QTc Max Research Articles

Evaluation of the Relationship Between Microalbuminuria/Creatinine Ratio and QTc Dispersion in Type 2 Diabetes Mellitus

Objective: The assessment of QTc dispersion (QTd) is of importance in determining the risk of ventricular arrhythmias and cardiac autonomic neuropathy (CAN) in patients with diabetic nephropathy (DN). Our study explored the relationship between the microalbumin/creatinine (MA/crea) ratio and QT(cd) in the context of CAN development in DN. Material and Methods: We selected fifty individuals with a spot urine MA/crea ratio of less than 30 as the control group and fifty individuals with an MA/crea ratio between 30 and 300 as the patient group. QT intervals were calculated using the Bazett formula, taking into account the heart rate. Results: In contrast to the control group, the patient group exhibited a considerably higher median QTc min value (380.63 msn, 361.44–397.30, p: 0.042) and a statistically significant increase in the median QTc max value (439.98 msn, 420.17–460.22, p=0.005). Furthermore, the median MA/crea value (82, 60–300, p<0.0001) was found to be highly significant. However, the median QT(cd) value (61.25 msn, 49.91–81.70, p=0.066) was only marginally significant, with no statistically significant difference between the two groups. It is worth noting that both groups showed a significant difference in terms of QTd (p<0.001). In the control group, where DN had not yet developed, the QT(cd) value could be detected before an increase in the MA/crea value. Conclusion: The findings that both the control group and the patient group exhibited elevated QTcd values suggest that this parameter may be a viable predictor of cardiovascular risk. Furthermore, it is conceivable that QTcd could serve as an early warning sign for cardiovascular risk in diabetic patients who have not yet reached the stage of microalbuminuria.

Assessment of cardiac arrhythmias, P wave and QT dispersion in systemic sclerosis

Cardiac involvement in systemic sclerosis (SSc) is significant cause of SSc-related mortality. The objective of the study was to assess cardiac arrhythmias, P wave and QT dispersion in SSc patients. 40 SSc patients and 40 healthy participants who had similar sociodemographic characteristics with the patients were enrolled in the study. P wave dispersion (Pd), QT dispersion (QTd), and corrected QT (QTc) dispersion (QTcd) were calculated by measuring maximum (max) and minimum (min) of P wave, QT interval, QTc in 12-leads electrocardiography (ECG). Cardiac arrhythmias and conduction disorders were assessed by ECG and Holter-ECG. The mean age of SSc patients (92.5% of females) was 50.9±13.9 years similar with the healthy group (51.4±8.9). Abnormal ECG findings were found in 27.5% of SSc patients and remarkably higher in comparison to the healthy participants (p=0.019). The most frequently reported abnormal ECG findings were left anterior fascicular block (15%), ventricular premature beat (10%) and first-degree atrioventricular heart block (5%). The comparison of dispersion showed no statistically important difference in Pd between two groups (p=0.69) while QTd, QTc, QTcd, QTc min, and QTc max were markedly prolonged in patients with SSc (p=0.039; p<0.001; p=0.021; p<0.001; p<0.001, respectively). The assessment of Holter-ECG demonstrated that supraventricular tachycardia was frequently detected in patients with SSc (22.5% vs 2.5%; p=0.007). This study indicated a significantly elevated incidence of abnormal ECG results and SVT, an arrhythmia not typically identifiable through standard ECG but detectable via Holter monitoring, in patients with SSc. In the study, QTd, QTc, and QTcd intervals were significantly longer in SSc patients, which may indicate a susceptibility to arrhythmias.

Evaluation of the changes in electrocardiographic ventricular repolarization parameters after COVID-19 recovery in hemodialysis patients.

Coronavirus disease-2019 (COVID-19) has cardiac manifestations. Data about electrocardiogram (ECG) changes after COVID-19 recovery is limited in hemodialysis patients. We aimed to investigate the changes in ventricular repolarization parameters after COVID-19 recovery in hemodialysis patients. Fifty-five hemodialysis patients who recovered from COVID-19 infection were included. QT interval, Tp-e interval, corrected QT (QTc), QTc dispersion, and Tp-e dispersion values were determined on the patients' ECGs, taken before COVID-19 and at least 1 month after recovery. The patients' data before COVID-19 infection and after recovery were compared. It was found that longest QTc (QTcmax) and QTc dispersion values after recovery were prolonged compared with pre-infection period (427 ± 28 ms vs. 455 ± 26 ms, p = 0.000 and 39 ± 16 ms vs. 65 ± 20 ms, p = 0.000). In our hemodialysis patients, ventricular repolarization parameters increased after COVİD-19 recovery. In hemodialysis patients, already predisposed to arrhythmic deaths, arrhythmia risk after COVİD-19 recovery may become more pronounced.

Management of cardiac arrhythmias in paediatric patients with TANGO2-deficiency disorder

Abstract Funding Acknowledgements Type of funding sources: None. Background TANGO2-deficiency disorder (TDD) is a rare paediatric condition caused by bi-allelic mutations in the TANGO2 gene. TDD is characterised by susceptibility to metabolic crises with rhabdomyolysis, encephalopathy, lactic acidosis, hypothyroidism and difficult to manage tachyarrhythmias. Aim We describe the electrocardiographic (ECG) findings at baseline and during metabolic crises in patients with TDD. Methods Retrospective, single-centre, case series study of patients with TDD (<18 years), with ECG and subcutaneous Holter monitoring, both during metabolic crises and compensated phases. Results During the period 2013-2021, 12 patients with TDD were found (median age 6.8 years, IQR 2-11.5 years). In the inter-crisis period, bradyarrhythmias were evidenced: 2/12 patients presented sinus bradycardia, 2/12 pauses of 4 and 10 seconds, 1/12 Wenckebach type block; and tachyarrhythmias: 1/12 presented paroxysmal supraventricular tachycardia and 1/12 flutter. 25% had long QT during non-acute phases (median QTc max 476 ms, IQR 456ms-530ms). There were 14 hospitalisations for metabolic crises. 57.1% had QTc interval prolongation, 35.7% ventricular tachycardias (4/14 monomorphic VT, 1/14 torsade de prongs) and 1/14 Brugada type 3 pattern. Three patients died in the context of severe metabolic acidosis and multi-organ involvement (2/12 due to VT and 1/12 due to cardiogenic shock, bradycardia associated with QTc of 635ms and severe ventricular dysfunction). Conclusions In paediatric patients with TDD, the most frequent ECG abnormality was QTc interval prolongation with or without metabolic crises. There is a high risk of tachyarrhythmias, mainly VT, being the main cause of death in children with TDD. Subcutaneous Holter monitoring is recommended. During metabolic crises, there should be close ECG monitoring.

Hydroxychloroquine and Azithromycin Combination in the Management of COVID-19 Infection: Safety and Effectiveness Challenges.

The treatment of COVID-19 disease remains a dilemma so far because there is no approved therapy for it. This study aimed to evaluate the use of hydroxychloroquine and azithromycin combination in treatment. This study was carried out to determine the safety and effectiveness of hydroxychloroquine and azithromycin combination in COVID 19 patients. This study included 90 adult COVID 19 patients. Treatment of all patients followed Egyptian Ministry of Health COVID-19 protocols, receiving a combination of hydroxychloroquine 400mg twice on day 1, then 200 mg twice daily in addition to azithromycin 500mg/day for 5 days. ECG findings, especially the QTc interval, were assessed before and after 5 days from the administration. All patients showed a statistically significant higher post-treatment QTc readings (433.6 ± 37.2) compared to baseline QTc (402.4 ± 31.3) at p<0.005 with a median QTc prolongation by 26 mSec and IQR (17.8-41.3), but without serious clinical complications. Only 5.6% of patients showed QTc more than 500 mSec and no torsade de points or cardiac arrest. Geriatric patients were at higher risk for QTc prolongation compared to patients aged less than 65 years but without a significant difference as regards the median max QTc difference p˂0.65. The expected therapeutic effectiveness was 82.5% for moderate patients compared to 26% for severe patients (P<0.005). In a modest safety profile, we support the evidence that HQ/AZ therapy can be used to treat Covid-19 infection with more effectiveness in moderate rather than severe cases, which might be a reflection of the time of administration in the disease course.

Effects of azithromycin on ventricular repolarization in children with COVID-19

IntroductionAzithromycin is used to treat pediatric COVID-19 patients. It can also prolong the QT interval in adults. This study assessed the effects of azithromycin on ventricular repolarization in children with COVID-19. MethodThe study prospectively enrolled children with COVID-19 who received azithromycin between July and August 2020. An electrocardiogram was performed before, one, three, and five days post-treatment. Using ImageJ®, the following parameters were measured: QT max, QT min, Tp-e max, and Tp-e min. The parameters QTc max, QTc min, Tp-ec max, Tp-ec min, QTcd, Tp-ecd, and the QTc/Tp-ec ratio were calculated using Bazett's formula. ResultsThe study included 105 pediatric patients (mean age 9.8±5.3 years). The pretreatment heart rate was higher than after treatment (before 92 [79–108]/min vs. Day 1 82 [69–108)]/min vs. Day 3 80 [68–92.2]/min vs. Day 5 81 [70–92]/min; p=0.05). ConclusionAzithromycin does not affect the ventricular repolarization parameters on ECG in pediatric COVID-19 cases.

Seven day continuous ambulatory electrocardiographic telemetric study with pocket electrocardiographic recording device for detecting hydroxychloroquine induced arrhythmias.

Objective:The use of hydroxychloroquine (HCQ) for COVID-19 treatment and prophylaxis raised issues concerning its cardiac safety owing to the possibility of QT prolongation and arrhythmias. There was no study on long-term electrocardiographic telemetry monitoring of patients taking HCQ. We planned a continuous electrocardiographic Holter telemetry of these patients for 7 days.Material and Methods:Health care workers taking HCQ as pre exposure prophylaxis and patients on HCQ were monitored using seven day Holter electrocardiographic telemetry with continuous beat to beat analysis. Telemetry can instantly convey any arrhythmic event or significant QT prolongation to the medical faculty.Results:Twenty-five participants with a mean age of 42.4 ± 14.1 years were included in the study; 40% were females. Twenty percent of participants needed to stop HCQ. Four patients developed QT prolongation >500 ms and needed to stop HCQ, one patient had accelerated idioventricular rhythm and stopped treatment, and one had short episodes of atrial fibrillation. No malignant arrhythmia or ventricular arrhythmia, or torsade de pointis were noted. No episode of significant conduction disturbance and arrhythmic death was noted. Baseline mean QTc was 423.96 ± 32.18 ms, mean QTc corrected at 24 h was 438.93 ± 37.95, mean QTc was 451.879 ± 37.99 at 48 h, and change in baseline mean QTc to max QTc was 30.74 ± 21.75 ms at 48 h. All those who developed QTc prolongation >500 ms were greater than 50 years of age.Conclusion:Ambulatory telemetry ECG monitoring detects early QT prolongation, and stopping drugs prevents malignant arrhythmias. HCQ seems to have less risk of QT prolongation in young, healthy individuals.

Comparison of ventricular repolarization parameters of Covid-19 patients diagnosed with chest CT and RT-PCR

Background and objectives The aim of the comparison is to evaluate the marker of ventricular repolarization parameters such as QT, QTc, cQT, Tp-e, Tp-e/QT, Tp-e/QTc, Tp-e/JT and Tp-e/JTc ratios and the risk of ventricular arrhtythmias in patients with newly diagnosed Covid-19. Methods The study included 2 separate groups. The first one consisted of 96 positive reverse transcriptase polymerase chain reaction (RT-PCR) Covid-19 patients and the second one of 106 patients with negative PCR but positive chest computed tomography (CT) findings consistent with Covid-19. We measured QTmax, QTmin, QRS, JT and Tp-e intervals and estimated Tp-e/QT max, Tp- e/QTc max, Tp-e/JT and Tp-e/JTc rates and QTc max, QTc min, cQTd and JTc intervals. Results QT max, QT min, JT, cQTd, Tp-e, Tp-e/QT max, Tp-e/QTc max, Tp-e/JT, Tp-e/JTc values were significantly higher in RT-PCR Covid-19 patient group. Conclusion Positive RT-PCR Covid-19 patients should be followed more closely, in terms of high ventricular repolarization parameters and preventing ventricular arrhythmias that may develop due to this.

Analysis of corrected QT dispersion, tp-e values in small heart syndrome patients

Abstract Funding Acknowledgements Type of funding sources: None. Background and objectives We aimed to evaluate the marker of ventricular arrhythmias such as Tp-e/QT, Tp-e/QTc, Tp-e/JT and Tp-e/JTc ratios in ‘Small Heart Syndrome’ female patients and also aimed to evaluate the association between ‘small heart syndrome’ and fibromyalgia in female patients. Methods A total of 94 female, including 47 small-heart and 47 normal-heart patients, who applied from March 2018 to February 2020 and who were examined by a physical therapy and rehabilitation specialist, were included in the study by calculating their cardiothoracic ratios (CTR) from the chest x-ray. QTmax, QTmin,QRS, JT and Tp-e intervals were measured. In addition, Tp-e/QTmax, Tp-e/QTc max, Tp-e/JT and Tp-e/JTc rates and QTc max, QTc min, cQTd and JTc intervals were calculated. Results cQTd (24,246 ± 9,046 ms vs. 35,495 ± 14,358 ms, p &amp;lt; 0.001), Tp-e (67,32 ± 11,661 ms vs. 72,67 ± 11,028 ms, p = 0.04), Tp-e/QTc max (0,166 ± 0.028 vs. 0.181 ± 0.027, p = 0,012), Tp-e/JTc (0,214 ± 0.038 vs. 0.232 ± 0.034, p = 0,022) values were significantly higher in small heart patient group. QT min (330,68 ± 26,611 ms vs. 323,04 ± 30,829 ms, p = 0,202) values were significantly lower in patient group. Conclusion Compared to control group potential ECG repolarization predictors were significantly increased in ‘Small Heart Syndrome’ patients. TableElectrocardiographic findings o Control group(n = 47) Patient group(n = 47) P value Heart rate, bpm 87,81 + 15,532 83,81 + 14,372 0,223 QRS; ms 83,23 + 6,948 81,91 + 10,052 0,206 QT max; ms 354,93 + 26,796 358,54 + 28,434 0,528 QT min; ms 330,68 + 26,611 323,04 + 30,829 0,202 JT; ms 265,7 + 25,16 271,88 + 23,104 0,218 QTc max; ms 403,59 + 18,208 400,20 + 18,336 0,371 QTc min; ms 379,34 + 20,064 364,71 + 23,149 0,004* JTc; ms 314,37 + 21,325 313,55 + 22,526 0,856 cQTd; ms 24,246 + 9,046 35,495 + 14,358 &amp;lt;0,001* Tp-e; ms 67,32 + 11,661 72,67 + 11,028 0,040* Tp-e/QT max 0,190 + 0,034 0,203 + 0,031 0,063 Tp-e/QTc max 0,166 + 0,028 0,181 + 0,027 0,012* Tp-e/JT 0,255 + 0,047 0,267 + 0,036 0,295 Tp-e/JTc 0,214 + 0,038 0,232 + 0,034 0,022*

Typical dynamic electrocardiographic changes in Takotsubo syndrome

Aims Negative T waves and QTc prolongation often occur in patients with Takotsubo syndrome. Description of typical electrocardiographic changes could be a diagnosis element of this syndrome. This study aimed to clarify on the one hand the more preciously possible the typical electrocardiographic changes, and on the other hand, the timing of occurrence of these abnormalities compared to the trigger occurrence, the symptoms onset and the hospital admission. Methods and results We studied ECGs at admission of 59 patients with Takotsubo syndrome, a ‘reference’ ECG and each one available during the first five days after admission. We observed significant changes on the pathological ECG compared to reference ECG: the mean number of leads with negative T waves (7.4 ± 1.9 mm vs 2.1 ± 1.4 mm, p < 0.0001), the highest value of negative T wave deflection among all the leads (−6.2 ± 4mm vs −1.4 ± 0.9 mm, p < 0.0001), the sum of all negative T waves (−27 ± 1.7 mm vs −2.8 ± 3.6 mm, p < 0.0001 and a QTc max and QTc mean prolongation (539 ± 63ms vs 457 ± 42ms, p < 0.0001 and 491 ± 52ms vs 421 ± 33ms, p < 0.0001 respectively). We also demonstrated that T waves were significantly more positive in pathological ECG in aVR and V1 compared to the reference one (mean value of T waves respectively of 1.8 ± 1.8 vs −1 ± 1.3, p < 0.0001 and 0.7 ± 1.6 vs 0.004 ± 1.2, p = 0.008). Conclusion The QTc prolongation, the profound negative T waves except in aVR and V1 occurring the first two days after admission are electrocardiographic changes typically of Takotsubo syndrome.

Evaluation of Changes in Ventricular Repolarization Parameters in Morbidly Obese Patients Undergoing Bariatric Surgery.

Weight loss after bariatric surgery has been associated with reduced cardiovascular mortality and overall mortality in obese patients. In this study, we aimed to analyze the changes between pre-operation and post-operation ventricular arrhythmia predictors in patients who underwent bariatric surgery. The study included 58 patients who underwent bariatric surgery. We measured QT max, QT min, QRS, JT, and Tp-e intervals, and we estimated Tp-e/QT max, Tp-e/QTc max, Tp-e/JT, Tp-e/JTc rates, QTc max, QTc min, cQTd, and JTc intervals both pre-op and 6 months post-op. Heart rate, PR, QT max, QTc max, QTc min, cQTd, JTc, Tp-e, Tp-e/QT max, Tp-e/QTc max, Tp-e/JT, and Tp-e/JTc values, which were close to the upper limit in the pre-op period, showed statistically significant decreases at 6 months post-op. The results of our study showed that bariatric surgery had positive effects on the regression of ventricular repolarization parameters and the possible development of ventricular arrhythmia.

The diagnostic value of QT dispersion for acute coronary syndrome in patients with nondiagnostic initial electrocardiograms

Introduction: Chest pain is a frequent cause for admission to the emergency department (ED). It can be a sign of various conditions, from a minor disorder to a life-threatening disease such as acute myocardial infarction (AMI). Despite the availability of modern-day tools for the diagnosis of AMI, about 5% of patients with AMI are missed in the ED, with subsequent associated morbidity and mortality. QT dispersion as a marker for arrhythmic potential being a marker of in-homogeneity of ventricular repolarization. The QT dispersion is increased in myocardial ischemia. Aims: This study we hypothesized that QTD could accurately identify patients with the acute coronary syndrome (ACS) who presented with chest pain and nondiagnostic initial electrocardiograms (ECGs). Subjects and Methods: The study population included (50) patients (37 males, 13 females) and (10) chronic stable ischemic patients as a control group, they were all in sinus rhythm on admission. All the studied patients were subjected to: History taking; complete physical examination was performed to rule out any other medical problems, standard 12-lead ECG, cardiac markers, echocardiographic examination. QT interval was calculated. The difference between the maximum and minimum QT intervals, occurring in any of the 12 leads, was measured as QTD. A corrected QT interval (QTc) of >440 ms is defined as abnormal, and the difference between QTc max and QTc min was calculated as QTcD. QT dispersion ≤40 ms was considered normal. Results: In the present study, we found that 26 patients (52%) have prolonged QTD (mean 78.800 ms, standard deviation [SD] ±49.555) and 44 patients (88%) have prolonged cQTD (mean 83.322 ms, SD ± 48.491) For patients who were admitted to the ED with chest pain and nondiagnostic initial ECG but later diagnosed as having ACS. Furthermore, we found that only 6 (12%) of patients have a significant prolongation QTD than normal in initial nondiagnostic ECG with elevated cardiac biomarkers (creatine kinase myocardial band at 0 h 48, mean creatine kinase myocardial band (CK MP) at 12 h was 145.833 ± SD 52.660, creatine phosphokinase (CPK) at 0 h: 635.33, mean CPK at 12 h 2448.66 ± SD 538.744). It has been suggested that the initial QTD level has a low predictive power for new cardiac events but that QTD can be more helpful for low-risk patients. Conclusion: Hence, in this study, we found that QTD and QTcD values are higher for ACS patients than for patients without ACS with nondiagnostic initial ECG.

The Evaluation of Electrocardiography Parameters Changes in Breath‐Holding Children Compared to Controls

Background Breath-holding spells (BHS) are brief periods when young children stop breathing for up to 1 minute and are widely recognized types of non-epileptic severe occasions in early stages of childhood. This study aimed to evaluate QTd and QTc changes in children with breath-holding spells compared with healthy children. Materials and Methods This case-control study was conducted to evaluate ECG parameters' changes in 90 children with breath-holding spells compared to 90 healthy children, who were included as controls, without any breath - holding in pediatric neurology clinic of Ali Asghar Hospital of Medical Sciences, University of Zahedan (ZaUMS), Iran, in 2018. Electrocardiography measures were measured from 12-lead surface electrocardiograms of the patients and the control group. Data were analyzed using SPSS software version 18.0. Results In the study there were 46 (51.1%), and 35(38.9%) females in controls and Breath Holding patients, respectively. QT max (p=0.002), S in V1 (p <0.001), R in V5 (p <0.001), R in aVL (p <0.001), S in V3 (p=0.002), LV mass (p <0.001), QTd (p <0.001), QTc max (p <0.001), and QTcd (p <0.001) were different in patients compared to controls, significantly (p <0.05). QTd (p <0.001), QTc max (p=0.03), and QTcd (p <0.001) were higher in pallid attacks, significantly. QT max (p=0.039), and QT min (p=0.039) were different in boys and girls so that QT max and QT min were higher in girls. Conclusion From the present study it can be concluded that QT, QTc, QTd and QTcd were higher in BHS. QTd, QTc max and QTcd were higher in pallid and QT max and QT min were higher in girls. However, in spite of what is reported in some studies, we suggest that obtaining ECG parameters is necessary to assess rhythm abnormality in children with BHS.

QTc dispersion as a novel marker in identifying patients requiring an epicardial approach for ablation of scar mediated ventricular tachycardia

IntroductionEpicardial exit sites of ventricular tachycardia (VT) are frequently encountered during VT ablation requiring an epicardial ablation approach for successful elimination of VT. We sought to assess the utility of repolarization markers in identifying individuals requiring an epicardial ablation approach in addition to an endocardial approach. Methods32 patients who underwent successful ablation for scar mediated VT were included in the study. Fourteen patients who required a combined endocardial and epicardial VT ablation were defined as epicardial VT group (Epi) whereas 18 patients who were successfully ablated from the endocardium alone constituted the endocardial VT group (Endo). Repolarization markers during sinus rhythm were compared between the two groups. ResultsA higher QTc max and QTc dispersion were seen in the Epi group compared to Endo group (479 ± 34 vs 449 ± 20, p = 0.008 and 63 ± 13 vs 38 ± 8, p = 0.001, respectively). Ts-p and Ts-p/Tp-e were higher in the Epi group (166 ± 23 vs 143 ± 23, p = 0.008 and 1.55 ± 0.26 vs 1.3 ± 0.21, p < 0.005). On multivariate regression, QTc dispersion was an independent predictor of the need for an epicardial approach to ablation. A QTc dispersion more than 51.5 msec identified individuals requiring a combined epicardial and endocardial approach to ablation with a sensitivity of 92.9% and a specificity of 100%. ConclusionsPatients requiring an epicardial ablation have a higher QTc dispersion. A value greater than 51.5 msec reliably differentiates between the two groups with high sensitivity and specificity.

A valproinsav, a carbamazepin és a levetiracetam hatása a Tp-e intervallumra, valamint a Tp-e/QT és a Tp-e/QTc arányra

To evaluate P-wave dispersion before and after antiepileptic drug (AED) treatment as well as to investigate the risk of ventricular repolarization using the Tpeak-Tend (Tp-e) interval and Tp-e/QT ratio in patients with epileptic disorder. A total of 63 patients receiving AED therapy and 35 healthy adults were included. ECG recordings were obtained before and 3 months after anti-epileptic treatment among patients with epilepsy. For both groups, Tp-e and Tp-e/QT ratio were measured using a 12-lead ECG device. Tp-e interval, Tpe/QT and Tp-e/QTc ratios were found to be higher in the patient group than in the control group (p<0.05, for all), while QTmax ratio was significantly lower in the patient group. After 3 months of AED therapy, significant increases in QT max, QTc max, QTcd, Tp-e, Tp-e/QT, and Tp-e/QTc were found among the patients (p<0.05). When the arrhythmic effects of the drugs before and after treatment were compared, especially in the valproic acid group, there were significant increases in Tp-e interval, Tp-e/QT and Tp-e/QTc values after three months of treatment (p<0.05). Carbamazepine and levetiracetam groups were not statistically significant in terms of pre- and post-treatment values. It was concluded that an arrhythmogenic environment may be associated with the disease, and patients who received AED monotherapy may need to be followed up more closely for arrhythmia.

Comparative Analysis of Cardiovascular Disorders in Patients with Chronic Myeloid Leukemia on Tyrosine Kinase Inhibitor Therapy

Aim. To analyze adverse cardiovascular events in chronic myeloid leukemia (CML) patients who received various tyrosine kinase inhibitors (TKI). Materials &amp; Methods. The trial included 97 CML patients with nilotinib, dasatinib or imatinib indications. By the time of examination the patients had undergone TKI therapy for 1-138 months. The three of them were sequentially treated with 2 drugs over the monitoring period. All CML patients were aged 22-79 years (median 53.5 years): 55 women were aged 22-71 years (median 53.5 years) and 42 men were aged 24-79 years (median 53 years). Results. The comparative analysis demonstrated significantly higher impact of nilotinib on daily maximum QTc duration compared with other TKIs. The patients who received nilotinib (n = 15) throughout 38 months had QTc of 0.47 s (interquartile range [IQR] 0.46-0.47 s), in imatinib group (n = 17) QTc was 0.43 s (IQR 0.43-0.44 s), and in dasatinib group (n = 4) QTc was 0.43 s (IQR 0.42-0.44 s) (p = 0.0008). Among all patients treated with nilotinib there were 62 % (31/50) with QTc &gt; 0.46 s, in imatinib (6/41) and dasatinib (2/18) groups it was detected in 14.6 % and 11.1 % of patients, respectively (p = 0.0008). Five patients had QTc &gt; 0.48 s, which is the criterion for discontinuation of treatment or dose reduction. In two patients the identified changes of QTc duration required TKI temporary suspension. After nilotinib dose reduction or discontinuation QTc duration normalized in all cases within 2 weeks. Decreased ankle-brachial index (ABI) &lt; 0.9 without pronounced clinical symptoms was identified in two patients who received nilotinib. Afterwards they showed peripheral occlusive disease of lower extremities, and nilotinib treatment was discontinued. In patients treated with other TKIs no occlusive vascular lesions were observed. A case of chronic heart failure with reduced left ventricular ejection fraction developing on nilotinib therapy was revealed and described. Conclusion. Despite high specificity for BCR-ABL tyrosine kinase, new TKIs can, although rarely, induce cardiovascular adverse events. Prior to TKI treatment assignment CML patients should be examined with ECG and EchoCG with systolic function evaluation, and the measurement of pulmonary artery pressure as well as ABI. The examination should be repeated in the end of the 1st year TKI treatment if there is no reason for extra examinations. It is recommended to hold 24-hour ECG monitoring with QTc max measurement prior to nilotinib assignment, then once a year within 2 years of nilotinib treatment, and once in 6 months after 3 years of therapy.

Evaluation of QT Dispersion and Tp-e interval in Children with Hypothyroidism

Background: Several studies in adults, showed increased dispersion of QT and corrected QT (QTc), peak-to-end interval of the T wave (Tp-e), Tp-e/QT ratio and Tp-e/QTc ratio in hypothyroidism. However, there were few studies in children with hypothyroidism. Objective: This study aimed to evaluate the relationship between hypothyroidism in children and increased QTd, QTc, Tp-e, Tp-e/QT ratio and Tp-e/QTc ratio. zPatients and methods: In this study we compared 50 hypothyroid children with 30 healthy children in respect of serum thyroid stimulating hormone (TSH), serum level of free triiodothyronine (fT3) and level of free thyroxine (fT4). Hypothyroidism diagnosed with TSH above the laboratory accepted upper limit and normal or decreased fT4 values. The patient and control group data were compared by calculating the QT interval, corrected QT(QTc), QT dispersion (QTd), QTc dispersion (QTcd), Tp-e, Tp-e/QT ratio and Tp-e/QTc ratio on 12-lead surface electrocardiogram (ECG). Results: In the hypothyroid group, the mean age was 10.36 ± 4.18 years old (ranged from 1-17 years). Regarding the control group, the mean age was 9.09 ± 4.58 years old (ranged from 1-17 years). The QT max, QTc max, QTd, QTcd, Tp-e, Tp-e/QT and Tp-e/QTc values were determined to be significantly higher in hypothyroid children than the control children (p=0.03, p=0.026, p< 0.001, p=0.004, p=0.003, p=0.034 and p=0.027 respectively). QT max, QTc max, QTd and QTcd in the hypothyroid group were 330 ± 38 ms, 406 ± 26 ms, 37 ± 17 ms and 39 ± 17 ms respectively. While in the control group, they were 315 ± 23 ms, 393 ± 26 ms, 18± 13 and 27 ± 16 respectively. Conclusion: It could be concluded that there was a significant increase in QTd, QTcd, Tp-e, Tp-e/QT ratio and Tp-e/QTc ratio values in children with hypothyroidism similar to that seen in adults. The use of 12- lead ECG for the measurements of QTd, QTcd and Tp-e can be considered necessary for the monitoring of children with hypothyroidism and in the evaluation of the risk of cardiovascular disease.

The Relationship Between QT Interval and Intra-Hospital Mortality in patients with Spontaneous Intracranial Hemorrhage.

Introduction:Repolarization abnormalities such as prolongation of QT interval and changes in ST segment and T wave are the most usual electrocardiogram (ECG) changes in patients with intracranial hemorrhage (ICH). It has recently been recommended that prolonged QTc interval raises the risk of death due to malignant ventricular arrhythmias or sudden cardiac death.Objective:The goal of this study was to evaluate the relationship between QT interval and death in patients with ICH.Method:This cross-sectional study was performed on patients with ICH who referred during 2015–2017 to Poursina Hospital, Rasht, Iran. The QT interval was manually measured based on the BAZETT formula. Max QT and Max QTc and QT dispersion were the variables evaluated by the ECG of the patients. The outcome under the study was the death or survival of patients during hospitalization.Results:Finally, 466 cases with the mean age of 69±12 years were studied of whom 68.7% were male. The average QT-Max interval was 350.4±56.5 milliseconds, and the average QTc-Max was 583.6±57.6 msec. Totally, 22.7% of the patients died. There was a significant statistical relationship between QTc-MAX and death (p=0.001). However, there was no statistically significant relationship between QT-MAX and the outcome (p=0.593).Conclusion:It is likely that, prolonged QT interval is correlated with in-hospital mortality of patients with ICH. Therefore, it can be expected that assessing ECG abnormalities, especially prolonged QTc could be valuable in these patients.

Electrocardiography Findings in Children with Epilepsy Compared with Healthy Children

Background Epilepsy is one of the most common neurological diseases. Over the last decades the hypothesis of cardiovascular effects from sudden seizure has been raised, and cardiac rhythm and ECG changes in these patients have been highlighted. The study aimed to evaluate the electrocardiography findings in children with epilepsy compared with healthy children. Materials and Methods In this case-control study, 90 patients aged between 6 months and 18 years who were matched with equal number of healthy children who referred to pediatric ward the of 'Ali Ebne Abi Talib' hospital in Zahedan, Iran. The study was performed in multicenter of Neurology and Cardiology centers. In the patients, the epilepsy was confirmed by a unique pediatric neurologist based on the definition of having at least two unprovoked seizures in 24 hours. ECG was captured from all participants by a pediatric cardiologist. Results In patients, 45.6% (n= 41) were females and in healthy 51.1% (n= 46) were females. Mean age of participants was similar in patients and healthy children (p=0.060). ECG findings such as QT min (p=0.001), R-R interval (p<0.001), Heart rate (p<0.001), S in V1 (p=0.002), R in aVL (p<0.001), S in V3 (p=0.003), QTd (p<0.001), QTcd (p<0.001), QTc max (p<0.001), and LV mass (p=0.007) were different in patients compared to controls. In patients, from ECG parameters, R in V5 was higher in male patients (p=0.043). Conclusion Based on the results, QTc, QTd, QTcd were prolonged in patients with epilepsy and, R in V5 was higher in male patients. To prevent abnormality rhythm in epilepsy, it is needed to evaluate QT to recognize the autonomic changes.

The dispersion of myocardial repolarization in ischemic stroke and intracranial hemorrhage

BackgroundMarkers of dispersion of myocardial repolarization have been proposed to identify the patients at higher risk of malignant arrhythmic events. The aim of the present study is to assess a possible association of the electrocardiografic (ECG) markers of the dispersion of repolarization with the type of stroke, involvement of insula, neurological severity (National Institutes of Health Stroke Scale, NIHSS score), and disability (modified Rankin Scale, mRS score) in patients with a cerebrovascular event. MethodsWe conducted a retrospective analysis based on data prospectively collected from consecutive patients with a cerebrovascular event who underwent 12‑lead ECG at admission to the Verona Stroke Unit. ResultsOf the 63 patients included in the study, 55 had ischemic stroke and 8 intracranial hemorrhage. TpTe (time between the peak and the end of the T wave) and TpTe/QTc (TpTe/corrected time between the start of the Q wave and the end of the T wave) in lead V5 were higher in intracranial hemorrhage than in ischemic stroke (p = 0.03 and p = 0.04, respectively) and QT max (the longest QT calculated in the 12 leads) was higher in patients with involvement of insula (p ≤ 0.01). A correlation was found between QTc max and NIHSS score at admission (p = 0.02), QT max and NIHSS score at discharge (p = 0.05), and QT max and mRS score at discharge (p = 0.02). ConclusionsTpTe and TpTe/QTc in V5 lead were associated with intracranial hemorrhage and QT max was associated with involvement of insula. The prolongation of QT was correlated with neurological severity and disability.