bluuebunny/crossref_metadata_2025 huggingface dataset:
Continuously Recorded Physical Activity Level During Myocardial Ischemia Detected by Ambulatory Electrocardiography
Authors: Podolec P. , Jasek S. , Droste C. , Kardos A. , Tracz W. , Roskammt H.
Published: October 2006

Background

The goal of the study was to establish the usefulness of a new device, the Actograph, to differentiate the causes of ischemia detected in ambulatory Holter monitoring. Twenty‐five patients (7 women, 18 men) with angiographically proven coronary artery disease and stable effort angina were evaluated.

Methods

Patients had their physical motor activity (PMA) registered by means of an Actograph simultaneously with Holter monitoring during 24 hours when they underwent a standardized bicycle exercise test and performed their usual daily activity with mandatory walking and stair climbing.

Results

Nineteen of 25 patients had 97 transient ischemic episodes (TIEs) in the postexercise monitoring period (5.1 episodes/patient and 91.5 min/patient). Seventy‐four TIEs were associated with a high heart rate (HR) increase and evidence of PMA. Seven TIEs occurred without HR increase, but with evidence of considerable physical exercise. During 13 TIEs there was HR increase without any proof of physical activity. In only three TIEs there was neither HR increase nor measurable PMA. Patients’activity period during 24 hours extended from 19.6%–48.9% of recording time. The higher the patients’activity level during the 24‐hour period, the higher the number of TIEs were noted (r = 0.57, P < 0.03). Increased activity was recorded in patients’diaries only during 51(69%) of TIE with evidence of increased HR and PMA. Patients who had only asymptomatic TIEs on the ambulatory ECG had significantly higher PMA than patients without ischemia during Holter monitoring (26% vs 33%; P < 0.001). PMA during walking was significantly higher than during bicycle exercise and climbing stairs (P < 0.001). Surprisingly, the physical activity episodes with lowest PMA, bicycle exercise testing, in all cases were accompanied by TIE, while activity episodes with highest PMA, walking, provoked TIEs only in 40% of cases. There is clearly no correlation between activity measured by the Actograph and HR increase during cycloergometer tests (R2 = 0.08), while stair climbing and walking shows good correlation (R2 = 0.6).

Conclusions

The Actograph is a useful device that gives additional insight into the pathophysiology of ischemia. The weakness of the method is lack of the ability to measure intensity of physical activity.
Heart Rate Variability Is Decreasing During Paroxysmal Atrial Fibrillation
Authors: Piot Olivier , Halimi Franck , Jouven Xavier , Lavergne Thomas , Guize Louis , Le Heuzey Jean‐Yves
Published: October 2006

Background

The high R‐R variability in permanent atrial fibrillation (AF) is stable. Its behavior in paroxysmal AF is unknown. The aim of this study was to examine heart rate variability behavior during paroxysmal AF and its relationship with clinical characteristics by using time‐domain indices and scatterplot analysis.

Methods

In 43 patients, R‐R variability was assessed by time‐domain indices and graphical measurements of scattering area (SA) on scatterplot for each sample of 150‐second ventricular rhythms extracted at the onset, the middle, and before termination of AF episodes recorded on Holter monitoring. Results were compared between the three time periods, and a nested procedure assessed the components of the SA variance.

Results

In 110 episodes lasting 89 ± 130 minutes with a mean of 2.5 ± 3 (1–12) per patient, mean R‐R interval did not significantly change while time‐domain indices and SA significantly decreased between the three time periods (P < 0.05 for SD and CV, P < 10−2 for rMSSD and pNN50, P < 10−4 for SA, ANOVA 1). The magnitude of the decrease in SA was not related to any episode characteristic; in addition, there was no variation from episode to episode within patient (1% of SA variance), and the high variation between patients (70%, P < 10−4) was not related to any clinical parameter.

Conclusions

Heart rate variability decreases gradually during paroxysmal AF. This decrease is peculiar to each patient, unrelated to clinical status. A.N.E. 1999; 4(2):144–151
Relationship Between Autonomic Control of Heart Rate and QT Dispersion in Patients with Acute Anterior Wall Myocardial Infarction
Authors: Mazur Alexander , Strasberg Boris , Kusniec Jairo , Imbar Shula , Sulkes Jacqueline , Abramson Evgeny , Sclarovsky Samuel
Published: October 2006

Background

Heart rate variability (HRV) and QT dispersion are new and promising noninvasive indices for postinfarction risk stratification. The relationship between measures in patients with acute myocardial infarction (AMI) is unknown.

Methods

We analyzed short‐term HRV and standard electrocardiogram recordings for QT dispersion in 56 patients with first Q‐wave anterior wall AMI.

Results

All frequency domain measures of HRV correlated inversely with the magnitude of QT dispersion. The correlations were relatively stronger for rate‐corrected (−0.46 to −0.59) than for original values (−0.37 to −0.5) of QT dispersion. Similarly, the average normal cardiac cycle length (average NN) computed from HRV recordings correlated weakly and inversely with the magnitude of noncorrected QT dispersion (r =−0.29).

Conclusions

The inverse relationships between QT dispersion and both NN interval and HRV found in the present study suggest impaired adaptation of ventricular repolarization to changes in heart rate in AMI patients. Abnormal autonomic modulation of ventricular repolarization may thus result in increased QT dispersion. This finding may provide some insight into the mechanism underlying increased risk of sudden death after AMI. A.N.E. 1999; 4(2):152–157
Alteration in QT‐RR Relationship in Diabetic Patients with Autonomic Dysfunction
Authors: Shimono Mayumi , Fujiki Akira , Asahi Toshimi , Inoue Hiroshi
Published: October 2006

Background

Impaired autonomic nervous activity and changes in ventricular repolarization might be related to catastrophic events in diabetic patients.

Methods

We analyzed the QT‐RR relationship and autonomic activity with Holter monitoring in 20 diabetic patients and 10 controls. The diabetic group was divided into two groups: 9 patients with normal coefficient of variance of RR interval (CVRR > 2.5%, DMN group) and 11 with low CVRR (CVRR≤; 2.5%, DML group). Mean hourly QT and RR intervals were determined using the first 10 sinus beats of every hour. Spectral power of heart rate variability was determined with the fast Fourier transform technique.

Results

The DML group had shorter RR and QT intervals during sleep compared with the DMN group and control group. There was no difference in corrected QT interval among the three groups. The DML group showed decreased circadian variation of high‐frequency (HF) power, and steeper regression line and smaller correlation coefficient of QT‐RR relationship compared with other groups. There was an inverse correlation between InHF and the slope of the regression line of the QT‐RR relationship.

Conclusions

These results indicate that modulation of QT interval with heart rate is impaired along with impairment of cardiac parasympathetic activity in the DML group. Altered modulation of ventricular repolarization might contribute to the pathogenesis of catastrophic cardiac events in diabetic patients with neuropathy.
Prediction of Cardiac Death in Patients with Bundle Branch Block After Myocardial Infarction
Authors: Sierra Gilberto , Morel Patrick , Jean‐Lucien Rouleau  , Ferguson John , Davies Richard F. , Stewart Duncan J. , Talajic Mario , Gardner Martin , Dupuis Robert , Lauzon Claude , Sussex Bruce , Warnica Wayne , Le Guyader Pierre , Nadeau Reginald , Savard Pierre
Published: October 2006

Background

Left (LBBB) and right (RBBB) bundle branch block (BBB) patients have an increased incidence of cardiac death after myocardial infarction (Ml). The purpose of this study was to assess the value of the signal‐averaged electrocardiogram (SAECG) and other clinical variables for the prediction of cardiac death after MI in BBB patients.

Methods

SAECGs were recorded 5–15 days after MI in 76 LBBB and 79 RBBB patients. The SAECG was analyzed in the time domain and the frequency domain (wavelet analysis in 7 frequency bands ranging from 0.05 to 250 Hz).

Results

During follow‐up (17 ± 8 months), cardiac death occurred in 22 LBBB (28.9%) and 12 RBBB patients (15.2%). None of the SAECG time‐domain variables were significantly different between patients with and without cardiac death. In LBBB patients, univariate analysis showed that one wavelet parameter in the 3.9‐ to 7.8‐ Hz frequency band (P = 0.008), inhospital recurrent Ml (P = 0.002), left ventricular ejection fraction (LVEF) < 30% (P = 0.004), lack of percutaneous transluminal coronary angioplasty (P = 0.02), and history of angina (P = 0.029) were significantly different in cardiac death patients. In RBBB patients, only recurrent angina was significantly different (P = 0.025). In LBBB patients, the combination of recurrent Ml or LVEF < 30% displayed the best predictive values: sensitivity (85.7%), specificity (76.6%), positive (52.2%), negative (94.7%), and total (78.7%) predictive accuracies and risk ratio of 9.9. The effect of recurrent Ml and LVEF < 30% remained after statistical adjustment by means of regression using Cox proportional hazards.

Conclusions

High‐risk Ml patients can be identified by recurrent Ml and LVEF < 30% in LBBB patients, and by recurrent angina in RBBB patients. SAECG did not demonstrate incremental information for the purpose of risk stratification in BBB patients.
Influence of Cigarette Smoking on Heart Rate Variability in Young Healthy Subjects
Authors: Andrikopoulos George K. , Dilaveris Polychronis E. , Richter Dimitris J. , Gialafos Elias J. , Lazaki Elena A. , Avgeropoulou Catherine K. , Gialafos John E.
Published: October 2006

Background

Cigarette smoking is strongly related to decreased vagal cardiac activity and increased cardiac death. We sought to examine the short‐term effects of smoking on heart rate variability (HRV) in healthy young subjects in the sitting position to investigate the influence of smoking on autonomic cardiac control.

Methods

Thirty‐two healthy volunteers (18 males, 14 females, 21 habitual smokers and 11 nonsmokers, mean age 30 ± 3 years, range 24–36 years) were studied. Smokers were asked not to smoke for 8 hours prior to examination. Mean, SDNN, rMSSD, pNN50, total power, LF, HF, and LF/HF ratio were measured for 30 minutes, divided into six periods of 5 minutes each. Smoking of a single cigarette took place during the second period.

Results

Smoking caused a significant increase of the LF/HF ratio and of the normalized values of the LF component. A significant decrease in absolute values of total power, LF, and HF components was noticed. All time‐domain indices were significantly decreased. We also noticed that although the changes appeared during smoking (second period) the maximal changes were documented 5 to 10 minutes after smoking cessation (third and fourth periods).

Conclusions

Cigarette smoking in the sitting position causes a transient decrease in vagal cardiac control and a moderate sympathetic activation. These changes last for at least 30 minutes and are compatible with a modulation of the autonomic control of the sinoatrial node toward sympathetic predominance. Despite the differences concerning the baseline HRV measures between nonsmokers and habitual smokers, an almost identical pattern of sympathovagal modulation was observed.
A Comparison of T‐Wave Alternans and QT Dispersion as Noninvasive Predictors of Ventricular Arrhythmias
Authors: Berul Charles I. , Michaud Gregory F. , Lee Victor C. , Hill Sharon Laneau , Estes Mark , Wang Paul J.
Published: October 2006

Background:The purpose of this study was to compare the utility of T‐wave alternans and dispersion markers for predicting vulnerability to ventricular arrhythmias. Microvolt level T‐wave alternans, QT dispersion (QTd), JT dispersion, and other dispersion indices have been postulated as noninvasive markers of vulnerability to ventricular arrhythmias. However, T‐wave alternans has not been directly compared to dispersion markers in the same patient population.

Methods:Twenty‐four patients underwent electrophysiological study to investigate recent syncope, ventricular tachycardia, or ventricular fibrillation. Digitized orthogonal ECGs were obtained to investigate the presence of T‐wave alternans using spectral analysis, and standard 12‐lead ECGs were obtained for QT and JT dispersion analysis.

Results:T‐wave alternans measurements showed greater sensitivity than QT or JT dispersion, but similar results as the variation coefficient of the JT interval. There was no statistically significant difference in specificity, predictive values, or clinical accuracy between T‐wave alternans and any of the dispersion markers (P = N.S.). The combination of increased QT or JT dispersion and T‐wave alternans was the most specific predictor.

Conclusions:Heterogeneity of repolarization amplitude and duration may both be important noninvasive ECG markers of ventricular vulnerability. In this small group of high‐risk patients, T‐wave alternans has similar clinical accuracy as the ECG interlead repolarization dispersion markers. The predictive ability of these markers may improve with standardization of methodology or a combination of these approaches. A.N.E. 1999;4(3):274–280
QT Dispersion in Healthy Chinese Children and Adolescents
Authors: Zhang Niu , Ho Ting Fei , Yip William C.L.
Published: October 2006

Background:QT dispersion (QTd) reflects the interlead difference in QT interval. It may provide a measure of repolarization inhomogeneity. Studies on QTd mainly involve adults, while QTd in children are less well studied. The aim of this study was to evaluate QTd in healthy children and assess the relationship of gender, age, and anthropometric parameters, viz. weight (W), height (H), body mass index (BMI), and body surface area (BSA) to QTd.

Methods:Five hundred and one Chinese children and adolescents (243 boys, 258 girls) with no history of cardiovascular diseases were studied. Their ages ranged from 6.3 to 17.5 years. Surface 12‐lead electrocardiograms were measured in each child at rest. QT and R‐R intervals in each of the 12 leads were manually measured at a magnification of 2X. QT was corrected to QTc according to Bazett's formula. QTd was calculated as the difference between the maximum and minimum QT of the measured leads, while corrected QTd (QTcd) was the difference between the maximum and minimum QTc of the measured leads. Adjusted QTd was QTcd divided by the square root of the number of measurable leads.

Results:Mean QTd of all subjects was 34 ms (95% Cl 33.6–35.1 msl. Mean QTd for boys and girls was 35 ms and 34 ms, respectively (P = 0.18). Mean QTcd for the whole group was 47 ms (95% Ci 45.8–48.2 ms), while mean adjusted QTcd was 14 ms (95% Cl 13.8–14.5 ms). There were no significant gender differences in QTcd or adjusted QTcd. Weak negative correlation existed between age and QTd, QTd and adjusted QTcd (r =−0.22, r =−0.26, r =−0.21, respectively, P < 0.001 Similarly, QTcd also had a weak significant negative correlation with W (r =−0.20), H (r =−0.21) and BSA (r =−0.22), P < 0.001. However, multiple stepwise regression analysis revealed that only age was significantly related to QTcd (R2 = 0.066) and QTd (R2 = 0.059), P < 0.001.

Conclusions:The results of this study indicate a trend of decreasing QTd and QTcd with increasing age, supported by multiple regression analysis. However indices of QTd in children are not influenced by anthropometry. This information may be useful for the clinical application of QTd in children. A.N.E. 1999;4(3):281–285
Signal‐Averaged ECG in Noninvasive Assessment of Reperfusion in the Acute Phase of Myocardial Infarction
Authors: Kulakowski Piotr , Karpiński Grzegorz , Szymot Joanna , Ceremuzyñki Leszek
Published: October 2006

Background:Coronary artery patency after thrombolytic therapy has important prognostic implications for survival after acute myocardial infarction (Ml). Several noninvasive methods have been tested to assess the effectiveness of thrombolytic therapy. However, the value late potential (LP) analysis from the signal‐averaged ECG for assessment of reperfusion has not been established.

Methods:In 50 patients (34 males, 16 females, mean age 59 ± 12 years, range, 35 years to 84 years) with acute Ml, signal‐averaged ECG recordings were performed using the FD‐3 solid‐state Holter recorder and analyzed prior to and 1, 2, and 3 hours from the initiation of thrombolytic treatment. Reduction in ST elevation of > 50% compared with baseline values was taken as a marker of successful reperfusion.

Results:At 2 hours, 28 (56 %) patients were considered to have successful reperfusion: LPS were not present in any patient with successful reperfusion compared with 8 (36%) patients without reperfusion (P = 0.002). At 3 hours 31 (62 %) patients were considered to have successful reperfusion: 1 (3%) had abnormal signal‐averaged ECG versus 6 (35%) patients without reperfusion (P = 0.01). An abnormal signal‐averaged ECG identified patients with failed reperfusion with very high specificity and positive predictive value (100% and 100% at 2 hours; 97% and 86% at 3 hours, respectively).

Conclusions:Patients with failed reperfusion have abnormal signal‐averaged ECGs more frequently than patients with successful reperfusion. Thus, signal‐averaged ECG may be helpful for identification of patients without reperfusion who may urgently need invasive treatment or rethrombolysis to restore blood flow in the infarct‐related artery. A.N.E. 1999;4(3):301–308
Effects of Left and Right Pneumonectomy on Time‐ and Frequency‐Domain Parameters of Heart Rate Variability
Authors: Amar David , Zhang Hao , Leung Denis H.Y. , Ginsburg Iliana
Published: October 2006

Background:Morbid cardiac events after pneumonectomy have been attributed to autonornic mechanisms. Analysis of heart rate variability (HRV) offers a noninvasive technique to assess modulation of sympathetic and parasympathetic activity. There is little data available on the systematic changes in time‐ and frequency‐domain parameters of HRV in response to pneumonectomy and cardiac plexus neural trauma.

Methods:We measured HRV parameters in 54 patients undergoing left (n = 28) and right (n = 26) pneumonectomy (age 55 ± 11 years) who were without congestive heart failure, active ischemic heart disease, or dysrhythmias, and were not taking β‐blocker or calcium channel blocker therapy. Time‐ and frequency‐domain indices of HRV were measured before surgery (1 hour) and continuously after surgery (Holter) for 3 days. HRV indices measured were: mean R‐R interval (ms), mean of all 5‐minute standard deviation of R‐Rs (SDSD; ms); root mean square of difference of successive R‐Rs (rMSSD; ms); proportion of adjacent R‐Rs > 50 ms different (pNN50;%); total (TF; 0.01–1.00 Hz), low (LF; 0.04 ‐ 0.15 Hz) and high frequency (HF; 0.15–0.40 Hz) power (ms2).

Results:Time (R‐R, SDSD, rMSSD, pNN50 and frequency (TF, LF, HF, LF/HF) indices of HRV decreased significantly in response to left or right pneumonectomy. The maximal decrease in HRV occurred during the first 24 to 48 hours. There were no differences between the groups in any measured HRV parameter. Mean heart rate ranged between 80 to 110 beats/min postoperatively for all patients.

Conclusions:Decrements in time‐ and frequency‐domain indices of HRV occurred after pneumonectomy independently of the operative side. Global reductions in HRV after surgery support the presence of parasympathetic withdrawal. Although global changes in HRV may reflect an individual's response to surgical stress, the usefulness of HRV to study fine changes in physiological control mechanisms in the postoperative state appears limited. A.N.E. 1999;4(3):325–332
Exercise Electrocardiography Testing in Patients with Aortic Stenosis
Authors: Gencbay Murat , Degertekin Muzaffer , Ermeydan Cern , Unalp Aynur , Turan Fikret
Published: October 2006

Background:Studies that have been conducted with exercise testing in patients with aortic stenosis (AS) have demonstrated that results of an exercise test can mimic coronary artery disease (CAD). The objective of our study was to investigate if there were any differential feature(s) of exercise testing in patients with AS compared to those with CAD.

Methods:We prospectively studied 42 patients with AS (age 37 ± 23, range 8–75) with an averaged maximal gradient of 42 ± 19 mmHg (range 26–95). All patients had undergone a coronary angiography within 1 week of exercise testing and none had CAD. Another 100 patients with CAD, diagnosis proven with coronary angiography, comprised our second group for the comparison (CAD group). Cornell protocol was used in all patients.

Results:ST segment depression was observed in all patients 160 ± 25 μV in AS group and 170 ± 20 μV in CAD group, P > 0.05). Thirty‐four (81%) patients in the AS group and 88 (88%) patients in the CAD group exceeded the classical threshold for the test positivity (P > 0.05), ST/HR slopes derived from heart rate adjustment to ST segment level did not differ between the study groups (3.2 ± 2.3 and 3.7 ± 2.2 μV/beat/min in AS and CAD groups, respectively, P > 0.05). Recovery phase patterns of ST segment in heart rate domain were different between AS and CAD (clockwise loop: 86% vs 0%; counterclockwise loop: 9% vs 88% in AS group and CAD group, respectively, both P < 0.001) Percentage of the intermediate loop was 5% in the AS group and 12% in the CAD group.

Conclusions:Our study demonstrated that patients with AS could be distinguished from those with CAD with the method of rate‐recovery loop analysis. A.N.E. 1999;4(3):333–339
Long‐Term (13‐Year) Follow‐up of Isolated Atrial Standstill
Authors: Kim Irine J. , Turitto Gioia , El‐Sherif Nabil
Published: October 2006

We describe a case of persistent atrial standstill (PAS) in the absence of other cardiac or extracardiac abnormalities. Long‐term (13‐year) follow‐up of this case suggests that the prognosis of isolated PAS, following institution of permanent pacing, may be benign. A.N.E. 1999;4(3):372–373
Nighttime Differential Autonomic Modulation of Sinus and Idioventricular Automaticity and of Atrioventricular Nodal Conduction
Authors: Mendoza Ivan J. , Castellanos Agustin , Lopera Gustavo , Moleiro Federico , Interian Alberto , Myerburg Robert J.
Published: October 2006

Background:Potential differential effects of the autonomous nervous system on sinus node and protected idioventricular automaticity and on atrioventricular nodal conduction have not been assessed in the same patients.

Methods:The sinus cycle lengths, parasystolic cycle lengths, uncorrected QT intervals, and PR intervals were measured in control epochs and epochs of transient spontaneous maximal nighttime heart rate accelerations occurring between 1 and 4 AM. Noncontiguous epochs were selected to avoid potential accommodation‐like, or memory effects that could occur at the moments of abrupt acceleration or decelerations of sinus rate.

Results: The longest sinus cycle lengths coincided with the longest parasystolic cycle lengths and uncorrected QT intervals, whereas the shortest sinus cycle lengths coexisted with the shortest parasystolic cycle lengths and the shortest QT intervals. In contrast, the PR intervals did not show a uniform behavior during the episodes of transient heart rate accelerations since they could increase, decrease, or remain the same.

Conclusion: The different behavior of cycle lengths and PR intervals during nighttime heart rate increases, suggests that the autonomic modulation of the sinus node, idioventricular focus, and the AV node can be independent from each other. A.N.E. 1999;4(4):385–390
Prognostic Significance and Long‐term Natural History of Heart Rate Variability in Survivors of First Myocardial Infarction
Authors: Johansen Allan , Mickley Hans , Junker Anders , Møller Mogens
Published: October 2006

Background:Reduced heart rate variability (HRV) is an established predictor of mortality after acute myocardial infarction (Ml). HRV is reduced early after Ml and begins to recover within a few weeks, reaching a plateau 3 to 6 months later and remains stable in the first year after Ml. How HRV develops during serial recordings beyond 1‐year follow‐up has not been studied.

Methods:Serial 24‐hour Holter monitoring (discharge, 6 months, 1, 2, and 3 years) was performed in 123 patients recovering from a first acute Ml. During 6 years of follow‐up, 73 patients were free from subsequent events (mortality, nonfatal reinfarction, or coronary revascularization). The prognostic importance of early HRV values for the total group was assessed, and potential long‐term changes in HRV measurements in the 73 event‐free patients were studied.

Results:HRV values at discharge (SDNN and HRV triangular index) were reduced compared with the findings in healthy controls, and the measurements predicted future mortality. In event‐free patients, SDNN and HRV triangular index improved over the following months, but the values did not reach the level of healthy controls, even at late follow‐up. No changes in HRV measurements were found between 1 and 3 years.

Conclusions: Measurement of HRV is a useful tool in the prediction of mortality after first acute Ml. During the first few months an improvement in HRV is observed. The results of late serial recordings, however, demonstrate no additional changes in HRV values. Even at 3 years, HRV measurements did not reach the qualitative level of healthy controls. A.N.E. 1999;4(4):391–396
Reevaluation of an Old Electrocardiographic Criterion for Coronary Disease: TV1 > TV6
Authors: Nalbantgil Sanem , Yilmaz Hasan , Gurgun Cemil , Gurcay Bulent , Zoghi Mehdi , Nalbantgil Istemi , Onder Remzi
Published: October 2006

Background:Two different studies were conducted to evaluate the value of T wave in V1 taller than T wave in V6 (TV1 > TV6) pattern as an indicator of coronary artery disease.

Method: In the first study 5,300 resting ECGs were examined and the criterion was found in 283 patients. All of these patients were examined with echocardiography. In the second study, ECG tracings and coronary angiograms of another 500 patients were evaluated.

Results:In the first study, in 59 of 283 patients left ventricular hypertrophy was detected and these patients were excluded from the study. There were ST segment‐T wave changes and/or Q wave on ECG suggesting coronary ischemia or myocardial infarction in 160 of the 224 patients. TV1, > TV6 criterion was the sole finding in 64 of the 224 patients. All of the 224 patients underwent coronary angiography and coronary artery disease was detected in 185 patients; 134 of the 160 patients (83.3%) and 51 of 64 patients (80%) had one‐vessel or multivessel disease. There was no significant difference among the groups regarding coronary artery disease. Left anterior descending artery was involved in all of the 185 patients. In the second study, 408 patients were found to have coronary disease involvement and 92 patients showed normal or insignificant coronary disease. Sixty‐six of the 408 patients with coronary disease and four of 92 patients were found to have the TV1 > TV6 pattern. Sensitivity of the criterion was 16.1%, specificity was 95.6%, and accuracy was 94.2%.

Conclusions: According to these results, it is concluded that TV1 > TV6 with or without other ECG findings is a good criterion suggesting coronary artery disease, especially left anterior descending artery involvement in patients without left ventricular hypertrophy. A.N.E. 1999;4(4):397–400
QT Dispersion as a Noninvasive Arrhythmiogenic Marker in Acute Myocardial Infarction
Authors: Papandonakis Emmanuel , Tsoukas Athanasios , Christakos Stamatios
Published: October 2006

Backround: Prolongation of QT dispersion (QTD), defined as the difference between maximum and minimum QT intervals on surface ECG, has been proposed as a noninvasive arrythmogenic marker. The aim of this study was to estimate the value of QTD in identifing patients susceptible to ventricular fibrillation or ventricular tachycardia (VF/VT) after an acute myocardial infarction (AMI) and to evaluate the behavior of QTD in relation to the thrombolytic therapy.

Methods: We studied 108 consecutive patients with AMI. All patients had a 12‐lead surface ECG recorded upon admission and a second ECG 24 hours later. QT interval was measured from the onset of Q to the end of T in each of 12 standard ECG leads. QTD was the difference between the longest and shortest values of QT. All QTD measurements were corrected for heart rate (QTcD) using QTc values according to Bazzet formula.

Results: Fifteen patients (13.8%) developed VF/VT in the first week after AMI (group 1A) and 93 patients (86.2%) did not have VF/NT (group 1B). QTD and QTcD values were significantly greater in group 1A in comparison to group 1B on admission and 24 hours later. Sixty‐five patients (60%) received intravenous thrombolysis in the acute phase of AMI (group 2A) and 43 patients (40%) did not (group 2B). No significant difference in QTD and QTcD was observed in the first ECG on admission between the two groups. Conversely, QTD and QTcD were lower in group 2A patients in the second ECG 24 hours after admission.

Conclusions: These results provide evidence that increased values of QTD are correlated well with occurrence of malignant ventricular arrhythmias after acute myocardial infarction while lower values associated with the thrombolytic therapy. A.N.E. 1999;4(1):35–38
Assessment of Multivessel Coronary Artery Disease by Means of Stress‐Recovery ST/HR Index in Postinfarction Patients on Beta‐Blocker Therapy
Authors: Bigi Riccardo , Curti Gianpiero , Sponzilli Carlo , Fuscaldo Giuseppe , Occhi Giuseppe , Fiorentini Cesare
Published: October 2006

Objective: The aim of this study was to evaluate the influence of pharmacological therapy on the assessment of coronary anatomy by means of, respectively, conventional ST depression and comparative heart‐rate adjusted ST segment (ST/HR) analysis during exercise and recovery following acute Ml.

Background: The withdrawal of therapy before stress testing is controversial. We previously demonstrated that a simple continuous variable (Stress‐Recovery Index [SRI] defined as the difference between the areas subtended to baseline and limited by ST trend against HR during exercise and recovery) can substantially improve the post‐MI identification of multivessel disease (MVD).

Methods: Seventy‐five patients underwent maximal exercise ECG test on and off beta‐blockers with or without additional therapy, in random sequence, within 2 weeks of infarction. Coronary angiography was done within 1 month. The test was considered positive for increased risk of MVD in case of ST depression < 2 mm and, respectively, SRI > 5 mm × beats × min−1, as previously suggested.

Results: Off therapy, ST depression was positive in 33 and negative in 42 patients, while SRI was positive in 35 and negative in 40; on therapy, ST depression was positive in 21 and negative in 54 patients, while SRI was positive in 44 and negative in 31. Forty‐four subjects had MVD. The sensitivity and specificity of SRI were, respectively, increased and reduced by therapy, while an opposite effect was found on ST depression. SRI on therapy was more sensitive (P > 0.001) and less specific (P > 0.05) than ST depression and was the most sensitive parameter in identifying only 3‐vessel. Positive ST depression and negative SRI on therapy were associated, respectively, with the highest and lowest Gensini's score.

Conclusions: The SRI is superior to ST depression in identifying complex coronary anatomy in post‐Ml patients, especially during beta‐blockade therapy. A.N.E. 1999;4(1):60–66
Comparison of Baroreflex Sensitivity with Age and Indices of Left Ventricular Function in Patients with Dilated Cardiomyopathy
Authors: Menz Volker , Hoffmann Jürgen , Grimm Wolfram , Born Stephan , Mey Nadja , Glaveris Christina , Maisch Bernhard
Published: October 2006

Background: BRS is an index of autonomic innervation of the heart. Depression of the BRS after Ml is correlated with an increased risk of cardiac mortality and sudden death. However, little is known about the BRS in patients with idiopathic dilated cardiomyopathy (IDC).

Methods: In a prospective study the BRS was measured in 89 patients with IDC by the noninvasive phenylephrine method. Mean age of the study population was 48 years, LVEF was 30.2 ± 9.5 %, and left ventricular enddiastolic diameter was 66.9 ± 7.6 mm.

Results: BRS did not significantly differ in patients with an LVEF > 30% compared to patients with an ejection fraction 30% (6.2 ± 4.1 vs. 7.3 ± 3.6 ms/mmHg, P > 0.05). There was no difference in the BRS slope between patients with a left ventricula‐ end‐diastolic diameter 65 mm compared to > 65 mm (6.4 ± 3.2 vs. 7.0 ± 4.4 ms/mmHg, P < 0.05) and in patients older than 50 years of age compared to younger patients (6.1 ± 3.7 vs. 7.3 ± 4.0 ms/mmHg, P < 0.05).

Conclusion: BRS may be an independent parameter useful for risk stratification in patients with dilated cardiomyopathy. A.N.E. 1999;4(1):67–71
Prognostic Significance of QTc Interval for Predicting Total, Cardiac, and Ischemic Heart Disease Mortality in Community‐Based Cohort from Warsaw Pol‐MONICA Population
Authors: Pytlak Aleksandra , Piotrowski Walerian
Published: October 2006

Background: QT interval in resting electrocardiogram (ECC) is a sum of ventricular depolarization and repolarization time. Its prolongation is associated with a worse prognosis for survival due to a high incidence of severe ventricular arrhythmias.

Methods: The random sample of the Warsaw Pol‐MONICA population consisting of 2646 men and women, aged 35–64, screened in 1984, was followed‐up until 1996. All deaths and their causes were registered based on death certificate diagnosis. QT interval was measured manually in three consecutive QRST complexes in each ECG and corrected using Bazett's formula (QT corrected: QTc). For statistical analyses the mean value of 3 QTc measurements were used. To assess the relationship between QTc and mortality, the Cox proportional hazards model with stepwise selection of variables was used.

Results: Out of the screened sample, 459 persons died (309 men, 150 women), 226 due to cardiovascular diseases (CVD) (162 men, 64 women), and 81 due to ischemic heart disease (IHD) (59 men, 22 women). Both men and women who died were significantly older at baseline and had significantly longer mean QTc as compared to survivors (men: 457 ms vs 446 ms, P = 0.0001; women: 469 ms vs 459 ms, P = 0.001). Among men, after adjustment for confounding variables, mean QTc was significantly associated with total and CVD mortality, and in women, with CVD and IHD mortality. The risk of death rose with an increase in QTc duration. In men, with every increase in QTc by 20 ms, the risk of all causes of death rose by 11% (95% CI: 1.04–1.18), CVD death by 9% (95% Cl: 1.01–1.19), and IHD death by 11 % (95%: 0.97–1.28). In women, the risk of all‐cause death increased by 9% (95% CI: 0.98–1.21), CVD death by 21% (95% Cl: 1.02–1.43), and IHD death by 41% (95% Cl: 1.08–1.85).

Conclusion: QTc interval was significantly related to all cause, cardiovascular and ischemic heart disease. The risk of death increased with longer QTc duration. A.N.E. 2000;5(4):322–329
Impedance Cardiographic Findings in Electrocardiographically Diagnosed Acute Right Ventricular Infarction
Authors: Tore Hasan Fehmi , Uzun Mehmet , Erinc Kursad , Kirilmaz Ata , Barcin Cem , Baysan Oben , Barindik Nadir , Demirtas Ertan
Published: October 2006

Background: Thorax impedance cardiography (TIC) can provide important information about the hemodynamic state of patients. In this study, we aimed at finding out if TIC can be used in the early follow‐up of acute right ventricular myocardial infarction (RVMI).

Methods: The study consisted of patients with RVMI who were admitted to our coronary care unit between March 1998 and October 1999. The patients were divided into two groups: group A: patients with hemodynamically significant RVMI, and group B: patients with hemodynamically insignificant RVMI. All impedance measurements were performed with the commercially available device BoMed NCCOM3. We measured stroke volume index, cardiac index and ejection fraction by TIC. The measurements were done on the day of admittance (day O), first day and second day continuously, and on the third to fifth day during bed rest. Comparisons of TIC measurements and vital signs were made by Friedman analysis. Group A and group B were compared by Mann Whitney U test and chi square. The level of statistical significance was set at P < 0.05.

Results: There were 26 patients in group A (mean age: 62 ± 10) and 14 patients in group B (mean age: 61 ± 12). There were no statistically significant differences between the groups in age and sex. There were statistically significant differences between group A and B with regard to stroke volume index (32 ± 5 vs 28 ± 5; P = 0.0147), total peripheral resistance (19 ± 5 vs 23 ± 5; P = 0.0084); ejection fraction (0.44 ± 0.16 vs 0.58 ± 0.08; P = 0.0131). The vital signs with statistically significant differences were systolic arterial blood pressure (110 ± 17 vs 88 ± 7, P < 0.0001); diastolic arterial blood pressure (72 ± 12 vs 55 ± 13; P = 0.0002) and heart rate (89 ± 12 vs 71 ± 11; P < 0.0001). The differences disappeared on the second day. The lack of significance continued on the fifth day. Friedman analysis revealed that all the TIC parameters except for left ventricular ejection fraction change towards the normal range. Ejection fraction did not change in group B but decreased in group A on the second day; however it was stable later.

Conclusion: TIC can provide easily obtained parameters which may have a role in the treatment of hemodynamically significant RVMI. This is particularly important in coronary care centers with limited invasive capabilities. A.N.E. 2000;5(4):330–335
Early Antiarrhythmic Therapy Is No Better than Rate Control Therapy Alone for Suppression of Atrial Fibrillation After Cardiac Surgery
Authors: Melecio Abordo M.D.  , Soucier Richard , Berns Ellison , Silverman David I.
Published: October 2006

Background: Despite recent advances in therapy for atrial fibrillation (AF) following cardiac surgery, the potential superiority of antiarrhythmics over rate control therapy for suppression of AF has not been convincingly demonstrated. We sought to determine whether early treatment of AF following cardiac surgery with antiarrhythmics improves clinical outcome, as measured by recurrence rate, length of stay, and adverse events.

Methods: Out of 1100 consecutive patients undergoing cardiovascular surgery from July 1997 to June 1998, AF was identified in 425 (38.6%) prior to discharge. Patients with a history of chronic AF prior to cardiovascular surgery and patients who died within 48 hours of cardiovascular surgery were excluded from the analysis; 365 patients were studied. Group I patients received rate control alone; Group II received antiarrhythmic drugs within 24 hours of the first onset of AF.

Results: With the exception of frequency of pulmonary disease (4 vs 17, P = 0.009), CABG rate (35 vs 45%, P = 0.045), and rate of valve surgery (24 vs 15%, P = 0.028), there were no significant differences in clinical characteristics between the two groups. The rate of return to sinus rhythm within 24 hours (80 vs 82%), and the percentage of patients leaving the hospital in sinus rhythm (90 vs 92%) were similar between the two groups, as were total length of stay (10.6 ± 6.0 vs. 11.4 ± 5.8, P = 0.159) and postoperative length of stay (8.4 ± 15.0 vs. 9.4 ± 5.3, P = 0.061). Embolic event rates were similar in both groups (eight in Group I and three in Group II). Proarrhythmia occurred in two patients receiving early antiarrhythmic therapy.

Conclusion: Traditional use of early antiarrhythmic therapy appears to provide no clear advantage to rate control after cardiovascular surgery in terms of length of stay, freedom from AF at discharge, and other common clinical outcomes. Routine use of antiarrhythmics for suppression of AF should be carefully reconsidered. A.N.E. 2000;5(4):365–372
Prevalence of Spectral Turbulence and Late Potentials in a Random Population Sample
Authors: Gottfridsson Christer , Beckman‐Suurküla Marie , Karlsson Thomas , Wilhelmsen Lars , Edvardsson Nils
Published: October 2006

Background:Late potentials (LP) and spectral turbulence (STU) in the signal‐averaged ECG (SAECG) in patients with heart disease mark a risk of malignant ventricular arrhythmias. The prevalence and cause of STU in otherwise healthy subjects have not been established.

Methods:The SAECGs of a randomly selected population sample without known heart disease, 55 men and 66 women aged 50 ± 10 years, were analyzed for LP and STU. An STU score > 1 qualified for an echocardiographic examination (echo) and a 24‐hour Holter ECG (Holter).

Results:The QRS duration in lead V2 in men was 99.5 ± 8.5 ms (mean ± SD) vs 94.2 ± 8.5 in women, P = 0.0008. The QT end was 406.7 ± 27.0 ms in women and 394 ± 24 in men, P = 0.01. The FQRSD (40 Hz) was 98.0 ± 8.6 ms in men vs 90.2 ± 9.0 in women, P = 0.0001. Subjects > 50 years of age had a lower RMS40 (33.0 ± 16.3 μV) than subjects < 50 years (40.2 ± 18.3 μV, P = 0.02). Nine (7%) subjects were LP‐positive. The STU score variables LSCR, ISCM, ISCSD and SE were positive in 12 (10%), 13 (11 %), 41 (34%) and 17 (14%) of the subjects, respectively. The mean spectral score was 0.69 ± 0.98. Eight (7%) subjects had a score of 3 or 4, considered STU‐positive. No correlation between score and gender, age or 12‐lead QRS duration was found. In score > 1, 27 (84%) had a completely normal ECHO and 31 (86%) a normal Holter. Cardiac dimensions measured by ECHO correlated with SAECG variables.

Conclusions: Men had a longer mean QRS duration than women. Women had longer mean QT and JT intervals than men, which might imply an increased risk during antiarrhythmic therapy. The STU variables were not gender‐ or age‐dependent. The variable ISCSD was positive in as many as 41 (34%) presumably healthy subjects and did not seem to be a useful variable. Seven percent of the subjects were spectral turbulence‐positive and 7% were LP‐positive. A.N.E. 2000;5(1):30–38
Clinical and Electrocardiographic Variables Can Predict Atrial Fibrillation in Patients with Atrioventricular Accessory Pathways
Authors: D'Avila André , Scanavacca Mauricio , Reolão Basileo , Darrieux Francisco , Savalli Carine , Sosa Eduardo
Published: October 2006

Background:Risk stratification of sudden death in patients with Wolff‐Parkinson‐White syndrome is based on the refractory period of the atrioventricular accessory pathway and the probability of spontaneous atrial fibrillation. Risk stratification based on invasive studies does not seem cost‐effective in the radiofrequency ablation era, and, although sensitive, noninvasive tests are not used because of their low specificity. We sought to determine whether clinical and electrocardiographic variables can predict spontaneous atrial fibrillation in patients with an accessory pathway.

Methods:We studied 420 consecutive patients treated by radiofrequency catheter ablation who had a single atrioventricular accessory pathway and the Influence of four variables: age, gender, location of the accessory pathway as determined by the site of successful radiofrequency ablation, and the presence of a manifest accessory pathway in the ECG was analyzed by multiple logistic regression analysis and a chi‐square test. The development model, comprised of data from the first 359 patients, included 58 patients with spontaneous atrial fibrillation and 301 patients without spontaneous atrial fibrillation during follow‐up. The likelihood ratio derived from the development model was validated in the last 61 patients.

Results:Patients with spontaneous atrial fibrillation occurring before accessory pathway ablation were more often male and were older than those without atrial fibrillation. Atrial fibrillation occurred more frequently in manifest than in concealed accessory pathways, and the presence of posteroseptal accessory pathway strongly correlated with spontaneous atrial fibrillation.

Conclusion:The probability of spontaneous atrial fibrillation was higher in men with a manifest posteroseptal accessory pathway and increased with age. A.N.E. 2000;5(1):45–52
Effects of Myocardial Perfusion on QT Dispersion in Patients with Hypertrophic Cardiomyopathy
Authors: Yamanari Hiroshi , Fukushima Kengo , Miyaji Katsusi , Yamamoto Mika , Nagase Satoshi , Otsuka Fuyou Misunaga , Nakayama Kazuaki , Matsubara Hiromi , Emori Tetsuro , Ohe Tohru
Published: October 2006

Background:In patients with hypertrophic cardiomyopathy (HCM), myocardial ischemia and myocardial fibrosis as well as ventricular tachyarrhythmia are frequently observed. An increase of heterogeneity of repolarization provided the development of ventricular tachyarrhythmia. The aims of the present study are to evaluate the influence of exercise‐induced myocardial perfusion abnormalities on QT dispersion and to assess whether QT dispersion was involved in ventricular tachycardia (VT) in patients with HCM.

Methods:Thirty‐eight patients with HCM and 20 control subjects underwent an exercise stress test, and QT intervals were measured pre‐exercise and at 3 minutes after peak exercise. All subjects underwent thallium (TI)‐201 stress myocardial imaging, and their TI‐201 defect score and exerciseinduced myocardial ischemia were evaluated.

Results:Twelve patients (31%) revealed sustained or nonsustained VT. The pre‐exercise QTc dispersion (QTcD) was significantly correlated with the Tl‐201 defect score (r = 0.61, P < 0.0001). The QTcD at 3 minutes after peak exercise was significantly greater in patients with exerciseinduced myocardial ischemia than without exercise‐induced myocardial ischemia (96 ± 36, 72 ± 24 ms1/2, P < 0.03). The QTcD at 3 minutes after peak exercise was significantly greater in patients with VT than without VT (111 ± 23, 64 ± 17 ms1/2, P < 0.0001).

Conclusion:It is suggested that the degree of myocardial fibrosis influences the pre‐exercise QTcD, and exercise‐induced myocardial ischemia precipitates the increase in the QTcD at 3 minutes after peak exercise in patients with HCM. The increased QTcD at 3 minutes after peak exercise may play a role in identifying patients at a potentially higher risk. A.N.E. 2000;5(1):60–67