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Body surface maps at rest reveal ischemic abnormalities undetectable by the 12-lead ECG
74
SELECTEDABSTRACTS
(A3-4) Relations of Heart Rate and Sinus Arrhythmia to Metabolism After Exercise Tests
Session C3/C4: Body Surface Mapping
Ernst Schubert, Winfried Dinter and Wolfgang Rielke. lnstitut of Physiology, Humboldt University, Berlin, German Democratic Republic. The recovery of heart rhythm data in exercise tests is supposed to contain information concerning resetting metabolic adaptations after load. To explore this we did simultaneous measurements of heart rate (HR), sinus arrhythmia, blood acid base status and lactate in young healthy persons after maximal ergometer load without and after compensation for the exercise acidosis. Recovery of HR was biphasic with a 70% initial resetting in 6 min and a slow remaining component. Sinus arrhythmia Like sinus recovered slowly within more than 60 min. arrhythmia, acidbase recovered slowly; after compensation it recovered completely within 10 min. Lactate showed slow recovery in both conditions. Compensation did not influence HR and sinus arrhythmia. Conclusions: Results demonstrate an independent fast central resetting of HR. As sinus arrhythmia recovers parallel to lactate without connections to acid-base status, this points to a relation between cardiac vagal tone and peripheral metabolic influences. Thus HR reactions reflect central regulations whereas sinus arrhythmia contributes additional information about metabolism.
(C3/C4-5) Discriminant Body Surface Map Patterns in Anterior and inferior-Posterior Myocardiai Infarction
(A3-5) Daily Variations of Electrocardiographic Changes at Exercise in Patients with Anginai Attacks but Normal Coronary Arteriograms Yasuro Sugishita, Susumu Koseki, Ryuichi Ajisaka, Mitsuo Matsuda, Kaname lida, Keiji lida, lwao Ito, Tohru Takeda,’ Department of Internal Medicine and Masayoshi Akisada.’ Radiology,’ Institute of Clinical Medicine, The University of Tsukuba, Ibaraki, Japan. In 21 patients with typical exercise-induced angina1 pain but normal coronary arteriograms (Group N) and in 14 patients with angiographically proved coronary stenosis (Group C), symptom- limited ergometer exercise ECG and radionuclide angiocardiography were performed twice on 2 different days. Exercise-induced ST changes showed larger variations between the 2 exercise tests in Group N than in Group C (IASTI-AST21:0.07*0.06 mV in Group N; 0.03+0.03mV in Group C, p ~0.05). Rate pressure product and left ventricular ejection fraction at exercise also showed larger variations between the 2 tests in Group N than in Group C (p
Fred Kornreich, Pentti M. Rautaharju, Terrence J. Montague and Milan B. Horacek. Unit for Cardiovascular Research and Engineering, Free University Brussels (VUB), Belgium. Body surface potential maps were recorded from 120 electrode sites in 236 normal subjects (N) and 258 patients with initial electrocardiographic evidence of either anterior myocardial infarction (AMI) or inferior-posterior myocardial infarction (IMI), in order to identify characteristic map patterns regarding both infarct groups. After separate time-normalization of the QRS and the STT waveforms, averaged isopotential map distributions were computed and displayed at 8 equal time-intervals during QRS and STT for the N, AMI and IMI groups, respectively. At each of these time- instants, the averaged 120-point AMI maps were subtracted from the corresponding N maps and the resulting differences at each electrode site divided by the standard deviation of the pooled population; the values obtained in this way were plotted on the map as iso-magnitude lines. Visual inspection of the latter discriminant map permitted the identification of the spatial and temporal distribution of the patterns that were significantly different in both groups. The same procedure was repeated for the IMI patients. Each patient was then individually reviewed in order to assess the presence of the characteristic group patterns; 96% of AMI and 92% of IMI patients exhibited one or more patterns typical of their respective groups. These results include 46 patients who no longer had diagnostic Q-waves in the 12-lead ECG at the time BSPM were recorded.
(WC49) Body Surface Maps at Rest Reveal ischemic Abnormalities Undetectable by the 1BLead ECG Ezio Musso, Donatella Stilli, Livio Dei Cas, Paolo Francescon, Carlo Manta, Odoardo Visioli and Bruno Taccardi, lstituto di Fisiologia Generale, Universita di Parma, Italy. Body surface maps recorded at rest from 22 ischemic patients with normal resting EGG (group I) were compared with maps of 36 normal subjects (group N) to detect abnormalities of the cardiac electrogenesis not apparent in the 12-lead ECG. In each subject we computed 227 variables related to the location of the potential extrema on the chest and the magnitude of the surface voltages during QRST. By means of a stepwise procedure, among these variables we selected 5 which were submitted to Fisher’s discriminant analysis. The 5 variables referred to the amplitude of the highest instantaneous positive potential during the ST segment and the location of the potential extrema during the initial and final phases of QRS. We succeeded in correctly classifying more than 90% of the cases. The same percentage of correct allocation was obtained by using one third of the cases as a test set to validate the efficacy of the method. Five new patients with abnormal resting ECG, for whom we used this classifying procedure, were allocated to group I suggesting that the anomalous potential patterns in both groups of ischemic patients were due to the same mechanism.
J. ELECTROCARDIOLOGY
20(l),
1987
SELECTEDABSTRACTS
(A3-4) Relations of Heart Rate and Sinus Arrhythmia to Metabolism After Exercise Tests
Session C3/C4: Body Surface Mapping
Ernst Schubert, Winfried Dinter and Wolfgang Rielke. lnstitut of Physiology, Humboldt University, Berlin, German Democratic Republic. The recovery of heart rhythm data in exercise tests is supposed to contain information concerning resetting metabolic adaptations after load. To explore this we did simultaneous measurements of heart rate (HR), sinus arrhythmia, blood acid base status and lactate in young healthy persons after maximal ergometer load without and after compensation for the exercise acidosis. Recovery of HR was biphasic with a 70% initial resetting in 6 min and a slow remaining component. Sinus arrhythmia Like sinus recovered slowly within more than 60 min. arrhythmia, acidbase recovered slowly; after compensation it recovered completely within 10 min. Lactate showed slow recovery in both conditions. Compensation did not influence HR and sinus arrhythmia. Conclusions: Results demonstrate an independent fast central resetting of HR. As sinus arrhythmia recovers parallel to lactate without connections to acid-base status, this points to a relation between cardiac vagal tone and peripheral metabolic influences. Thus HR reactions reflect central regulations whereas sinus arrhythmia contributes additional information about metabolism.
(C3/C4-5) Discriminant Body Surface Map Patterns in Anterior and inferior-Posterior Myocardiai Infarction
(A3-5) Daily Variations of Electrocardiographic Changes at Exercise in Patients with Anginai Attacks but Normal Coronary Arteriograms Yasuro Sugishita, Susumu Koseki, Ryuichi Ajisaka, Mitsuo Matsuda, Kaname lida, Keiji lida, lwao Ito, Tohru Takeda,’ Department of Internal Medicine and Masayoshi Akisada.’ Radiology,’ Institute of Clinical Medicine, The University of Tsukuba, Ibaraki, Japan. In 21 patients with typical exercise-induced angina1 pain but normal coronary arteriograms (Group N) and in 14 patients with angiographically proved coronary stenosis (Group C), symptom- limited ergometer exercise ECG and radionuclide angiocardiography were performed twice on 2 different days. Exercise-induced ST changes showed larger variations between the 2 exercise tests in Group N than in Group C (IASTI-AST21:0.07*0.06 mV in Group N; 0.03+0.03mV in Group C, p ~0.05). Rate pressure product and left ventricular ejection fraction at exercise also showed larger variations between the 2 tests in Group N than in Group C (p
Fred Kornreich, Pentti M. Rautaharju, Terrence J. Montague and Milan B. Horacek. Unit for Cardiovascular Research and Engineering, Free University Brussels (VUB), Belgium. Body surface potential maps were recorded from 120 electrode sites in 236 normal subjects (N) and 258 patients with initial electrocardiographic evidence of either anterior myocardial infarction (AMI) or inferior-posterior myocardial infarction (IMI), in order to identify characteristic map patterns regarding both infarct groups. After separate time-normalization of the QRS and the STT waveforms, averaged isopotential map distributions were computed and displayed at 8 equal time-intervals during QRS and STT for the N, AMI and IMI groups, respectively. At each of these time- instants, the averaged 120-point AMI maps were subtracted from the corresponding N maps and the resulting differences at each electrode site divided by the standard deviation of the pooled population; the values obtained in this way were plotted on the map as iso-magnitude lines. Visual inspection of the latter discriminant map permitted the identification of the spatial and temporal distribution of the patterns that were significantly different in both groups. The same procedure was repeated for the IMI patients. Each patient was then individually reviewed in order to assess the presence of the characteristic group patterns; 96% of AMI and 92% of IMI patients exhibited one or more patterns typical of their respective groups. These results include 46 patients who no longer had diagnostic Q-waves in the 12-lead ECG at the time BSPM were recorded.
(WC49) Body Surface Maps at Rest Reveal ischemic Abnormalities Undetectable by the 1BLead ECG Ezio Musso, Donatella Stilli, Livio Dei Cas, Paolo Francescon, Carlo Manta, Odoardo Visioli and Bruno Taccardi, lstituto di Fisiologia Generale, Universita di Parma, Italy. Body surface maps recorded at rest from 22 ischemic patients with normal resting EGG (group I) were compared with maps of 36 normal subjects (group N) to detect abnormalities of the cardiac electrogenesis not apparent in the 12-lead ECG. In each subject we computed 227 variables related to the location of the potential extrema on the chest and the magnitude of the surface voltages during QRST. By means of a stepwise procedure, among these variables we selected 5 which were submitted to Fisher’s discriminant analysis. The 5 variables referred to the amplitude of the highest instantaneous positive potential during the ST segment and the location of the potential extrema during the initial and final phases of QRS. We succeeded in correctly classifying more than 90% of the cases. The same percentage of correct allocation was obtained by using one third of the cases as a test set to validate the efficacy of the method. Five new patients with abnormal resting ECG, for whom we used this classifying procedure, were allocated to group I suggesting that the anomalous potential patterns in both groups of ischemic patients were due to the same mechanism.
J. ELECTROCARDIOLOGY
20(l),
1987