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At least 451 records · Page 25Linked to original sources
PubMed2001

Use of ambulatory electrocardiography for detection of ventricular premature complexes in healthy dogs.

OBJECTIVE: To evaluate the use of 24-hour ambulatory electrocardiography (AECG) for the detection of ventricular premature complexes (VPC) in healthy dogs. DESIGN: Case series. ANIMALS: 50 healthy mature dogs. PROCEDURE: A 24-hour AECG was performed on each dog and evaluated for the presence of VPC. RESULTS: Fifty dogs weighing between 18.2 to 40.9 kg (40 and 90 lb) representing 13 breeds were evaluated; there were 4 sexually intact females, 21 spayed females, 4 sexually intact males, and 21 castrated males. Ages ranged from 1 to 12 years. Thirty-four dogs had no VPC; 16 dogs had between 1 and 24 VPC. The grade of arrhythmia ranged from 1 to 4, with 4 dogs having an arrhythmia with a grade > 1. Significant differences were not detected between the group of dogs with VPC and those without VPC with regard to sex, age, and minimum, maximum, or mean heart rate. CONCLUSIONS AND CLINICAL RELEVANCE: We conclude that healthy mature dogs have infrequent VPC, as detected by use of 24-hour AECG. The presence of numerous or sequential VPC may be suggestive of cardiac or systemic disease and may indicate the need for thorough clinical evaluation.

Animals↗
PubMed2001

Comparison of in-hospital versus 24-hour ambulatory electrocardiography for detection of ventricular premature complexes in mature Boxers.

OBJECTIVE: To evaluate the use of in-hospital electrocardiography (ECG) for detection of ventricular premature complexes (VPC), compared with 24-hour ambulatory ECG. DESIGN: Original study. ANIMALS: 188 Boxers > 9 months old; 31 had a history of syncope, and 157 were healthy (no history of syncope). PROCEDURE: In-hospital ECG was performed on all Boxers for at least 2 minutes. Within 7 days after the in-hospital ECG was completed, 24-hour ambulatory ECG was performed. RESULTS: The specificity of in-hospital ECG was 100% for the detection of at least 50 VPC in a 24-hour period in dogs with syncope and 93% in healthy dogs. In-hospital ECG had poor sensitivity, although sensitivity increased as the number of VPC per 24 hours increased. CONCLUSIONS AND CLINICAL RELEVANCE: Use of in-hospital ECG is highly specific for detection of at least 50 VPC during a 24-hour period. However, in-hospital ECG is insensitive, and a lack of VPC does not suggest that the dog does not have a substantial number of VPC during that same period. The use of in-hospital ECG appears to be inadequate for screening purposes and therapeutic evaluations in mature Boxers with ventricular arrhythmic disease.

Animals↗
PubMed2005

Results of 24-hour ambulatory electrocardiography in dogs undergoing ovariohysterectomy following premedication with medetomidine or acepromazine.

OBJECTIVE: To investigate heart rate characteristics in dogs undergoing ovariohysterectomy following premedication with medetomidine or acepromazine. DESIGN: Clinical trial. ANIMALS: 43 client-owned dogs. PROCEDURE: 24-hour ambulatory electrocardiography was performed beginning approximately 1 hour prior to administration of premedications. Dogs were premedicated with medetomidine and butorphanol (n = 21) or acepromazine and butorphanol (22) and, approximately 85 minutes later, were anesthetized with propofol and isoflurane. Electrocardiographic recordings were examined to determine heart rate, cardiac conduction disturbances (ventricular premature complexes and atrioventricular block), and indices of heart rate variability (HRV). RESULTS: Minimum heart rate during the 24-hour recording period was significantly lower among dogs given medetomidine than among dogs given acepromazine, but during the postoperative period, heart rate increased in all dogs as they became physically active. Intraoperative time domain HRV indices were lower and the low frequency-to-high frequency ratio was higher among dogs given acepromazine than among dogs given medetomidine; however, significant differences between groups were no longer seen by 6 hours after surgery. There was no significant difference between groups with regard to the number of ventricular premature complexes or to values of scaling exponent alpha2 (a nonlinear measure of HRV). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that there are greater enhancements in vagally related heart rate indices in medetomidine-treated dogs that may persist until 6 hours after surgery. Despite the low heart rates, dogs given medetomidine showed expected responses to surgery and positional stimuli, and the 2 preanesthetic protocols may not result in different prevalences of ventricular premature complexes.

Acepromazine↗
PubMedDate not supplied

Common standards for quantitative electrocardiography.

A large international co-operative project, sponsored by the European Commission, was launched in 1980 aimed at developing common standards for quantitative electrocardiography. The first and main objective of the project was to reduce the wide variation in wave measurements currently obtained by electrocardiographic computer programs. To this end a reference library was developed and a comprehensive reviewing scheme was devised for the visual determination of the onsets and offsets of P, QRS and T. This task was performed by a board of cardiologists on highly amplified recordings, in an interactive four round Delphi-type analysis. The reference library, so obtained, has become an internationally recognized yardstick for the evaluation and improvement of ECG measurement programs. It has been used to test the performance of 9 VCG and 10 standard 12-lead programs. The library proved to be a useful instrument in the establishment of recommendations for more precise measurement rules and definitions. Records with added noise and multi-lead ECGs were subsequently analysed to meet specific objectives. The project was expanded in 1984 towards testing and improvement of diagnostic criteria and classification programs.

Cardiomyopathy, Hypertrophic↗
PubMed1998

[Comparison of electron beam computed tomography and exercise electrocardiography in detecting coronary artery disease in the elderly].

Although exercise electrocardiography (ECG) is a useful noninvasive screening test for coronary artery disease (CAD), one prerequisite for ECG screening is that patient be able to exercise enough to evoke myocardial ischemia. Thus, exercise ECG may not be suitable for, some elderly people with CAD who cannot exercise enough. We compared electron beam Computed Tomography (EBCT) with exercise ECG for detecting CAD in 196 patients (mean age, 58.4 +/- 12.5 [standard deviation]) who had undergone coronary angiography. Using the angiographic findings as the "gold standard", we found that the sensitivity, specificity, positive predictive value, and negative predictive value were 88%, 77%, 89%, and 77%, respectively, for EBCT, and 66%, 72%, 83%, and 52%, respectively, for exercise ECG. Although the results were similar when the subjects were divided into different age groups, the negative predictive value for exercise ECG, among older patients was very low. These findings suggest that EBCT is superior to exercise ECG in detecting CAD in the elderly.

Aged↗
PubMed2005

Effects of a Web-based teaching method on undergraduate nursing students' learning of electrocardiography.

This study examined the effects of a Web-based teaching method (versus a traditional lecture method) on undergraduate nursing students' learning of electrocardiography (ECG). The Web-based learning program was developed by the authors and implemented for 4 weeks. The study used a pretest-posttest experimental design. A total of 105 senior nursing students were recruited at a university in Korea. Fifty-four students were assigned to an experimental group in 2002, and 51 were assigned to a control group in 2003. Knowledge about ECG among students in the Web-based group was significantly lower than that of students in the control group (p < .01). Conversely, the ability to interpret ECG recordings was significantly higher among students in the Web-based group (p < .05). No significant differences were found between the two groups in level of motivation or satisfaction with learning. The self-directed, Web-based ECG learning program appears to be effective in helping nursing students to interpret ECG recordings.

Adult↗
PubMed1995

Failure of signal-averaged electrocardiography with use of time-domain variables to predict inducible ventricular tachycardia in patients with conduction defects.

OBJECTIVE: To extend the application of signal-averaged electrocardiography (SAECG) to patients with ventricular conduction defects by analysis of electrocardiographic (ECG) time-domain variables. MATERIAL AND METHODS: In 123 consecutive patients with a QRS duration of 118 ms or more on a resting ECG and without evidence of an accessory pathway, SAECG was done at the time of electrophysiologic (EP) study. For EP testing, up to three stimuli were delivered during two paced drives from two right ventricular sites. A "positive" EP result was defined as monomorphic ventricular tachycardia that lasted for more than 30 seconds or necessitated intervention. Data were obtained for four time-domain variables. All variables were analyzed for differences between patients with EP-positive and those with EP-negative results. RESULTS: Unfiltered QRS duration was the only time-domain ECG variable that was statistically different (P = 0.02) between patients with EP-positive and those with EP-negative results (141.3 and 147.8 ms, respectively); this difference persisted when patients with right bundle branch block were excluded from analysis. This finding is the opposite of previously reported observations. When only patients with ischemic heart disease were analyzed, no SAECG variables were significantly different between patients with inducible ventricular tachycardia and those without it. CONCLUSION: High-resolution ECG time-domain variables cannot be used to predict inducibility of ventricular tachycardia during EP testing in patients with conduction defects.

Bundle-Branch Block↗
PubMed1981

Simplified esophageal electrocardiography using bipolar recording leads.

Diagnosing cardiac arrhythmias is easier if the P wave can be identified clearly. Esophageal electrocardiography with a unipolar recording lead attached to the V1 terminal of an ECG machine has been used in the past to show P waves. We used both bipolar and unipolar recording leads and standard ECG equipment to record the esophageal ECG and then compared the results obtained with both leads. Twenty-two cardiac rhythms were evaluated in 15 patients. The unipolar lead recorded a P wave that was smaller than the QRS complex (0.83 +/- 0.47 mV and 1.28 +/- 0.79 mV, respectively, p less than 0.01) and was obscured when the two depolarizations were nearly simultaneous. The bipolar lead recorded a P wave that was larger than the QRS complex (0.93 +/- 0.62 mV and 0.33 +/- 0.3 mV, respectively, p less than 0.001) and was never obscured. The unipolar lead recorded a P-to-QRS ratio that was smaller than that recorded by the bipolar lead (0.8 +/- 0.5 and 3.3 +/- 1.8, respectively, p less than 0.001). A bipolar esophageal lead can be recorded simply at the bedside using a standard ECG machine and is superior to the conventional unipolar lead.

Electrocardiography↗
PubMed1999

Diagnostic value of exercise electrocardiography for predicting a positive scintigraphic test in patients with complete right bundle branch block.

BACKGROUND: The diagnostic value of exercise electrocardiography (ECG) in patients with complete right bundle block (cRBBB) remains controversial. The aim of this study was to investigate the diagnostic accuracy of exercise ECG for predicting ischemia in the presence of cRBBB. METHODS: From a series of 1300 consecutive patients attending for exercise ECG and 99mTc-tetrofosmin single photon emission computed tomography (SPECT), we identified 38 male patients with cRBBB and 38 matched controls with normal intraventricular conduction. Patients with left ventricular hypertrophy or previous revascularization were excluded. Exercise ECG (modified Bruce protocol) was considered positive at > or = 1 mm ST horizontal or downsloping depression in > or = 2 adjacent leads. SPECT imaging at rest and post-exercise was performed at least 48 hours apart. RESULTS: The odds ratio for ischemia comparing patients with positive and negative exercise ECGs was 11.0 (95% confidence interval 2.49-48.64, p = 0.002) in controls and 2.49 (95% confidence interval 0.64-9.08, p = 0.32) in cRBBB. The prior probability of ischemia was 0.37 in controls and 0.58 with cRBBB. The posterior probability after a positive test was 0.65 in controls and 0.68 in cRBBB. Thus, the utility of the test (posterior probability minus prior probability) was greater in controls (+0.28) than in cRBBB (+0.1). This difference was most pronounced in the anterior leads V1-V4 (controls +0.63 vs cRBBB +0.01) but less significant in the lateral leads V5-V6 (controls +0.26 vs cRBBB +0.21). Similar analysis also indicated reduced diagnostic value of negative exercise ECGs in cRBBB patients. CONCLUSIONS: The diagnostic value of exercise ECG is reduced in patients with cRBBB, although ST-segment changes in the lateral ECG territory provide superior predictive accuracy to those in the anterior leads. The use of SPECT as a first-line investigation may be justified in patients with cRBBB.

Aged↗
PubMed2000

[Electrocardiography and myocardial viability].

After an acute myocardial infarction, the cardiologist cannot discard data regarding myocardial viability. The most frequently used diagnostic methods for this are echocardiographic or scintigraphic techniques; unfortunately, these techniques are operator sensitive or expensive. However, also by simple electrocardiography is it possible to obtain important information about myocardial viability, in an objective and economic way. There are three electrocardiographic modifications potentially related to myocardial viability: 1) spontaneous modifications after an acute myocardial infarction: early or late T wave normalization, and Q wave regression; 2) exercise-induced modifications: ST segment elevation, T wave normalization, ventricular arrhythmias; 3) dobutamine-induced modifications: ST segment elevation and T wave normalization. In this editorial, the authors report the literature data on the various electrocardiographic signs and analyze their accuracy and utility in myocardial viability assessment.

Arrhythmias, Cardiac↗
PubMed1999

[The diagnostic value of resting electrocardiography in stable coronary artery disease].

The relation of resting electrocardiographic (ECG) patterns to angiographic features was assessed in 566 patients with chest pain regarded as definite or probable stable angina pectoris. The indications for catheterization in each patient were determined at the discretion of the attending physician. All patients underwent diagnostic coronary angiography (clinically important coronary artery disease was defined as > or = 70 per cent narrowing of the diameter of at least one major vessel or > or = 50 per cent of the left main coronary artery) and standard 12 lead electrocardiography which was interpreted by 2 cardiologists independently in coordinating centre. The signs of impaired coronary blood flow were assessed by abnormalities of repolarization (among others S-T segment, the T wave), depolarization and presence of disturbances of cardiac rythm. The resting routine electrocardiogram was assigned to one of three categories: normal, nonspecific abnormalities or typical for coronary insufficiency. The typical pattern for ischemia was present in 104 patients (18%), nonspecific abnormalities were present in 185 patients (33%) and electrocardiogram was normal in 277 patients (49%). Sensitivity and specificity of the typical for coronary insufficiency resting ECG was calculated: 23% and 87% respectively for the entire group, 33% and 81% in women, 20% and 93% in men. In the group with normal resting electrocardiographic pattern 55% of patients have significant stenosis in at least one major coronary artery.

Cardiac Catheterization↗
PubMed1979

[Value of continous electrocardiography (Holter monitoring) in mitral valve prolapse].

Twenty three patients with mitral valve prolapse underwent ambulatory 20 to 24 hour electrocardiography to study the incidence and severity of ventricular arrhythmias. These arrhythmias were found in 20 cases (87 p. 100). Ventricular extrasystoles were usually grouped (14 cases) causing doublets in 8 cases and bursts of ventricular tachycardia in the 6 others. The importance of the information obtained by Holter monitoring should not detract from the value of the standard resting electrocardiogramme. In fact, there appears to be a good correlation between the severity of the ventricular arrhythmia and the presence of ST changes over the postero-inferior zones. These abnormalities were never present in patients without ventricular extrasystoles but on the other hand they were observed in 5 of the 6 patients with ventricular tachycardia. From a practical point of view this may represent a simple means of identifying patients at high risk of dangerous arrhythmias.

Adolescent↗
PubMed2000

[Evaluation of cardiac autonomic nerves by iodine-123 metaiodobenzylguanidine scintigraphy and ambulatory electrocardiography in patients after arterial switch operations].

The autonomic cardiac nerves reach the heart after passing through the vicinity of the aortic root and the pulmonary trunk. The arterial switch operation (ASO) completely transects the ascending aorta and the pulmonary trunk. Therefore, this surgical procedure virtually denerves the heart. Cardiac sympathetic denervation and reinnervation were evaluated in patients after ASO using iodine-123 metaiodobenzylguanidine (MIBG) myocardial scintigraphy and parasympathetic denervation and reinnervation using ambulatory electrocardiography [Holter electrocardiogram (ECG)]. MIBG scintigraphy was performed in 14 patients who underwent ASO (ASO group) and 3 patients who underwent other open heart surgery (control group). All patients in the ASO group underwent the operation in the neonatal or infantile period. Planar and single photon emission computed tomography (SPECT) images of the myocardium were obtained. Defect score was determined by the SPECT images as a semi-quantitative index. The mean interval between ASO and MIBG scintigraphy was 25.6 +/- 14.6 months. Holter ECG was also performed in 14 patients in the ASO group and 19 age-matched normal children. The Holter ECGs were plotted on a Lorenz plot. The H index, which is related to vagal tone for the cardiovascular system, was calculated from the R-R intervals. The mean interval between the ASO and Holter ECG was 8.3 +/- 9.7 months. MIBG scintigraphy in the control group demonstrated an almost normal homogeneous tracer uptake, but showed extremely reduced tracer uptake and significantly higher defect score in the ASO group. The extent and degree of the reduction of MIBG uptake improved with time after the ASO. The heart-to-mediastinum MIBG count ratio tended to increase with time. The H index of the ASO group was lower than that of normal children (< 12 months: Control group 0.0280 +/- 0.0068 vs ASO group 0.0219 +/- 0.0083), and gradually increased with time (1-3 years: 0.0470 +/- 0.0157 vs 0.0314 +/- 0.0124). These results indicate that MIBG scintigraphy reflects the presence of sympathetic denervation and the possibility of reinnervation after ASO, and that H index reflects the presence of parasympathetic denervation and the possibility of reinnervation after ASO. These are simple and useful methods for assessing the extent and degree of autonomic denervation and reinnervation.

3-Iodobenzylguanidine↗
PubMed1975

[The use of computers in the exercise of electrocardiography (author's transl)].

The use of computers in the exercise of electrocardiography is considered. The problems related to this use concern the choice of leads, the filtration of the signal, the recognition of characteristic segments of ECG, the calculation of various indexes and their statistical evaluation for diagnostic purposes. The authors use a bipolar derivation filtered by averaging and digital filters. The characteristic points of ECG are recognized by the analysis of the curvature. The Tchebycheff coefficients of the S-T tract are evaluated; they appeared to be a very good means for judging positive and negative cases.

Cardiac Output↗
PubMed2000

[Definitions of second degree atrioventricular block. An exercise in logic in clinical electrocardiography].

Second degree atrioventricular block has received different definitions which make it difficult for physicians to interpret certain cases. This review of the literature provides an accurate definition of the criteria of Mobitz I and Mobitz II atrioventricular block, and proposes simple diagnostic methods based on conventional electrocardiography. The importance of the definitions is underlined and the consequences in terms of permanent cardiac pacing are emphasised.

Electrocardiography↗
PubMed1997

Evaluation of oral dipyridamole electrocardiography test in ischaemic heart disease.

Forty-three cases of ischaemic heart disease of the age group 35-72 yrs with positive treadmill test (TMT) results were administered dipyridamole in the morning on empty stomach. Heart rate, BP and ECG were recorded before and every 15 mins after oral dipyridamole upto 2 hrs. ECG was repeated every 5 mins when patients developed angina or ischaemic ECG changes. Oral dipyridamole electrocardiography test (ODET) was found to be positive in 21 (48.83%) cases and majority of them developed ST depression in 25-40 mins and persisted for less than 30 mins. While compared with TMT results patients having chest pain, lower target heart rate (< 75%), shorter time to onset (< 2 mins) of ST depression and longer duration (> 8 mins) of ST depression had significantly higher rates of positivity on ODET than those without these manifestations. There were minor changes in hemodynamic parameter (heart rate, systolic and diastolic blood pressure) and other minor side effects encountered include mild headache and benign unifocal VPCs. Oral dipyridamole is viewed as a safe drug and may be used as a substitute for TMT specially in economically poor and physically disabled patients with significant coronary artery disease.

Administration, Oral↗
PubMed1975

Three years' experience of electrocardiography in a general practice.

Electrocardiography has a useful place in general-practice cardiology:(1) by bringing to light unexpected findings thereby altering the diagnostic spectrum and, in some cases at least, management.(2) by acting as a monitor in the continuing management of patients suffering from some forms of cardiovascular disease, and, in particular, from essential hypertension.In 1970 the purchase of a ;Cambridge Transrite' 4-2 battery two-speed electrocardiograph made it possible to test the value of this working tool in a practice population of about 5,300 patients. Before this, members of the medical staff of the Department who needed electrocardiograms for any of their patients made the appointments with the Cardiology Department, The Royal Infirmary, Edinburgh, or, later, with the nearby Family Doctor Centre of the Scottish Home and Health Department.

Adult↗