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PubMedDate not supplied

[Electrocardiography changes in scoliosis and kyphosis deformities of the thorax].

Preoperative electrocardiograms and lung function tests in patients with severe scoliosis were compared. The electrocardiograms were analysed by recognizing signs of right ventricular hypertrophy and signs of right ventricular strain. The results are as follows: Dates of electrocardiography and lung function testing show a very good correlation. Scoliotic and kyphotic deformities show a clear dependency on grade of scoliosis and age. Electrocardiographic changes do not depend on additive kyphotic deformity.

Adolescent↗
PubMed1986

[Significance of fundus evaluation in the staging of hypertensive disease compared to electrocardiography and renal circulation].

In order to determine the relevance of ophthalmoscopic findings in cases of hypertension as compared to electrocardiographic abnormalities and disorders of the renal function, the authors examined 728 patients admitted to the German diagnostic Clinic (Wiesbaden) with hypertension over a period of 2 years. In all cases blood pressure was measured twice, and ophthalmoscopy, electrocardiography, a chest X-ray, and a laboratory checkup were performed. The effective renal plasma flow was measured in 100 cases using the 131 iodine-Hippuran clearance method. The results revealed that ophthalmoscopy is the most reliable method for classifying early and more advanced stages of hypertension, as compared to ECG and measurement of the effective renal plasma flow.

Electrocardiography↗
PubMed1982

[Electrocardiography and quantitative levocardiography in chronic transmural infarct. A correlative study].

For evaluation of a connection between the electrocardiographic diagnosis and localisation of chronic infarction and the angiographic results left ventriculography data of 97 patients with coronary heart disease were assessed quantitatively according to the method of Mathes. According to electrocardiographic criteria of infarction six subgroups were distinguished: anteroseptal, anterior, anterolateral, inferior, inferiolateral, and posterolateral. Asynergies were demonstrable in 87% of patients with infarct electrocardiograms, normal ventricular function was seen in 80% of patients without infarct ECG. Asynergies were seen in 75% of electrocardiographically diagnosed anterior wall infarcts and in 92% of posterior wall infarcts. The sensitivity of the ECG in chronic infarction was 83%, the specificity 84%. Pronounced differences in the number of involved segments were found between inferior and inferiolateral infarction. In contrast, no clear-cut differentiation of electrocardiographic findings judged by segmental involvement in the left ventriculography was seen for the anterior wall. The extent of the anterior wall infarction diagnosed by electrocardiography did not correlate with results of left ventriculography. The ECG is a suitable means for detection of segmental disturbances of contraction also in the chronic infarction stage. However, localisation and extent of the lesion can only be assessed within limits.

Angiocardiography↗
PubMed2002

A combination of troponin T and 12-lead electrocardiography: a valuable tool for early prediction of long-term mortality in patients with chest pain without ST-segment elevation.

BACKGROUND: Electrocardiography (ECG) obtained on admission and a troponin T (tn-T) level measured early after admission are simple and accessible methods for predicting outcome in patients with suspected unstable angina or myocardial infarction without persistent ST-elevations. However, there are few studies about the combination of these 2 methods as a means of predicting long-term outcome. METHODS: ECG was obtained on admission, and a tn-T level was analyzed on admission and after 6 hours in 710 consecutive patients admitted because of chest pain and no ST-elevations. Patients were observed for a median time of 40 months for death. RESULTS: ST-segment depressions > or =0.05 mV were present in 266 patients (37%). These patients had a 9.7-fold increased risk of death, compared with patients with normal ECG results. Isolated T-Wave inversions or pathological signs other than ST-T changes were present in 196 patients (28%), who had a 4.5-fold increased risk of death compared with patients who had normal ECG results. At 6 hours after admission, 169 patients (24%) had at least 1 sample of tn-T > or =0.10 microg/L, which resulted in an 3.7-fold increased risk of death. In a multivariate analysis, both ECG on admission and tn-T level came out as independent predictors of outcome. When these methods were combined, patients could be divided into low- (tn-T level <0.10 microg/L and no ST-segment depression), intermediate- (tn-T level > or =0.10 microg/L or ST-segment depression), and high-risk groups (tn-T level > or =0.10 microg/L and ST-segment depression). CONCLUSIONS: ECG and tn-T level are valuable tools to quickly risk stratify patients with chest pain. The combination of these methods is superior to either one alone.

Aged↗
PubMedDate not supplied

Increased prognostic value of combined myocardial perfusion imaging and exercise electrocardiography in patients with coronary artery disease.

BACKGROUND: Myocardial perfusion imaging (MPI) with technetium-99m-labeled sestamibi and exercise electrocardiography (EECG) are widely used for risk stratification of patients with known or suspected coronary artery disease (CAD). However, no large-scale studies have addressed the prognostic power of the combined information from these diagnostic tools. METHODS AND RESULTS: We studied 697 consecutive patients who underwent a 2-day Tc-99m sestamibi cardiac perfusion imaging protocol. The EECG was performed on a bicycle ergometer by symptom-limited exercise. Causes of death were obtained from death certificates. Univariate survival analyses were performed with a Kaplan-Meier estimate and a corresponding log-rank test. A multivariate Cox proportional hazards model was applied to test for potential predictor covariates obtained from hospital records. The predominant risk factors of cardiac death were fixed perfusion defects (relative risk, 2.55; range, 1.43 to 4.55) and an impaired circulatory exercise response (relative risk, 3.26; range, 1.74 to 6.08). The major prognostic information of MPI was the ability to detect patients with a definitively low risk. Patients with impaired circulatory response to exercise test and fixed perfusion defects were at a very high risk. CONCLUSION: The combined results of MPI and EECG provide substantial information on the long-term risk of cardiac death in patients with suspected CAD.

Coronary Circulation↗
PubMedDate not supplied

Serial assessment of left ventricular function during dobutamine stress by means of electrocardiography-gated myocardial SPECT: combination with dual-isotope myocardial perfusion SPECT for detection of ischemic heart disease.

BACKGROUND: Technetium-labeled myocardial perfusion tracers allow simultaneous assessment of myocardial perfusion and left ventricular function by electrocardiography (ECG)-gated myocardial single photon emission computed tomography (SPECT). The purpose of this study was to evaluate left ventricular performance during dobutamine stress by means of ECG-gated myocardial perfusion SPECT with short-time data collection. METHODS AND RESULTS: After administration of Tc-99m sestamibi or tetrofosmin (600-740 MBq), 67 patients with ischemic heart disease, including 35 with prior myocardial infarction, were examined by ECG-gated myocardial perfusion SPECT at rest and during dobutamine stress (at dosages of 4, 8, 12, 16, and 20 microg/kg/min, with increments every 8 minutes). The ECG-gated data collection time was 5 minutes for each dobutamine dosage. After acquisition of gated SPECT data at the highest dose, thallium 201 chloride (111 MBq) was injected, and dual-isotope SPECT was also performed to assess the myocardial ischemia. In 32 patients without prior myocardial infarction, the sensitivity of individual stenosed-vessel detection with dual-isotope perfusion SPECT, with wall motion abnormality obtained from gated SPECT, and with the combined method was 55.9%, 52.9%, and 73.5%, respectively, based on coronary angiography. ECG-gated SPECT during dobutamine infusion revealed regional wall motion abnormalities (worsening or biphasic response) in 19 (57.6%) of 33 infarcted areas with culprit coronary arterial stenosis. The prevalence of reversible perfusion defects on dual-isotope SPECT was higher in segments with wall motion abnormalities than in segments with normal wall motion response (89.5% vs 42.9%, P <.02). CONCLUSIONS: Myocardial perfusion and left ventricular function during dobutamine infusion were analyzed in a single examination by means of the combined method. This procedure has the potential to provide comprehensive information with which to evaluate patients with ischemic heart disease.

Blood Pressure↗
PubMedDate not supplied

Failure of right precordial electrocardiography during stress testing to identify coronary artery disease.

BACKGROUND: It has been reported that the use of right precordial leads results in the same diagnostic accuracy as thallium-201 exercise scintigraphy for the detection of coronary artery disease (CAD). The aim of this study was to evaluate the utility of right precordial leads in the detection of CAD. METHODS AND RESULTS: We evaluated 900 consecutive patients (514 men, 386 women) ranging in age from 39 to 84 years (mean +/- SD, 64 +/- 11 years). Seven hundred forty patients underwent treadmill exercise testing, and 160 underwent pharmacologic stress testing for the diagnosis of chest pain or dyspnea. All received either Tl-201 or technetium-99m sestamibi during stress. During stress testing, the ECG was recorded every minute with 12 limb and left precordial leads and 3 right precordial leads (V(3)R, V(4)R, and V(5)R). The electrocardiogram was considered positive when the ST segment was either elevated or depressed by at least 0.1 mV at 80 ms after the J point, and results were also compared with single photon emission computed tomography myocardial perfusion imaging results. Of the 900 patients, 158 had significant positive changes in the limb or left precordial leads. Only 4 patients had positive changes in the right precordial leads (Fisher exact test, P <.001). Of the patients who had positive electrocardiographic changes, 95 (60%) had abnormal myocardial perfusion scans, with 91 in patients with normal right precordial leads. All 4 patients with ischemic changes in the right precordial leads had abnormal scans, but the left leads were also positive. Three hundred seventy-three of 900 patients (41%) had abnormal scans with no electrocardiographic evidence of ischemia. CONCLUSIONS: Our experience is far different than that published and suggests that the use of right precordial leads during stress testing fails to provide the same diagnostic accuracy as either the standard left-sided electrocardiography or myocardial perfusion imaging for the detection of CAD.

Adult↗
PubMedDate not supplied

Optimal 3-dimensional method for right and left ventricular fourier phase analysis in electrocardiography-gated blood-pool SPECT.

BACKGROUND: To overcome some of the limitations imposed by planar imaging, we aimed to optimize the use of first harmonic Fourier phase analysis (FPA) in electrocardiography-gated blood-pool single photon emission computed tomography (GBPS) by comparing different quantitative, 3-dimensional methods. METHODS AND RESULTS: Three groups of patients who underwent GBPS were evaluated: group 1, 8 patients with no heart disease; group 2, 10 patients with left ventricular disease; and group 3, 6 patients with right ventricular disease. Six different methods for FPA were compared: surface, cylindrical, spherical, and hybrid methods with fixed thresholding and spherical and hybrid methods with multiple thresholding. The hybrid method with multiple thresholding for the left ventricle and the spherical method for the right ventricle provided the highest discrimination score (phase) between normal and abnormal ventricles. Among methods with similar discrimination score for these 2 methods, the cylindrical and hybrid methods for the left ventricle and the spherical method for the right ventricle provided the best homogeneity of phase distribution histogram in normal ventricles. These were considered the optimal methods for FPA. CONCLUSIONS: The hybrid or cylindrical method for the left ventricle and the spherical method for the right ventricle with fixed thresholding are the optimal methods for FPA in GBPS.

Electrocardiography↗
PubMedDate not supplied

Visual assessment of left ventricular perfusion and function with electrocardiography-gated SPECT has high intraobserver and interobserver reproducibility among experienced nuclear cardiologists and cardiology trainees.

BACKGROUND: Stress electrocardiography (ECG)-gated single photon emission computed tomography (SPECT) for assessment of left ventricular perfusion and function improves the confidence of interpretation and enhances specificity for detection of coronary artery disease. The reproducibility of visual interpretation of ECG-gated SPECT images and the significance of training and experience have not been reported previously in a large series of consecutive patients. We evaluated both intraobserver and interobserver agreement of interpretation of ECG-gated SPECT images among 3 cardiology trainees and 3 experienced nuclear cardiologists from 3 institutions. METHODS AND RESULTS: Three nuclear cardiologists and 3 cardiology trainees who had fulfilled American College of Cardiology/American Society of Nuclear Cardiology Core Cardiology Training Symposium (ACC/ASNC COCATS) guidelines for level II training in nuclear cardiology independently evaluated 106 consecutive technetium 99m sestamibi SPECT images with ECG gating of either the stress or rest images. All cases were interpreted blindly, twice in random sequence, without clinical data. We assessed intraobserver and interobserver agreement for myocardial perfusion, left ventricular regional and global systolic function, and overall clinical impression, by means of percent agreement and Cohen's kappa statistic. Intraobserver agreement was good (82%-92%, kappa = 0.54-0.84) for assessment of myocardial perfusion, systolic function, and overall impression. Interobserver agreement was also good, ranging from 65% to 90% (kappa = 0.32-0.76), with better agreement found for assessment of function (77%-85%, kappa = 0.52-0.7) than for perfusion (65%-80%, kappa = 0.32-0.6). For all measures, there were no significant differences in reproducibility between nuclear cardiologists and cardiology trainees. CONCLUSIONS: Interpretation of ECG-gated SPECT images has high reproducibility and agreement among both nuclear cardiologists and cardiology trainees.

Electrocardiography↗
PubMed2003

Fetal electrocardiography in labor and neonatal outcome: data from the Swedish randomized controlled trial on intrapartum fetal monitoring.

OBJECTIVE: Cardiotocography plus automatic ST analysis of the fetal electrocardiography has been shown recently to reduce both the operative delivery rate for fetal distress and the cord artery metabolic acidosis rate. The purpose of this study was to analyze findings that were related to cases with a complicated/adverse neonatal outcome in the Swedish randomized controlled trial. STUDY DESIGN: Of the 4966 term fetuses that were included in the trial, all 351 newborn infants who required special neonatal care were identified. Cases of perinatal death, neonatal encephalopathy, or metabolic acidosis at birth were reviewed. RESULTS: Of the 29 fetuses with adverse/complicated neonatal outcome, 22 fetuses had cardiotocography and ST patterns that indicated a need for intervention, according to the cardiotocography plus ST clinical guidelines. The number of live-born with moderate or severe neonatal encephalopathy showed a significant decrease from 0.33% (8/2447 fetuses) in the cardiotocography-only group to 0.04% (1/2519 fetuses) in the cardiotocography plus ST group. CONCLUSION: Cardiotocography plus ST analysis provides accurate information about intrapartum hypoxia and may prevent intrapartum asphyxia and neonatal encephalopathy by giving a clear alert to the staff members who are in charge.

Acidosis↗
PubMed2000

A methodology for the development of software agent based interoperable telemedicine systems: a tele-electrocardiography perspective.

Telemedicine involves the integration of information, human-machine, and healthcare technologies. Because different modalities of patient care require applications running on heterogeneous computing environment, software interoperability is a major issue in telemedicine. Software agent technology provides a range of promising techniques to solve this problem. This article discusses the development of a methodology for the design of interoperable telemedicine systems (illustrated with a tele-electrocardiography application). Software interoperability between different applications can be modeled at different levels of abstraction such as physical interoperability, data-type interoperability, specification-level interoperability, and semantic interoperability. Software agents address the issue of software interoperability at semantic level. A popular object-oriented software development methodology - unified modeling language (UML) - has been used for this development. This research has demonstrated the feasibility of the development of agent-based interoperable telemedicine systems. More research is needed before widespread deployment of such systems can take place.

Computer Systems↗
PubMed1992

Reduction in cardiac conduction velocity delay by angiotensin converting enzyme inhibition in hypertensive patients with left ventricular hypertrophy. Detection by signal averaged electrocardiography.

Hypertensive patients with left ventricular hypertrophy (LVH) have increased prevalence of ventricular arrhythmias. Slow conduction velocity at the level of hypertrophic myocardial cells has been one of the postulated mechanisms for these arrhythmias. To assess the effects of angiotensin converting enzyme inhibition on modification in ventricular conduction velocities, we studied 25 hypertensive patients with LVH using signal averaged electrocardiography (SAECG) in a randomized double-blind placebo controlled and cross-over trial. Data were acquired at baseline and 10 min after a double-blind intravenous infusion of saline placebo or 2.5 mg enalaprilat. Sequential cross-over was done the next day. Root mean square vector was 55 +/- 5 microV at baseline, 55 +/- 5 microV after placebo and 54 +/- 4 microV after enalaprilat (P = NS). Low amplitude signal < 40 msec was 45 +/- 4 msec at baseline, 45 +/- 4 msec after placebo, and 43 +/- 4 msec after enalaprilat (P = NS). There was no change in filtered QRS (fQRS) duration between baseline (113 +/- 10 msec) and placebo (113 +/- 11 msec) measurements. However, after enalaprilat infusion, there was a significant reduction in fQRS to 106 +/- 7 msec (P = .04), and five patients (20%) with late potentials had normalization of this feature (P = .001). The data suggest that angiotensin converting enzyme inhibition with enalaprilat reduces conduction velocity delay in hypertensive patients with LVH.

Adult↗
PubMed2006

Head-to-head comparison of multislice computed tomography and exercise electrocardiography for diagnosis of coronary artery disease.

AIMS: To prospectively compare multislice computed tomography (MSCT) and exercise electrocardiography (ex-ECG) for diagnosis of coronary artery disease (CAD) with conventional coronary angiography as the reference standard. METHODS AND RESULTS: A consecutive cohort of 80 patients with suspected CAD was examined with MSCT using 16 x 0.5 mm detector collimation, ex-ECG, and conventional coronary angiography according to standard protocols. Results were compared using the paired McNemar's test, the chi(2) test, and 95%CIs. Both the sensitivity and specificity of MSCT [91% (40 of 44 patients, 95%CI 78-97%) and 83% (30 of 36 patients, 95%CI 67-94%)] were significantly higher (P = 0.039 and P < 0.001) than those for ex-ECG [73% (32 of 44 patients, 95%CI 57-85%) and 31% (11 of 36 patients, 95%CI 16-48%)]. The pairwise McNemar's test showed significant differences between MSCT and ex-ECG in the overall diagnosis in patients with suspected CAD (P = 0.036). The rate of non-diagnostic examinations was not significantly (P = 0.078) different between MSCT and ex-ECG [8% (6 of 80 patients, 95%CI 3-16%) vs. 19% (15 of 80 patients, 95%CI 11-29%)]. CONCLUSION: In this consecutive cohort of patients scheduled to undergo conventional coronary angiography, the performance of MSCT for diagnosis of CAD was superior to that of ex-ECG.

Aged↗
PubMed2006

Comparison of magnetocardiography and electrocardiography: a study of automatic measurement of dispersion of ventricular repolarization.

AIMS: There is some dispute over the clinical significance of dispersion of ventricular repolarization measurements from the electrocardiogram. Recent studies have indicated that multichannel magnetocardiograms (MCGs), which non-invasively measure cardiac magnetic field strength from many sites above the body surface, may provide independent information from ECGs about ventricular repolarization dispersion. For this study, magnetocardiography and electrocardiography were compared from automatic measurements of dispersion of ventricular repolarization. METHODS AND RESULTS: Dispersion of ventricular repolarization time was determined in MCGs and standard ECGs recorded simultaneously from 27 healthy volunteers and 22 cardiac patients. Two automatic techniques were used to determine the interval of ventricular repolarization. There were significant differences in ventricular dispersion between ECG and MCG measurements, with multichannel MCG greater than ECG by 52 (47) ms [mean (SD)] (P<0.00001) and 12-channel MCG greater by 17 (40) ms (P<0.004) across techniques and all subjects. Magnetocardiograms had the greater discriminating power between normal and cardiac patients with differences of 46 (18) ms (P<0.017) for multichannel MCG and 44 (16) ms (P<0.005) for 12-channel MCG, compared with 16 (7) ms (P<0.04) for ECG. CONCLUSION: Magnetocardiography has the power to discriminate regional cardiac conduction differences.

Electrocardiography↗
PubMed1990

Sensitivity and specificity of dobutamine--electrocardiography test to detect multivessel disease after acute myocardial infarction.

The value of dobutamine-electrocardiography (ECG) as a stress test to detect multivessel coronary disease after non-complicated acute myocardial infarction (AMI) was assessed in 75 patients before hospital discharge. Dobutamine-ECG test (dose of 5, 10, 15 and 20 micrograms kg-1 min-1 every 5 min) was performed 5 to 12 days after the beginning of the symptoms of AMI, and coronary angiography within the first month. Heart rate increased from 71 +/- 12 to 106 +/- 17 beats min-1, and systolic blood pressure from 111 +/- 15 to 139 +/- 20 mmHg. Dobutamine test was negative (neither anginal pain, nor ST-segment depression) in 33 patients and positive in 42. The angiographic study showed the presence of non-significant (less than or equal to 50%) coronary lesions in 11 patients, one-vessel disease in 33, two-vessel disease in 18 and three-vessel disease in 13 patients. Sensitivity of dobutamine-ECG test to detect multivessel (two- or three-vessel) disease was 84%, specificity 64%, predictive value of a positive test: 62%, predictive value of a negative test: 85%, and diagnostic efficiency: 72%. In conclusion dobutamine-ECG is a highly sensitive test to diagnose multivessel disease in patients with non-complicated AMI. The specificity is lower, probably due to detection of peri-infarction ischaemia in cases of one-vessel disease.

Adult↗
PubMed1991

Standards for analysis of ventricular late potentials using high resolution or signal-averaged electrocardiography. A statement by a Task Force Committee between the European Society of Cardiology, the American Heart Association and the American College of Cardiology.

Sufficient data are available to recommend that the high-resolution or signal-averaged electrocardiogram can be used in patients recovering from myocardial infarction without bundle branch block to help to determine their risk for developing sustained ventricular tachyarrhythmias. However, no data are available regarding the extent to which pharmacologic or non-pharmacologic interventions in patients with late potentials have an impact on the incidence of sudden cardiac death. Therefore, controlled, prospective studies are required before this issue can be definitely answered. As refinements in techniques evolve, it is anticipated that the clinical value of high-resolution or signal-averaged electrocardiography will continue to increase in the future.

Arrhythmias, Cardiac↗
PubMed1986

Prevalence and prognostic significance of cardiac arrhythmias detected by ambulatory electrocardiography in subjects 85 years of age.

24 hour ambulatory electrocardiography was performed in a representative group of people born in 1897. Out of 73 people included in the study, 22 were without known heart disease, 15 had definite ischaemic heart disease (IHD) and 36 symptoms of possible cardiac origin. An R-R interval in excess of 2000 ms was seen in only 3 subjects and Wenckebach A-V block in only one. One subject without a history of syncope had a nocturnal episode of complete A-V block with an escape interval of 8000 ms. The most striking difference between healthy subjects and patients with IHD was the higher number of patients with more than 1000 ventricular premature beats (VPBs) per 24 hour and ventricular couplets compared with the number of healthy subjects with such findings. At follow-up two years later 11% had died, with the highest mortality in patients with IHD (33%), and out of 8 patients with IHD who had more than 1000 VPBs per 24 hour, 4 (50%) had died compared with only one (14%) of those with less than 1000 VPBs. Our results seem to indicate that more than 1000 VPBs per 24 hour is a very unusual finding in healthy 85 year old individuals. When it occurs in very old people, it is usually in connection with IHD, and in this setting it signifies a poor prognosis.

Age Factors↗