ECG Score Research Articles

Affective disorders and survival after acute myocardial infarction<xref ref-type="fn" rid="fn1">*</xref><subtitle>Results from the post-infarction late potential study</subtitle>

Psychological data from 560 male survivors of acute myocardial infarction (AMI) were documented in the third week after onset of AMI. The psychodiagnostic assessment was designed to detect different forms of depression as well as hyperactive behaviour. A complete follow-up of these patients, which covers a period of 6 months, is available. Our findings indicate that affective disorders play an important role in the post-acute phase after AMI although the extent of myocardial infarction (as defined by an ECG score) and behaviour responses are not significantly related to one another. Different subforms of depression are not influenced by a history of angina pectoris, the degree and location of myocardial infarction, the occurrence of late potentials and age, whereas dyspnoea (P less than 0.001) and the recurrence of myocardial infarction (P less than 0.001) favour depressive mood states. Twelve cardiac deaths and 17 arrhythmic events occurred during the study period; they were significantly predicted by severe forms of post-AMI depression as revealed by univariate analysis. The evidence was stronger for predicting cardiac death (P less than 0.001) than for arrhythmic events (P = less than 0.035). The effect remains of borderline significance for cardiac death if all risk factors with a significant univariate influence are included in a multiple logistic regression model. The effect of depression is illustrated by Kaplan-Meier survival curves separated for patient groups with high as compared to low degrees of depression. Hyperactivity showed no impact on patient survival.

Significance of U Wave Polarity in Patients with a Prior Inferior Myocardial Infarction

Sixty consecutive patients who underwent coronary angiography and left ventriculography from six to eight weeks after the onset of definite inferior myocardial infarction were divided into three groups according to the polarity of U waves in (1) leads II, III, a VF and (2) in leads V4 to V6 (positive = Group P, flat or isoelectric = Group F, and negative = Group N). The following parameters were analyzed: (1) ECG score; (2) global ejection fraction: (3) regional area change: (4) number of asynergic, and akinetic segmental radii; (5) number of asynergic and akinetic areas: and (6) number of diseased coronary arteries and the incidence of left anterior descending artery (LAD) disease. There were no significant differences among the three groups according to the polarity of U waves in two subgroups by the site of U waves in age, gender, systemic blood pressure, and ECG scores. The polarity of U waves in leads II.III.a VF (subgroup 1) correlated with the size of myocardial infarction; regional area changes in inferior segment (Area 2) were 64.1 +/- 8.2 in group P1, 31.8 +/- 14.7 in group F1, and 21.0 +/- 15.8 in group N1 (p less than 0.01, F = 32.8). The polarity of U waves in leads V4-6 (subgroup2) correlated with anterolateral wall motion; regional area changes in anterolateral segments (Area 5) were 76.8 +/- 11.6 in group P, 66.5 +/- 18.5 in group F, and 48.9 +/- 17.1 in group N (p less than 0.01, F = 18.6). The incidence of multivessel disease increased from group P2 (36.4%), to group F2 (54.5%), to group N2 (75.0%), and the incidence of LAD disease increased from 27.3%, to 45.5%, to 68.8%, respectively. A negative U wave in either location suggested severely decreased apical wall motion, and there was a tendency for global ejection fractions to decrease in the following order: group P, group F, and group N. From these results, the authors conclude that the polarity of U waves may be one of the parameters correlating with the wall motion and left ventricular function in prior inferior myocardial infarction.

The significance of U wave polarity in patients with a prior anterior myocardial infarction

The significance of the polarity of U waves in left precordial leads in patients with a prior anterior myocardial infarction was evaluated in relation to left ventricular function and wall motion by left ventriculography. Ninety-six such patients, with a mean age of 53 years, were divided into three groups according to the polarity of U waves: positive U waves (group P), isoelectric or flat U waves (group F), and negative U waves (group N). The following parameters were analysed: (1) Selvester ECG score; (2) global ejection fraction (EF); (3) regional area change; (4) number of asynergic and akinetic segmental radii; (5) asynergic and akinetic areas. Fifteen patients served as controls. The Selvester ECG scores increased progressively and EF decreased successively with statistically significant differences between groups P, F, and N (P less than 0.01, respectively). The sensitivity of negative U waves for predicting EF of less than 50% was 88.0%, the specificity 81.9%, and the accuracy 84.4%. The incidence of regional area change at the apex of less than 20% was 10.0% in group P, 35.9% in group F, and 74.3% in group N (P less than 0.01). The number of dyssynergic and akinetic radii, and asynergic and akinetic areas increased progressively from group P to F, to N (P less than 0.01). These results demonstrate that the polarity of U waves correlated significantly with left ventricular function and wall motion as well as the size of myocardial infarction. Negative U waves are an important sign of extensive myocardial infarction involving the apex with global ejection fraction of less than 50%. Negative U waves may be associated with lateral ischaemia.

An Investigation Into the Influence of the pH of a Cardioplegic Solution on Markers of Myocardial Damage

Although crystalloid cardioplegic solutions are generally buffered to be alkalotic, some workers have advocated the use of an acidotic solution. In order to evaluate the influence of the pH of a crystalloid cardioplegic solution on post-ischaemic markers of myocardial injury, we studied 30 rat hearts using an isolated perfused heart model, with a one hour ischaemic arrest at 20°C following single dose cardioplegia. The pH of the cardioplegic solution was varied by adjusting the pCO2. Six pH levels were studied with five hearts at each level, (group 1 pH = 7.0102 ±0.0106 (±SEM) group 2 = 7.2044 ±0.0077, group 3 = 7.4074 ±0.0068, group 4 = 7.6082 ±0.0071, group 5 = 7.8010 ±0.0082, group 6 = 8.0352 ±0.0129). Pre-arrest (control) and post-arrest coronary effluent enzyme levels, heart rate, coronary vascular resistance and ECG score were determined. In addition, times to spontaneous defibrillation were noted. There were no statistically significant differences between the control values. The mean time in seconds from institution of reperfusion to spontaneous defibrillation in groups 1 to 6 respectively were 67.6 ±2.379, 62 ±1.949, 62 ±1.483 52.4 ±3.326, 58.6 ±1.631 and 55 ±2.55 (p<0.01 Kruskal-Wallis Test). Post-arrest mean heart rates were 190 (one heart only), 203.33 ±26.034, 217.5 ±17.017, 235 ±26.552, 214 ±16 and 208 ±15.29 (NS). The post-arrest mean ECG scores were 2.4 ±0.5099, 1.2 ±0.5831, 1.2 ±0.7348, 0.2 ±0.2, 0.6 ±0.2449 and 0.6 ±0.2449. (NS). Of note is that ECG scores of two or more were only seen in groups 1, 2 and 3. Post-arrest mean coronary vascular resistances were 134.6 ±18.819, 118.6 ±6.653, 78 ±4.461, 65.8 ±2.01, 68 ±1.342 and 72.2 ±5.774 (p<0.001). Post-arrest coronary effluent mean creatine phosphokinase levels were 703.21 ±149.97, 152.34 ±27.959, 141.11 ±12.67 ,80.568 ±16.025, 88.854 ±17.391 and 88.108 ±17.225 (p<0.005). Post-arrest coronary effluent mean lactate dehydrogenase levels were 244.02 ±60.516, 192.46 ±68.234, 141.66 ±56.317, 25.55 ±10.974, 41.366 ±4.428 and 35.2 ±8.473 (p<0.001).

Functional status and left ventricular performance late after valve replacement for aortic stenosis. Relation to preoperative data

Relations between preoperative data and status at one- and 10-year control and left ventricular performance (radionuclide angiocardiography) at follow-up 10-17 years (mean 12 years) after valve replacement (1965-73) for aortic stenosis were studied. Marked improvements at one-year were noted for New York Heart Association (NYHA) functional classes, cardiothorac index (CTI), and ECG hypertrophy (Romhilt-Estes) score. One-year status did not influence that at 10 years. In 59 patients who were in NYHA class I at one year, class I was maintained in 75% of those who were in class II preoperatively, compared with 47% of those who had been in class III, and 23% of those who had been in class IV, (P less than 0.05). The same relation to preoperative level was found for patients with CTI less than or equal to 0.50 at one-year control. The ECG score did not change after the first year. Left ventricular hypertrophy (ECG score greater than or equal to 4) was present in 90% and 84% of the patients at one and 10 years, respectively. Ejection fraction (EF) and peak filling rate (PFR) at follow-up were (mean +/- SD) 65 +/- 13% and 3.14 +/- 1.05 end-diastolic volume s-1, respectively; only 13 patients had a radionuclide study within the normal range for all parameters measured. A normal study was found predominantly in patients with complete regression of hypertrophy. Multiple linear regression models incorporating preoperative data allowed calculation of predicted EF (65 +/- 9) and PFR (3.17 +/- 0.92) which did not differ from the measured values. Functional status and left ventricular systolic and diastolic performance late after the operation depended closely on preoperative status. Improvements noted at one year were only temporary in patients with preoperative advance disease. Normal left ventricular performance late after valve replacement was related to complete reversibility of hypertrophy. Our results argue for operation in minimally symptomatic patients.

Relationship of QRS scoring system to enzymatic and pathologic infarct size: The role of infarct location

A method for estimating infarct size from 12-lead ECGs has been developed but not extensively validated. To assess its accuracy, ECG scores from 62 patients admitted to the coronary care unit at Barnes Hospital were compared to infarct size calculated from plasma MB creatine kinase (MB-CK) activity. A second cohort of 29 patients enrolled in the Multicenter Investigation of the Limitation of Infarct Size (MILIS) was evaluated as a test set and to provide pathologic correlates. Patients with conduction system disease, ventricular hypertrophy, or multiple infarctions were excluded, as were those in the Barnes group who had undergone thrombolytic therapy. ECGs obtained early (days 3 to 7 in the Barnes group and day 3 in the MILIS group) or late (days 8 to 14 in the Barnes group) were scored manually and by computer. QRS scores from early ECGs of patients with anterior infarctions correlated closely with MB-CK estimates of infarct size ( r = 0.71 [Barnes] and 0.85 [MILIS]) and with anatomic data ( r = 0.78). Enzymatic and pathologic infarct size also correlated well ( r = 0.85). Correcting for body surface area by means of total CK-derived infarct size or use of QRS scores from late ECGs did not alter the correlation coefficients. Among patients with inferior infarctions QRS scores corresponded poorly with MB-CK infarct size ( r = 0.28 [Barnes] and r = −0.42 [MILIS]) and pathologic infarct size ( r = −0.20), despite a significant relationship between pathologic and MB-CK estimates ( r = 0.62). Correction for body surface urea, use of total CK-derived infarct size, and use of QRS scores from late ECGs did not improve the results. Thus, the QRS scoring system provides reliable estimates of infarct size in patients with anterior infarctions but correlates poorly and may be misleading in patients with inferior infarctions.

Alterations in Fetal Heart Rate and ECG Correlated to Glycogen, Creatine Phosphate and ATP Levels during Graded Hypoxia

The depletion of glycogen, creatine phosphate and ATP in the fetal heart, liver and brain was studied in 40 mature guinea pig fetuses acutely exteriorized and submitted to a graded hypoxia. A strong linear correlation was found between an ECG scoring system, taking the severity of the ST-T changes into account, and the depletion of heart glycogen and creatine-P. ATP was unaffected until glycogen was almost depleted (25 % of initial value). At this point, brain and liver glycogen were also severely affected. Bradycardia (AV-block, type II) was strongly correlated to failing myocardial metabolism. It is concluded that the changes in the fetal ECG pattern could be regarded as a sign of myocardial glycolysis and early hypoxic stress.

The Depletion of Energy Rich Substances Correlated To Changes In Fetal Heart Rate And Ecg

Previous findings have indicated that changes in the fetal ECG convay information about fetal hypoxic stress, well in advance of any alteration in fetal heart rate and blood pressure. To define a possible relation between the ECG changes and myocardial metabolism, a study was performed on 40 mature guinea-pig fetuses acutely exteriorized and submitted to a graded hypoxia. The depletion of glycogen, creatinephosphate and ATP in the fetal heart, liver and brain was correlated to an ECG-scoring system taking the severity of the ST-T changes into account. A strong linear correlation was found between the ECG scores and the depletion of heart glycogen and creatine-P. The ATP was unaffected until the glycogen was depleted /25 % of initial value/. At this point, brain and liver glycogen were also severly affected. Bradycardia /AV-block, type II/ was strongly correlated to failing myocardial metabolism. It is concluded that the changes in the fetal ECG pattern could be regarded as a sign of myocardial glycolysis and early hypoxic stress.