QTc prolongation after aneurysmal subarachnoid hemorrhage might be associated with worse neurologic outcome in patients receiving microsurgical clipping or embolization of the intracranial aneurysms: a retrospective observational study.

PURPOSE: QT interval prolongation is one of the most common electrocardiographic (ECG) abnormalities in patients with aneurysmal subarachnoid hemorrhage (aSAH). Whether corrected QT interval (QTc) prolongation is associated with perioperative cardiac events and dismal neurological outcome in mid to long-term follow-up in patients after aSAH is insufficiently studied and remains controversial. METHODS: We retrospectively studied the adult (≥ 18 years) patients admitted to our institution between Jan 2018 and Dec 2020 for aSAH who underwent intracranial aneurysm clipping or embolization. The patients were divided into 2 groups (normal and QTc prolongation groups) according to their QTc. To minimize the confounding bias, a propensity score matching (PSM) analysis was performed to compare the neurologic outcomes between patients with normal QTc and QTc prolongation. RESULTS: After screening, 908 patients were finally included. The patients were divided into 2 groups: normal QTc groups (n = 714) and long QTc group (n = 194). Female sex, hypokalemia, posterior circulation aneurysm, and higher Hunt-Hess grade were associated with QTc prolongation. In multiple regression analysis, older age, higher hemoglobin level, posterior circulation aneurysm, and higher Hunt-Hess grade were identified to be associated with worse outcome during 1-year follow-up. Before PSM, patients with QTc prolongation had higher rate of perioperative cardiac arrest or ventricular arrhythmias. After PSM, there was no statistical difference between normal and QTc prolongation groups in perioperative cardiac events. However, patients in the QTc prolongation group still had worse neurologic outcome during 1-year follow-up. CONCLUSIONS: QTc prolongation is associated with worse outcome in patients following SAH, which is independent of perioperative cardiac events.

Current updates on arrhythmia within Timothy syndrome: genetics, mechanisms and therapeutics.

Timothy syndrome (TS), characterised by multiple system malfunction especially the prolonged corrected QT interval and synchronised appearance of hand/foot syndactyly, is an extremely rare disease affecting early life with devastating arrhythmia. In this work, firstly, the various mutations in causative gene CACNA1C encoding cardiac L-type voltage-gated calcium channel (LTCC), regard with the genetic pathogeny and nomenclature of TS are reviewed. Secondly, the expression profile and function of CACNA1C gene encoding Cav1.2 proteins, and its gain-of-function mutation in TS leading to multiple organ disease phenotypes especially arrhythmia are discussed. More importantly, we focus on the altered molecular mechanism underlying arrhythmia in TS, and discuss about how LTCC malfunction in TS can cause disorganised calcium handling with excessive intracellular calcium and its triggered dysregulated excitation-transcription coupling. In addition, current therapeutics for TS cardiac phenotypes including LTCC blockers, beta-adrenergic blocking agents, sodium channel blocker, multichannel inhibitors and pacemakers are summarised. Eventually, the research strategy using patient-specific induced pluripotent stem cells is recommended as one of the promising future directions for developing therapeutic approaches. This review updates our understanding on the research progress and future avenues to study the genetics and molecular mechanism underlying the pathogenesis of devastating arrhythmia within TS, and provides novel insights for developing therapeutic measures.

Prognostic significance of prolonged corrected QT interval in cerebral contusion.

Background & objectives: Cerebral contusion (CC) results in a release of catecholamines, autonomic dysfunction and neural stimulation that can lead to a number of cardiac adverse events, so it is critical to determine these. So the objective of this study was to investigate the prognostic significance of electrocardiographic changes, particularly the effects of a prolonged corrected QT (QTc) interval in CC. Methods: In this retrospective cohort study, 110 patients with CC were evaluated. Age, sex, concomitant diseases, Glasgow Coma Scale on admission, radiological assessment of the contusion (location, size, course and presence of cerebral oedema), need for surgical intervention, length of hospital stay and the extended Glasgow Outcome Scale (GOS-E) were statistically analysed within the QTc interval by routine electrocardiography (ECG) on admission. Results: The prolonged QTc interval was found to be associated with a higher incidence of cerebral oedema and a significantly higher risk of needing surgery. Patients with a prolonged QTc interval had a significantly larger contusion volume, greater midline shift and longer hospital stay, so their GOS-E score was significantly lower. A prolonged QTc interval on admission resulted in a hospital stay of more than eight days (sensitivity: 0.97 and specificity: 0.86), a higher risk of midline shift of more than 0.45 cm (P=0.006, sensitivity: 0.80 and specificity: 0.99) and a GOS-E score of <7 (sensitivity: 0.97 and specificity: 0.85). Interpretation & conclusions: ECG changes on admission showing a prolonged QTc interval have prognostic significance in CC. This simple and easily applicable information should be taken into consideration at the time of clinical decision making which may prevent an adverse events survivor.

Prolongation of the QTc interval is associated with an increased risk of cardiovascular diseases: The Hoorn study.

BACKGROUND/OBJECTIVE: Prolonged heart rate-corrected QT interval (QTc) on the electrocardiogram (ECG) is maybe associated with the occurrence of cardiovascular diseases (CVD), but the evidence is inconsistent. Therefore, we investigated whether baseline prolongation of the QTc interval is associated with CVD morbidity and mortality and its subtypes and whether glucose tolerance modifies this association in a population-based cohort study with a mean follow-up of 10.8 years. METHODS: We analyzed a glucose tolerance stratified sample (N = 487) from the longitudinal population-based Hoorn Study cohort (age 64 ± 7 years, 48% female). Cox regression was used to investigate the association between sex-specific baseline QTc quartiles and CVD morbidity and mortality. The risk was also estimated per 10 ms increase in QTc. All analyses were adjusted for age, sex, smoking status, systolic blood pressure, prevalent CVD, glucose tolerance status, hypertension and total cholesterol. In addition, stratified analyses were conducted for glucose tolerance status. RESULTS: During a mean follow-up of 10.8 years, 351 CVD events were observed. The adjusted hazard ratios (95% CI) for each 10 ms increase in QTc interval were 1.06 (95% CI: 1.02-1.10) for CVD, 1.06 (95% CI: 0.97-1.15) for acute myocardial infarction, 1.07 (95% CI: 1.01-1.13) for stroke, 1.12 (95% CI: 1.06-1.19) for heart failure, 1.04 (95% CI: 0.96-1.12) for peripheral arterial disease and 1.01 (95% CI:0.95-1.08) for coronary heart disease. Glucose tolerance status did not modify the association (P > 0.2). CONCLUSION/INTERPRETATION: Prolongation of the QTc interval is associated with morbidity and mortality due to general CVD. Glucose tolerance status did not modify these associations.

Gefitinib Increases the Incidence of QT Prolongation in Patients with Non-Small Cell Lung Cancer.

Gefitinib (GEF) may increase the risk of corrected QT prolongation (QTc). We aimed to evaluate whether gefitinib increases the risk of corrected QT interval (QTc) prolongation and analyze the associated risk factors.A total of 122 cases of advanced EGFR-mutated non-small cell lung cancer (NSCLC) who received gefitinib therapy from January 2015 to December 2020 were evaluated. The results of at least two resting 12-lead electrocardiogram before and after gefitinib treatment were obtained. The Bazett and Fridericia formulas were used to calculate the QTc interval, and the changes of QTc interval values before and after treatment were evaluated. The correlation between gefitinib and QTc interval prolongation and related risk factors were analyzed.After gefitinib-targeted therapy, 23 patients (18.9%) had a prolonged QTc interval, which increased from a mean of 446 ± 25 ms at baseline to 478 ± 18 ms (P < 0.001). Three of the patients met criteria for Grade 3 QTc prolongation in the common term V5.0 for clinical adverse events. Univariate analysis showed that age (ORR, 1.054; 95% confidence interval [CI], 1.003-1.107; P = 0.038), history of hypertension (ORR, 3.409; 95% CI, 1.334-8.713; P = 0.01), CCB medication history (ORR, 0.259; 95% CI, 0.094-0.712; P = 0.009), history of lung cancer surgery (ORR, 0.231; 95% CI, 0.064-0.829; P = 0.025), and baseline QT interval (ORR, 0.978; 95% CI, 0.964-0.993; P = 0.004) were important predictors of QTc interval prolongation in patients treated with gefitinib. The results of multivariate analysis showed that the history of lung cancer surgery and the baseline QT interval were important factors affecting QTc interval prolongation in patients treated with gefitinib.Gefitinib increases the risk of QTc prolongation in NSCLC patients, which may be more pronounced in patients with advanced age, hypertension, CCB therapy, lung cancer surgery, and a long QT interval at baseline.

The effects of peritoneal dialysis on QT interval in ESRD patients.

BACKGROUND: Patients with chronic kidney disease (CKD) are at a high risk of fatal arrhythmias. The extended corrected QT (QTc) interval is a hallmark of ventricular arrhythmias and sudden cardiac death. Previous studies have shown that QT interval and QTc are prolonged with the decline in renal function. However, there were no available results for patients with peritoneal dialysis (PD). In this study, we examined changes in QT interval and QTc in patients with end-stage renal disease (ESRD) who underwent peritoneal dialysis. METHODS: A total of 66 ESRD patients who received PD, including 50 males and 16 females, with an average age of 43.56 ± 15.15 years, were enrolled. The follow-up lasted 1 year. The demographics and the etiology of patients were recorded. QTc and clinical/biochemical indexes before dialysis and at 6 and 12 months were determined and analyzed. Dialysis adequacy and peritoneal transport function were assessed in each patient. Analysis of variance (ANOVA), least significant difference (LSD) or Tamhane's T2, Paired T-test, Chi-square test, multiple linear regression analysis, and Pearson correlation coefficient were used to analyze the data. P < 0.05 was considered as statistically significant. RESULTS: With reference to etiology, 37 patients (56.06%) had chronic nephritis, and 11 (16.67%) had diabetic nephropathy. Most of the peritoneal transport functions were low average transport (25, 37.88%), while the least were high transport (2, 3.03%).During the follow-up period, all patients had adequate peritoneal dialysis. Compared with a baseline before dialysis, anemia, low albumin, blood pressure, blood urea nitrogen, creatinine, uric acid, potassium, calcium, phosphorus, and parathyroid hormone improved after 6 and 12 months, while the residual renal function gradually decreased during the follow-up. The mean QTc of all patients was stable during the follow-up period. According to gender, the QTc in males and female patients were similar. Before PD, diastolic blood pressure, calcium concentration, and hemoglobin level were negatively correlated with QTc in end-stage renal disease patients; After PD, the observed clinical indexes were no longer relevant to QTc. CONCLUSION: Unlike hemodialysis-induced QTc prolongation, PD did not increase the patient's QT interval and QTc interval, which suggested that myocardial electrical activity might be more stable in patients with adequate peritoneal dialysis.

QTc interval prolongation due to spinal anesthesia in patients with and without diabetes: an observational study.

BACKGROUND: Spinal anesthesia and autonomic neuropathy (caused by diabetes) prolong the QTc interval. Changes in the duration of the QTc interval following subarachnoid blockade in patients with diabetes have not been evaluated. We hypothesized that after subarachnoid blockade, QTc interval prolongation would be greater in patients with diabetes than in those without. Accordingly, we compared the QTc interval, T wave peak-to-end interval (Tp-e interval), blood pressure, heart rate, and heart rate variability before and after spinal anesthesia in patients with and without diabetes. METHODS: This prospective observational study (Clinical Research Information Service identifier: KCT0004897) was conducted in a tertiary university hospital and included 24 patients with diabetes mellitus (DM group) and 24 patients without it (control group) who were scheduled for spinal anesthesia. The QTc interval, Tp-e interval, heart rate variability, blood pressure, and heart rate were measured before (T1) and 1 (T2), 5 (T3), and 10 min (T4) following subarachnoid blockade. RESULTS: Ten minutes following subarachnoid blockade, the QTc intervals of patients in the DM group were significantly longer than the baseline values, whereas the change in the QTc interval in the control group was not significant (p < 0.0001 vs. p = 0.06). CONCLUSION: Spinal anesthesia caused a more significant prolongation of the QTc interval in patients with diabetes than in those without.

Elevated plasma fatty acid-binding protein 3 is related to prolonged corrected QT interval and reduced ejection fraction in patients with stable angina.

Background: Higher concentrations of plasma fatty acid-binding protein 3 (FABP3) play a role in the development of cardiovascular events, cerebrovascular deaths, and acute heart failure. However, little is known about the relationship between plasma FABP3 level and prolonged QT interval and reduced ejection fraction (EF). This study aimed to investigate the relationship between plasma FABP3 level and prolonged corrected QT (QTc) interval and reduced EF in patients with stable angina. Inflammatory cytokine and adipocytokine levels were also measured to investigate their associations with plasma FABP3. Methods: We evaluated 249 consecutive patients with stable angina. Circulating levels of FABP3 were measured by ELISA. In addition, 12-lead ECG and echocardiography recordings were obtained from each patient. Results: Multiple regression analysis showed that high-density lipoprotein cholesterol, high sensitivity C-reactive protein (hs-CRP), white blood cell (WBC) count, visfatin, adiponectin, FABP4, heart rate, QTc interval, left atrial diameter, left ventricular mass index, end-systolic volume, end-systolic volume index, fractional shortening, and EF were independently associated with FABP3 (all p<0.05). Patients with an abnormal QTc interval had a higher median plasma FABP3 level than those with a borderline and normal QTc interval. With increasing FABP3 tertiles, the patients had higher frequencies of abnormal QTc interval, left ventricular systolic dysfunction, and all-cause mortality, incrementally lower EF, higher WBC count, and higher levels of hs-CRP, visfatin, adiponectin, and FABP4. Conclusion: This study indicates that plasma FABP3 may act as a surrogate parameter of prolonged QTc interval and reduced EF in patients with stable angina, partially through the effects of inflammation or cardiomyocyte injury. Further studies are required to elucidate whether plasma FABP3 plays a role in the pathogenesis of QTc prolongation and reduced EF.

QT correction using Bazett's formula remains preferable in long QT syndrome type 1 and 2.

BACKGROUND: The heart rate (HR) corrected QT interval (QTc) is crucial for diagnosis and risk stratification in the long QT syndrome (LQTS). Although its use has been questioned in some contexts, Bazett's formula has been applied in most diagnostic and prognostic studies in LQTS patients. However, studies on which formula eliminates the inverse relation between QT and HR are lacking in LQTS patients. We therefore determined which QT correction formula is most appropriate in LQTS patients including the effect of beta blocker therapy and an evaluation of the agreement of the formulae when applying specific QTc limits for diagnostic and prognostic purposes. METHODS: Automated measurements from routine 12-lead ECGs from 200 genetically confirmed LQTS patients from two Swedish regions were included (167 LQT1, 33 LQT2). QT correction was performed using the Bazett, Framingham, Fridericia, and Hodges formulae. Linear regression was used to compare the formulae in all patients, and before and after the initiation of beta blocking therapy in a subgroup (n = 44). Concordance analysis was performed for QTc ≥ 480 ms (diagnosis) and ≥500 ms (prognosis). RESULTS: The median age was 32 years (range 0.1-78), 123 (62%) were female and 52 (26%) were children ≤16 years. Bazett's formula was the only method resulting in a QTc without relation with HR. Initiation of beta blocking therapy did not alter the result. Concordance analyses showed clinically significant differences (Cohen's kappa 0.629-0.469) for diagnosis and prognosis in individual patients. CONCLUSION: Bazett's formula remains preferable for diagnosis and prognosis in LQT1 and 2 patients.

Serum High-sensitivity C-reactive Protein Level and Corrected QT Interval in Agricultural Workers in Myanmar Exposed to Chronic Occupational Organophosphate Pesticides.

Although acute organophosphate (OP) pesticide poisoning is associated with the risk cardiovascular diseases (CVD), the association between chronic occupational OP pesticide exposure and CVD risk is limited. We investigated serum high-sensitivity C-reactive protein (hs-CRP) levels and QTc intervals in 45 agricultural workers who were chronically exposed to OP pesticides and 45 non-exposed subjects. Serum hs-CRP level was determined by enzyme-linked immunosorbent assay (ELISA) and a level >1.0 mg/l was regarded as CVD risk. The QT interval was measured by routine 12-lead Electrocardiogram (ECG) with Lead II rhythm, and QTc was calculated. The median value of the serum hs-CRP level [1.20 (0.67-2.38) vs 0.74 (0.41-1.17) mg/l, P <0.05] and the mean QTc interval (422.71 ± 23.73 vs 396.27 ± 18.48 ms, P <0.0001) was significantly higher in the OP pesticide exposed subjects. Pesticide exposure was significantly associated with CVD risk (Chi-Square χ2 = 6.480, P = 0.011) and QTc interval prolongation (χ2 = 13.846, P <0.001). A higher risk of CVD (odds ratio = 3.030; 95% confidence interval = 1.276 - 7.197) was observed in the OP pesticide exposed subjects. This study suggested that OP pesticide exposure should be considered as one of the significant risk factors for CVDs.

RISK PREDICTION FOR ARRHYTHMIA IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE.

OBJECTIVE: The aim: To evaluate P-wave dispersion (PwD), as an independent predictor of atrial fibrillation, corrected QT interval dispersion (cQTD), the noninvasive marker of ventricular arrhythmia and sudden cardiac death, investigate the atrial electromechanical delay in patients with COPD and assess their relation with the severity of the disease. PATIENTS AND METHODS: Materials and methods: We prospectively enrolled consecutive patients with newly diagnosed COPD (n = 53, age 41.2 ± 6.8 years), compared with an age-matched healthy control group (n = 51, age 40.9 ± 6.5 years). A standard 12-lead electrocardiogram of each patient was analyzed for PwD and сQTD. Atrial electromechanical delay was analyzed by echocardiographic tissue Doppler imaging. The difference between PAs-PAl, PAs-PAt, and PAl-PAt were defined as left intra-atrial, right intra-atrial, and interatrial electromechanical delays (EMD), respectively. RESULTS: Results: PwD was higher in COPD patients than in control subjects (39.47 ± 3.12 ms vs. 30.29 ± 3.17 ms, p < 0.05). In comparison between control group and COPD subgroups (mild, moderate and severe), there was a statistically significant difference among these free groups in terms of PwD. Subgroup analyses showed that this difference was mainly due to patients with severe COPD. Regarding cQTD, there was a statistically significant increase in COPD patients 57.92 ± 3.43 ms vs 41.03 ± 5.21 ms, p < 0.05 respectively. PAs, PAl and PAt durations, right intra-atrial and interatrial EMD were also significantly longer in COPD patients (p < 0.05). Furthermore, there were significant negative correlations between FEV1 and PwD (r = - 0.46, p < 0.05), right intra-atrial (r = - 0.39 ms, p < 0.05), interatrial EMD ( r = - 0.35 ms, p < 0.05) and cQTD (r = - 0.32, p < 0.05). CONCLUSION: Conclusions: Atrial conduction time, such as inter- and intra-atrial EMD intervals, PwD and cQTD were longer than in healthy controls and correlated with the severity of COPD. These parameters offer a non-invasive and cost-effective assessment method for detecting patients at high risk of arrhythmia. Nevertheless, further prospective investigations on this issue are required.

Should we still monitor QTc duration in frail older patients on low-dose haloperidol? A prospective observational cohort study.

BACKGROUND: Haloperidol at high dosage is associated with QTc prolongation and polymorphic ventricular arrhythmia but the effects of low-dose haloperidol remain unknown. OBJECTIVE: To evaluate the effects of low-dose haloperidol on QTc-duration in frail hospitalized elderly patients with delirium. METHODS: A prospective observational study including hospitalized patients aged ≥70 years with Groningen Frailty Index-score > 3. We included 150 patients who received haloperidol and 150 age- and frailty-matched control patients. Serial ECG recordings were performed at hospital admission and during hospitalization. QT-interval was corrected according to Framingham (QTc). Patients were grouped according to baseline QTc in normal (nQTc), borderline (bQTc) or abnormal (aQTc). Primary outcome was change in QTc-duration between first and second ECG. Potentially dangerous QTc was defined as QTc >500 ms or an increase of >50 ms. RESULTS: Patients in the haloperidol group (48% male, mean age 85y, nQT n = 98, bQT n = 31, aQT n = 20) received an average dose of 1.5 mg haloperidol per 24 hours. QTc decreased in patients with borderline (mean - 15 ± 29 ms, P < 0.05) or abnormal (-19 ± 27 ms, P < 0.05) QTc at baseline, no patients developed dangerous QTc-duration. In the control group (41% male, mean age 84y, nQT n = 99 bQT n = 29, aQT n = 22) QTc decreased to a similar extent (bQT -7 ± 16 ms, aQTc -23 ± 20 ms). CONCLUSION: A trend to QTc shortening was seen, especially in patients with borderline or abnormal QTc at baseline, regardless of haloperidol use. These findings suggest that ECG monitoring of frail elderly patients who receive low-dose haloperidol, may not be necessary.

Trouble begets trouble; overcounting the heart rate by the interpretation software results in overestimation of the QTc.

A man in his 70s was taking a medication that required routine electrocardiographic (ECG) monitoring for possible QT prolongation. On one of these occasions, four consecutive ECGs were recorded within 1 min. Unexpectedly, the rate-corrected QT intervals (QTc) reported by the interpretation software showed marked fluctuation ranging from 426 ms to 498 ms. Was there a rational explanation for the widely different QTc measurements? Was it necessary to hold the culprit medication?

Successful Combination of Landiolol and Levosimendan in Patients with Decompensated Heart Failure.

Tachycardia and supraventricular tachyarrhythmias often impair cardiovascular capacity in patients with decompensated heart failure (dHF) treated with inotropes. Normalization of heart rhythm or rate typically improves diastolic filling and stroke volume (SV). Thus, isochronal administration of an ultra-short-acting and highly selective ß1-blockers, such as landiolol, along with inotropic calcium-sensitizer medications, such as levosimendan, could benefit patients with dHF.We present a case series of three patients with severe dHF and low ejection fraction who were successfully treated with a combination of landiolol and levosimendan. The co-administration of landiolol and levosimendan was well tolerated, improved cardiac function, normalized SV, and enabled the reduction of norepinephrine dosing in all patients. Additionally, the combination improved the vectorcardiographic spatial QRS-T angle and decreased the corrected QT interval. All patients were successfully discharged from the intensive care unit (ICU).A combination of levosimendan and landiolol was safe and well-tolerated. This combination may be a new option for successful treatment of patients with acute dHF complicated by sinus or supraventricular tachycardias.

Chloroquine, hydroxychloroquine, and COVID-19: Systematic review and narrative synthesis of efficacy and safety.

The COVID-19 pandemic has required clinicians to urgently identify new treatment options or the re-purposing of existing drugs. Of particular interest are chloroquine (CQ) and hydroxychloroquine (HCQ). The aims of this systematic review are to systematically identify and collate 24 studies describing the use of CQ and HCQ in human clinical trials and to provide a detailed synthesis of evidence of its efficacy and safety. Of clinical trials, 100% showed no significant difference in the probability of viral transmission or clearance in prophylaxis or therapy, respectively, compared to the control group. Among observational studies employing an endpoint specific to efficacy, 58% concurred with the finding of no significant difference in the attainment of outcomes. Three-fifths of clinical trials and half of observational studies examining an indicator unique to drug safety discovered a higher probability of adverse events in those treated patients suspected of, and diagnosed with, COVID-19. Of the total papers focusing on cardiac side-effects, 44% found a greater incidence of QTc prolongation and/or arrhythmias, 44% found no evidence of a significant difference, and 11% mixed results. The strongest available evidence points towards the inefficacy of CQ and HCQ in prophylaxis or in the treatment of hospitalised COVID-19 patients.

What Every Intensivist should Know about Impairment of Cardiac Function and Arrhythmias in Liver Disease Patients: A Review.

OBJECTIVES: Impairment of cardiac function and arrhythmias often coexist in patients with liver diseases. Many studies have proved this coexistence and put forward various theories toward its pathophysiology. This narrative review tries to find the answers with supporting evidence on five main questions:Do high serum bilirubin levels have a strong association with cardiac arrhythmias?Can corrected QT interval (QTc) be relied upon for predicting a risk factor toward imminent arrhythmias?Is there an association between QTc prolongation and mortality?Are high serum bilirubin and cardiac dysfunction closely associated?What is the probable pathophysiology behind this association? MATERIALS AND METHODS: Clinical evidence was obtained by using search engines, namely, Cochrane Library, PubMed, and Google Scholar. Studies published in journals in the English language, between January 1969 and December 2019, which mentioned the relationship between cardiac arrhythmia and liver disease, were included. We used the keywords: jaundice, bilirubin, arrhythmia, ECG, QTc interval, QT dispersion, liver, and cirrhosis. Relevant animal or human studies answering the five main questions were extracted and reviewed. CONCLUSION: The evidence included in our review sheds light on the fact that approximately 50% of liver cirrhosis cases develop cirrhotic cardiomyopathy (CC) and there has been an association between liver abnormalities and cardiac pathology. The present review also supports that there exists a strong association between high levels of serum bilirubin levels and cardiac arrhythmias, QTc value can be relied upon as a risk factor for predicting imminent arrhythmias, and that it is associated with mortality. Its basic pathophysiology can be explained by the potential action of bile acids in prolonging the QT interval. It also causes cardiac hypertrophy and apoptosis of cardiomyocytes leading to cardiac dysfunction. HOW TO CITE THIS ARTICLE: Arya S, Kumar P, Tiwari B, Belwal S, Saxena S, Abbas H. What Every Intensivist should Know about Impairment of Cardiac Function and Arrhythmias in Liver Disease Patients: A Review. Indian J Crit Care Med 2020;24(12):1251-1255.

QT as a predictor of recurrence after atrial fibrillation ablation and the impact of amiodarone: results from the placebo-controlled AMIO-CAT trial.

AIMS: Prolonged corrected QT interval (QTc) might be associated with arrhythmia recurrence after atrial fibrillation (AF) ablation. The effect of short-term amiodarone in this setting remains unknown. This study seeks to quantify short-term amiodarone's impact on QTc, and to investigate QTc and amiodarone treatment as predictors of recurrence of arrhythmia after ablation. METHODS AND RESULTS: The Short-term AMIOdarone treatment after CATheter ablation for atrial fibrillation (AMIO-CAT) trial randomized patients to 8 weeks of oral amiodarone or placebo following AF ablation. Scheduled and symptom-driven 12-lead electrocardiography and 3-day Holter-monitorings were performed. The endpoint was atrial fibrillation, atrial flutter or atrial tachycardia (AF/AT) lasting >30 s. The cut-off for prolonged QTc was 450 ms for men and 460 ms for women. A total of 212 patients were included, of which 108 were randomized to amiodarone and 104 to placebo. From baseline to 1 month QTc in the amiodarone group increased by 27 (±30) ms, while at 6 months QTc had normalized. After 3-months of blanking, new AF/AT recurrence was detected in 63% of patients with prolonged QTc vs. 41% of patients with normal QTc at baseline, and in multivariate Cox regression, prolonged QTc was associated with AF/AT recurrence [hazard ratio (HR) 2.19, P = 0.023]. Among patients with baseline QTc below median, amiodarone treatment decreased the rate of AF/AT recurrences (HR 0.43, P = 0.008). CONCLUSIONS: Amiodarone increased QTc with 27 ms compared to placebo, and this effect decreased rapidly after drug discontinuation. Prolonged QTc at baseline independently predicted AF/AT recurrence, and baseline QTc identified patients who would possibly benefit from short-term amiodarone following ablation.

Magnetocardiographic identification of prolonged fetal corrected QT interval in women receiving treatment for opioid use disorder.

AIM: Pregnant women undergoing treatment for opioid use disorder (OUD) may be exposed to multiple QT prolonging agents. We used magnetocardiography to measure fetal QT intervals in mothers with OUD on buprenorphine therapy. METHODS: Fetal and maternal magnetocardiography was performed in pregnant women receiving buprenorphine-assisted treatment (Disorder group); these were matched by gestational age to pregnant women who were opiate naïve (Reference group). Corrected QT intervals were determined using Bazett's formula and compared between groups. RESULTS: A total of eight women in the Disorder group matched to eight in the Reference group. Seven of the mothers (88%) in the Disorder group were smokers; there were no smokers in the Reference group. The average fetal corrected QT was significantly longer (P = 0.022) in the Disorder group than that in the Reference group (505 milliseconds [ms] ± 68.6 [standard deviation] vs 383 ms ± 70.3 [standard deviation]). CONCLUSION: Novel data from this small sample demonstrate prolongation of fetal corrected QT in women with OUD participating in buprenorphine assisted therapy. Additional investigation from a larger sample is needed to clarify if fetal buprenorphine and/or tobacco exposure is associated with changes in fetal QT which would warrant further prenatal and postnatal testing.

Serum albumin level and abnormal corrected QT interval in patients with coronary artery disease and chronic kidney disease.

BACKGROUND: Lower concentrations of serum albumin appear to be associated with an increased risk of all-cause and cardiovascular mortality, coronary heart disease, heart failure and stroke. However, little is known about the relationship between serum albumin level and prolonged QT interval. AIM: To investigate whether lower serum albumin is associated with prolonged QT interval by recording 12-lead electrocardiography in patients with coronary artery disease and chronic kidney disease. METHODS: This study included 1383 consecutive patients with coronary artery disease and chronic kidney disease (841 with acute coronary syndrome and 542 with elective percutaneous coronary intervention patients) who were enrolled in a disease management programme. Twelve-lead electrocardiography was recorded in each subject. We assessed the relationship between albumin levels (both as a continuous variable and stratified by tertile) at admission and corrected QT (QTc) prolongation. RESULTS: Patients with abnormal QTc interval had lower serum albumin levels than those with normal and borderline QTc intervals. Statistically significant negative associations were observed between serum albumin levels and QTc interval (ß = -0.211, P < 0.0001). Using multivariate and trend analyses, a lower concentration of serum albumin was independently associated with QTc prolongation in both the patients with acute coronary syndrome and elective percutaneous coronary intervention patients. CONCLUSION: Concentrations of serum albumin were significantly lower in the patients with an abnormal QTc interval and were associated with QTc prolongation. Further studies are needed to clarify whether lower serum albumin plays a role in the pathogenesis of QTc prolongation.

Maximum QTc on Holter electrocardiography in children.

BACKGROUND: Corrected QT interval (QTc) on electrocardiography (ECG) at rest and after exercise in a short daytime recording period may be insufficient for the diagnosis and management of long QT syndrome (LQTS), especially for LQTS type 2 and 3. Therefore, examination of QTc on Holter ECG is important. We designed a method of analyzing QTc on Holter ECG that can be performed in daily clinical practice by combining automatic and manual measurements. METHODS: We reviewed the charts of healthy children (n = 210) and LQTS patients (n = 35) aged <16 years and analyzed QTc at rest and after exercise, and the maximum QTc on Holter ECG. RESULTS: The QTc (Fridericia's correction) of most controls and LQTS patients reached the maximum at night or early in the morning. QTc differed according to sex and age. In the control group, QTc on ECG of all three types tended to lengthen with age. QTc after exercise was slightly longer than QTc at rest, and the maximum QTc on Holter ECG was much longer than both, reaching >450 ms in boys and 500 ms in girls. In most LQTS type 1 patients, QTc after exercise and that on Holter ECG tended to be long. In most LQTS type 2 and 3 patients, QTc at rest and that after exercise was long, and that on Holter ECG tended to be much longer. CONCLUSIONS: The present method of analyzing QTc on Holter ECG, in which automatic and manual measurements are combined, is practical and may be useful for diagnosis and risk stratification of LQTS.