Heart rate variability in elderly patients before and after electroconvulsive therapy.

Earlier studies have found major depression to be associated with increased cardiac mortality, hypothesized to result from reduced vagal modulation. Since reduced heart rate variability is part of normal aging, depression might predispose elderly patients to a higher risk. The authors investigated cardiac autonomic modulation, using spectral analysis, in 11 elderly depressed inpatients before and after electroconvulsive therapy (ECT). Cardiac vagal modulation increased significantly after ECT and was associated with symptom improvement, assessed by a significant decrease in the Hamilton Rating Scale for Depression. Further research is needed to elucidate the relationship between depression, autonomic modulation, and clinical risks in elderly patients.

QT dispersion in the surface electrocardiogram in elderly patients with major depression.

BACKGROUND: QT dispersion (QTd) is a measure of interlead variations of QT interval of the surface 12-lead electrocardiogram (ECG). Increased QTd, found in various cardiac diseases, reflects cardiac instability and is associated with increased cardiac death. Major depressive disorder (MDD) was found to be associated with high cardiovascular mortality rates. This study compares QTd in elderly patients with MDD to normal controls. METHODS: QTd and rate-corrected QTd of 18 physically healthy elderly patients (69.9 +/- 7.6 years) with MDD was compared to nine physically and mentally healthy age- and gender-matched controls (64.1 +/- 12.2 years). RESULTS: QTd and rate-corrected QTd were significantly higher in MDD compared to controls (68 +/- 30 vs. 40 +/- 13 ms, P=0.002 and 81 +/- 39 vs. 43 +/- 13 ms, P=0.001, respectively). Intra- and inter- observer reproducibilities were highly correlated (r=0.96, P <0.0001; r=0.88, P <0.001, respectively). LIMITATIONS AND CONCLUSIONS: The major limitations of this study are the small number of subjects and the fact that all the patients were maintained on antidepressant medication. However, it seems that QTd analysis might shed light on possible autonomic imbalance and also provide a novel cardiovascular risk factor for increased cardiac death in MDD.

Correlation of predischarge electrocardiographic patterns with left ventricular function in patients with anterior wall myocardial infarction.

The aim of this prospective study was to assess the correlation between different predischarge electrocardiographic patterns and left ventricular function, evaluated by physical examination and echocardiography, in patients with first Q wave anterior acute myocardial infarction. A positive correlation was found between the electrocardiographic pattern and wall motion score assessed by echocardiography, reflecting a gradual worsening in left ventricular function among the different patterns. Patients with an isoelectric ST segment and negative T waves had a 73% decrease in the risk of clinical heart failure compared to those who continued to have ST elevation. Thus, a predischarge electrocardiogram can be used as a simple, noninvasive method for the risk stratification of patients with acute myocardial infarction.

Correlation between electrocardiographic subtypes of anterior myocardial infarction and regional abnormalities of wall motion.

BACKGROUND: Examination of the electrocardiogram is the most widely used means for diagnosis and early stratification of risk of acute myocardial infarction (AMI). The classical classification of the subtypes of anterior AMI is based on results of studies comparing the electrocardiograms recorded at various stages, mostly in the subacute or chronic stage of AMI, with autopsy findings. Reports regarding the correlation between electrocardiographic findings in the acute phase and regional abnormality of wall motion (AWM) detected by echocardiographic evaluation are sparse. OBJECTIVE: To investigate the relationship between the electrocardiographic and two-dimensional echocardiographic findings regarding patients with their first anterior AMI. DESIGN AND METHODS: We studied 58 patients, 44 men and 14 women of mean age 61.5 +/- 14.6 years, with their first anterior AMI who had undergone two-dimensional echocardiographic evaluation within 48 h of admission. Deviation of ST-segment trace from baseline was measured manually 0.06 s after the J point for all leads on the admission electrocardiogram. ST-segment elevation in the various leads was correlated to the incidence of regional AWM detected by echocardiography. RESULTS: ST-segment elevations > or = 0.1 mV in V1 leads were found for 21 (36.2%) patients. Basal anterior, basal anteroseptal, and basal septal AWM were seen more often for patients with than they were for patients without ST-segment elevation in V1 (57 versus 16%, P=0.003; 43 versus 13.5%, P=0.03; 43 versus 11%, P=0.01 respectively). In contrast to ST-segment elevation in lead V1, the only statistically significant difference in prevalence in the presence of regional AWM between patients with (n = 48) and without (n = 10) ST-segment elevation > or = 0.2 mV in lead V2 was in the inferoapical region (87.5 versus 40%; P=0.003). ST-segment elevation > or = 0.1 mV in leads aVL and V5 was found for 11 (19%) and 23 (40%) patients, respectively. There was no correlation between either lateral or apical regional AWM and the presence of ST-segment elevation in the anterolateral leads except for mid-lateral AWM, which was more often detected for patients with than it was for patients without ST-segment elevation in aVL leads (36.3 versus 6.4%, P=0.026). CONCLUSIONS: ST-segment elevation in lead V1 during the acute phase of anterior AMI is associated with a high incidence of regional AWM in the basal anterior, anteroseptal, and anterior regions, whereas ST-segment elevation in lead V2 is more often associated with AWM in the inferoapical region. ST-segment elevation in aVL leads is related to mid-lateral regional AWM.

Correlation between the admission electrocardiogram and regional wall motion abnormalities as detected by echocardiography in anterior acute myocardial infarction.

We correlated ST elevation in various leads on admission and regional dysfunction in 132 patient with first anterior acute myocardial infarction using echocardiography. ST elevation in leads I and a VL and II, III and aVF was not associated with a specific pattern of regional dysfunction. Basal anterior and septal regional dysfunction were seen more often in patients with ST elevation in V1 (49 vs. 25%, p = 0.006; 35 vs. 17%, p = 0.048, respectively). Patients with ST elevation in V2 had more regional dysfunction of the apical inferior region (84 vs. 53%; p = 0.01). ST elevation in V5 and V6 was not associated with more apical or lateral wall motion abnormalities. ST elevation in lead V1 in anterior myocardial infarction is associated with a high incidence of regional dysfunction of the basal anterior, anteroseptal and septal regions.

Relation between QT dispersion and slow intraventricular conduction in patients with acute anterior wall myocardial infarction.

BACKGROUND: QT dispersion has been proposed as a simple, noninvasive measure for identifying patients at risk of postinfarction arrhythmia. It is assumed to reflect nonuniform ventricular repolarization, which, in turn, may result from regional differences in repolarization time as well as from localized activation delay. The aim of this study was to examine the relation between QT dispersion and intraventricular conduction abnormalities in patients with acute anterior wall myocardial infarction. METHODS AND RESULTS: Standard 12-lead electrocardiographic and 12-lead signal-averaged electrocardiographic recordings were performed in 25 patients with a first Q-wave anterior wall myocardial infarction. Measures calculated by using the 6 precordial (V1 through V6) leads for QT dispersion were (1) difference between maximum and minimum QT and QTc intervals and (2) standard deviation of QT and QTc intervals. Measures calculated from the signal-averaged electrocardiogram were (1) maximum filtered QRS duration; (2) mean; and (3) standard deviation of filtered QRS duration. No relation was found between any measure of filtered QRS duration and that of QT dispersion by using linear correlation analysis. Similarly, no significant association was demonstrated between the filtered QRS duration and corresponding QT interval measurements (total 131 leads). CONCLUSIONS: The lack of correlation between signal-averaged electrocardiogram indexes of slow intraventricular conduction and electrocardiogram variables of QT dispersion suggests an independent predictive value for the 2 methods in identifying patients at risk of postinfarction arrhythmia. This suggestion is further supported by the finding that altered activation sequence is an unlikely mechanism of QT dispersion in patients with acute myocardial infarction, as indicated by the lack of association between the filtered QRS duration and corresponding QT interval measurements.

Pathophysiology of precordial ST-segment depression in inferior wall acute myocardial infarction: an echocardiographic appraisal.

Precordial ST-segment depression (PSD) in inferior wall acute myocardial infarction (IAMI), especially when maximal in leads V4-V6, has been shown to portend a higher rate of heart failure and mortality. To better understand the pathophysiology behind this phenomenon, we evaluated patients with a first IAMI by echocardiography 48-72 h after the acute event, using segmental scoring (0 = normal to 3 = dyskinesia) of left ventricle wall motion, and a dichotomous assessment of right ventricle involvement. Patients were categorized into 3 groups: I = no PSD (n = 14); II = maximal PSD in leads V1-V3 (n = 28); III = maximal PSD in leads V4-V6 (n = 8). As compared with group I, patients in groups II-III had more severe wall motion abnormalities in inferior segments (1.36 +/- 0.97 vs. 2.19 +/- 1.74, p = 0.04), and a similar trend for posterior and lateral segments (1 +/- 1.75 vs. 2 +/- 2.41, p = 0.11), translating into a worse total left ventricle score (2.36 +/- 2.34 vs. 4.25 +/- 4.05, p < 0.05). Frequency of right ventricle involvement was similar in patients with and without PSD (6 (43%) vs. 9 (25%), p = 0.37). Segmental scores for groups I, II, and III, respectively, were not different for inferior (1.36 +/- 1, 2.25 +/- 1.82 and 2 +/- 1.51, p = 0.24), posterior and lateral (1 +/- 1.75, 1.96 +/- 2.32 and 2.13 +/- 2.9, p = 0.38), and septal, anteroseptal and anterior segments (0 +/- 0, 0.04 +/- 0.19 and 0.13 +/- 0.35, p = 0.28). Right ventricle abnormalities occurred in 43, 21 and 38% of patients in groups I, II and III, respectively, p = 0.3. Thus, IAMI with PSD is associated with worse left ventricle wall motion. However, since patients with maximal PSD in leads V4-V6 do not have greater wall motion abnormalities or higher rate of right ventricle involvement, their poorer prognosis cannot be explained by worse systolic dysfunction. We propose that maximal PSD in leads V4-V6 reflects transient diffuse ischemia and altered diastolic distensibility due to extensive coronary artery disease, causing increased left ventricle end-diastolic pressure.

Relationship between late potentials and the predischarge electrocardiographic pattern in patients with acute anterior wall myocardial infarction.

HYPOTHESIS: The presence of late potentials on the signal-averaged electrocardiogram (SAECG) identifies patients at high risk for development of ventricular tachyarrhythmias after myocardial infarction (MI). METHODS: The electrocardiogram and left ventricular function in 65 patients recovering from a first acute anterior wall MI were analyzed. We compared the pattern of the ST segment (isoelectric or elevated) and of the T wave (positive or negative) with the SAECG using an orthogonal bipolar lead configuration (X, Y, Z) with bidirectional Butterworth filtering (Simson's method). RESULTS: Abnormal SAECG was found in 17 (26%) patients; 11 of 18 patients with ST elevation had abnormal SAECG, and only 6 of 47 patients with isoelectric ST segment developed abnormal SAECG (p < 0.0001, odds ratio = 10.74). Of 19 patients with positive T waves, 10 had abnormal SAECG, and abnormal SAECG was found in 7 of 46 patients with negative T waves (p < 0.003, odds ratio = 5.27). When both parameters were considered together, 9 of 12 patients with ST elevation and positive T wave developed abnormal SAECG, and 35 of 40 patients with isoelectric ST and negative T wave had normal SAECG (p < 0.0002). Left ventricular ejection fraction was similar in patients with abnormal SAECG (43 +/- 14%) and normal SAECG (46 +/- 11%). CONCLUSION: These findings suggest that patients with anterior wall MI and a predischarge pattern of ST elevation and positive T wave have a higher incidence of abnormal SAECG and therefore may have a worse prognosis, especially related to the subsequent development of ventricular arrhythmias.