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PubMed1982

[Heart rhythm disorder in congestive cardiomyopathy (data from ECG at rest and from daily ECG monitoring)].

In 55 patients with congestive cardiomyopathy, types of arrhythmias were studied according to the 12 lead data of the ECG at rest and daily monitoring observation. Arrhythmias have ascertained to be one of the constant signs of this disease. Interventricular conduction disturbances (72.7%), atrioventricular block of low degree (56.1%), ventricular extrasystole (40%), and atrial fibrillation (20%) are most frequently recorded on the ECG at rest. While recording the ECG for a day with a Holter monitor, polytopic ventricular extrasystole was revealed in 100% of the patients studied. Ventricular and supraventricular tachycardia paroxysms were found in 54.5% of the cases. This observation is of prognostic significance as it indicates a risk of sudden death.

Adolescent↗

PubMed1982

[Integral ECG and ventricular gradients, differential ECG, their diagnostic potentials].

Synchronous recording of the integral ECG (IECG), ECG and is first derivative (DECG), made according to the original method, shows that the measurement of the amplitude of IECG elements can substitute the difficult calculations of the area of ECG waves, required for the determination of AQRS, AT and the ventricular gradient (G). On this basis the normal dimensions and directions of the AQRS, AT, G vectors were calculated in the frontal and horizontal planes, the typical changes were recorded in the blocks of the His' bundle, ischaemic heart disease and myocardial infarction. The offered methods of calculation make easily accessible the determinations of G in the right-angle system of coordinates, open new possibilities of the quantitative assessment of ST segment displacement. Recording of DECG permits one to detect P waves in those cases when they coincide with the QRS complex, with ST--T interval, which helps differential diagnosis of rhythm disorders of the heart.

Arrhythmias, Cardiac↗

PubMed1977

Long-term ECG in ambulatory clinical practice. Analysis and 2-year follow-up of 100 patients studied with a portable ECG tape recorder.

A portable tape recorder for long-term ECG monitoring is described. Its light weight (500 g) and small size (138 X 115 X 39 mm) make its usage in routine clinical practice a practical proposition. The most important application has been in the differential diagnosis of Adams--Strokes syndrome. The results from the first 100 patients with a 2-yr follow-up are presented. The importance of GCG recording during the patients' relevant subjective symptoms is stressed. The mean duration of recording was 2.8 days. In the 28 patients with histories which fitted the symptoms of Adams--Stokes syndrome this diagnosis was confirmed by an arrhythmia recorded simultaneously with the symptoms. In 36 other patients with a similar history the diagnosis was excluded becase of a normal ECG during subjective symptoms. Of the 28 patients with Adams--Stokes sydrome, bradyarrhthmia was the causal factor in 20 patients and these had a pacemaker implanted, whereas the remaining 8 patients had a tachyarrhythmia, which wa treated with antiarrhythmic drugs. The 2-yrs follow-up revealed an improvement and a disappearance of the Adams--Stokes attack in all the patients with an implanted pacemaker. In several of the 36 patients in whom Adams--Stokes syndrome could not be confirmed the syncopal attacks disappeared spontaneously. A large number of arrhythmias, including ventricular and supraventricular tachycardia, 2nd degree AV block and sinus bradycardia were observed during symptom-free intervals in these 36 patients. The introduction of long-term ECG recording routinely in patients with dizziness and syncope of unknown reason has resulted in an increase of the number of patients with a confirmed diagnosis of the Adams--Stokes syndrome, and it has contributed to an increase in the incidence of pacemaker implantation in Malmö from 130 per million inhabitants in 1971 to 220 in 1973, and 1974, respectively.

Adams-Stokes Syndrome↗

PubMed1991

ECG-gated thallium-201 myocardial SPECT in patients with old myocardial infarction compared with ECG-gated blood pool SPECT.

We evaluated one of the merits of ECG-gated thallium-201 single photon emission computed tomography (g-T1 SPECT), i.e., the ability to appreciate left ventricular (LV) wall motion. LV wall motion assessed by g-T1 SPECT and by ECG-gated Blood Pool SPECT (g-BP SPECT) was classified into three grades and compared segment by segment. T1-201 uptake by g-T1 SPECT was also classified into three grades and compared with those of wall motion in g-BP SPECT. Fifty patients with prior myocardial infarction were injected intravenously at rest with 111 to 185 M Bq (3 to 5 mCi) of Tl-201. The left ventricular regions were divided into anterior, septal, inferior and lateral segments (50 patients X 4 segments = 200 segments in total). The grades of wall motion and Tl-201 uptake detected by g-Tl SPECT correlated well with those of wall motion in g-BP SPECT (94.5% and 85%, respectively). With g-Tl SPECT it was possible to evaluate left ventricular wall motion, providing clear perfusion images.

Adult↗

PubMed2003

Comparative value of ECG-gated blood pool SPET and ECG-gated myocardial perfusion SPET in the assessment of global systolic left ventricular function.

Both electrocardiographically (ECG) gated blood pool SPET (GBPS) and ECG-gated myocardial perfusion SPET (GSPET) are currently used for the measurement of global systolic left ventricular (LV) function. In this study, we aimed to compare the value of GSPET and GBPS for this purpose. The population included 65 patients who underwent rest thallium-201 GSPET imaging at 15 min after (201)Tl injection followed by planar (planar(RNA)) and GBPS equilibrium radionuclide angiography immediately after 4-h redistribution myocardial perfusion SPET imaging. Thirty-five patients also underwent LV conventional contrast angiography (X-rays). LV ejection fraction (EF) and LV volume [end-diastolic (EDV) and end-systolic (ESV) volumes] were calculated with GBPS and GSPET and compared with the gold standard methods (planar(RNA) LVEF and X-ray based calculation of LV volume). For both LVEF and LV volume, the inter-observer variability was lower with GBPS than with GSPET. GBPS LVEF was higher than planar(RNA) (P<0.01) and GSPET LVEF (P<0.01). Planar(RNA) LVEF showed a slightly better correlation with GBPS LVEF than with GSPET LVEF: r=0.87 and r=0.83 respectively. GSPET LV volume was lower than that obtained using X-rays and GBPS (P<0.01 for both). LV volume calculated using X-rays showed a slightly better correlation with GBPS LV volume than with GSPET LV volume: r=0.88 and r=0.83 respectively. On stepwise regression analysis, the accuracy of GSPET for the measurement of LVEF and LV volume was correlated with a number of factors, including planar(RNA) LVEF, signal to noise ratio, LV volume calculated using X-rays, summed rest score and acquisition scan distance (i.e. the radius of rotation). The accuracy of GBPS for the measurement of LVEF and LV volume was correlated only with the signal level, the signal to noise ratio and the acquisition scan distance. Both GSPET and GBPS provide reliable estimation of global systolic LV function. The better reliability of GBPS and in particular its lower sensitivity to different variables as compared with GSPET favours its use when precise assessment of global systolic LV function is clinically indicated.

Adult↗

PubMed1997

[QT dispersion in surface ECG and QT dynamics in long-term ECG in patients with coronary heart disease in the chronic post-infarct stage with and without ventricular tachyarrhythmias--correlation with other risk parameters].

QT-dispersion (QTD) in 12-lead surface-ECG and QT-dynamics in Holter-ECG, defined as the time-course of the frequency corrected QT-interval (mQTc), were determined in 42 patients with coronary artery disease in chronic postinfarction stadium without ventricular tachyarrhythmias (CAD/VTA-) and in 24 CAD patients with ventricular tachyarrhythmias (CAD/VTA+). 14 healthy volunteers served as control group (CG). Correlations with hemodynamic data (LVEF, severity of CAD) and with other risk-parameters (ventricular late potentials, short-time heart rate variability) were calculated. QTD in CAD/VTA-was significantly higher compared to CG (48.4 ms+/- 19.6 vs 31.4 ms +/- 9.8, p < 0.05). There were no intergroup differences in QT-dynamics. CAD/VTA+ patients showed the highest QTD-values (59.5 ms +/- 31.1, p < 0.05 compared to CG/CAD/VTA0) and a significantly altered QT-dynamics compared to CG/CAD/VTA- (mQTc: 431.3 ms +/- 38.8 vs 400.8 ms +/- 25.5 vs 406.3 ms +/- l0.6, p < 0.05). Only parameters of QTD were significantly correlated to severity of CAD (r = +0.41, p < 0.01) and to LVEF (r = 0.43, p < 0.01). We did not find significant correlations between the parameters of QT-dispersion/QT-dynamics among one another and to the risk-parameters. These results indicate that the QT-dispersion in CAD-patients also in chronic post-infarction stadium is elevated and that CAD-patients with VTA are characterized by an altered QT-dynamics. Parameters of both methods are independent of other validated risk-parameters. So the measurement of QT-dispersion and QT-dynamics as markers of inhomogenous repolarization could contribute to an improvement of risk-stratification of CAD-patients.

Coronary Disease↗

PubMed1983

Cluster headache: a computerized analysis of 24 h Holter ECG recordings and description of ECG rhythm disturbances.

Continuous ECG recording has been carried out for at least 24 h in 27 patients suffering from cluster headache. During the study a total of 84 attacks occurred in 25 of the 27 patients who took part. A computerized analysis of the heart rate changes accompanying attacks showed the following: (i) an increase in heart rate at the onset of attacks; the degree of this increase being dependent on the heart rate before attacks, (ii) a relative decrease in heart rate and increased variations in heart rate during attacks, (iii) a relative increase in heart rate at the end of attacks, and (iv) a relative decrease in heart rate after attacks. Five patients (18.5%) showed ECG rhythm disturbances: two frequent premature ventricular beats, one transient attacks of atrial fibrillation, one first degree atrio-ventricular block, and one patient sinoatrial block.

Adult↗

PubMed2005

Comparison between QRS duration at standard ECG and signal-averaging ECG for arrhythmic risk stratification after surgical repair of tetralogy of fallot.

INTRODUCTION: Surgical repair of tetralogy of Fallot is complicated by the occurrence of ventricular tachycardia (VT). Among different indexes proposed to assess prognosis of these patients, the study of QRS and repolarization provided useful information. Controversial results come from the analysis of signal-averaging ECG (SAECG). The aim of our study was to identify patients operated for tetralogy of Fallot at higher risk of sudden death by means of SAECG. METHODS AND RESULTS: Sixty-six consecutive patients, mean age 26 +/- 10 years, were studied 17.7 +/- 5.8 years after total correction for tetralogy of Fallot using standard ECG, 24-hour Holter recordings, SAECG, and echocardiography. The following variables were measured: standard QRS duration, filtered QRS duration (fQRS), high-frequency and low-amplitude signal duration (HFLA), root mean square of the mean voltage in the terminal portion of filtered QRS (RMS), left and right end-diastolic volumes, and ejection fractions. During a mean follow-up period of 7.3 +/- 3.1 years, 12 patients had episodes of sustained VT and two of them suddenly died. All patients had complete right bundle branch block. Patients with VT were characterized by a significantly longer fQRS duration at all filter settings. On the contrary, there was no difference in standard QRS duration in patients with or without VT. At a multivariate analysis, left ventricular ejection fraction and fQRS were independent predictors for VT. CONCLUSIONS: A longer fQRS duration is associated with an increased risk in developing malignant ventricular arrhythmias in asymptomatic patients after total correction of tetralogy of Fallot.

Adolescent↗

PubMed2000

The combination of a continuous 12-lead ECG and troponin T; a valuable tool for risk stratification during the first 6 hours in patients with chest pain and a non-diagnostic ECG.

AIMS: The aim was to examine the early prognostic value of a combination of a continuous 12-lead ECG and troponin T in patients with chest pain and an ECG non-diagnostic for acute myocardial infarction. METHODS AND RESULTS: ST monitoring was performed and samples for analysis of troponin T were collected from admission for 12 h from 598 patients. After 6 h, the peak value of troponin T in 27% was > or = 0.10 microg.l(- 1), while 15% had had ST episodes, defined as transient ST deviations of at least 0.1 mV. Both a troponin T > or = 0.10 microg. l(-1) and ST episodes predicted worsening outcome. After 30 days, there were 6.8% and 1.4% (P<0.01) cardiac deaths or myocardial infarctions in the group with and without troponin T > or = 0.10 microg.l(-1), respectively. The corresponding event rates in patients with and without ST episodes were 10% and 1.6% (P<0.001). In a multivariate analysis both troponin T and ST episodes were independent predictors of cardiac death or myocardial infarction. When ST monitoring and troponin T status were combined, patients could be divided into low-, intermediate-, and high-risk groups. CONCLUSIONS: A combination of continuous 12-lead monitoring and troponin T seems to be a valuable tool for risk stratification during the first 6 h in this population.

Aged↗

PubMed1997

Induction of apoptosis in equine chorionic gonadotropin (eCG)-primed rat ovaries by anti-eCG antibody.

We have established a model to examine the early events of apoptosis in small antral follicles in vivo. Immature female rats injected with 15 IU eCG, and subsequently (24 h later) with an anti-eCG antibody to induce gonadotropin withdrawal, displayed a significantly lower ovarian weight and increased incidence of follicular atresia and granulosa cell death, especially in small- to medium-sized follicles. Evidence of apoptosis was apparent in a significantly higher proportion of granulosa cells from antibody-treated rats, which exhibited membrane blebbing, nuclear and cytoplasmic condensation, fragmentation, and phagocytosis. In addition, there was a loss of the regular organization of the lamina densa in the follicular basement membrane. Degradation of DNA was consistently found by 24 h in the antibody-treated group, and ladders could be observed as early as 1 h after treatment. Although cell death was observed after antibody treatment in some larger antral follicles, the occurrence of apoptosis was less frequent. These results demonstrate that gonadotropin withdrawal in vivo rapidly induces apoptosis in small- to medium-sized antral follicles at the critical stage of development when atresia is commonly observed, suggesting that this model is ideal for studying apoptosis in the ovary.

Animals↗

PubMed2006

Wavelet-based low-delay ECG compression algorithm for continuous ECG transmission.

The delay performance of compression algorithms is particularly important when time-critical data transmission is required. In this paper, we propose a wavelet-based electrocardiogram (ECG) compression algorithm with a low delay property for instantaneous, continuous ECG transmission suitable for telecardiology applications over a wireless network. The proposed algorithm reduces the frame size as much as possible to achieve a low delay, while maintaining reconstructed signal quality. To attain both low delay and high quality, it employs waveform partitioning, adaptive frame size adjustment, wavelet compression, flexible bit allocation, and header compression. The performances of the proposed algorithm in terms of reconstructed signal quality, processing delay, and error resilience were evaluated using the Massachusetts Institute of Technology University and Beth Israel Hospital (MIT-BIH) and Creighton University Ventricular Tachyarrhythmia (CU) databases and a code division multiple access-based simulation model with mobile channel noise.

Algorithms↗

PubMed2002

[Number of classes from ECG and its application to ECG analysis].

The aim of this study was to detect QRS complex powers accurately. ECG was approximated by lines. It produced number of classes with main features of the whole ECG. Then these number of classes were analyzed in detail. The QRS detection rate reached 99.9% as validated by using single lead signals from MIT/BIH database. Complex powers can be recognized accurately with this method.

Algorithms↗

PubMed1977

[Study of ECG in lactating cows. 2nd communication: ECG compared to behavior of various parameters of mineral and carbohydrate-fat metabolism].

Metabolism checks were carried out on eight dairy cow stocks, with 155 high-performance cows in first lactation being electrocardiographically and biochemically tested. Determined with the blood-borne concentrations of glucose, ketone body, calcium, magnesium, and inorganic phosphorus. The electrocardiographic recording were compared with behaviours of the blood parameters, and PQ conduction was found to be shortened in hypoglycaemic animals. Changes in calcium and magnesium serum concentrations were found to produce tbe most unambiguous effects on a number of ECG components, and reciprocal influence of these two components was as well observed. No correlation with ECG were recordable from the other parameters.

Animals↗

PubMed1995

[ECG-dipyridamole and ECG-exercise test in the assessment of ischemic cardiopathy: effects of the acute administration of nitroglycerin].

It is known that intravenous administration of dipyridamole can induce chest pain and ECG signs of ischemia in patients with coronary artery disease. In the present study we evaluated ECG and hemodynamic changes in response to dipyridamole (0.56 mg/kg in 10 min) under basal conditions and 3 hours after administration of nitroglycerin (10 mg/24 h patch) in 14 patients with coronary artery disease. The effects of nitroglycerin were also compared to those induced by the same drug on a bicycle stress test in the same patients. Exercise stress test induced specific ST changes in all patients when performed off-drug. Nitroglycerin administration completely prevented exercise-induced ischemia in 2 patients, and significantly prolonged exercise time in the remaining patients (p < 0.01). This effect was accompanied by a significant increase in heart rate (HR) and rate-pressure product at the threshold of ischemia (HRBP, p < 0.01); furthermore we observed a significant increase in HR at the maximal work load (p < 0.05). In the absence of treatment, dipyridamole infusion induced ST segment changes and/or typical chest pain in 12/14 patients. Moreover we observed a significant increase (p < 0.05) in HR, BP and HRBP during the test with respect to basal conditions. Following nitroglycerin administration, dipyridamole infusion failed to induce ischemia in 4 patients, and the time to ST depression in the remaining 8 patients (459 +/- 69 vs 610 +/- 127 s; p < 0.05) was significantly prolonged.(ABSTRACT TRUNCATED AT 250 WORDS)

Dipyridamole↗

PubMedDate not supplied

Diagnostic accuracy of rest/stress ECG-gated Rb-82 myocardial perfusion PET: comparison with ECG-gated Tc-99m sestamibi SPECT.

BACKGROUND: Although single photon emission computed tomography (SPECT) and positron emission tomography (PET) myocardial perfusion imaging (MPI) have evolved considerably over the last decade, there is no recent comparison of diagnostic performance. This study was designed to assess relative image quality, interpretive confidence, and diagnostic accuracy by use of contemporary technology and protocols. METHODS AND RESULTS: By consensus and without clinical information, 4 experienced nuclear cardiologists interpreted 112 SPECT technetium-99m sestamibi and 112 PET rubidium-82 MPI electrocardiography (ECG)-gated rest/pharmacologic stress studies in patient populations matched by gender, body mass index, and presence and extent of coronary disease. The patients were categorized as having a low likelihood for coronary artery disease (27 in each group) or had coronary angiography within 60 days. SPECT scans were acquired on a Cardio-60 system and PET scans on an ECAT ACCEL scanner. Image quality was excellent for 78% and 79% of rest and stress PET scans, respectively, versus 62% and 62% of respective SPECT scans (both p<.05). An equal percent of PET and SPECT gated images were rated excellent in quality. Interpretations were definitely normal or abnormal for 96% of PET scans versus 81% of SPECT scans (p=.001). Diagnostic accuracy was higher for PET for both stenosis severity thresholds of 70% (89% vs 79%, p=.03) and 50% (87% vs 71%, p=.003) and was higher in men and women, in obese and nonobese patients, and for correct identification of multivessel coronary artery disease. CONCLUSION: In a large population of matched pharmacologic stress patients, myocardial perfusion PET was superior to SPECT in image quality, interpretive certainty, and diagnostic accuracy.

Aged↗

PubMed1984

Chronic paroxysmal hemicrania: heart rate changes and ECG rhythm disturbances. A computerized analysis of 24 h ambulatory ECG recordings.

Ambulatory ECG recordings have been carried out in five patients suffering from CPH. During the study a total of 105 attacks occurred. Contrary to findings in cluster headache, no typical pattern of heart rate change was found in association with attacks of CPH. A striking finding in all patients, however, was that there were often large and rapid variations in heart rate which could be observed "before", "during" or "after" the attacks. One patient developed bradycardia and sino-atrial block and another bundle branch block together with episodes of atrial fibrillation in association with attacks.

Adult↗

PubMed1989

On the consistency of ECG reports from two different computer-based ECG recorders.

Four consecutive computer-based ECG recordings/interpretations were made on each of 100 patients. Two of the recordings were made with the MAC II recorder (Marquette Electronics Inc., Milwaukee, USA) and two with the Cardisuny IC503FA (Fukuda M-E Kogyo Co. Ltd, Tokyo, Japan). Computer measurements of PQ interval, Q-width in III, R-amplitude in V5 and QRS axis in the frontal plane were compared between recordings, as also were diagnostic statements pertaining to the presence of atrial fibrillation and myocardial infarction. The MAC II was found to be more consistent than the Cardisuny as regards the measurements. There was a tendency that the MAC II was more specific than the Cardisuny and the Cardisuny more sensitive than the MAC II. The MAC II gave no false positive reports of atrial fibrillation and only one false positive report of myocardial infarction.

Atrial Fibrillation↗

PubMed1979

Effect of acebutolol on dynamic ischemic ECG changes: a study using ambulatory twenty-four-hour ECG monitoring.

The clinical effect of the beta-adrenergic blocking drug acebutolol hydrochloride (SECTRAL) was studied in 18 patients with angina pectoris. Ambulatory 24-h ECG monitoring proved to be a useful method for assessing the efficacy of this drug in individual patients in their own daily stresses and environment. Patients were studied in the control state, after two weeks' treatment with placebo, and after two weeks' constant oral dose of the drug. It was found that acebutolol produced a significant decrease in ischemic ST segment depression in patients in whom good beta-blockade was achieved. The drug was less effective in patients in whom the heart rate response to exercise was not suppressed and in those with critical coronary artery obstructions.

Acebutolol↗