. Fifteen (1.66%) of 906 patients had severe transient bradycardia develop (asystole or second- to third-degree atrioventricular block) after intracoronary administration of adenosine, 14 of which occurred in the right coronary artery and 1 in the left anterior descending artery. Nine (0.99%) of 906 patients had coronary spasm during the passage of the Doppler wire (5 in the right coronary artery, 4 in the left anterior descending artery). Two (0.22%) of 906 patients had ventricular fibrillation during the procedure. Hypotension with bradycardia and ventricular extrasystole each occurred in 1 (0.11%) of 906 patients. The incidence of complication was significantly higher in transplant recipients than in patients who underwent either diagnostic or interventional procedures (12.99% vs 2.43% vs 0.94%, P <.001). The Doppler measurements in the right coronary artery were associated with a higher incidence of complications, especially bradycardia, compared with the left anterior descending and the left circumflex arteries (right coronary, 5.87% vs left anterior descending, 1.05% vs left circumflex, 0.17%; P <.001). All complications were cured medically. CONCLUSION: Intracoronary Doppler flow measurement with Doppler wires and intracoronary administration of adenosine is a safe method. However, severe complications such as bradycardia and coronary spasm can occur. Attention should be paid to the examination of the right coronary artery, especially in heart transplant recipients.

Adenosine↗