Myocardial Repolarization Research Articles

Antipsychotic drugs and QT interval prolongation

Prolongation of myocardial repolarization, i.e. lengthening of the QTc interval on surface electrocardiogram (ECG), with increased risk of cardiac arrhythmias, has been recognized as a side effect of many drugs. Most first and second generation antipsychotic drugs can cause dose-related prolongation of QTc, although there are important differences in the potency of individual agents. ECGs in 46 patients suffering from schizophrenic disorder and treated with different antipsychotic drugs one week after the admission to the psychiatric hospital were analyzed in this prospective observational study. Hearth rate, QT interval and QTc interval were assessed. The average daily dose of prescribed antipsychotic drugs was calculated. Average QTc interval was 417 msec, only 3 out of 46 (6,5%) patients had QTc over 450 msec and only one patient (2,2%) had QTc over 500 msec. No differences in QTc interval between patients who were treated either with first or second generation antipsychotic drug or with combination of both were found. Female participants had significantly longer OTc interval than male participants (p < 0,05). Results raise the question of the clinical relevance of a single ECG for diagnostics of cardiac complications in schizophrenia patients and suggest the need to conduct ECG monitoring in patients with high risk for cardiac complications during antipsychotic treatment.

Effect of Hypothermia on Myocardial Depolarization and Repolarization in Neonates with Hypoxic-Ischemic Encephalopathy Due to Asphyxia.

Therapeutic hypothermia (TH) is effective for neonatal hypoxic-ischemic encephalopathy (HIE). The combination of abnormal myocardial repolarization and fatal arrhythmia in patients with accidental hypothermia has prompted clinical validation of the proarrhythmic potential of TH. However, to our knowledge, there have been few clinical studies on myocardial depolarization and repolarization abnormalities caused by TH in neonates. Therefore, we investigated the effects of TH on neonatal myocardial depolarization and repolarization by capturing the waveform changes in electrocardiograms (ECGs) associated with body temperature (BT) before and after TH. We included three neonates with HIE diagnosed at birth who were treated with TH in our hospital. The heart rate, RR interval, P wave duration, PR interval, QRS duration, QT interval, corrected QT (QTc) interval by Fridericia's formula, J point-T end (JT) interval, corrected JT (JTc) interval by Fridericia's formula, T peak-T end (Tpe) interval, Tpe/QT, and QRS/QTc were calculated retrospectively using an ECG. The correlations of ECG parameters recorded concurrently with 33 samples in which BT measurements were confirmed were performed. BT and heart rate were positively correlated (R: 0.589, p = 0.0003). BT was negatively correlated with Tpe/QT (R: - 0.470, p = 0.0058), the QTc interval (R: - 0.680, p < 0.0001), and the corrected JT interval (R: - 0.697, p < 0.0001). TH does not affect atrial or ventricular depolarization but prolongs the ventricular repolarization process in a temperature-dependent manner.

QT Prolongation: Psychotropic medication versus illicit drugs

IntroductionCountless substances used for their psychotropic effects may induce adverse cardiac effects, such as QT prolongation. This category of substances holds illicit drugs as well as medications, with their effects influenced by dosage, concomitant use and patient specific factors. The appraisal of cardiac consequences is essential as delayed repolarization may lead to the rare but potentially deadly polymorphic ventricular tachycardia.ObjectivesThe goal of this presentation is to underscore the cardiac risks associated with both medication use and substance abuse in order to ensure the suitable psychopharmacological treatment, especially in particular situations of drug using patients.MethodsThe subject of the presentation is a 17-year-old female adolescent hospitalized in our clinic, with multiple substance abuse, as seen in qualitative multidrug test (cannabis, amphetamines, ecstasy, barbiturates, benzodiazepines), previously under complex treatment prescribed by an adult psychiatrist (3 atypical antipsychotics, 1 selective serotonin reuptake inhibitor, 1 anticonvulsant, 1 benzodiazepine). Specialty literature has been reviewed concerning the cardiac effects of both the abuse substances and the psychiatric medications.ResultsMultiple drugs involved may cause a myocardial repolarization delay, the patient having a QTc of 508 msec at the admission. Consequent to parenteral fluids and treatment managing, ECG revealed a decrease to 379 msec 7 days later in the stay. This finding could not be viewed solely as caused by drug use, psychiatric medication or individual factors, but rather as their aggregation.ConclusionsPsychotropic substances use may lead to QT prolongation, which calls for close cardiac supervision whenever patient’s behaviour warrants or when pharmacologic intervention is required.DisclosureNo significant relationships.

235-OR: Sustained QTc Prolongation during Recovery from Hypoglycemia in Patients with Type 1 Diabetes

Hypoglycemia and increased glycemic variability have been associated with cardiac arrhythmias and sudden cardiac death. We investigated cardiac repolarization during acute hypoglycemia followed by recovery to hyperglycemia or euglycemia in patients with type 1 diabetes. In a randomized crossover study, patients with type 1 diabetes (N=24, (mean±SD) age 53±years, HbA1c 7.5±0.8% [57.6±8.9 mmol/mol], diabetes duration 23±14 years, BMI 25.7± 3.1 kg/m2) underwent two clamps with three steady-state phases: 1) a hyperinsulinemic-euglycemic phase for 45 minutes, 2) a hyperinsulinemic-hypoglycemic phase for 60 minutes, and 3) a recovery phase in hyperglycemia (clamp A) or euglycemia (clamp B) for 60 minutes. Continuous ECG (Holter) monitoring and blood samples for counterregulatory hormones and plasma potassium were obtained. Linear mixed models were used to assess the impact of hypoglycemia and recovery to hyperglycemia vs. euglycemia on cardiac repolarization. Heart rate-corrected QT (QTc) (Fridericia’s formula) progressively increased from baseline (mean (95% CI) , clamp A: 415 msec (409;421) ; clamp B: 418 msec (412;424)) during hypoglycemia on both clamp days (∆mean (95% CI) , clamp A: 21 msec (11;31) ; clamp B: 22 msec (12;31)) . In the recovery phase, QTc remained increased during hyperglycemia and euglycemia (17 msec (11;21) vs. 14 msec (10;20)) with no difference in change between recovery to hyperglycemia compared to euglycemia (3 msec (-6;11) , P=0.5442) . No significant changes from baseline were observed in QTc dispersion (heterogeneity of myocardial repolarization) during hypoglycemia or in the recovery phases. We conclude that clinically significant QTc prolongations during insulin-induced hypoglycemia remain during a 60-minute recovery period independently of recovery to hyperglycemia or euglycemia in patients with type 1 diabetes. Thus, vulnerability for serious cardiac arrhythmias and sudden cardiac death may extend beyond a hypoglycemic event itself. Disclosure C.R.Andreasen: None. A.Andersen: n/a. P.G.Hagelqvist: None. J.V.Lauritsen: None. S.Engberg: Employee; Novo Nordisk A/S. J.J.Holst: Advisory Panel; Novo Nordisk, Board Member; Antag Therapeutics, Bainan Biotech. U.Pedersen-bjergaard: Advisory Panel; Novo Nordisk A/S, Sanofi. F.K.Knop: Advisory Panel; Boehringer Ingelheim International GmbH, Eli Lilly and Company, Merck Sharp &amp; Dohme Corp., Novo Nordisk, Sanofi, ShouTi, Zucara Therapeutics, Consultant; AstraZeneca, Eli Lilly and Company, Novo Nordisk, Pharmacosmos A/S, Sanofi, ShouTi, Zealand Pharma A/S, Zucara Therapeutics, Research Support; AstraZeneca, Novo Nordisk, Sanofi, Zealand Pharma A/S, Speaker's Bureau; AstraZeneca, Bayer AG, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Novo Nordisk, Sanofi, Stock/Shareholder; Antag Therapeutics. T.Vilsbøll: Consultant; AstraZeneca, Bristol-Myers Squibb Company, Eli Lilly and Company, Gilead Sciences, Inc., GlaxoSmithKline plc., Merck Sharp &amp; Dohme Corp., Mundipharma, Novo Nordisk, Sun Pharmaceutical Industries Ltd. Funding Danish Diabetes Academy (NNF17SA0031406)

P15 AN OLD MYOCARDIAL INFARCTION UNMASKED BY UPGRADE TO HIS BUNDLE PACING: A CASE REPORT

Abstract Case Report We report the clinical case of a 71–year–old man who was implanted with a dual–chamber PMK for complete atrioventricular block in 2012. In 2013 he was treated with two percutaneous coronary intervention (PCI) and stenting of the left anterior descending coronary artery (LAD) and right coronary artery (RCA).In March 2021, he was referred to our hospital for acute heart failure. Transthoracic echocardiography showed diffuse hypokinesis, with a left ventricular ejection fraction (LVEF) of 28% (46% six months earlier). ECG showed atrial flutter and paced ventricular rhythm with notch of the QRS complex in all 12 leads (Figure B). After achieving good clinical compensation with intravenous diuretics, the patient underwent coronary angiography with evidence of an unchanged coronary situation compared with 2013; Given the constant right ventricular pacing in the apex, we considered the LVFE decline as a consequence of pacemaker–induced cardiomyopathy (PICM)5 and a successful upgrade to HB pacing was performed. The surface ECG showed selective HB pacing with QRS width comparable to the native ECG (Figure A) but different morphology, because of evidence of QS complexes in V3–V6 and II, III, aVF (Figure C); physiological pacing obtained with selective HBP had made evident electrocardiographic signs of a previous myocardial infarction (MI). Discussion Very difficult is the diagnosis of a previous MI during RV pacing; to date, although considered questionable, we have only the criteria of Kochiadakis and colleagues (Figure 2A): – Notch of 0.04–second duration on the ascending limb of the S–wave of leads V3, V4, or V5 (Cabrera‘s sign). – Notching of the ascending stroke of the R wave in leads I, aVL, or V6 (Chapman‘s sign).– Q waves of 0.03 second duration in leads I, aVL, or V6. – Notch of the first 0.04 seconds of the QRS complex in leads II, III, and aVF. – Q wave of 0.03 seconds duration in leads II, III, and aVF. Occurring through the normal conduction system, HB pacing should generate a physiological myocardial repolarization resulting in a paced QRS complex with morphology and duration equal to the basal ECG, without alterations in the ventricular repolarization phase. As proof of the above, it was possible to appreciate that the transition from RV pacing to selective HB pacing allowed to unmasked the signs of a previous infero–lateral IMA, showing clear QS complexes in II, III, aVF, V3–V6. Conclusion Extremely old age should not discourage PM implantation, when indicated; age is obviously predictor of long–term death but is not predictor of precocious mortality. Acute periprocedural complication rate is low and generally comparable to that of younger populations.

The Tp-e/QT ratio as a predictor of nocturnal premature ventricular contraction events in patients with obstructive sleep apnea.

Obstructive sleep apnea (OSA) is significantly associated with a higher risk of ventricular arrhythmia (VA). QT, the Tp-e/QT ratio, and QT dispersion (QTd) are used to evaluate myocardial repolarization and are highly correlated with VA. The aim was to evaluate the predictive value of the Tp-e/QT ratio and other electrocardiogram (ECG) parameters for nocturnal premature ventricular contractions (PVCs) in patients withOSA. We retrospectively analyzed data from patients withOSA and conducted a 1:1 matched cohort study. Patients diagnosed with OSA whomet our criteria for the PVC group, and sex- and age-matched patients withOSA who met our criteria for the control groupwere enrolled in the study. The Tp-e, Tp-e/QT ratio, corrected QT interval (QTc), corrected Tp-e interval (Tp-ec), and QTd were measured, calculated and analyzed. Patients in the PVC group(n = 31) showed a greater Tp-e, Tp-ec, QTc, Tp-e/QT ratio, and QTd than patients in the control group(n = 31). In the univariate binary logistic regression analysis, higher Tp-ec (OR: 1.025; P = 0.042), QTc (OR: 1.014; P = 0.036), Tp-e/QT ratio (OR: 1.675; P < 0.001), and QTd (OR: 1.052; P = 0.012) values were all significantly associated with nocturnal PVCs. In multivariate analysis and receiver operating characteristic analysis, a higher Tp-e/QT ratio (OR: 2.168; 95% CI: 0.762-0.952; P < 0.001) was an independent predictor of nocturnal PVCs. The QTc, Tp-e/QT ratio, and QTd in patients withOSA with nocturnal PVCs were significantly increased compared with those in patients without nocturnal PVCs. A prolonged Tp-e/QT ratio was an independent predictor of nocturnal PVCs in patients with OSA.

Qt-Prolongation Associated with Medication Combination in Hospitalized Patients at Johns Hopkins Aramco Healthcare (JHAH), KSA

Background: Long QT syndrome (LQTS) is a myocardial repolarization dysfunction characterized by QT-interval prolongation on electrocardiogram (ECG). Patients with long QT syndrome have a corrected QT interval (QTc) prolongation greater than 460 milliseconds (0.46 seconds). The long QT syndrome has a direct association with an increased risk of a serious type of arrhythmias called ‘Torsades de Pointes (TdP)’, a polymorphic ventricular tachycardia. QT-interval prolongation and the consequent life-threatening Torsade de Pointes may develop in both outpatient and inpatient setting, however, the risk is thought to be higher among hospitalized patients. This is mainly because admitted patients usually receive multiple drugs and may have other risk factors, including electrolyte disturbances and hepatic or renal impairment. This study is an attempt to address the issue of QT-prolongation and its prevalence among hospitalized patients, and evaluate the safety of prescribing patterns of QT-prolonging drugs selected in the study. The aim is to determine which drugs physicians more commonly prescribe and whether or not they cause long QT-interval in patients. Our paper also aims to provide general recommendations for a safer practice. We aim to extend the current knowledge and highlight this overlooked adverse effect in the clinical practice.&#x0D; Methods: This retrospective study was conducted based on electronic health records (EHRs). The Institutional Review Board (IRB) of Johns Hopkins Aramco Hospital approved the study. The data were extracted from EPIC healthcare system at Johns Hopkins Aramco Healthcare (JHAH) in Dhahran, Saudi Arabia on 122 hospitalized patients. The statistical software program GraphPad Prism 9.0.0 version was used to analyze and generate the figures.&#x0D; Results: Nearly half of them (51.6%) were arrhythmic patients. The duration of therapy was also considered, and we found that the majority of patients were on a short-term therapy (76.2%). Two-drug regimen was the most commonly observed (46.6% of patients), whereas nearly 30% were prescribed three or more QT-prolonging drugs. In respect to drug classes, the serotonin antagonist drug (ondansetron) was the most commonly prescribed agent among our patient population (69.6%). The corrected QT-interval (ECG reading) varied among patients; however, all subjects experienced QT-prolongation with varying degrees. Fifty-five per cent of patients fell into the 440-469 ms category, 22.9% were borderline (470-499 millisecond) and 12.3% had a clinically significant long QT syndrome (≥500 millisecond).&#x0D; Conclusion: A substantial number of patients presented with drug-induced QT prolongation with varying degrees. Scores of ≤500 ms does not mean nor eliminate the risk of developing fatal arrhythmias. Proper considerations are needed in order to optimize and minimize the use of drugs that are associated with long QT syndrome. This adverse effect usually goes undetected in real-world practice. ECG monitoring should be recommended in patients who are receiving two or more QT-prolonging drugs, elderly, and/or have other risk factors.

Comparison of frontal QRS-T angle in patients with schizophrenia and healthy volunteers

Cardiovascular diseases are the most prominent cause of death in patients with schizophrenia. Frontal QRS-T (fQRS-T) angle is a novel marker of myocardial depolarization and repolarization heterogeneity. Recent studies have indicated that the fQRS-T angle is associated with some cardiovascular abnormalities. This study aimed to investigate the fQRS-T angle and its relationship with symptoms severity in patients with schizophrenia.One hundred-six patients with schizophrenia and sixty-four healthy controls were included in this study. fQRS-T angle and QT interval measurements were calculated for each participant from the automatic report of the 12-lead electrocardiography (ECG) device. The Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) and The Positive and Negative Syndrome Scale (PANSS) were performed on the patients with schizophrenia.Corrected QT (QTc) interval and fQRS-T angle were significantly higher in the patients with schizophrenia than healthy controls (p < 0.001 and p < 0.001, respectively). fQRS-T angle was positively correlated with age (r = 0.43), duration of disease (r = 0.37), and negative symptoms scores (r = 0.39). In linear regression analysis, the disease duration and negative symptom severity were the independent predictors of fQRS-T angle in patients with schizophrenia (t = 3.730, p = 0.003 and t = 2.257, p = 0.023, respectively).The fQRS-T angle may be an important ECG parameter to interpret cardiovascular disease risk in patients with schizophrenia.

Repolarization Dispersion Is Associated With Diastolic Electromechanical Discoordination in Children With Pulmonary Arterial Hypertension.

BackgroundElectromechanical dyssynchrony is a well described comorbidity in pulmonary arterial hypertension (PAH). ECG‐derived measurements reflective of diastolic dysfunction and electromechanical imaging markers are yet to be investigated. In this study we investigated the ECG‐ derived marker of repolarization dispersion, interval between the peak and end of T wave (TpTe), in pediatric patients with PAH and left ventricular (LV) diastolic dysfunction.Methods and ResultsWe measured TpTe from a standard 12‐lead ECG and in 30 children with PAH and matched control subjects. All participants underwent same‐day echocardiography and myocardial strain analysis to calculate the diastolic electromechanical discoordination marker diastolic relaxation fraction. When compared with control subjects, patients with PAH had increased TpTe (93±15 versus 81±12 ms, P=0.001) and elevated diastolic relaxation fraction (0.33±0.10 versus 0.27±0.03, P=0.001). Patients with PAH with LV diastolic dysfunction had significantly increased TpTe when compared with patients with PAH without diastolic dysfunction (P=0.012) and when compared with control group (P<0.001). Similarly, patients with PAH with LV diastolic dysfunction had increased diastolic relaxation fraction when compared with PAH patients without diastolic dysfunction (P=0.007) and when compared with control group (P<0.001). A 10‐ms increase in TpTe was significantly associated with 0.023 increase in diastolic relaxation fraction (P=0.008) adjusting for body surface area, heart rate, right ventricular volumes, and function.ConclusionsProlonged myocardial repolarization and abnormal LV diastolic electromechanical discoordination exist in parallel in children with PAH and are associated with worse LV diastolic function and functional class.

The Effect of Carbetocin Dose on Transmural Dispersion of Myocardial Repolarization in Healthy Parturients Scheduled for Elective Cesarean Delivery Under Spinal Anesthesia: A Prospective, Randomized Clinical Trial

(Anesth Analg. 2021;132:485–492) Transmural dispersion of myocardial repolarization (TDR) is the interval between the peak of the T wave and end of the TV wave (Tp-e). Increased TDR is a more reliable predictor of drug torsadogenicity than prolonged QT interval. Carbetocin, a synthetic analog of oxytocin, is used to prevent postpartum hemorrhage (PPH) following cesarean delivery (CD), though the effect dose varies. Carbetocin has been shown to increase mean correct QT, but there is a paucity of information on the effects of carbetocin of TDR. This study examined the effects of carbetocin dose on TDR in patients undergoing CD under spinal anesthesia.

Long QT syndrome: Identification of a novel de novo mutation of calmodulin in a newborn girl

Background: Long QT syndrome (LQTS) is a genetically and phenotypically heterogeneous disorder of ventricular myocardial repolarization that is typically characterized by prolongation of the heart rate-corrected QT interval on a 12-lead electrocardiogram (ECG). LQTS has a complicated etiology since great genotypic and phenotypic overlapping among LQTSs limits the establishment of a diagnosis based solely on clinical features. Case presentation: Here, we describe a Vietnamese newborn with a novel calmodulin (CALM2) variant. The patient was referred to the Department of Cardiology at Children's Hospital 2 in Ho Chi Minh City, Vietnam for multiple clinical cardiac presentations. The patient's family history was negative for cardiovascular diseases; however, she suffered from recurrent syncope and QT interval prolongation on resting in a 12-lead surface ECG. A fetal echocardiogram at 29 weeks detected signs of congenital heart disease. The newborn patient then suffered from sudden cardiac arrest and required cardiopulmonary resuscitation. Two weeks later, the patient suffered from torsade de pointes for the third time and required electrical shocks. An endotracheal tube was placed through the mouth into the trachea to facilitate breathing. Unfortunately, the patient expired at 3 months of age due to serious inflammatory issues. Whole exome sequencing (WES) — a technique used to determine variations in all coding regions (exons) of the known genes — validated a total of four rare variants in four cardiomyopathy (CM) genes, the CALM2, DSP, MYBPC3, and SPEG genes. We identified a novel de novo heterozygous missense mutation, c.280G &gt; T (p.Asp94Tyr), in the CALM2 gene (NM_001305626) encoding calmodulin, which is a ubiquitous calcium-binding protein that is important for a myriad of intracellular signaling events of cardiac function. Conclusion: The results obtained in this study support the ``pan-cardiomyopathy panel'' approach, in which the molecular diagnosis of LQTS, the early identification of arrhythmia development, and the improved clinical management of cardiovascular disease patients are applied. Trial registration: The procedures were reviewed and approved by the Ethical Committee of the University of Medicine and Pharmacy, Ho Chi Minh City, Vietnam, under the number UMP-VN 2018-10a12.

A neonate with acquired long QT from placental transfer of medications

Long QT Syndrome (LQTS) can present in the neonate with bradycardia and AV block and confers significant risk for life threatening ventricular arrhythmias. We report a case of a neonate presenting with complex bradyarrhythmias secondary to acquired LQTS after maternal overdose of QT-prolonging medications (haloperidol and sertraline). When the mother was brought in to the delivery center unconscious, fetal bradycardia was noted and the baby was emergently delivered prematurely. The newborn’s initial ECG showed bradycardia with AV node conduction block, rate related His-Purkinje conduction aberration with varying QRS morphology and a QTc &gt;600 ms. She continued to be bradycardic through her first day of life with echocardiogram showing mild cardiac dysfunction. With the elimination of the offending medication from her circulation, the infant’s rate and function abnormalities resolved and QTc normalized. Both haloperidol and sertraline are known to be strong suppressors of the HERG potassium channel that plays an important role in myocardial repolarization and both medications can cross the placenta. Maternal overdose can cause transient QT-prolonging effect similar to that of inherited LQTS type 2. Given the high risk for sudden death in affected newborns, reporting this case is aimed to raise the awareness of acquired LQTS by placental transfer of medication. Early identification of neonates at risk should prompt ECG testing. If long QT is identified, the newborn should be closely monitored with care to avoid any further QT prolonging medications or conditions, until the toxic medication effect resolves.

Karbonmonoksit zehirlenmesi olan çocuklarda hiperbarik ve normobarik oksijen tedavilerinin elektrokardiyografinin repolarizasyon parametreleri üzerindeki etkilerinin karşılaştırılması

Purpose: The aim of this study was to compare the effects of hyperbaric oxygen therapy (HBOT) induced hyper-oxygenation and normobaric oxygen therapy (NBOT) on myocardial repolarisation parameters in children with carbon monoxide (CO) poisoning.&#x0D; Materials and Methods: This prospective study included 77 girls and boys aged 0–18 years who were diagnosed and treated for CO poisoning. There were no changes in the routine clinical evaluation and treatment practices of patients. Patients who received NBOT (n=40) and HBOT (n=37) were divided into two groups. These groups were compared in terms of their demographic characteristics, carboxyhaemoglobin, lactate, troponin levels and myocardial repolarisation parameters of electrocardiography (ECG) (Tp-e interval, Tp-e dispersion, QTc and Tp-e/QTc ratio).&#x0D; Results: There were no significant intergroup differences in terms of carboxyhaemoglobin, lactate and troponin levels at the time of admission; admission and post-treatment Tp-e, Tp-e dispersion, corrected QTc and TPe/QTc ratio and post-treatment change rates of each ECG parameter.&#x0D; Conclusion: There was no intergroup difference in terms of repolarisation parameters of ECG in children with CO poisoning. The possible reason for this may be myocardial reperfusion damage due to hyper-oxygenation associated with HBOT therapy.

Structure and predictors of repolarization disorders in patients with severe COVID-19 infection

BackgroundCOVID-19 infection can adversely affect the function of cardiac ion channels, leading to changes of the properties of conductivity and repolarization, which increases arrhythmogenesis.PurposeTo determine the features of the structure and predictors of repolarization disorders in the patients with severe COVID-infection.Methods133 patients with severe COVID-19 infection were examined, who were in the intensive care unit of the clinical hospital No. 1 in our city in the period from April to December 2020 and as a result of treatment with improved health were discharged from the hospital.Among them there were 65 (48.9%) men and 68 (51.1%) women (X2=0.068, p=0.79). The age of patients ranged from 24 to 90 years, averaging 61.38±12.96 years. Middle-aged and elderly patients were dominated at age structure (p=0.001). The total duration of staying in the hospital was 18.9±9.12 days. The duration of staying in the intensive care unit was 8.32±6.91 days. Statistical processing of the obtained data was performed using the statistical software package SPSS 12.0 for Windows.ResultsECG analysis showed that most of the patients had various ischemic changes and/or myocardial repolarization disorders – in 119 (89.5%) patients. Thus, inversion of the T wave was registered – in 91 (68.4%), signs of early ventricular repolarization – in 14 (10.5%), elevation of ST segment – in 6 (4.5%), depression of ST segment – in 54 (40.6%), pathological Q wave – in 9 (6.8%). In turn, signs of an overload of a left ventricle (LV) – in 27 (20,3%), signs of an overload of a right ventricle (RV) – in 8 (6,0%), a sign of SIQIIITIII – in 7 (5,3%), prolongation of QT interval – in 6 (4.5%) patients, respectively. Also signs of LV hypertrophy – in 45 (33.8%), signs of RV hypertrophy – in 12 (9.0%), the presence of p-pulmonale – in 6 (4.5%), p-mitrale – in 7 (5.3%) patients, respectively.Predictors of ischemic changes and/or repolarization disorders in the patients with severe COVID infection are: a decrease of glomerular filtration rate (GFR) <60 ml/min/1.73 m2 – r=0.580, p=0.006; time of hospitalization r=−0,204, p=0,02; elderly patients – r=0,184; p=0.02.ConclusionsThe prevalence of ischemic changes and/or myocardial repolarization disorders according to ECG data is 89.5%. Presence of inversion of T wave (68.4%) and depression of ST segment (40.6%) were dominated in the structure of ischemic changes and/or myocardial repolarization disorders. Their predictors are: decrease of GFR <60 ml/min/1.73 m2; time of hospitalization; elderly patients.FUNDunding AcknowledgementType of funding sources: None.

CHANGES IN ELECTROENCEPHALOGRAM INDICATORS IN ADOLESCENTS WITH VEGETATIVE DYSFUNCTION

This work is based on the results of a study of the assessment of physical parameters of the electroencephalogram in adolescents with autonomic dysfunction, depending on gender and the presence of perinatal pathology in the anamnesis. We examined 87 adolescents 12-18 years old with clinically and laboratory-instrumental confirmed dysfunction of the autonomic nervous system -autonomic dystonia syndrome (ADS). The average age of the clinical manifestation of ADS in girls was 12.2 ± 1.8 years, in boys -13.5 ± 2.1 years. As a result of the study, it was revealed that adolescents with a history of perinatal pathology have the maximum risk of disturbances in the processes of myocardial repolarization at the end of the recovery period after physical exertion, especially in females

Прогнозування та діагностика правошлуночкової серцевої недостатності та дисфункції шлуночків серця в період загострення бронхіальної астми у дітей

Актуальність. Бронхіальна астма (БА) вже в дитячому віці може супроводжуватись серцево-судинними ускладненнями у вигляді синдрому гострого легеневого серця, дисфункції шлуночків серця, метаболічної кардіоміопатії, порушень ритму і провідності, що не тільки обтяжує перебіг захворювання, але й додатково знижує якість життя пацієнтів. Ремоделювання серця при БА передує клінічним проявам серцевої недостатності та може самостійно поглиблювати систолічну і діастолічну дисфункцію шлуночків. Мета. Удосконалення прогнозування розвитку серцево-судинних ускладнень у період загострення БА в дітей шляхом визначення факторів ризику розвитку дисфункції шлуночків і розробки додаткових інформативних клініко-ехокардіографічних діагностичних критеріїв правошлуночкової серцевої недостатності. Матеріали та методи. Під нашим спостереженням перебували 85 дітей, хворих на БА, віком від 5 до 17 років, у яких застосовано методи пульсоксиметрії, спірографії, електрокардіографії, допплер-ехокардіографії. Обстеження проводилось у періоді загострення БА при госпіталізації хворого і в періоді поліпшення стану, на 5–6-ту добу перебування у відділенні пульмоалергології комунального закладу «Обласна дитяча клінічна лікарня» Дніпропетровської обласної ради. Критеріями включення в дослідження були алергічна та змішана персистуюча средньотяжка і тяжка астма в період загострення. В дослідження не ввійшли хворі на БА діти в період ремісії, діти з інтермітуючим перебігом астми та легкою персистуючою БА. Для визначення типу й ступеня вентиляційної недостатності використовували метод спірографії з оцінкою показників життєвої ємності легень (ЖЄЛ), об’єму форсованого видиху за 1 секунду (ОФВ1), ОФВ1/ЖЄЛ. Математичне і статистичне опрацювання матеріалів дослідження проводили з використанням методів біостатистики, реалізованих у пакетах програм Microsoft Excel (Office Home Business 2KB4Y-6H9DB-BM47K-749PV-PG3KT), Statistica 6.1 (StatSoft Inc., серійний № AGAR909E415822FA). Результати. Визначено прогностичні клінічні фактори ризику розвитку систоло-діастолічної дисфункції шлуночків серця у випадку можливого нападу БА, до яких було віднесено: наявність у хворої дитини БА тяжкого перебігу; наявність тахікардії у спокої; порушення реполяризації в міокарді шлуночків на електрокардіограмі; наявність у хворого на астму супутнього хронічного тонзиліту; бактеріоносійство у носоглотці; жіночу стать. Розроблено додаткові інформативні діагностичні критерії розвитку правошлуночкової серцевої недостатності в період загострення БА у дітей. Установлено, що застосування еуфіліну поряд із ­b2-агоністами для бронхолітичної терапії дітей у період загострення БА негативно впливає на діастолічну функцію шлуночків серця і сприяє збереженню підвищеного тиску в легеневій артерії. Висновки. Питання покращення можливостей прогнозування розвитку дисфункції шлуночків серця та своєчасної діагностики серцево-судинних ускладнень у період загострення БА у дітей вирішується шляхом визначення клінічних факторів ризику розвитку дисфункції шлуночків і розробки додаткових інформативних клініко-ехокардіографічних діагностичних критеріїв правошлуночкової серцевої недостатності.

The Effect of Carbetocin Dose on Transmural Dispersion of Myocardial Repolarization in Healthy Parturients Scheduled for Elective Cesarean Delivery Under Spinal Anesthesia: A Prospective, Randomized Clinical Trial

(Anesth Analg. 2021;132:485–492) Transmural dispersion of myocardial repolarization (TDR) is the interval between the peak of the T wave and end of the TV wave (Tp-e). Increased TDR is a more reliable predictor of drug torsadogenicity than prolonged QT interval. Carbetocin, a synthetic analog of oxytocin, is used to prevent postpartum hemorrhage following cesarean delivery, though the effect dose varies. Carbetocin has been shown to increase mean correct QT, but there is a paucity of information on the effects of carbetocin of TDR. This study examined the effects of carbetocin dose on TDR in patients undergoing cesarean delivery under spinal anesthesia.

Genomic and pleiotropic analyses of resting QT interval identifies novel loci and overlap with atrial electrical disorders.

The resting QT interval, an electrocardiographic (ECG) measure of ventricular myocardial repolarization, is a heritable risk marker of cardiovascular mortality, but the mechanisms remain incompletely understood. Previously reported candidate genes have provided insights into the regulatory mechanisms of the QT interval. However, there are still important knowledge gaps. We aimed to gain new insights by (i) providing new candidate genes, (ii) identifying pleiotropic associations with other cardiovascular traits, and (iii) scanning for sexually dimorphic genetic effects. We conducted a genome-wide association analysis for resting QT interval with ~9.8 million variants in 52 107 individuals of European ancestry without known cardiovascular disease from the UK Biobank. We identified 40 loci, 13 of which were novel, including 2 potential sex-specific loci, explaining ~11% of the trait variance. Candidate genes at novel loci were involved in myocardial structure and arrhythmogenic cardiomyopathy. Investigation of pleiotropic effects of QT interval variants using phenome-wide association analyses in 302 000 unrelated individuals from the UK Biobank and pairwise genome-wide comparisons with other ECG and cardiac imaging traits revealed genetic overlap with atrial electrical pathology. These findings provide novel insights into how abnormal myocardial repolarization and increased cardiovascular mortality may be linked.

Repolarization disparity as a predictor of response to Head up Tilt-table Test in pediatric syncope.

Head up Tilt-table Test (HUTT) is a practical examination of the most common type of pediatrics syncope. The electrocardiographic (ECG) changes during this test, show the autonomic defects that cause neuraly-mediated syncope in response to tilting process. All pediatric syncope patients referred to our center in a 1-year period, were included in the study. HUTT was performed and patients were classified into two groups of Negative and Positive HUTT results, and the latter group was subclassified as three subgroups of "vasodepressor", "cardioinhibitory" and "mixed type" responses to HUTT. QT and corrected QT (QTc) dispersion was measured by the baseline standard 12-lead ECG obtained before HUTT. Eighty-six patients with a mean age of 12.19 ± 5.34 were included. Patients with positive HUTT were significantly younger and male gender was more prevalent in this group. Mean QT dispersion was significantly higher in patients with positive HUTT result and also in patients with mixed response to HUTT compared to isolated vasodepressor response. Duration of QTc interval did not change between different study groups. Reciever-Operating-Characteristic (ROC) analysis showed that QT dispersion higher than 32ms is a significant predictor of positive HUTT result (with 92% sensitivity and 98% specificity) and values higher than 40ms can predict the mixed type of response to HUTT (with 84% sensitivity and 63% specificity). Baseline myocardial repolarization disparity significantly correlates with susceptibility to symptomatic vasovagal syncope. This pathology seems to play its role mainly via excessive vagotonic response to sympathetic activation during HUTT process (known as cardioinhibitory response).

Myocardial repolarization is affected in patients with diabetic retinopathy

Background/Aim: Diabetes Mellitus (DM), considered the equivalent of coronary artery disease, is one cause of ventricular repolarization (VR) dispersion. Retinopathy is one of the vascular consequences of diabetes. The association between myocardial repolarization dispersion and diabetic retinopathy is not fully elucidated. We aimed to evaluate ventricular repolarization using Tp-e interval and corrected (c) Tp-e/QT ratio in DM patients with and without retinopathy. Methods: A total of 124 diabetic subjects were included in this retrospective cohort study. All medical data were obtained from the electronic database of our university hospital. The subjects were divided into the no diabetic retinopathy (NDR) group (n=45), and the diabetic retinopathy (DR) group (n=79), which were compared in terms of demographic features, clinic and laboratory findings, and electrocardiographic findings such as QT, QTc, Tp-e, Tp-e/QT, Tp-e/QTc. Results: The groups were similar in terms of demographic features (P>0.05). Both Tp-e interval and Tp-e/QTc were significantly prolonged in the DR group compared to the NDR group. There were significant correlations between Tp-e, Tp-e/QTc, DM duration, and age. In multivariate logistic regression analysis, Tp-e (OR=6.01, %95 CI=4.17-7.52, P=0.012), Tp-e/QTc (OR=1.215, 95% CI=0.874-1.612, P=0.029), and DM duration (OR=1.422, 95% CI= 1.146–1.712, P<0.001) were independent predictors of DR. Conclusion: We showed that DM patients with retinopathy may also have an increased risk for sudden cardiac death due to ventricular arrhythmogenesis.