Biomedical subjects

Miia Holmström

Publications and source records attributed to Miia Holmström.

6 recordsLinked to original sources

PubMed2006

Eight-row multidetector computed tomography coronary angiography evaluation of significant coronary artery disease in patients with severe aortic valve stenosis.

BACKGROUND: The aim of this study was to evaluate whether 8-row multidetector computed tomography coronary angiography (MDCT-CA) could replace invasive conventional coronary angiography (CCA) in patients with acquired severe aortic valve stenosis (AS). Coronary artery disease (CAD) diagnosis should be obtained with a noninvasive method in patients with AS undergoing valvular replacement. We evaluated the diagnostic accuracy of MDCT-CA in detecting high-grade (> or =50%) stenoses in the main coronary arteries in patients with AS. METHODS: Twenty-three patients with acquired severe AS underwent both CCA and MDCT-CA. We calculated the total and volumetric calcium scores and evaluated the image quality of each coronary segment as assessable or nonassessable for stenosis. The images of the arteries were evaluated for the occurrence of artifacts and the presence of high-grade stenoses (> or =50%) by visual estimation and comparison with that of CCA. RESULTS: Of the 322 segments screened 224 were assessable for stenosis. Heavy calcium load rendered 37 (38%) of the 98 coronary segments nonassessable. Compared to CCA, MDCT-CA had a sensitivity of 63%, a specificity of 96%, a positive predictive value of 52%, and a negative predictive value of 98% for > or =50% stenoses in the main coronary arteries. CONCLUSIONS: Eight-row MDCT-CA revealed a low sensitivity in detecting significant coronary artery disease in patients with acquired severe AS. High calcium burden decreased visualization of the lumen and complicated most often a correct assessment. In this patient group, CCA should still remain the primary pre-surgical test to rule out coronary lesions requiring revascularization.

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PubMed2006

Noninvasive analysis of coronary artery disease with combination of MDCT and functional MRI.

RATIONALE AND OBJECTIVES: We evaluated the diagnostic accuracy of an eight-row multidetector computed tomography coronary angiography (MDCT-CA) in detecting high-grade (>50%) stenoses in the three main coronary arteries in patients with coronary artery disease (CAD). Side branches were excluded. We correlated magnetic resonance imaging (MRI) findings of the myocardium with MDCT-CA of the coronary arteries. MATERIALS AND METHODS: Fourteen CAD patients underwent conventional coronary angiography (CCA), MDCT-CA, and MRI. We determined the calcium burden with non-enhanced MDCT scan. Then MDCT-CA was performed after intravenous contrast injection during a single breathhold. The left ventricular (LV) MR cine imaging was assessed at rest and perfusion defects were observed during pharmacologic stress after contrast administration. Delayed contrast-enhanced MRI was performed to picture infarctions. RESULTS: MDCT-CA had sensitivity 82%, specificity 94%, positive predictive value 79%, and negative predictive value 95% of stenoses of more than 50% in the main coronary arteries when compared with CCA. LV 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. CONCLUSIONS: CCA and MDCT-CA revealed comparable results in evaluating stenotic lesions above 50% in the main subepicardial coronary branches. There were no significant correlations between the degree of stenosis or calcification at MDCT-CA and the MR findings, but the combined information of MDCT-CA and MRI showed the variability of myocardial changes in regions perfused by significantly stenosed, calcified, and normal main coronary arteries.

Adult↗

PubMed2006

Magnetocardiographic assessment of healed myocardial infarction.

BACKGROUND: We evaluated the capability of multichannel magnetocardiography (MCG) to detect healed myocardial infarction (MI). METHODS: Multichannel MCG over frontal chest was recorded at rest in 21 patients with healed MI, detected by cine- and contrast-enhanced magnetic resonance imaging, and in 26 healthy controls. Of the 21 MI patients, 11 had non-Q wave and 10 Q wave MIs. QRS, ST-segment, T wave and ST-T wave integrals, ST-segment and T wave amplitudes, and QRS and ST-T wave magnetic field map orientations were measured. RESULTS: The MCG repolarization indexes, such as ST segment and ST-T wave integrals, separated the MI group from the controls (ST-T wave integral -1.4 +/- 5.3 vs 1.5 +/- 4.7 pTs, P = 0.034). The abnormalities were more distinct in the Q wave-MI than in the non-Q wave MI subgroup. In the latter, however, a trend similar to the Q wave MI group was found. The relation of QRS area to ST segment and T wave integral improved the detection of healed MIs compared to the ST-T wave indexes alone (QRS-ST-T discordance 14 +/- 10 vs 5.0 +/- 7.1 pTs, P = 0.003). When comparing the MI group to the controls, the orientation of the magnetic field maps differed in the ST-T wave maps (163 +/- 119 degrees vs 58 +/- 17 degrees, P < 0.001) but not in the QRS maps (111 +/- 95 degrees vs 106 +/-93 degrees, P = 0.646). CONCLUSIONS: The MCG repolarization variables can detect healed MI. These ST-T wave abnormalities are more pronounced in patients with Q wave MI than in patients with non-Q wave MIs. Relating the signals of depolarization and repolarization phases improves the detection of healed MI. Repolarization abnormalities are common in healed MI and thus should not always be interpreted as present ongoing ischemia.

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PubMed2005

Spatial repolarization abnormalities in old myocardial infarction.

Conventional electrocardiogram criteria for myocardial infarction (MI) rely on QRS features, but ST-T segment is also affected. We recorded body surface potential mapping in 24 patients with prior MI and in 24 controls. T-wave maximum amplitude and QRS and ST-T integrals were automatically determined. Old MI was verified by magnetic resonance imaging. ST-T integral and T-wave maximum amplitude outperformed QRS integral in detecting MI, with area under receiver operating characteristic curve of 94%, 95%, and 83%, respectively. ST-T integral performed better in non-Q-wave than Q-wave MI, with area under receiver operating characteristic curve of 97% and 92%, respectively. QRS integral correlated negatively with ST-T integral in patients with MI (r = -0.58, P < .001) and positively in controls (r = 0.45, P < .001). In conclusion, ST-T integral proved equal to QRS integral in old MI detection. Inclusion of ventricular repolarization phase and development of electrocardiographic analysis over larger chest area may improve the QRS-based diagnosis of old myocardial infarction.

Adult↗

PubMed2004

Temporal analysis of the depolarization wave of healed myocardial infarction in body surface potential mapping.

BACKGROUND: We studied the ability of different time segments of the depolarization wave recorded with body surface potential mapping (BSPM) to detect and localize myocardial infarction (MI). METHODS: BSPM was recorded in 24 patients with remote MI and in 24 healthy controls. Cine and contrast-enhanced magnetic resonance imaging (MRI) was used as a reference method. Patients were grouped according to anatomical location of their MI. The QRS complex was divided into six temporally equal segments, for which time integrals were calculated. RESULTS: The time segments of the QRS complex showed different MI detection capability depending on MI location. For anterior infarction the second segment of the QRS complex was the best in MI detection and the optimal area was on the right inferior quadrant of the thorax (time integral average -1.5 +/- 1.8 mVms patients, 1.0 +/- 1.6 mVms controls, P = 0.002). For lateral infarction the first segment of the QRS complex performed best and the optimal area for MI detection was the left fourth intercostal area (time integral average 1.8 +/- 1.0 mVms patients, 0.7 +/- 0.5 mVms controls, P = 0.024). For inferior and posterior MI the mid-phases of the QRS complex were the best and the optimal area was the mid-inferior area of the thorax (time integral average -6.2 +/- 8.3 mVms patients, 3.3 +/- 4.3 mVms controls, P = 0.002; -9.1 +/- 6.1 mVms patients, 0.6 +/- 7.1 mVms controls, P = 0.001, respectively). CONCLUSIONS: Time segment analysis of the depolarization wave offers potential for improving the detection and localization of healed MI.

Aged↗

PubMed2003

Wall motion and perfusion analysis of transmyocardial laser revascularization.

OBJECTIVE: Transmyocardial laser revascularization (TMLR) creates channels in the myocardium. The aim of the treatment is to relieve angina in patients with end-stage coronary artery disease. We studied the effect of TMLR on myocardial function and perfusion with the combination of cine magnetic resonance imaging (MRI) and thallium scintigraphy. DESIGN: Eight patients with severe triple-vessel coronary artery disease were studied with MRI and thallium scintigraphy before and 6 months after laser treatment. RESULTS: TMLR did not improve global left ventricular (LV) function or myocardial perfusion. However, systolic wall thickening deprived in segments with fixed perfusion defects in 6 months and laser treatment prevented this deprivation (p = 0.03). In addition single photon emission computed tomography (SPECT) imaging indicated that TMLR prevented conversion of reversible into fixed defects. CONCLUSION: In severe, progressing coronary artery disease TMLR does not improve global LV function or myocardial perfusion, but it preserves systolic wall thickening in fixed defects (scar). It also prevents changes from ischemic myocardial regions to scar.

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