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Identification of risk of ventricular tachycardia in patients with hypertrophic cardiomyopathy
Selected Abstracts From the Nineteenth International
169
Congress on Electrocardiology
Exercise Stress Test Versus Dobutamine Stress Echocardiography in the Detection of Myocardial lschemia
The regression line of the data shows that approximately 75% of the maximal ST body surface depression can be detected by the XECG on average. The loss in XECG ST depression amplitudes was due to the significant mean distance between the location of the maximal body surface ST depression area and the nearest exploring XECG electrodes (average, >5 cm; maximal distance set, >25 cm).
A. Pereirinha, M. Fiuza, P. Pedro, E. Dias, F. dePadua, M. G. Lopes, Med. IV-A (UCIM), Hospital de Santa Maria, and LA3-CCUL, F.M.L., Lisboa, Portugal In order to analyze the behavior of left ventricle wall motion (LVWM), 63 patients with known or suspected coronary artery disease (CAD) were studied with dobutamine stress echocardiography (DOBEchocg). In 35 patients (30 men, 5 women; mean age + SD, 55 + 11 years), a treadmill exercise test was also performed (Bruce or Naughton Protocol). DOB-Echocg protocol included a stepwise infusion of dobutamine to a maximal dose of 40 mg/kg/min or until a new LVWM abnormality, 85% of predicted maximal heart rate, or an indication for interruption occurred. In patients not achieving any of these endpoints atropine was administered intravenously, up to 1 mg. When we compared the results of both tests, the results were concordant in 19 patients (54%). In the other 16 patients, 9 had a positive treadmill exercise test and a negative DOB-Echocg (56%), the majority of whom had normal nonsignificant CAD. On the contrary, in the seven patients with a positive DOBEchocg and a negative treadmill exercise test, CAD was always present. In conclusion, there was good agreement between the results of the treadmill exercise test and DOBEchocg for detecting CAD. Nevertheless, DOBEchocg seems superior for the diagnosis of myocardial ischemia.
Identification of Risk of Ventricular Tachycardia in Patients With Hypertrophic Cardiomyopathy S. Trzos, W. J. Musial, W. Kozlowski, M. Kurpesa, Medical University, Lodz, Poland The aim of this study was to assess the main factors influencing the risk of malignant ventricular arrhythmia in patients with hypertrophic cardiomyopathy. In 5 5 patients, 48-hour electrocardiographic (ECG) monitoring was performed twice a year, and the presence of nonsustained ventricular tachycardia was classified as arrhythmic events. Patients were divided into two groups. Group 1 consisted of 30 patients with arrhythmic events and group 2 consisted of 25 patients without arrhythmic events. The type of left ventricular hypertrophy (LVH) and the presence of systolic anterior motion (SAM) were diagnosed by two-dimensional echocardiography. In all patients, signal-averaged ECG and assessment of autonomic regulation were carried out. Ventricular late potentials (VLP) were analyzed using 40 Hz filter frequencies and sympathovagal balance (SVB) was assessed by low (LF) and high (HF) frequency bands. Comparisons of the two groups were made and differences in clinical features (syncope) and other symptoms such as SAM, LVH, VLP, and SVB were analyzed, and the results are shown in the table. Occurrence of VLP was similar in both groups. There was a significant positive relationship (p < 0.02) between lower HF values and higher LF/HF ratio and the presence of malignant arrhythmia. In conclusion, the presence of severe arrhythmic events in patients with hypertrophic cardiomyopathy may be associated with impaired parasympathetic activity.
Analysis of Nonhomogeneous Intracardiac Propagation of Ventricular Fibrillation on a Three-dimensional Cardiac Computer Model 0. Okazaki, D. Wei,* K. Harumi, Division of Cardiology, Nakano National Chest Hospital, “Nihon Koden Corporation, Tokyo, Japan The excitation pattern of ventricular fibrillation (VF) induced by extra-stimuli was studied using a three-dimensional (3-D) computer cardiac model. SVB
Syncope Group Group
1 2
10 9
SAM 11 10
SAM = systolic anterior motion; LVH = left ventricular LF = low frequency; HF = high frequency.
Progression
of LVH
VLP
LF
HF
LFIHF
18 11
7.2 7.8
2.5 5.1
2.8 1.2
15 13 hypertrophy;
VLP = ventricular
late potentials;
SVB = sympathovagal
balance;
169
Congress on Electrocardiology
Exercise Stress Test Versus Dobutamine Stress Echocardiography in the Detection of Myocardial lschemia
The regression line of the data shows that approximately 75% of the maximal ST body surface depression can be detected by the XECG on average. The loss in XECG ST depression amplitudes was due to the significant mean distance between the location of the maximal body surface ST depression area and the nearest exploring XECG electrodes (average, >5 cm; maximal distance set, >25 cm).
A. Pereirinha, M. Fiuza, P. Pedro, E. Dias, F. dePadua, M. G. Lopes, Med. IV-A (UCIM), Hospital de Santa Maria, and LA3-CCUL, F.M.L., Lisboa, Portugal In order to analyze the behavior of left ventricle wall motion (LVWM), 63 patients with known or suspected coronary artery disease (CAD) were studied with dobutamine stress echocardiography (DOBEchocg). In 35 patients (30 men, 5 women; mean age + SD, 55 + 11 years), a treadmill exercise test was also performed (Bruce or Naughton Protocol). DOB-Echocg protocol included a stepwise infusion of dobutamine to a maximal dose of 40 mg/kg/min or until a new LVWM abnormality, 85% of predicted maximal heart rate, or an indication for interruption occurred. In patients not achieving any of these endpoints atropine was administered intravenously, up to 1 mg. When we compared the results of both tests, the results were concordant in 19 patients (54%). In the other 16 patients, 9 had a positive treadmill exercise test and a negative DOB-Echocg (56%), the majority of whom had normal nonsignificant CAD. On the contrary, in the seven patients with a positive DOBEchocg and a negative treadmill exercise test, CAD was always present. In conclusion, there was good agreement between the results of the treadmill exercise test and DOBEchocg for detecting CAD. Nevertheless, DOBEchocg seems superior for the diagnosis of myocardial ischemia.
Identification of Risk of Ventricular Tachycardia in Patients With Hypertrophic Cardiomyopathy S. Trzos, W. J. Musial, W. Kozlowski, M. Kurpesa, Medical University, Lodz, Poland The aim of this study was to assess the main factors influencing the risk of malignant ventricular arrhythmia in patients with hypertrophic cardiomyopathy. In 5 5 patients, 48-hour electrocardiographic (ECG) monitoring was performed twice a year, and the presence of nonsustained ventricular tachycardia was classified as arrhythmic events. Patients were divided into two groups. Group 1 consisted of 30 patients with arrhythmic events and group 2 consisted of 25 patients without arrhythmic events. The type of left ventricular hypertrophy (LVH) and the presence of systolic anterior motion (SAM) were diagnosed by two-dimensional echocardiography. In all patients, signal-averaged ECG and assessment of autonomic regulation were carried out. Ventricular late potentials (VLP) were analyzed using 40 Hz filter frequencies and sympathovagal balance (SVB) was assessed by low (LF) and high (HF) frequency bands. Comparisons of the two groups were made and differences in clinical features (syncope) and other symptoms such as SAM, LVH, VLP, and SVB were analyzed, and the results are shown in the table. Occurrence of VLP was similar in both groups. There was a significant positive relationship (p < 0.02) between lower HF values and higher LF/HF ratio and the presence of malignant arrhythmia. In conclusion, the presence of severe arrhythmic events in patients with hypertrophic cardiomyopathy may be associated with impaired parasympathetic activity.
Analysis of Nonhomogeneous Intracardiac Propagation of Ventricular Fibrillation on a Three-dimensional Cardiac Computer Model 0. Okazaki, D. Wei,* K. Harumi, Division of Cardiology, Nakano National Chest Hospital, “Nihon Koden Corporation, Tokyo, Japan The excitation pattern of ventricular fibrillation (VF) induced by extra-stimuli was studied using a three-dimensional (3-D) computer cardiac model. SVB
Syncope Group Group
1 2
10 9
SAM 11 10
SAM = systolic anterior motion; LVH = left ventricular LF = low frequency; HF = high frequency.
Progression
of LVH
VLP
LF
HF
LFIHF
18 11
7.2 7.8
2.5 5.1
2.8 1.2
15 13 hypertrophy;
VLP = ventricular
late potentials;
SVB = sympathovagal
balance;