RESULTS OF NON-INVASIVE ACTIVATION MAPPING OF THE HEART IN “IDIOPATHIC” VENTRICULAR ARRHYTHMIAS IN COMPARISON WITH STRUCTURAL CHARACTERISTICS OF MYOCARDIUM BY MAGNETIC RESONANCE IMAGING

Aim.To compare the results of non-invasive activational mapping in patients with “idiopathic” ventricular arrhythmias (IVA) with the data on myocardial structure obtained by late enhancement magnetic resonance tomography (MRI).Material and methods.Twenty eight IVA patients, mean age 37 y. o. [26; 45], with ventricular arrhythmias of the heart (VA) of 2nd or higher grade by Lown, and 5 healthy volunteers (HV), mean age 29 [29; 30], underwent surface epiand endocardial non-invasive mapping (SEENIM) of the heart with the system for noninvasive electrophysiological investigation of the heart “Amicard 01C” with the analysis of duration of the activation-recovery interval (ARI) of the ventricles, and high resolution MRI (voxel 1,25x1,25x2,5mm) with delayed contrasting.Results.The number of VA in IVA group was 20196 [11479; 29834] for 24 hours. In 11 patients there were episodes of non-sustained ventricular tachycardia (VT). By SEENIM, predominating morphological type of ventricular ectopic activity in 22 patients sourced from the right ventricle myocardium (RV), of those in 20 from outflow tract of the LV (OTLV). There was significantly prolonged ARI in OTLV patients with IVA comparing to HV (p<0,05). In IVA and non-sustained ventricular tachycardia patients, by contrast MRI of the heart, in LV myocardium there were small foci of contrast retention found. There was no correlation of the areas of contrast retention and topography of VA sources.Conclusion.In most of IVA patients the source of VA was outflowing tract of the RV. The revealed prolongation of the ARI of this area in IVA patients can be an important factor of IVA onset. Small foci of LV fibrosis, found in late enhancement MRI of the heart and episodes of so called idiopathic VT, might be the earliest presentation of the “tachycardiopathy” at the step of pathology development when there are no signs of LV dilation.

To the question of electrophysiological remodeling role in the genesis of ventricular ectopy in patients with postinfarction cardiosclerosis

Aim. To study the character and intensity of relationship between left ventricular dilatation, severity of electrophysiological myocardium remodeling and ectopic ventricular activity in patients with postinfarction cardiosclerosis. Methods. 46 patients with postinfarction cardiosclerosis were examined (males, average age 57.9 years). All patients underwent echocardiography with detection of end diastolic volume of left ventricle and its ejection fraction, Holter monitoring with determining signal-averaged electrocardiogram and severity of ventricular ectopic activity with calculation of ventricular ectopic activity index. Based on the ejection fraction the patients were divided into two groups. Group 1 included 17 patients with ejection fraction ≥45%, and group 2 - 29 patients with ejection fraction <45%. Results. Left ventricle ejection fraction in patients from group 2 was lower, and parameters of signal-averaged electrocardiogram were worse than in patients from group 1. Ventricular ectopic activity index in patients from group 2 was 5 times higher than the average index in group 1. According to correlation analysis in the combined group, signal-averaged electrocardiogram parameters more tightly correlated with end diastolic volume than with ventricular ectopic activity index. The latter more tightly correlated with end diastolic volume (r=0.67, p <0.001), than with signal-averaged electrocardiogram parameters. After calculating partial correlation coefficient and excluding the effect of end diastolic volume, correlation coefficients of ventricular ectopic activity index and signal-averaged electrocardiogram parameters became insignificant. The received data put in question the view that electrophysiological remodeling is an independent cause of severity increase of ventricular arrhythmias. More probable is that electrophysiological remodeling and ventricular ectopic activity are related pathogenetically, and correlation between them is determined by the fact that both depend on left ventricle end diastolic volume. Conclusion. Relation between electrophysiological myocardium remodeling and ectopic ventricular activity in patients with postinfarction cardiosclerosis may depend on severity of left ventricular dilatation.

Dynamics of cardiovascular risk factors in patients with obstructive sleep apnoe syndrom undergoing CPAP-therapy

The aim of the study was to investigate the intensity of a number of risk factors resulting in cardiovascular complications, such as body mass index (BMI), level of mean arterial pressure (MAP), left ventricular mass index (LVMI), left ventricular ejection fraction (LVEF) and also ECG data (heart rate variability and ventricular ectopic activity) depending on the severity of obstructive respiratory disturbances during sleep. 76 patients with obstructive sleep apnea syndrome (OSAS) were included in the study. 38 patients with a severe form of OSAS underwent prolonged apparatus treatment which included generating positive pressure in their upper airways. After 4-month treatment the patients of this group underwent another examination to estimate all the parameters studied. Examination of patients with OSAS revealed that a number of indices (BMI, LVMI and MAP) showing the intensity of basic modified cardiovascular risk factors, such as obesity and arterial hypertension, correlate to the level of obstructive respiratory disturbances during sleep, which was estimated according to apnea-hypopnea index (AHI). Twenty-four-hour ECG monitoring of patients with OSAS showed a tendency for a decrease in heart rate variability and an increase in ventricular ectopic activity in patients with more apparent obstructive respiratory disturbances during sleep and with negative disease dynamics against the background of CPAP therapy.

Novel Therapies for Myocardial Irritability following Extreme Hydroxychloroquine Toxicity

Introduction. Hydroxychloroquine (HCQ) overdose is rare and potentially deadly when consumed in large doses. Management of severe HCQ toxicity is limited and infrequently reported. This report presents the case of a massive ingestion of HCQ.Case Report. A 23-year-old female presents following an intentional ingestion of approximately 40 g of HCQ. Within six hours after ingestion, she developed severe hemodynamic instability resulting from myocardial irritability with frequent ventricular ectopic activity leading to runs of polymorphic ventricular tachycardia (PMVT) and ventricular fibrillation (VF) requiring multiple defibrillations. Additional treatments included intravenous diazepam, epinephrine, norepinephrine, sodium bicarbonate, and magnesium sulfate. Despite the ongoing hemodynamic instability, the patient was also treated with Intralipid (ILE) and received hemodialysis. Improvements in her hemodynamics were observed after 18 hours. She survived her massive overdose of HCQ.Conclusion. HCQ poisoning is rare but serious because of its rapid progression to life-threatening symptoms. Hemodynamic support, gastric decontamination, electrolyte monitoring and replacement, and management of arrhythmias are the mainstays of treatment. The combined role of dialysis and ILE in the setting of massive HCQ overdose may improve outcomes.

Prognostic value of heart rate variability in post-infarction patients

Background/Aim. Depressed heart rate variability (HRV) indicating autonomic disequilibrium and propensity to ventricular ectopy can be useful for risk stratification in patients following acute myocardial infarction (AIM). The aim of the study was to assess heart rate variability as a predictor of allcause mortality in post-infarction patients. Methods. We analyzed the 24-hour electrocardiographic (ECG) recordings of 100 patients (80 males) during hospitalization for AIM. The mean age of patients was 56.99 + 11.03 years. Time domain heart rate variability analysis was obtained from 8 to 13 days after index infarction by mean of a 24- hour ECG recording, and the calculated parameters were: standard deviation of all normal to normal RR intervals (SDNN), RRmax-RRmin (difference between the longest RR interval and the shortest RR interval), mean RR interval. We also analyzed ventricular premature complexes from the ECG data. The patients underwent clinical evaluation, laboratory tests and echocardiography. Results. Within a oneyear follow-up period 11 patients experienced death, 10 of them because of cardiac reason and one because of stroke. There were significantly lower values of SDNN (60.55 ? 12.84 ms vs 98.38 ? 28.21 ms), RRmax-RRmin (454.36 ? 111.00 ms vs 600.99 ? 168.72 ms) and mean RR interval (695.82 ? 65.87 ms vs 840.07 ? 93.97 ms) in deceased patients than in the survivors, respectively (p < 0.01). The deceased patients were of higher mean age, with lower left ventricular ejection fraction (0.46 ? 0.05 vs 0.56 ? 0.06 in survivors), and more frequent clinical signs of heart failure and ventricular ectopic activity (> 10VPCs/h; p < 0.01). Multivariate Cox analysis showed that SDNN was a significant, independent predictor of all-cause mortality in postinfarction patients. The other independent predictors were clinical signs of heart failure - Killip class II and III and ventricular ectopic activity. Conclusion. Depressed HRV is an independent predictor of mortality in post-infarction patients and may provide useful additional prognostic information in non-invasive risk stratification of these patients.