34 research outputs found
Sepelvaltimotaudin noninvasiivinen tutkiminen
Conventional invasive coronary angiography is the clinical gold standard for detecting of coronary artery stenoses. Noninvasive multidetector computed tomography (MDCT) in combination with retrospective ECG gating has recently been shown to permit visualization of the coronary artery lumen and detection of coronary artery stenoses. Single photon emission tomography (SPECT) perfusion imaging has been considered the reference method for evaluation of nonviable myocardium, but magnetic resonance imaging (MRI) can accurately depict structure, function, effusion, and myocardial viability, with an overall capacity unmatched by any other single imaging modality. Magnetocardiography (MCG) provides noninvasively information about myocardial excitation propagation and repolarization without the use of electrodes. This evolving technique may be considered the magnetic equivalent to electrocardiography.
The aim of the present series of studies was to evaluate changes in the myocardium assessed with SPECT and MRI caused by coronary artery disease, examine the capability of multidetector computed tomography coronary angiography (MDCT-CA) to detect significant stenoses in the coronary arteries, and MCG to assess remote myocardial infarctions.
Our study showed that in severe, progressing coronary artery disease laser treatment does not improve global left ventricular function or myocardial perfusion, but it does preserve systolic wall thickening in fixed defects (scar). It also prevents changes from ischemic myocardial regions to scar.
The MCG repolarization variables are informative in remote myocardial infarction, and may perform as well as the conventional QRS criteria in detection of healed myocardial infarction. These STT abnormalities are more pronounced in patients with Q-wave infarction than in patients with non-Q-wave infarctions.
MDCT-CA had a sensitivity of 82%, a specificity of 94%, a positive predictive value of 79%, and a negative predictive value of 95% for stenoses over 50% in the main coronary arteries as compared with conventional coronary angiography in patients with known coronary artery disease. Left ventricular wall dysfunction, perfusion defects, and infarctions were detected in 50-78% of sectors assigned to calcifications or stenoses, but also in sectors supplied by normally perfused coronary arteries.
Our study showed a low sensitivity (sensitivity 63%) in detecting obstructive coronary artery disease assessed by MDCT in patients with severe aortic stenosis. Massive calcifications complicated correct assessment of the lumen of coronary arteries.Sepelvaltimotaudin noninvasiivinen tutkiminen
Perinteinen sepelvaltimoiden varjoainekuvaus on ollut kulmakivi sepelvaltimotaudin tutkimisessa. Kuitenkin pieni vakavien komplikaatioiden riski, tutkimuksen epämukavuus ja sairaalahoitopäivät potilaalle ovat johtaneet potilaasta vähemmän rasittavien, noninvasiivisten, tutkimusmenetelmien etsimiseen. Sydämen noninvasiivisen tutkimisen mahdollisuudet ovat kehittyneet viime vuosina huimaa vauhtia.
Tutkimuksessa selvitettiin sydämen isotooppitutkimuksen lisäksi uusien tutkimusmenetelmien, monileiketietokonetomografian, magneettikuvauksen ja magnetokardiografian, käyttökelpoisuutta sepelvaltimotaudin eri ilmentymien tutkimisessa. Sepelvaltimoiden tietokonetomografia on uusi lupaava menetelmä sepelvaltimoahtaumien, kalkkikertymien ja pehmeiden plakkien tutkimisessa. Magneettikuvauksella voidaan arvioida sydänlihaksen toimintaa ja mahdollisia infarktialueita. Monikanavainen magnetokardiografia antaa tarkkaa tietoa sydämen sähköisestä toiminnasta.
Tutkimukseen osallistui 43 eriasteista sepelvaltimotautia, 23 aorttaläpän ahtaumaa sairastavaa potilasta ja 26 tervettä verrokkihenkilöä.
Tutkimuksessa todettiin, että sydänlihaksen laserkanavointi pitkälle edenneessä sepelvaltimotaudissa ei parantanut sydänlihaksen pumppaus- tehokkuutta eikä sydänlihaskudoksen verenvirtausta, joita mitattiin magneetti- ja isotooppikuvauksella. Laserkanavointi näytti 6 kk:n seurannassa kuitenkin hidastavan sydänlihaksen pysyvien vaurioiden syntyä. Yhdistämällä informaatiota sydämen magneettikuvauksesta ja sepelvaltimoiden monileiketietokonetomografiasta, totesimme että sydämen seinämän liikehäiriöitä, verenvirtauspoikkeavuuksia ja infarkteja oli myös alueilla, joiden sepelvaltimoissa ei todettu mitään poikkeavaa. Tietokonetomografian osuvuus perinteiseen varjoainekuvaukseen verrattuna on varsin hyvä, mutta aorttaläpän ahtaumaa sairastavilla potilailla runsaat kalkkikertymät vaikeuttivat sepelvaltimoahtaumien löytymistä. Monikanavaisen magnetokardiografia osuvuus perinteiseen 12-kytkentäiseen EKG:hen ja magneettikuvaukseen sydäninfarktiarpien osoittamisessa todettiin hyväksi sekä Q- että non-Q-aalto infarkteissa.
Noninvasiivisten tutkimusmenetelmien käyttö tulee lisääntymään laitteiden kehittyessä nopeasti. Monileiketietokonetomografia sepelvaltimoiden kuvantamisessa voi osalla potilaista korvata perinteisen sepelvaltimoiden varjoainekuvauksen. Myös magneettikuvauksen antamat mahdollisuudet sydänlihaksen toimintahäiriöiden ja infarktien kuvantamisessa sopivat enenevässä määrin kliiniseen käyttöön
Myocardial tissue characterization in patients with hereditary gelsolin (AGel) amyloidosis using novel cardiovascular magnetic resonance techniques
Gelsolin (AGel) amyloidosis is a hereditary condition with common neurological effects. Myocardial involvement, especially strain, T1, or extracellular volume (ECV), in this disease has not been investigated before. Local myocardial effects and possible amyloid accumulation were the targets of interest in this study. Fifty patients with AGel amyloidosis were enrolled in the study. All patients underwent cardiovascular magnetic resonance imaging, including cine imaging, T1 mapping, tagging, and late gadolinium enhancement (LGE) imaging at 1.5 T. Results for volumetry, myocardial feature-tracking strain, rotation, torsion, native T1, ECV, and LGE were investigated. The population mean native T1 values in different segments of the left ventricle (LV) varied between 1003 and 1080 ms. Myocardial mean T1 was 1031 ± 37 ms. T1 was highest in the basal plane of the LV (1055 ± 40 ms), similarly to ECV (30.0% ± 4.4%). ECV correlated with native T1 in all LV segments (p Peer reviewe
Non-invasive dye dilution method for measuring an atrial septal defect shunt size
Aims Objective of this study was to evaluate the feasibility of the non-invasive dye dilution method to quantify shunt size related to atrial septal defects (ASD). The diagnostic accuracy of shunt size determination in ASD's has been suboptimal with common non-invasive methods. We have previously developed a cost-effective and time-effective non-invasive dye dilution method. In this method, the indocyanine green solution is injected into the antecubital vein and the appearance of the dye is detected with an earpiece densitometer. Methods and results We studied 192 patients with an ASD. Mean pulmonary blood flow/systemic blood flow (Qp/Qs) was measured with dye dilution technique and compared with following methods: Fick's invasive oximetry (n=49), transoesophageal echocardiography (TEE) measuring ASD size (n=143) and cardiac MR (CMR) (n=9). For the first 49 patients, Qp/Qs was 2.05 +/- 0.70 with the Fick's invasive oximetry and 2.12 +/- 0.68 with dye dilution method with an excellent correlation between the two methods (R=0.902, p Conclusion The dye dilution method with earpiece densitometer recording is a clinically feasible and reliable method to assess shunt size in ASDs.Peer reviewe
Reducing cardiac implantable electronic device-induced artefacts in cardiac magnetic resonance imaging
Objectives Cardiac implantable electronic device (CIED)-induced metal artefacts possibly significantly diminish the diagnostic value of magnetic resonance imaging (MRI), particularly cardiac MR (CMR). Right-sided generator implantation, wideband late-gadolinium enhancement (LGE) technique and raising the ipsilateral arm to the generator during CMR scanning may reduce the CIED-induced image artefacts. We assessed the impact of generator location and the arm-raised imaging position on the CIED-induced artefacts in CMR. Methods We included all clinically indicated CMRs performed on patients with normal cardiac anatomy and a permanent CIED with endocardial pacing leads between November 2011 and October 2019 in our institution (n = 171). We analysed cine and LGE sequences using the American Heart Association 17-segment model for the presence of artefacts. Results Right-sided generator implantation and arm-raised imaging associated with a significantly increased number of artefact-free segments. In patients with a right-sided pacemaker, the median percentage of artefact-free segments in short-axis balanced steady-state free precession LGE was 93.8% (IQR 9.4%, n = 53) compared with 78.1% (IQR 20.3%, n = 58) for left-sided pacemaker (p < 0.001). In patients with a left-sided implantable cardioverter-defibrillator, the median percentage of artefact-free segments reached 87.5% (IQR 6.3%, n = 9) using arm-raised imaging, which fell to 62.5% (IQR 34.4%, n = 9) using arm-down imaging in spoiled gradient echo short-axis cine (p = 0.02). Conclusions Arm-raised imaging represents a straightforward method to reduce CMR artefacts in patients with left-sided generators and can be used alongside other image quality improvement methods. Right-sided generator implantation could be considered in CIED patients requiring subsequent CMR imaging to ensure sufficient image quality.Peer reviewe
Clinical experience of magnetic resonance imaging in patients with cardiac pacing devices : unrestricted patient population
Background Magnetic resonance imaging (MRI) in patients with cardiac pacing devices has become available despite previously being considered absolutely contraindicated. However, most institutional safety protocols have included several limitations on patient selection, leaving MRI unavailable for many patients. Purpose To evaluate the first 1000 MRI examinations conducted on patients with cardiac pacing devices at Helsinki University Hospital for any potential safety hazards and also to evaluate the long-term functionality of the safety protocol in "real-life" clinical practice. Material and Methods A total of 1000 clinically indicated MRI scans were performed with a 1.5-T MRI scanner according to the safety protocol. The following information was collected from the electronic medical record (EMR): patients' date of birth; sex; pacing device generator model; date of MRI scan; date of the latest pacing device generator implantation; and the body region scanned. The EMR of these patients was checked and especially searched for any pacing device related safety hazards or adverse outcomes during or after the MRI scan. Results Only one potentially dangerous adverse event was noted in our study group. In addition, patients with abandoned leads, temporary pacing devices, and newly implanted pacing device generators were scanned successfully and safely. Conclusion MRI scans can be performed safely in patients with cardiac pacing devices if the dedicated safety protocol is followed.Peer reviewe
Cardiac Magnetic Resonance Imaging-Based Screening for Cardiac Sarcoidosis in Patients With Atrioventricular Block Requiring Temporary Pacing
Background Some myocardial diseases, such as cardiac sarcoidosis, predispose to complete atrioventricular block. The European Society of Cardiology Guidelines on cardiac pacing in 2021 recommend myocardial disease screening in patients with conduction disorder requiring pacemaker with multimodality imaging, including cardiac magnetic resonance (CMR) imaging. The ability of CMR imaging to detect myocardial disease in patients with a temporary pacing wire is not well documented. Methods and Results Our myocardial disease screening protocol is based on using an active fixation pacing lead connected to a reusable extracorporeal pacing generator (temporary permanent pacemaker) as a bridge to a permanent pacemaker. From 2011 to 2019, we identified 17 patients from our CMR database who underwent CMR imaging with a temporary permanent pacemaker for atrioventricular block. We analyzed their clinical presentations, CMR data, and pacemaker therapy. All CMRs were performed without adverse events. Pacing leads induced minor artifacts to the septal myocardial segments. The extent of late gadolinium enhancement in CMR imaging was used to screen patients for the presence of myocardial disease. Patients with evidence of late gadolinium enhancement underwent endomyocardial biopsy. If considered clinically indicated, also 18-F-fluorodeoxyglucose positron emission tomography and extracardiac tissue biopsy were performed if sarcoidosis was suspected. Eventually, 8 of 17 patients (47.1%) were diagnosed with histologically confirmed granulomatous inflammatory cardiac disease. Importantly, only 1 had a previously diagnosed extracardiac sarcoidosis at the time of presentation with high-degree atrioventricular block. Conclusions CMR imaging with temporary permanent pacemaker protocol is an effective and safe early screening tool for myocardial disease in patients presenting with atrioventricular block requiring immediate, continuous pacing for bradycardia.Peer reviewe
Late gadolinium enhancement (LGE) progresses with right ventricle volume in children after repair of tetralogy of fallot
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