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J Nenonen - One of the best experts on this subject based on the ideXlab platform.

  • temporal analysis of the depolarization wave of healed myocardial infarction in Body Surface Potential mapping
    Annals of Noninvasive Electrocardiology, 2004
    Co-Authors: Paula Vesterinen, Kirsi Lauerma, Milla Karvonen, Miia Holmstrom, Markku Makijarvi, J Nenonen, Toivo Katila, Heikki Väänänen, Helena Hanninen, Lauri Toivonen
    Abstract:

    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.

  • st t integral and t wave amplitude in detection of exercise induced myocardial ischemia evaluated with Body Surface Potential mapping
    Journal of Electrocardiology, 2003
    Co-Authors: Helena Hanninen, Markku Makijarvi, J Nenonen, Toivo Katila, Panu Takala, Juha Rantonen, Kari S Virtanen
    Abstract:

    Body Surface Potential mapping is superior to 12-lead electrocardiogram in detection of acute and old myocardial infarctions. We examined the capability of the ST-T integral and T wave to detect exercise-induced ischemia in Body Surface Potential mapping. Body Surface Potential mapping with 123 channels was recorded in 70 subjects: 45 coronary artery disease (CAD) patients and 25 healthy controls during supine bicycle exercise testing. Of the patients, 18 had anterior, 14 posterior, and 13 inferior ischemia documented by coronary angiography and thallium scintigraphy. The ST-T isointegral area, as well as the positive and negative ST-T area, and the T-wave apex amplitude were determined. Discriminant index analysis was used to find the sites that optimally separated patient subgroups from other patients and controls. In the pooled CAD group, the optimal sites for detecting the decrease in ST-T isointegral, in the positive ST-T area and in the T-wave amplitude were over the left side (ST-T isointegral area: CAD −3.8 ± 14 μVs and controls 24 ± 14 μVs; T-wave amplitude: CAD 3 ± 110 μV and controls 190 ± 90 μV; P < .001, both). The area under the receiver operating characteristic curve for the decrease in ST-T isointegral, in the positive ST-T area, and in the T-wave amplitude and for the ST depression were 94%, 95%, 92%, and 93%, respectively. T wave performed especially well in patients with multivessel disease. In stepwise logistic regression analysis, using the presence of CAD as the dependent parameter, the decrease in the positive ST-T area and ST depression were the only parameters that entered the model. ST-T area and T-wave amplitude are sensitive and specific markers of transient myocardial ischemia. ST-T area contains information additional to ST depression and has thus independent discriminative value in ischemia detection.

  • st segment level and slope in exercise induced myocardial ischemia evaluated with Body Surface Potential mapping
    American Journal of Cardiology, 2001
    Co-Authors: Helena Hanninen, Markku Makijarvi, J Nenonen, Panu Takala, Petri Korhonen, Lasse Oikarinen, Kim Simelius
    Abstract:

    Abstract Body Surface Potential mapping (BSPM) is superior to 12-lead electrocardiography for detection of acute and old myocardial infarctions (MIs). We used BSPM to examine electrocardiographic criteria for acute reversible myocardial ischemia. BSPM with 123 channels was performed in 45 patients with coronary artery disease (CAD) and 25 healthy controls during supine bicycle exercise testing. Of the 45 patients, 18 patients had anterior, 14 had posterior, and 13 had inferior ischemia documented by coronary angiography and thallium scintigraphy. The ST amplitude was measured 60 ms after the J-point and the ST slope calculated by fitting a regression line from the J-point to 60 ms after it. The optimal locations for detecting ST depression and ST-slope decrease were identified. In the pooled CAD patient group, the optimal location for ST depression was 5 cm below standard lead V 5 (CAD group: −70 ± 70 μV; controls: 70 ± 80 μV, p

  • recording locations in multichannel magnetocardiography and Body Surface Potential mapping sensitive for regional exercise induced myocardial ischemia
    Basic Research in Cardiology, 2001
    Co-Authors: Helena Hanninen, Markku Makijarvi, J Nenonen, Toivo Katila, Panu Takala, Petri Korhonen, Lasse Oikarinen, Kim Simelius, J Montonen, Lauri Toivonen
    Abstract:

    Introduction This study aimed to identify the optimal locations in multichannel magnetocardiography (MCG) and Body Surface Potential mapping (BSPM) to detect exercise-induced myocardial ischemia. Methods We studied 17 healthy controls and 24 coronary artery disease (CAD) patients with stenosis in one of the main coronary artery branches: left anterior descending (LAD) in 11 patients, right (RCA) in 7 patients, and left circumflex (LCX) in 6 patients. MCG and BSPM signals were recorded during a supine bicycle stress test. The capability of a recording location to separate the groups was quantified by subtracting the mean signal amplitude of the normal group from that of the patient group during the ST segment and at the T-wave apex, and dividing the resulting amplitude difference by the corresponding standard deviation within all subjects. Results In MCG the optimal location for ST depression was at the right inferior grid for the RCA, at the mid-inferior grid for the LCX, and in the middle of these locations for the LAD subgroup (mean ST amplitudes: CAD −80 ± 360fT, controls 610 ± 660fT; p < 0.001). In BSPM it was on the left upper anterior thorax for the LAD, left lower anterior thorax for the RCA, and on the lower back for the LCX subgroup (mean ST amplitudes: CAD −39 ± 61 μV and controls 38 ± 38 μV; p < 0.001). In MCG the optimal site for T-wave amplitude decrease was the same as the one for the ST depression. In BSPM it was on the middle front for the LAD, on the back for the LCX and on the left abdominal area for the RCA group. In accordance with electromagnetic theory, the largest ST segment and T-wave amplitude changes took place in MCG in locations orthogonal to those in BSPM. Conclusion This study identified magnetocardiographic and BSPM recording locations which are sensitive for detecting transient myocardial ischemia by evaluation of the ST segment as well as the T-wave. These locations strongly depend on ischemic regions and are outside the conventional 12-lead ECG recording sites.

Lauri Toivonen - One of the best experts on this subject based on the ideXlab platform.

  • Complex T-wave morphology in Body Surface Potential mapping in prediction of arrhythmic events in patients with acute myocardial infarction and cardiac dysfunction
    Europace, 2009
    Co-Authors: Petri Korhonen, Markku Makijarvi, Heikki Väänänen, Teijo Konttila, Terhi Husa, Ilkka Tierala, Lauri Toivonen
    Abstract:

    Aims Heterogeneous ventricular repolarization is associated with sudden cardiac death after myocardial infarction (MI). This prospective study investigated repolarization disparity with parameters based on T-wave morphology in Body Surface Potential mapping (BSPM) in the assessment of arrhythmia risk in patients with a recent MI and cardiac dysfunction. Methods and results Patients ( n = 158) had 120-lead BSPM and 12-lead electrocardiogram (ECG) registered soon after acute MI. Principal component analysis (PCA) of the T-wave and T-wave vector loop descriptors were applied to compute parameters describing T-wave morphology and its variation. The study endpoints were arrhythmic events and all-cause mortality. During a mean follow-up of 50 months, 30 patients (19%) died and 16 (10%) had an arrhythmic event. Most of the parameters differed significantly between patients with and without arrhythmic events. In univariate analysis, T-wave vector loop length (TLL) and PCA parameter PCA3 in BSPM and TLL in ECG were significant predictors of arrhythmic events. In multivariate analysis including several clinical variables, these parameters also showed an independent prediction, with parameters in BSPM performing somewhat better. None of the parameters predicted all-cause mortality. Conclusion Complex T-wave morphology in BSPM is a marker of arrhythmia propensity in patients with a recent MI and cardiac dysfunction.

  • temporal analysis of the depolarization wave of healed myocardial infarction in Body Surface Potential mapping
    Annals of Noninvasive Electrocardiology, 2004
    Co-Authors: Paula Vesterinen, Kirsi Lauerma, Milla Karvonen, Miia Holmstrom, Markku Makijarvi, J Nenonen, Toivo Katila, Heikki Väänänen, Helena Hanninen, Lauri Toivonen
    Abstract:

    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.

  • recording locations in multichannel magnetocardiography and Body Surface Potential mapping sensitive for regional exercise induced myocardial ischemia
    Basic Research in Cardiology, 2001
    Co-Authors: Helena Hanninen, Markku Makijarvi, J Nenonen, Toivo Katila, Panu Takala, Petri Korhonen, Lasse Oikarinen, Kim Simelius, J Montonen, Lauri Toivonen
    Abstract:

    Introduction This study aimed to identify the optimal locations in multichannel magnetocardiography (MCG) and Body Surface Potential mapping (BSPM) to detect exercise-induced myocardial ischemia. Methods We studied 17 healthy controls and 24 coronary artery disease (CAD) patients with stenosis in one of the main coronary artery branches: left anterior descending (LAD) in 11 patients, right (RCA) in 7 patients, and left circumflex (LCX) in 6 patients. MCG and BSPM signals were recorded during a supine bicycle stress test. The capability of a recording location to separate the groups was quantified by subtracting the mean signal amplitude of the normal group from that of the patient group during the ST segment and at the T-wave apex, and dividing the resulting amplitude difference by the corresponding standard deviation within all subjects. Results In MCG the optimal location for ST depression was at the right inferior grid for the RCA, at the mid-inferior grid for the LCX, and in the middle of these locations for the LAD subgroup (mean ST amplitudes: CAD −80 ± 360fT, controls 610 ± 660fT; p < 0.001). In BSPM it was on the left upper anterior thorax for the LAD, left lower anterior thorax for the RCA, and on the lower back for the LCX subgroup (mean ST amplitudes: CAD −39 ± 61 μV and controls 38 ± 38 μV; p < 0.001). In MCG the optimal site for T-wave amplitude decrease was the same as the one for the ST depression. In BSPM it was on the middle front for the LAD, on the back for the LCX and on the left abdominal area for the RCA group. In accordance with electromagnetic theory, the largest ST segment and T-wave amplitude changes took place in MCG in locations orthogonal to those in BSPM. Conclusion This study identified magnetocardiographic and BSPM recording locations which are sensitive for detecting transient myocardial ischemia by evaluation of the ST segment as well as the T-wave. These locations strongly depend on ischemic regions and are outside the conventional 12-lead ECG recording sites.

Helena Hanninen - One of the best experts on this subject based on the ideXlab platform.

  • assessment of myocardial infarct size with Body Surface Potential mapping validation against contrast enhanced cardiac magnetic resonance imaging
    Annals of Noninvasive Electrocardiology, 2015
    Co-Authors: Minna Kylmala, Kirsi Lauerma, Paula Vesterinen, Heikki Väänänen, Teijo Konttila, Sari Kivisto, Mats Lindholm, Matti Stenroos, Markku S Nieminen, Helena Hanninen
    Abstract:

    Background Assessment of myocardial infarct (MI) size is important for therapeutic and prognostic reasons. We used Body Surface Potential mapping (BSPM) to evaluate whether single-lead electrocardiographic variables can assess MI size. Methods We performed BSPM with 120 leads covering the front and back chest (plus limb leads) on 57 patients at different phases of MI: acutely, during healing, and in the chronic phase. Final MI size was determined by contrast-enhanced cardiac magnetic resonance imaging (DE-CMR) and correlated with various computed depolarization- and repolarization-phase BSPM variables. We also calculated correlations between BSPM variables and enzymatic MI size (peak CK-MBm). Results BSPM variables reflecting the Q- and R wave showed strong correlations with MI size at all stages of MI. R width performed the best, showing its strongest correlation with MI size on the upper right back, there representing the width of the “reciprocal Q wave” (r = 0.64–0.71 for DE-CMR, r = 0.57–0.64 for CK-MBm, P < 0.0001). Repolarization-phase variables showed only weak correlations with MI size in the acute phase, but these correlations improved during MI healing. T-wave variables and the QRSSTT integral showed their best correlations with DE-CMR defined MI size on the precordial area, at best r = −0.57, P < 0.0001 in the chronic phase. The best performing BSPM variables could differentiate between large and small infarcts at all stages of MI. Conclusions Computed, single-lead electrocardiographic variables can estimate the final infarct size at all stages of MI, and differentiate large infarcts from small.

  • temporal analysis of the depolarization wave of healed myocardial infarction in Body Surface Potential mapping
    Annals of Noninvasive Electrocardiology, 2004
    Co-Authors: Paula Vesterinen, Kirsi Lauerma, Milla Karvonen, Miia Holmstrom, Markku Makijarvi, J Nenonen, Toivo Katila, Heikki Väänänen, Helena Hanninen, Lauri Toivonen
    Abstract:

    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.

  • st t integral and t wave amplitude in detection of exercise induced myocardial ischemia evaluated with Body Surface Potential mapping
    Journal of Electrocardiology, 2003
    Co-Authors: Helena Hanninen, Markku Makijarvi, J Nenonen, Toivo Katila, Panu Takala, Juha Rantonen, Kari S Virtanen
    Abstract:

    Body Surface Potential mapping is superior to 12-lead electrocardiogram in detection of acute and old myocardial infarctions. We examined the capability of the ST-T integral and T wave to detect exercise-induced ischemia in Body Surface Potential mapping. Body Surface Potential mapping with 123 channels was recorded in 70 subjects: 45 coronary artery disease (CAD) patients and 25 healthy controls during supine bicycle exercise testing. Of the patients, 18 had anterior, 14 posterior, and 13 inferior ischemia documented by coronary angiography and thallium scintigraphy. The ST-T isointegral area, as well as the positive and negative ST-T area, and the T-wave apex amplitude were determined. Discriminant index analysis was used to find the sites that optimally separated patient subgroups from other patients and controls. In the pooled CAD group, the optimal sites for detecting the decrease in ST-T isointegral, in the positive ST-T area and in the T-wave amplitude were over the left side (ST-T isointegral area: CAD −3.8 ± 14 μVs and controls 24 ± 14 μVs; T-wave amplitude: CAD 3 ± 110 μV and controls 190 ± 90 μV; P < .001, both). The area under the receiver operating characteristic curve for the decrease in ST-T isointegral, in the positive ST-T area, and in the T-wave amplitude and for the ST depression were 94%, 95%, 92%, and 93%, respectively. T wave performed especially well in patients with multivessel disease. In stepwise logistic regression analysis, using the presence of CAD as the dependent parameter, the decrease in the positive ST-T area and ST depression were the only parameters that entered the model. ST-T area and T-wave amplitude are sensitive and specific markers of transient myocardial ischemia. ST-T area contains information additional to ST depression and has thus independent discriminative value in ischemia detection.

  • st segment level and slope in exercise induced myocardial ischemia evaluated with Body Surface Potential mapping
    American Journal of Cardiology, 2001
    Co-Authors: Helena Hanninen, Markku Makijarvi, J Nenonen, Panu Takala, Petri Korhonen, Lasse Oikarinen, Kim Simelius
    Abstract:

    Abstract Body Surface Potential mapping (BSPM) is superior to 12-lead electrocardiography for detection of acute and old myocardial infarctions (MIs). We used BSPM to examine electrocardiographic criteria for acute reversible myocardial ischemia. BSPM with 123 channels was performed in 45 patients with coronary artery disease (CAD) and 25 healthy controls during supine bicycle exercise testing. Of the 45 patients, 18 patients had anterior, 14 had posterior, and 13 had inferior ischemia documented by coronary angiography and thallium scintigraphy. The ST amplitude was measured 60 ms after the J-point and the ST slope calculated by fitting a regression line from the J-point to 60 ms after it. The optimal locations for detecting ST depression and ST-slope decrease were identified. In the pooled CAD patient group, the optimal location for ST depression was 5 cm below standard lead V 5 (CAD group: −70 ± 70 μV; controls: 70 ± 80 μV, p

  • recording locations in multichannel magnetocardiography and Body Surface Potential mapping sensitive for regional exercise induced myocardial ischemia
    Basic Research in Cardiology, 2001
    Co-Authors: Helena Hanninen, Markku Makijarvi, J Nenonen, Toivo Katila, Panu Takala, Petri Korhonen, Lasse Oikarinen, Kim Simelius, J Montonen, Lauri Toivonen
    Abstract:

    Introduction This study aimed to identify the optimal locations in multichannel magnetocardiography (MCG) and Body Surface Potential mapping (BSPM) to detect exercise-induced myocardial ischemia. Methods We studied 17 healthy controls and 24 coronary artery disease (CAD) patients with stenosis in one of the main coronary artery branches: left anterior descending (LAD) in 11 patients, right (RCA) in 7 patients, and left circumflex (LCX) in 6 patients. MCG and BSPM signals were recorded during a supine bicycle stress test. The capability of a recording location to separate the groups was quantified by subtracting the mean signal amplitude of the normal group from that of the patient group during the ST segment and at the T-wave apex, and dividing the resulting amplitude difference by the corresponding standard deviation within all subjects. Results In MCG the optimal location for ST depression was at the right inferior grid for the RCA, at the mid-inferior grid for the LCX, and in the middle of these locations for the LAD subgroup (mean ST amplitudes: CAD −80 ± 360fT, controls 610 ± 660fT; p < 0.001). In BSPM it was on the left upper anterior thorax for the LAD, left lower anterior thorax for the RCA, and on the lower back for the LCX subgroup (mean ST amplitudes: CAD −39 ± 61 μV and controls 38 ± 38 μV; p < 0.001). In MCG the optimal site for T-wave amplitude decrease was the same as the one for the ST depression. In BSPM it was on the middle front for the LAD, on the back for the LCX and on the left abdominal area for the RCA group. In accordance with electromagnetic theory, the largest ST segment and T-wave amplitude changes took place in MCG in locations orthogonal to those in BSPM. Conclusion This study identified magnetocardiographic and BSPM recording locations which are sensitive for detecting transient myocardial ischemia by evaluation of the ST segment as well as the T-wave. These locations strongly depend on ischemic regions and are outside the conventional 12-lead ECG recording sites.

Markku Makijarvi - One of the best experts on this subject based on the ideXlab platform.

  • Complex T-wave morphology in Body Surface Potential mapping in prediction of arrhythmic events in patients with acute myocardial infarction and cardiac dysfunction
    Europace, 2009
    Co-Authors: Petri Korhonen, Markku Makijarvi, Heikki Väänänen, Teijo Konttila, Terhi Husa, Ilkka Tierala, Lauri Toivonen
    Abstract:

    Aims Heterogeneous ventricular repolarization is associated with sudden cardiac death after myocardial infarction (MI). This prospective study investigated repolarization disparity with parameters based on T-wave morphology in Body Surface Potential mapping (BSPM) in the assessment of arrhythmia risk in patients with a recent MI and cardiac dysfunction. Methods and results Patients ( n = 158) had 120-lead BSPM and 12-lead electrocardiogram (ECG) registered soon after acute MI. Principal component analysis (PCA) of the T-wave and T-wave vector loop descriptors were applied to compute parameters describing T-wave morphology and its variation. The study endpoints were arrhythmic events and all-cause mortality. During a mean follow-up of 50 months, 30 patients (19%) died and 16 (10%) had an arrhythmic event. Most of the parameters differed significantly between patients with and without arrhythmic events. In univariate analysis, T-wave vector loop length (TLL) and PCA parameter PCA3 in BSPM and TLL in ECG were significant predictors of arrhythmic events. In multivariate analysis including several clinical variables, these parameters also showed an independent prediction, with parameters in BSPM performing somewhat better. None of the parameters predicted all-cause mortality. Conclusion Complex T-wave morphology in BSPM is a marker of arrhythmia propensity in patients with a recent MI and cardiac dysfunction.

  • temporal analysis of the depolarization wave of healed myocardial infarction in Body Surface Potential mapping
    Annals of Noninvasive Electrocardiology, 2004
    Co-Authors: Paula Vesterinen, Kirsi Lauerma, Milla Karvonen, Miia Holmstrom, Markku Makijarvi, J Nenonen, Toivo Katila, Heikki Väänänen, Helena Hanninen, Lauri Toivonen
    Abstract:

    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.

  • st t integral and t wave amplitude in detection of exercise induced myocardial ischemia evaluated with Body Surface Potential mapping
    Journal of Electrocardiology, 2003
    Co-Authors: Helena Hanninen, Markku Makijarvi, J Nenonen, Toivo Katila, Panu Takala, Juha Rantonen, Kari S Virtanen
    Abstract:

    Body Surface Potential mapping is superior to 12-lead electrocardiogram in detection of acute and old myocardial infarctions. We examined the capability of the ST-T integral and T wave to detect exercise-induced ischemia in Body Surface Potential mapping. Body Surface Potential mapping with 123 channels was recorded in 70 subjects: 45 coronary artery disease (CAD) patients and 25 healthy controls during supine bicycle exercise testing. Of the patients, 18 had anterior, 14 posterior, and 13 inferior ischemia documented by coronary angiography and thallium scintigraphy. The ST-T isointegral area, as well as the positive and negative ST-T area, and the T-wave apex amplitude were determined. Discriminant index analysis was used to find the sites that optimally separated patient subgroups from other patients and controls. In the pooled CAD group, the optimal sites for detecting the decrease in ST-T isointegral, in the positive ST-T area and in the T-wave amplitude were over the left side (ST-T isointegral area: CAD −3.8 ± 14 μVs and controls 24 ± 14 μVs; T-wave amplitude: CAD 3 ± 110 μV and controls 190 ± 90 μV; P < .001, both). The area under the receiver operating characteristic curve for the decrease in ST-T isointegral, in the positive ST-T area, and in the T-wave amplitude and for the ST depression were 94%, 95%, 92%, and 93%, respectively. T wave performed especially well in patients with multivessel disease. In stepwise logistic regression analysis, using the presence of CAD as the dependent parameter, the decrease in the positive ST-T area and ST depression were the only parameters that entered the model. ST-T area and T-wave amplitude are sensitive and specific markers of transient myocardial ischemia. ST-T area contains information additional to ST depression and has thus independent discriminative value in ischemia detection.

  • st segment level and slope in exercise induced myocardial ischemia evaluated with Body Surface Potential mapping
    American Journal of Cardiology, 2001
    Co-Authors: Helena Hanninen, Markku Makijarvi, J Nenonen, Panu Takala, Petri Korhonen, Lasse Oikarinen, Kim Simelius
    Abstract:

    Abstract Body Surface Potential mapping (BSPM) is superior to 12-lead electrocardiography for detection of acute and old myocardial infarctions (MIs). We used BSPM to examine electrocardiographic criteria for acute reversible myocardial ischemia. BSPM with 123 channels was performed in 45 patients with coronary artery disease (CAD) and 25 healthy controls during supine bicycle exercise testing. Of the 45 patients, 18 patients had anterior, 14 had posterior, and 13 had inferior ischemia documented by coronary angiography and thallium scintigraphy. The ST amplitude was measured 60 ms after the J-point and the ST slope calculated by fitting a regression line from the J-point to 60 ms after it. The optimal locations for detecting ST depression and ST-slope decrease were identified. In the pooled CAD patient group, the optimal location for ST depression was 5 cm below standard lead V 5 (CAD group: −70 ± 70 μV; controls: 70 ± 80 μV, p

  • recording locations in multichannel magnetocardiography and Body Surface Potential mapping sensitive for regional exercise induced myocardial ischemia
    Basic Research in Cardiology, 2001
    Co-Authors: Helena Hanninen, Markku Makijarvi, J Nenonen, Toivo Katila, Panu Takala, Petri Korhonen, Lasse Oikarinen, Kim Simelius, J Montonen, Lauri Toivonen
    Abstract:

    Introduction This study aimed to identify the optimal locations in multichannel magnetocardiography (MCG) and Body Surface Potential mapping (BSPM) to detect exercise-induced myocardial ischemia. Methods We studied 17 healthy controls and 24 coronary artery disease (CAD) patients with stenosis in one of the main coronary artery branches: left anterior descending (LAD) in 11 patients, right (RCA) in 7 patients, and left circumflex (LCX) in 6 patients. MCG and BSPM signals were recorded during a supine bicycle stress test. The capability of a recording location to separate the groups was quantified by subtracting the mean signal amplitude of the normal group from that of the patient group during the ST segment and at the T-wave apex, and dividing the resulting amplitude difference by the corresponding standard deviation within all subjects. Results In MCG the optimal location for ST depression was at the right inferior grid for the RCA, at the mid-inferior grid for the LCX, and in the middle of these locations for the LAD subgroup (mean ST amplitudes: CAD −80 ± 360fT, controls 610 ± 660fT; p < 0.001). In BSPM it was on the left upper anterior thorax for the LAD, left lower anterior thorax for the RCA, and on the lower back for the LCX subgroup (mean ST amplitudes: CAD −39 ± 61 μV and controls 38 ± 38 μV; p < 0.001). In MCG the optimal site for T-wave amplitude decrease was the same as the one for the ST depression. In BSPM it was on the middle front for the LAD, on the back for the LCX and on the left abdominal area for the RCA group. In accordance with electromagnetic theory, the largest ST segment and T-wave amplitude changes took place in MCG in locations orthogonal to those in BSPM. Conclusion This study identified magnetocardiographic and BSPM recording locations which are sensitive for detecting transient myocardial ischemia by evaluation of the ST segment as well as the T-wave. These locations strongly depend on ischemic regions and are outside the conventional 12-lead ECG recording sites.

Panu Takala - One of the best experts on this subject based on the ideXlab platform.

  • st t integral and t wave amplitude in detection of exercise induced myocardial ischemia evaluated with Body Surface Potential mapping
    Journal of Electrocardiology, 2003
    Co-Authors: Helena Hanninen, Markku Makijarvi, J Nenonen, Toivo Katila, Panu Takala, Juha Rantonen, Kari S Virtanen
    Abstract:

    Body Surface Potential mapping is superior to 12-lead electrocardiogram in detection of acute and old myocardial infarctions. We examined the capability of the ST-T integral and T wave to detect exercise-induced ischemia in Body Surface Potential mapping. Body Surface Potential mapping with 123 channels was recorded in 70 subjects: 45 coronary artery disease (CAD) patients and 25 healthy controls during supine bicycle exercise testing. Of the patients, 18 had anterior, 14 posterior, and 13 inferior ischemia documented by coronary angiography and thallium scintigraphy. The ST-T isointegral area, as well as the positive and negative ST-T area, and the T-wave apex amplitude were determined. Discriminant index analysis was used to find the sites that optimally separated patient subgroups from other patients and controls. In the pooled CAD group, the optimal sites for detecting the decrease in ST-T isointegral, in the positive ST-T area and in the T-wave amplitude were over the left side (ST-T isointegral area: CAD −3.8 ± 14 μVs and controls 24 ± 14 μVs; T-wave amplitude: CAD 3 ± 110 μV and controls 190 ± 90 μV; P < .001, both). The area under the receiver operating characteristic curve for the decrease in ST-T isointegral, in the positive ST-T area, and in the T-wave amplitude and for the ST depression were 94%, 95%, 92%, and 93%, respectively. T wave performed especially well in patients with multivessel disease. In stepwise logistic regression analysis, using the presence of CAD as the dependent parameter, the decrease in the positive ST-T area and ST depression were the only parameters that entered the model. ST-T area and T-wave amplitude are sensitive and specific markers of transient myocardial ischemia. ST-T area contains information additional to ST depression and has thus independent discriminative value in ischemia detection.

  • st segment level and slope in exercise induced myocardial ischemia evaluated with Body Surface Potential mapping
    American Journal of Cardiology, 2001
    Co-Authors: Helena Hanninen, Markku Makijarvi, J Nenonen, Panu Takala, Petri Korhonen, Lasse Oikarinen, Kim Simelius
    Abstract:

    Abstract Body Surface Potential mapping (BSPM) is superior to 12-lead electrocardiography for detection of acute and old myocardial infarctions (MIs). We used BSPM to examine electrocardiographic criteria for acute reversible myocardial ischemia. BSPM with 123 channels was performed in 45 patients with coronary artery disease (CAD) and 25 healthy controls during supine bicycle exercise testing. Of the 45 patients, 18 patients had anterior, 14 had posterior, and 13 had inferior ischemia documented by coronary angiography and thallium scintigraphy. The ST amplitude was measured 60 ms after the J-point and the ST slope calculated by fitting a regression line from the J-point to 60 ms after it. The optimal locations for detecting ST depression and ST-slope decrease were identified. In the pooled CAD patient group, the optimal location for ST depression was 5 cm below standard lead V 5 (CAD group: −70 ± 70 μV; controls: 70 ± 80 μV, p

  • recording locations in multichannel magnetocardiography and Body Surface Potential mapping sensitive for regional exercise induced myocardial ischemia
    Basic Research in Cardiology, 2001
    Co-Authors: Helena Hanninen, Markku Makijarvi, J Nenonen, Toivo Katila, Panu Takala, Petri Korhonen, Lasse Oikarinen, Kim Simelius, J Montonen, Lauri Toivonen
    Abstract:

    Introduction This study aimed to identify the optimal locations in multichannel magnetocardiography (MCG) and Body Surface Potential mapping (BSPM) to detect exercise-induced myocardial ischemia. Methods We studied 17 healthy controls and 24 coronary artery disease (CAD) patients with stenosis in one of the main coronary artery branches: left anterior descending (LAD) in 11 patients, right (RCA) in 7 patients, and left circumflex (LCX) in 6 patients. MCG and BSPM signals were recorded during a supine bicycle stress test. The capability of a recording location to separate the groups was quantified by subtracting the mean signal amplitude of the normal group from that of the patient group during the ST segment and at the T-wave apex, and dividing the resulting amplitude difference by the corresponding standard deviation within all subjects. Results In MCG the optimal location for ST depression was at the right inferior grid for the RCA, at the mid-inferior grid for the LCX, and in the middle of these locations for the LAD subgroup (mean ST amplitudes: CAD −80 ± 360fT, controls 610 ± 660fT; p < 0.001). In BSPM it was on the left upper anterior thorax for the LAD, left lower anterior thorax for the RCA, and on the lower back for the LCX subgroup (mean ST amplitudes: CAD −39 ± 61 μV and controls 38 ± 38 μV; p < 0.001). In MCG the optimal site for T-wave amplitude decrease was the same as the one for the ST depression. In BSPM it was on the middle front for the LAD, on the back for the LCX and on the left abdominal area for the RCA group. In accordance with electromagnetic theory, the largest ST segment and T-wave amplitude changes took place in MCG in locations orthogonal to those in BSPM. Conclusion This study identified magnetocardiographic and BSPM recording locations which are sensitive for detecting transient myocardial ischemia by evaluation of the ST segment as well as the T-wave. These locations strongly depend on ischemic regions and are outside the conventional 12-lead ECG recording sites.