Goran Vukomanovic

Heart rate variability in children with idiopathic ventricular tachycardia

Idiopathic ventricular tachycardia (IVT) is a rare arrhythmia in children. A great deal of uncertainty and numerous questions still remain regarding the extent of investigation, therapy, and long-term prognosis for children with IVT. The existence of subclinical cardiac disease, as well as of autonomic dysfunction in patients with ventricular arrhythmias, has been well documented. A number of experimental and clinical studies have suggested that imbalances within the cardiac autonomic system’s activity may be crucial in the generation of ventricular tachycardia, irrespective of the presence of cardiovascular pathological substrate. Heart rate variability (HRV) analysis provides a useful method for measuring the autonomic activity. This study evaluates HRV in children with IVT. The study included 31 children with ventricular arrhythmia who were divided into two groups: (1) patients with frequent ventricular extrasystoles (VES) and (2) patients with IVT. The control group comprised 23 healthy children without pathological findings on 24-h ECG Holter. Twenty-four-hour ambulatory electrocardiography recordings were obtained, and the time-domain variables were calculated. HRV was compared to age-related normal values. It was observed that the overall heart rate variability is diminished in children with IVT. We recommend HRV analysis of any child with IVT. Quantification of the autonomic nervous system activity using time domain analyses may be a helpful diagnostic tool in the clinical assessment and initial evaluation of these children.

Prenatal growth retardation, microcephaly, and eye coloboma in infant with multiple congenital anomalies: Further delineation of presumed new dysmorphic syndrome

BACKGROUND Ten years ago an unusual association of prenatal growth retardation, microcephaly, coloboma of the iris/eye anomalies, congenital heart defects, and urogenital anomalies was reported for the first time in three siblings. Autosomal recessive inheritance was presumed. This finding has been included in London Winter-Baraitser Dysmorphology Database as a separate entity, but still has not been classified as a distinct syndrome. CASE We report an infant with an association of prenatal growth retardation, microcephaly, facial dysmorphism, eye anomalies, congenital heart defects, and testis retention. Mild craniofacial dysmorphism consists of sloped forehead, bulbous nose tip, and micrognathia. Eye anomalies include coloboma of the iris, choroidea, and optic nerve as well as lens dislocation. The patient also presents with ventricular and atrial septal defects, hypoplastic mitral valve, persistent left superior vena cava, accessory spleen, and club foot. CONCLUSIONS To the best of our knowledge, this is the second family and the fourth case with this pattern of birth defects reported worldwide so far. We presume that this combination of multiple congenital anomalies and growth retardation constitutes a newly recognized syndrome of likely autosomal recessive inheritance. So far no data suggest etiological impact of consanguinity, parental age, or environmental factors.

Influence of heart failure severity on heart rate variability

INTRODUCTION Autonomic regulation of cardiovascular functions in congestive heart failure is characterised by enhanced sympathetic and diminished parasympathetic activity. The long term predominance of sympathetic tone is a significant factor in arrhythmogenesis, sudden cardiac death, and progressive pump failure. Heart rate variability (HRV) is a noninvasive method for estimating the sympatho vagal balance in cardiovascular control. AIM The aim of this study was to analyse the influence of heart failure severity on HRV. METHOD HRV was estimated through the spectral analysis of short term ECG (Cardiovit AT 60, Schiller, CH) in 63 patients (78% male, mean age 56.9 +/- 10.9 years) and 14 healthy volunteers (57.1% male, mean age 53.1 +/- 8.2 years). The following spectral components were measured: VLF (very low frequency), LF (low frequency), HF (high frequency), and total power (Tot Power). RESULTS All spectral componentswere statistically, significantly lower in patients with heart failure in comparison to healthy controls (VLF: 159.89 +/- 147.02 vs. 285.50 +/- 202.77 ms2; p = 0.023, LF: 161.48 +/- 204.01 vs. 474.57 +/- 362.93 ms2; p < 0.001, HF: 88.58 +/- 102.47 vs. 362.71+/- 318.28 ms2; p < 0.001), as well as total power (Tot Power: 723.39 +/- 644.52 vs. 1807.29 +/- 1204.74 ms2; p < 0.001). A significant, negative correlation between HRV parameters and NYHA class was detected in heart failure patients (VLF: r = -0.391; p = 0.002, LF: r = -0.401; p = 0.001, and Tot Power r = -0.372; p = 0.003). Ejection fraction proved to be in significant, positive correlation to VLF (r = 0.541; p = 0.002), LF (r = 0.531; p = 0.003), HF (r = 0.418; p = 0.020), and Tot Power (r = 0.457; p = 0.013). CONCLUSION Significant HRV reduction is a precursor to incipient heart failure (NYHA I). In heart failure progression, total power as well as the power of all spectral components is progressively reduced. LF and Tot Power are the most prominent parameters for discriminating between the different stages of heart failure. These results could promote HRV as an important decision-making tool in heart failure treatment as well as in monitoring the results of that treatment.

Oral propranolol for infantile hemangiomas: a prospective study on the role of 48-hour Holter monitoring in additional safety assessment

Abstract Purpose: Oral propranolol has been recently approved for infantile hemangiomas (IHs), but potential side effects stay a challenge. We sought to make an additional assessment on oral propranolol safety for this indication. Materials and methods: Prospective study included 108 infants consecutively treated for IHs at the University Children’s Hospital Tirsova, Belgrade from January 2010 to December 2013. Propranolol was administered orally at a daily dose of 0.5 mg/kg and doubled every 48 hours in the absence of side effects until reaching the maximum dose of 2 mg/kg daily. Systolic and diastolic blood pressure and heart rate were measured every 48 hours with clinical observation. Heart rate was monitored by standard electrocardiogram (ECG) and 48-hour Holter ECG. Results: Statistically significant, but asymptomatic decreases in systolic blood pressure and heart rate recorded by Holter ECG were observed during the first doubling of dose and then remained stable. Arrhythmias were not detected. Despite mild sleep disturbance observed in 31% of infants in the hospital milieu, Holter monitoring indicated circadian rhythm maintenance. Conclusions: Oral propranolol for IHs does not remarkably affect heart rhythm including circadian variations throughout hospital initiation. Therefore, there is no necessity for Holter monitoring in additional safety assessment.

Multi-purpose ECG telemetry system

BackgroundThe Electrocardiogram ECG is one of the most important non-invasive tools for cardiac diseases diagnosis. Taking advantage of the developed telecommunication infrastructure, several approaches that address the development of telemetry cardiac devices were introduced recently. Telemetry ECG devices allow easy and fast ECG monitoring of patients with suspected cardiac issues. Choosing the right device with the desired working mode, signal quality, and the device cost are still the main obstacles to massive usage of these devices.MethodsIn this paper, we introduce design, implementation, and validation of a multi-purpose telemetry system for recording, transmission, and interpretation of ECG signals in different recording modes. The system consists of an ECG device, a cloud-based analysis pipeline, and accompanied mobile applications for physicians and patients. The proposed ECG device’s mechanical design allows laypersons to easily record post-event short-term ECG signals, using dry electrodes without any preparation. Moreover, patients can use the device to record long-term signals in loop and holter modes, using wet electrodes. In order to overcome the problem of signal quality fluctuation due to using different electrodes types and different placements on subject’s chest, customized ECG signal processing and interpretation pipeline is presented for each working mode.ResultsWe present the evaluation of the novel short-term recorder design. Recording of an ECG signal was performed for 391 patients using a standard 12-leads golden standard ECG and the proposed patient-activated short-term post-event recorder. In the validation phase, a sample of validation signals followed peer review process wherein two experts annotated the signals in terms of signal acceptability for diagnosis.We found that 96% of signals allow detecting arrhythmia and other signal’s abnormal changes. Additionally, we compared and presented the correlation coefficient and the automatic QRS delineation results of both short-term post-event recorder and 12-leads golden standard ECG recorder.ConclusionsThe proposed multi-purpose ECG device allows physicians to choose the working mode of the same device according to the patient status. The proposed device was designed to allow patients to manage the technical requirements of both working modes. Post-event short-term ECG recording using the proposed design provide physicians reliable three ECG leads with direct symptom-rhythm correlation.

Echocardiographic evaluation of left ventricular outflow tract hemodynamics in healthy children with anomalous left ventricular band.

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Treatment of cyanotic heart diseases in children

Cyanotic heart diseases are relatively rare, but they are severe and heterogeneous congenital heart diseases, which require complex surgery. Development of different advanced surgical procedures, such as arterial switch operation (ASO), Fontan and its modifications, Norwood etc. operations, as well as better perioperative care significantly improved survival rate and quality of life of these children. The study group included 308 children treated for cyanotic heart disease in Yugoslavia, in the period January 2000 to July 2004. Some of them (239, 77.6%) were treated at the University Childrens Hospital in Belgrade, and others (69, 22.4%) in different institutions abroad. The age of the operated patients varied between 1 day and 19 years (median 12 months). The patients (pts) were divided into four groups, according to the disease and type of the operation. In the whole group of 308 patients treated due to cyanotic heart disease, there were 232 (75.3%) cases with open heart surgery and 76 (24.7%) with closed procedures. The mortality rate was significantly different between disease/operation groups, and age groups. Average mortality rates differed from 11.8% for palliative procedures to 12.5% for complete corrections. Mortality rate and achieved surgical results in treatment of children with cyanotic heart diseases were significantly worse than those published by leading cardiac surgery centers in the world. However, there is a clear tendency in introducing new surgical procedures, lowering the age at which the operation is done and decreasing the mortality rates.