24-hour Holter ECG Research Articles

Abstract 2147: Utility of Multichannel Holter ECG Recording at the Third Intercostal Space to Diagnose A Type 1 Brugada ECG; Comparison with Repeated 12-Lead ECGs

The detection of a type 1 Brugada ECG is essential for diagnosis and risk stratification in Brugada syndrome. In this study, we evaluated the detection rate of a type 1 ECG on the multichannel Holter ECG, compared with the 12-lead ECGs recorded repeatedly. We enrolled consecutive 60 patients who had eventually exhibited a diagnostic type 1 ECG in the presence or absence of Na+ channel blockers at either standard or the third intercostal position. All patients underwent 12-lead ECGs recorded at both standard and the third intercostal position at least 5 times between 0 p.m and 2 p.m (4L-ECGs, 3L-ECGs, respectively). The 24-hour Holter ECG was performed in all patients, using a 12-lead Holter recording system. The precordial electrodes were attached at the standard position of V1, V2, V5, V6 and the third intercostal space of V1 and V2 (V1 IC3 , V2 IC3 , respectively). The leads V1 and V2, and V1 IC3 and V2 IC3 on the Holter ECG were expressed as 4L-Holter and 3L-Holter, respectively. The diagnostic type 1 ECG on the Holter ECG was defined as a presence of a coved-type ST-segment elevation >0.2mV over continuous 60 seconds at least one lead. We evaluated the detection rate of the type 1 ECG in 4L-ECGs, 3L-ECGs, 4L-Holter and 3L-Holter, and compared them among the 4 different recording methods. Among 60 patients, the patients showing the type 1 ECG on 4L-ECGs, 3L-ECGs, 4L-Holter and 3L-Holter were 15 (25%), 26 (43.3%), 23 (38.3%) and 33 patients (55%), respectively. The detection rate in 3L-ECGs and 3L-Holter was significantly larger than that in 4L-ECGs (p=0.03, p<0.001, respectively). Additionally, in 8 (23.5%) out of 34 patients with drug-induced type 1 ECG at standard and/or the third intercostal position, a spontaneous type 1 ECG was detected in 3L-Holter. Although the detection rate of a type 1 ECG in 3L-Holter was not significantly different with that in 3L-ECGs, the 3L-Holter was the most sensitive to detect a type 1 ECG among the 4 recording methods. In patients with Brugada type ECG, the Holter ECG recorded in the right precordial leads at the third intercostal space is more sensitive method to detect a diagnostic type 1 ECG than repeated 12-lead ECGs or the Holter ECG at standard position.

Particulate air pollution as a risk factor for ST-segment depression in patients with coronary artery disease.

The association of particulate matter (PM) with cardiovascular morbidity and mortality is well documented. PM-induced ischemia is considered a potential mechanism linking PM to adverse cardiovascular outcomes. In a repeated-measures study including 5979 observations on 48 patients 43 to 75 years of age, we investigated associations of ambient pollution with ST-segment level changes averaged over half-hour periods measured in the modified V(5) position by 24-hour Holter ECG monitoring. Each patient was observed up to 4 times within 1 year after a percutaneous intervention for myocardial infarction, acute coronary syndrome without infarction, or stable coronary artery disease without acute coronary syndrome. Elevation in fine particles (PM(2.5)) and black carbon levels predicted depression of half-hour-averaged ST-segment levels. An interquartile increase in the previous 24-hour mean black carbon level was associated with a 1.50-fold increased risk of ST-segment depression > or =0.1 mm (95% CI, 1.19 to 1.89) and a -0.031-mm (95% CI, -0.042 to -0.019) decrease in half-hour-averaged ST-segment level (continuous outcome). Effects were greatest within the first month after hospitalization and for patients with myocardial infarction during hospitalization or with diabetes. ST-segment depression is associated with increased exposure to PM(2.5) and black carbon in cardiac patients. The risk of pollution-associated ST-segment depression may be greatest in those with myocardial injury in the first month after the cardiac event.

Circa-and ultradians in the occurrence of simple extrasystoles in healthy men at lowland in the light of inferential statistics

An exact description of circadian and ultradian rhythms of simple extrasystoles in healthy subjects is lacking. Thirty-seven healthy male subjects, aged 50-76, were randomly taken. Simple extrasystoles from 24-hour Holter ECG were registered and calculated per each hour and processed by cosinor regression. Their occurrence is formulated by 95% confidence and tolerance corridors for supraventricular and ventricular extrasystoles. The number of extrasystoles is relatively low, dispersion of ventricular extrasystoles is significantly higher than supraventricular ones. A significant increase of their frequency versus the general zero trend straight line was found only around 9 a.m. In supraventricular ones a significant increase around 6-7 a.m., 9 a.m., noon, and 4-5 p.m. and a significant depression around 1-2 a.m. and 10 p.m. was present. Only the 24-hour rhythm is significantly present (alpha=0.05) in ventricular beats while in supraventricular ones also the period lengths of 12, 6, 4, 3.4 and 2.4 hours are significant. The significant difference between supraventricular and ventricular extrasystoles exists in the 24-hour amplitudes and 6-hour acrophases. One circadian and several ultradian rhythms of simple extrasystoles are present in healthy male subjects over 50 years of age. The 95% tolerance chronograms can be exploited in clinical practice.

Evaluation of autonomic malfunction in idiopathic normal pressure hydrocephalus

The autonomic nervous system plays an important role in urinary disturbance which is one of the main symptoms of idiopathic normal pressure hydrocephalus (iNPH); thus, the focus of the present study was to identify the autonomic function parameters that would be useful as clinical indicators of iNPH. The subjects consisted of 18 iNPH patients (group N) and 31 normal controls (group C). Before and after a lumbar puncture test, they were examined for CVR-R and total heart rate. A power spectral analysis of R-R interval variability of their 24-hour Holter ECGs was also done. High frequency (HF) was an indicator of parasympathetic activity, while the low to high frequency ratio (L/H) was used as an indicator of sympathetic activity. Urinary incontinence was evaluated using the overactive bladder symptom score (OABSS) questionnaire and bladder capacity. Correlations between the above indicators and clinical indicators of iNPH, such as the mini-mental state examination and the Evans index, were examined. The HF values (ms(2)) were 190.3 in group C and 237.2 in group N; the difference was statistically significant. In group N, the HF value after the lumbar puncture test was lower (160.3) than the value before the lumbar puncture test, confirming that the increased parasympathetic state returned to a near normal level after CSF drainage. A significant positive correlation was noted only between the pre-lumbar puncture HF value and the OABSS. iNPH is associated with increased parasympathetic activity, and the lumbar puncture test and shunt surgery may correct this autonomic imbalance to near normal levels.

Long-term Prognosis for Non-ischemic Heart Disease Patients with Premature Ventricular Contraction and Non-sustained Ventricular Tachycardia

There are few long-term reports of patients with frequent PVCs in the absence of ischemic heart disease. In 86 patients without ischemic heart disease, who had 1000 or more PVCs in 24-hour Holter ECG, the number of PVCs during 24-hours Holter ECG and echocardiographic parameters were followed at least 1 year (66.5 ± 39.7 months). PVC was significantly reduced in the patients with or without underlying diseases (UD). The reduction rate in the number of PVCs was prominent in patients with UD. PVC was significantly reduced in patients under medication, but not in patients without medication. In the comparison between the initial and follow up observation using Wilcoxon's rank test, the number of PVC was significantly reduced (P < 0.05), and EF was also improved (P < 0.05) in angiotensin converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) group, and in β-blocker group. In Ca-antagonist group and antiarrhythmic drug group, the number of PVCs was also significantly reduced (P < 0.05). Multivariate analysis revealed significantly higher incidence (60% or more with PVC reduction) in ACEI/ARB group. These results suggest that the administration of ACEI/ARB may contribute to the reduction of PVC in non-ischemic heart disease cases with multiple PVC.

QT/RR Relationship in Patients after Remote Anterior Myocardial Infarction with Left Ventricular Dysfunction and Different Types of Ventricular Arrhythmias

QT/RR relationship was found to be both rate-dependent and rate-independent, what suggests the influence of autonomic drive and other not-autonomic related factors on it. The steeper QT/RR slope in patients after acute myocardial infarction (MI) was described, but the relationship to ventricular arrhythmias is unknown. The purpose of this study was to calculate differences in QT/RR relationship in patients after remote anterior MI with left ventricular dysfunction and different types of ventricular arrhythmias. The cohort of 95 patients (age: 63 +/- 11 years, LVEF: 35 +/- 9%) with previous anterior MI (mean 1.1 years) was divided into two well-matched groups-50 patients without episodes of ventricular tachycardia (VT) or ventricular fibrillation (VF) (NoVT/VF: 39 males, 64 +/- 12 years, LVEF 37 +/- 8%) and 45 patients with VT and/or VF (all with ICD implanted) (VT/VF: 35 males, 62 +/- 10 years, LVEF 34 +/- 10%). No true antiarrhythmics were used. QT/RR slope was calculated from 24-hour Holter ECG for the entire recording (E), daytime (D) and nighttime (N) periods. Groups did not differ in basic clinical data (age, LVEF, treatment). QT/RR slopes were steeper in VT/VF than in NoVT/VF group in all analyzed periods: E - 0.195 +/- 0.03 versus 0.15 +/- 0.03 (P < 0.001), N - 0.190 +/- 0.03 versus 0.138 +/- 0.03 (P < 0.001) and D - 0.200 +/- 0.04 versus 0.152 +/- 0.03 (P < 0.001). No significant day-to-night differences were found in both groups. Steeper QT/RR slope and complete lack of day-to-night differences in VT/VF patients show inappropriate QT adaptation to the heart rate changes. The prognostic significance of this parameter needs prospective studies.

Involvement of Carotid Baroreceptor Function in Blood Pressure Control in the Chronic Phase: Effect on 24-Hour Ambulatory Blood Pressure

Background. It is generally thought that the sole function of baroreceptors is for the regulation of rapid blood pressure fluctuations caused by postural changes and other motion. However, recent studies have suggested that baroreceptors may also be involved in blood pressure control in the chronic phase. Purpose.The study was performed to examine the involvement of carotid baroreceptors in blood pressure control in the chronic phase, through determination of the relationship between 24-hour blood pressure data and carotid baroreceptor function. Methods.Ambulatory blood pressure, ECG, and the number of steps during exercise were measured every 15 minutes with an ambulatory blood pressure monitor and a 24-hour Holter ECG fitted with an accelerometer (Cardy-II-p, Suzuken KK, Japan). In addition, the dependence of blood pressure on autonomic nerve activity and exercise was analyzed based on the frequency of the RR interval. Patients were divided into three groups based on different blood-pressure types: autonomic nerve-dependent, exercise-dependent, and independent types. Carotid baroreceptor function was evaluated using the sequence method; subjects adopted a supine position on a tilt table and their arterial pressure was monitored continuously using a Finapress finger cuff (Finapress, Ohmeda, Louisville, Colorado, USA). The study was performed in 90 patients, including 42 with essential hypertension whose blood pressure was well controlled. Results and Conclusions.A significant negative correlation was found between the mean 24-hour blood pressure and baroreceptor function for both systolic and diastolic pressure. Systolic pressure in patients of the independent type was significantly higher than that in patients of the exercise-dependent type. Furthermore, non-dipper hypertension was noted more frequently and baroreceptor function was significantly lower in independent-type patients, compared with autonomic nerve-dependent and exercise-dependent types, suggesting that independent-type blood pressure may be due to baroreceptor dysfunction. In conclusion, our results suggest that baroreceptor function might be involved in blood pressure control in the chronic phase, and baroreceptor dysfunction may contribute to the development of essential hypertension.

Sudden cardiac death during Holter recording in a patient with vasospastic angina

Rest angina with transient ST segment elevation is the more frequent clinical presentation of coronary vasospasm. However, ventricular arrhythmias may be triggered by vasospasm episodes or reperfusion phenomenon, being vasospastic angina a rare but possible cause of sudden cardiac death in patients with structurally normal heart. We report of a patient admitted to the hospital presenting with recurrent nonexertional substernal chest pain who experienced an episode of sudden cardiac death due to malignant ventricular arrhythmias during a 24-hour Holter ECG.

Predictive Value of Differential Pulse Pressure in the Diagnosis of Silent Myocardial Ischemia in Patients With Type-2 Diabetes

Silent myocardial ischemia occurs more frequently in diabetics. Differential arterial pulse pressure is a valuable predictor of cardiovascular disease. We studied 48 consecutive male patients with type-2 diabetes and no known history of ischemic heart disease. Ambulatory monitoring of arterial pressure was carried out and the presence of silent myocardial ischemia was studied using a protocol that involved: resting ECG, echocardiography, 24-hour Holter ECG, conventional exercise stress testing, and exercise testing with nuclear scanning. Nine patients (19%) had silent myocardial ischemia. Differential pulse pressure had good discriminative ability in identifying the presence of silent ischemia: the area under the receiver operating characteristic (ROC) curve was 0.83 (95% confidence interval [CI], 0.71-0.96; P=.002). This predictive ability was also observed on adjusted logistic regression modeling (odds ratio [OR], 1.24, 95% CI = 1.02-1.49). We found that the OR for the risk of silent ischemia for every 10-mmHg increase in differential pulse pressure was 8.5 (95% CI 1.7-31.2). Age and differential pulse pressure were the only independent predictors of silent myocardial ischemia found in this study.

Circadian Variation of the Myocardial Ischemic Threshold in Patients with Ischemic Heart Disease

Purpose. Circadian variation of the heart rate (HR) at the myocardial ischemic threshold was compared with that of the HR at the sympathetic tone threshold in 16 cases of effort angina pectoris. Methods. The high (0.15–0.40 Hz, Hf) and low (0.03–0.15 Hz, Lf) frequency spectral components were extracted every twenty seconds, using frequency domain analysis of the RR interval recorded by a 24-hour Holter ECG with an accelerometer. HR-Hf data collected every five minutes were plotted as the X-Y coordinates, and a two-compartment analysis was performed. The HR at the autonomic tone threshold was then determined at the intersection point of the lines. A loop of the HR-ST segment was drawn during walking to determine the ischemic threshold at which heart rate ischemic ST segment depression began and circadian variation was observed. Results. The circadian rhythm at the sympathetic tone threshold and the HR at the ischemic threshold were high during the day and low at night. The HR at the ischemic threshold was 15–20% higher than that at the sympathetic tone threshold at night but only 9–13% higher during the day. Also, there was a period during which there was no significant difference between the HR at the two thresholds. Conclusion. In comparing circadian variation between HR at the sympathetic tone threshold and HR at the ischemic threshold, there was a period during which there was no significant difference between the HRs. This might suggest a period in which a high incidence of cardiac ischemic attack is likely. This information could provide a feasible indicator for appropriate exercise training for patients with ischemic heart disease.

Relationship Between the Mismatch of 123I-BMIPP and 201Tl Myocardial Single-Photon Emission Computed Tomography and Autonomic Nervous System Activity in Patients With Acute Myocardial Infarction

The purpose of this study was to elucidate the relationship between the mismatch of thallium-201(Tl) and iodine-123-beta-methyl-iodophenyl-pentadecanoic acid (BMIPP) myocardial single-photon emission computed tomography (SPECT) and autonomic nervous system activity in myocardial infarction (MI) patients. The subjects were 40 patients (34 males, 6 females) who underwent examinations by 123I-BMIPP and 201Tl myocardial SPECT imaging and 24-hour Holter monitoring within a 3-day period 3 weeks after the onset of their first MI. R-R intervals were analyzed every hour over a period of 24 hours by fast Fourier transformation (FFT). High frequency (HF) and low frequency (LF) were defined as markers of cardiac vagal activity in the former and the LF/HF ratio as sympathetic activity. Greater or more extensive decreases in the BMIPP image than that in the Tl image were defined as a positive mismatch. Patients were divided into positive and negative mismatch groups of 20 patients each. There were no significant differences between the 2 groups in age, sex, site of infarction, max CK (creatine kinase), max CK-MB, or left ventricular ejection fraction. The incidences of clinical signs suggesting residual myocardial ischemia were significantly greater in the positive than in the negative mismatch group (P < 0.05). The mean values for HF over the entire 24-hour period and over the 5-hour nocturnal period (0-5 AM) in the positive mismatch group were both significantly lower than those in the negative mismatch group (P < 0.001 in both groups). The 24-hour mean HF and mean nighttime HF in patients with signs of residual ischemia were both significantly lower than in those without signs of residual ischemia in the positive mismatch group (P < 0.05 in both groups). The mean LF/HF ratio for both the entire 24-hour and the nocturnal period in the positive mismatch group were significantly higher than those in the negative mismatch group (P < 0.001, P < 0.05, respectively). The daily profile of hourly HF measurements was significantly lower in the positive mismatch group than in the negative mismatch group (P < 0.02). The mean values of HF for 24-hour and 5-hour periods were significantly lower in patients with signs of residual ischemia in the positive mismatch group than in those with signs of residual ischemia in the negative mismatch group (P < 0.01, P < 0.02, respectively). There were no significant differences between the patients with signs of residual ischemia in the negative mismatch group and those without signs of residual ischemia in the positive and negative mismatch group with regard to the mean values of HF and the LF/HF ratio measured every hour for 24 hours and 5 hours. It is concluded from the present study that the findings of a mismatch on 123I-BMIPP and 201Tl myocardial SPECT 3 weeks after a first acute myocardial infarction with uncomplicated moderate or severe heart failure and decreased heart rate variability are related to residual myocardial ischemia. A combined assessment of heart rate variability in 24-hour Holter ECG monitoring and perfusion-metabolism mismatch in 123I-BMIPP and 201Tl myocardial SPECT is useful for determining residual myocardial ischemia in the follow-up of those with acute myocardial infarction.

Repolarization Dynamics in Patients with Idiopathic Ventricular Fibrillation

The electrocardiographic parameters relating occurrence of ventricular fibrillation (VF) episodes in patients with idiopathic VF (IVF) are still unknown. The aim of this study was to clarify efficacy of pharmacological therapy in patients with IVF with respect to repolarization dynamics. The study group consisted of 8 men (age 43.6 +/- 9.1 years) with IVF (Brugada type 5 patients, prominent J wave in the inferior leads 3 patients) who had documented spontaneous episodes of VF, 7 of whom had implantable cardioverter defibrillators. The relation between QT and RR interval was analyzed from 24-hour Holter ECG using an automatic analyzing system before and after pharmacological therapy (bepridil 5 and disopyramide 3). From QT-RR linear regression lines, QT intervals were determined at RR intervals of 0.6 second [QT(0.6)], 1.0 second [QT(1.0)], and 1.2 seconds [QT(1.2)]. Pharmacological therapy increased the slope of QT-RR regression line from 0.105 +/- 0.020 to 0.144 +/- 0.037 (P < 0.05). Accordingly, QT(1.0) and QT(1.2) became longer after drug therapy [QT(1.0), 0.382 +/- 0.016 seconds vs 0.414 +/- 0.016 seconds (P < 0.01); QT(1.2), 0.403 +/- 0.017 seconds vs 0.442 +/- 0.021 seconds (P < 0.01)]. However, QT(0.6) did not change after drug administration. Before drug therapy the average episodes of VF were 5.5 +/- 5.8 (range 1 to 17) during the observation period of 19.3 +/- 17.6 months (range 6 to 60 months). After drug therapy, 6 patients had no episode of VF for 24 to 120 months (66.0 +/- 38.5 months). Two patients had a single episode of VF for 12- and 96-month follow-ups. Pharmacological therapy decreased the frequency of VF episodes in association with prolongation of QT intervals at slower heart rates. Not only J wave and ST elevation but also shorter QT intervals at slower heart rates may represent an electrophysiological substrate for development of VF episodes in these specific IVF patients.

Dynamics of Ventricular Repolarization in Patients with Dilated Cardiomyopathy Versus Healthy Subjects

Patients with impaired left ventricular function have a high risk of developing ventricular arrhythmias and sudden death. Among different markers of risk, the prolongation and regional heterogeneity of repolarization are of increasing interest. However, there are limited data regarding feasibility of analyzing repolarization parameters and their dynamics in 24-hour Holter ECG recordings. Dynamic behavior of repolarization parameters was studied with a new automatic algorithm in digital 24-hour Holter recordings of 60 healthy subjects and 55 patients with idiopathic dilated cardiomyopathy (IDC). Repolarization parameters included the mean value of QT and QTc durations, QT dispersion, and peaks of QT duration and QT dispersion above prespecified thresholds. In comparison to healthy subjects, patients with IDC had lower heart rate variability, longer mean QT and QTc durations, higher content of QTc peaks >500 ms, longer QT dispersion and its standard deviation, and a higher content of peaks >100 ms of QT dispersion (P < 0.01 for all comparisons). These repolarization parameters were significantly higher in IDC patients after adjustment for age, sex, and heart rate variability. The parameters of repolarization dynamics correlated with SDNN in healthy subjects but not in dilated cardiomyopathy patients. The automatic assessment of repolarization parameters in 24-hour digital ECG recordings is feasible and differentiates dilated cardiomyopathy patients from healthy subjects. Patients with dilated cardiomyopathy have increased QT duration, QT dispersion, and increased variability of QT dispersion reflecting variations in T-wave morphology, the factors which might predispose them to the development of arrhythmic events.

QT dynamicity in patients with worsening heart failure

Alteration of ventricular repolarization is associated with the increased risk of sudden cardiac death in various cardiac diseases. Little information is available as to the dynamic QT interval changes in patients with worsening heart failure (HF). In 109 patients with CHF (age 65 ± 8 years; 90 men), we recorded 24-hour Holter ECG recorded at hospital admission and discharge and compared with age- and sex-matched controls (n = 55). RR, QT and rate-corrected QT intervals were automatically calculated by the analyzer, and hourly and 24-hour mean values were derived. At hospital admission, RR (722 ± 19 ms) and QT intervals (390 ± 3 ms) were decreased significantly compared with those in controls (RR 890 ± 75 ms, QT 409 ± 16 ms) and exhibited blunted circadian variation. At discharge from hospital, RR interval increased to similar value in controls (919 ± 50 ms) but QT interval significantly prolonged than controls (430 ± 10 ms). There was a pronounced circadian variation in the QT interval in parallel with the trend in the RR interval in controls and HF patients before discharge. Improvement of heart failure associated with the normalization of RR and QT intervals obtained from 24-hour Holter ECG. Such phase-dependent alterations in the QT interval dynamicity may help to understand complex arrhythmogenic substrates in HF.

Analysis of heart rate variability in hypertensive patients before and after treatment with angiotensin II-converting enzyme inhibitors.

To compare heart rate variability in normotensive and hypertensive individuals and to observe the behavior of the autonomic nervous system after treatment with angiotensin II-converting enzyme inhibitors. The study comprised 286 patients diagnosed with arterial hypertension (AH) for the first time and divided into 4 groups according to diastolic blood pressure (DBP) levels: group A -- DBP<90 mmHg; group B -- DBP 90-99 mmHg; group C -- DBP 100-109 mmHg; group D -- DBP>110 mmHg. Group A (110 healthy individuals) and group C (79 patients with moderate AH) underwent 24-hour Holter-ECG with analysis of heart rate variability in time domain (TD) and frequency domain (FD). The group C patients were treated with ACE inhibitors for 3 months, and, after this period, they underwent a new 24-hour Holter-ECG study for assessing heart rate variability, the values being compared with those of normotensive individuals. The SDNN and PNN50 parameters (TD), and the LF spectrum (FD) were significantly different in the 2 groups, with clearly reduced values in hypertensive individuals (P<0.05). Group C patients, after treatment with ACE inhibitors, showed a recovery in all variables of heart rate variability, achieving values close to those of normotensive individuals. Heart rate variability was reduced in hypertensive patients when compared with that in normotensive individuals, indicating a decrease in the baroreceptor reflex. A functional autonomic adjustment after the antihypertensive treatment with ACEI was observed, indicating recovery of parasympathetic tonus.

Restoration of heart rate turbulence by titrated beta-blocker therapy in patients with advanced congestive heart failure: positive correlation with enhanced vagal modulation of heart rate.

Heart rate turbulence (HRT) is a powerful novel predictor for cardiovascular mortality. Chronic congestive heart failure is associated with abnormal HRT. Whether antiadrenergic beta-blocker therapy can restore control of HRT in patients with chronic congestive heart failure is unknown. A 24-hour Holter ECG recording was obtained before and 1 and 3 months after titrated addition of atenolol therapy in 10 consecutive patients with advanced congestive heart failure. Two parameters derived from HRT, turbulence slope (TS) and turbulence onset (TO), and time- and frequency-domain heart rate variability (HRV) parameters (SDNN, RMSSD, VLF, LF, HF) from 24-hour ECG were compared before and after beta-blocker therapy, together with the same parameters in age-matched normal control. Results showed that TS (3.1 +/- 2.2 vs 6.2 +/- 3.0; P = 0.001) and all HRV parameters were increased after 3 months of atenolol treatment. No changes in TO were evident (0.6 +/- 0.5 vs -0.2 +/- 1.3; P = 0.13). The improvement of TS and the vagally mediated parameters of mean R-R interval, RMSSD, and the HF component of HRV were positively correlated. Abnormal HRT caused by chronic congestive heart failure can be restored by beta-blocker therapy. The evolution of TS was positively correlated with measures of vagal modulation of heart rate.

P0962 GASTROESOPHAGEAL REFLUX AS THE REASON OF CHEST PAIN IN CHILDREN

Introduction: Chest pain is a worrying symptom in adults usually associated with coronary heart disease and with gastro-esophageal reflux disease (GERD). Both of these pathological states occur in children. Recently the role of GERD has been emphasized in many pediatric diseases. Similarly as with adults the pain in tha chest in a child may be associated with heart disease. Thus a majority of patients aged 6–16 are admitted to the cardiology departments. The purpose of our study was the assessment of frequency of GERD cases in children with chest pains who were hospitalized in the department of cardiology of Children University Hospital Methods: Patients: the prospective study included 154 patients aged 6–16 admitted to the cardiology department due to chest pain. A detailed family history was obtained from all of the patients according to the prepared questionnaire and a medical examination was made. Also the following tests were performed: chest x-ray, ECG and in some cases ECHO-cardiographic examination, 24-hour Holter ECG monitoring, ECG exercise testing, psychological test, end 24-hour esophageal ph monitoring and in some cases gastroscopy. Results: The esophageal ph-monitoring was performed in 35 children with no other cause of pain detected or the family history suggested a possibility of GERD. In 3 cases due to technical reasons the result was not valid. From among the remaining 32 children in 17 cases (53%) the result was correct. Acid gastro-esophageal reflux was noticed in 14 children, in one case alkaline shift was confirmed.Seven patients complained of gastritis. So in the studied group GERD was diagnosed in approximately 10% of the patients. In the whole group of 154 patients, chest pain was connected with the cardiovascular system in 29% of cases, with alimentary tract disease in 14% of cases and with respiratory system disease in 6% of cases. In the remaining group of children there were diagnosed pathological states which are not unambiguously related with chest pains or which are not related with chest pains or with psychogenous base of the symptoms Conclusion: 1. GERD was diagnosed in 10% of children hospitalized in the department of pediatric cardiology due to chest pain 2.In the studied group of children chest pain was caused by gastrological diseases in 14%.

Cardiac abnormalities 15 years and more after adriamycin therapy in 229 childhood survivors of a solid tumour at the Institut Gustave Roussy.

The purpose of this paper was to determine the cardiac status in children 15 years or more after adriamycin therapy for a solid tumour. Of the 447 pts, 229 pts were fully studied and 218 were not. The following cardiac evaluations were proposed to all the 447 consecutive patients (pts): (1) cardiac Doppler US by one of two expert cardiologists; (2) cardiac rhythm and conduction abnormalities including 24-hour holter ECG; (3) 131l-mlBG myocardial scintigraphy; (4) serum brain natriuretic peptide levels at rest; (5) an exercise test with VO2 max measurement. The radiation doses delivered to 6 points in the heart were estimated for all patients who had received radiotherapy. Congestive heart failure was diagnosed in 24 of 229 (10%) evaluated pts, with a median interval of 15 years (0.3–24 years) from the first symptom after adriamycin treatment. Among the 205 remaining pts, 13 asymptomatic pts (6%) had severe (n=4) (FS<20%) or marked (n=9) (20⩽FS<25%) systolic dysfunction. In the 192 others, the median meridional end-systolic wall stress was 91 (53–135) and it exceeded 100 g cm−2 in 52 pts. Using a Cox model, only the cumulative dose of adriamycin and the average radiation dose to the heart, were identified as risk factors for a pathological cardiac status. In conclusion, the risk of cardiac failure or severe abnormalities increases with adriamycin treatment, radiotherapy and time since treatment, even after a follow-up of 15 years or more. In our series, after an average follow-up of 18 years, 39% of the children had a severe cardiac dysfunction or major ventricular overload conditions. The risk increases with the dose of adriamycin and radiation received to the heart, without evidence for threshold.

Acute Antiarrhythmic Effects of Bi-Level Positive Airway Pressure Ventilation in Patients with Acute Respiratory Failure Caused by Chronic Obstructive Pulmonary Disease: A Randomized Clinical Trial

Background: Cardiac arrhythmias are common in patients with chronic obstructive pulmonary disease (COPD) and acute respiratory failure (ARF) and may be life threatening. Recently, non-invasive positive pressure ventilation has been advanced as a useful tool in COPD patients with ARF. This method can affect global cardiac performance through its effects on many determinants of cardiac function and may be helpful in reducing arrhythmias. Objective: To assess the role of bi-level positive pressure ventilation (BiPAP) in the management of cardiac arrhythmias in patients with ARF caused by COPD. Methods: We studied 30 consecutive patients with ARF related to COPD diagnosed according to American Thoracic Society criteria. All subjects were smokers; the mean age was 68 ± 7 years. They were randomly assigned to receive BiPAP plus standard therapy (group 1) or standard therapy alone (group 2). Patients randomized to receive BiPAP were first fitted with a nasal mask, and BiPAP was administered after 12 h of standard therapy. All subjects were studied using a computerized 24-hour Holter ECG. Blood gases, plasma electrolytes, respiratory rate and blood pressure were measured at study entry, at 30, 60 and 120 min and then every 3 h. Results: Heart rate decreased from 86.08 ± 7.86 to 74.92 ± 5.39 in group 1 (p < 0.001) versus 82.77 ± 8.78 to 75.82 ± 6.76 in group 2 (p = 0.033). Ventricular premature complexes decreased from 564.38 ± 737.36 to 166.15 ± 266.26 in group 1 (p < 0.001) versus 523.38 ± 685.75 to 353.54 ± 469.93 in group 2 (p = 0.021). Atrial premature complexes decreased from 570.00 ± 630.36 to 152.31 ± 168.88 in group 1 (p < 0.001) versus 513.77 ± 553.81 to 328.62 ± 400.81 in group 2 (p = 0.021). Conclusions: Cardiac arrhythmias decreased significantly in both groups after the start of both treatments, although data obtained from group 1 revealed a more important statistical significance. Our data seem to support the hypothesis that BiPAP may be a useful tool in managing COPD patients with ARF and mild arrhythmias.

Electrocardiologic and echocardiographic features of patients exposed to scorpion bite.

The purpose of this study is to examine clinical progress and hemodynamic and electrocardiologic features (QT depression and heart rate variability [HRV]) of patients exposed to a scorpion bite. Seventeen patients bitten by scorpions, and, as a control group, 15 healthy subjects were included in the study. Standard electrocardiograph (ECG) records, 24-hour Holter-ECG, and Doppler echocardiographic examinations were performed. Holter ECG indicated sinus tachycardia, sinus bradycardia, paroxysmal supraventricular tachycardia, atrial fibrillation, first-degree and second-degree atrioventricular block not requiring treatment, early atrial beats, and early ventricular beats in the patients at frequencies of 82%, 12%, 35%, 12%, 8%, 70%, and 47%, respectively. HRV parameters that reflected parasympathetic activity (SD 35+/-13-43+/-16, RMS-SD: 20+/-9-30+/-12, high frequency: 7.8+/-2-4.3+/-3, p<0.05) were significantly lower (p<0.05). Low frequency, which especially showed sympathetic activity (LF: 11+/-13-11+/-23, p>0.05), was similar in both groups. In addition, the LF/HF ratio, which reflected sympathovagal balance, was significantly increased in the patient group (1.5+/-1-3.0+/-2, p=0.005). Corrected QT and QT dispersion values were not significantly different with respect to the control (p>0.05). In the patient group compared to the control, a significant decrease was determined in the proportion of mitral E velocity to mitral A velocity (mEv/mAv), diastolic filling period (DFP), and left ventricular ejection fraction (LVEF), while a significant increase was noticed in pulmonary artery pressure (PAP) (mEv/mAv: 0.9+/-0.4-1.7+/-0.6, DFP: 362+/-8.5-425+/-89, LVEF: 53.1+/-6.7-68.6+/-5.8, PAP: 38.1+/-13-27.2+/-6, p<0.05). Scorpion bite leads to serious cardiovascular disorders, associated with decreased HRV, decreased systolic and diastolic functions, increased arrhythmic events, and hemodynamic disturbance with sympathetic and parasympathetic balance disturbance.