Sudden death of cardiac origin and psychotropic drugs

Spiked Helmet Sign: An Uncommon Electrocardiographic Marker

The spiked helmet sign (SHS) is a rare electrocardiographic marker associated with an increased risk of lethal ventricular tachyarrhythmias and sudden cardiac death. To our knowledge, this is the first study aimed at reviewing recent research progress on this electrocardiogram (ECG) pattern to summarize its electrophysiological mechanisms, epidemiological features, clinical characteristics, and clinical significance. SHS formation is attributed to sympathetic hyperactivity, which mediates increased dispersion of ventricular repolarization, leading to marked QT prolongation and macroscopic T-wave alternans. This pattern can be observed in critically ill patients with cardiac or noncardiac conditions. In particular, immediate identification of this ECG abnormality is crucial in recognizing and treating noncardiac conditions in older male patients.

Abnormal blood lipid and electrocardiogram characteristics in common mental disorders

BACKGROUND

At present, there is not enough evidence to prove the relationship between blood lipid and electrocardiogram (ECG) abnormalities in common mental disorders (CMD). This study aimed to explore the relationship between them, to detect and prevent arrhythmia or sudden death.

METHODS

We collected 272 CMD patients (maintained a fixed drug dose pattern for 1 year or more), including 95 schizophrenias (SC), 90 bipolar disorders (BD) and 87 major depressive disorders (MDD), and 78 healthy controls (HC) from the Third People's Hospital of Foshan, China. We analyzed and compared their blood lipid and ECG indicators, to clarify the relationship between them.

RESULTS

350 participants were included. There were no significant differences in age, gender, total cholesterol (TC), low density lipoprotein (LDL) and QTc (p > 0.05) among subjects. And there were significant differences in body mass index (BMI), triglyceride (TG), high density lipoprotein (HDL), heart rate, PR interval and QRS width (p < 0.05). Person correlation analysis showed that QRS width was positively correlated with BMI and TG. And negatively correlated with HDL. Meanwhile, QTc was positively correlated with BMI. Multiple linear regional analysis further proved that TG (B = 3.849, p = 0.007) and LDL (B = 11.764, p = 0.018) were the risk factors, and HDL (B = -9.935, p = 0.025) was the protective factor for QRS width increase.

CONCLUSION

Long term medication of CMD patients should strengthen weight management, and conduct regular blood lipid and ECG examinations to achieve early detection and intervention in order to promote their health.

Genetic basis of sudden death after COVID-19 vaccination in Thailand

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 vaccination reduces morbidity and mortality associated with coronavirus disease 2019 (COVID-19); unfortunately, it is associated with serious adverse events, including sudden unexplained death (SUD).

OBJECTIVE

We aimed to study the genetic basis of SUD after COVID-19 vaccination in Thailand.

METHODS

From April to December 2021, cases with natural but unexplained death within 7 days of COVID-19 vaccination were enrolled for whole exome sequencing.

RESULTS

Thirteen were recruited, aged between 23 and 72 years; 10 (77%) were men, 12 were Thai; and 1 was Australian. Eight (61%) died after receiving the first dose of vaccine, and 7 (54%) died after receiving ChAdOx1 nCoV-19; however, there were no significant correlations between SUD and either the number or the type of vaccine. Fever was self-reported in 3 cases. Ten (77%) and 11 (85%) died within 24 hours and 3 days of vaccination, respectively. Whole exome sequencing analysis revealed that 5 cases harbored SCN5A variants that had previously been identified in patients with Brugada syndrome, giving an SCN5A variant frequency of 38% (5 of 13). This is a significantly higher rate than that observed in Thai SUD cases occurring 8-30 days after COVID-19 vaccination during the same period (10% [1 of 10]), in a Thai SUD cohort studied before the COVID-19 pandemic (12% [3 of 25]), and in our in-house exome database (12% [386 of 3231]).

CONCLUSION

These findings suggest that SCN5A variants may be associated with SUD within 7 days of COVID-19 vaccination, regardless of vaccine type, number of vaccine dose, and presence of underlying diseases or postvaccine fever.

The Risk of Fatal Arrhythmias Associated With Sertraline in Patients With Post-myocardial Infarction Depression

Sertraline is a first-line antidepressant and the most commonly used in the treatment of selective serotonin reuptake inhibitor (SSRI) in major depression. It is preferred due to its central and peripheral actions on the serotonergic system in patients with mental health issues as well as cardiovascular disease, particularly post-myocardial infarction depression. Some of the feared adverse effects include QT prolongation, arrhythmias including Torsades de pointed, and sudden cardiac death, which are associated with older antidepressants and are rarely seen with SSRIs, including sertraline. We tried to understand the risks associated with sertraline use in cardiac patients. We reviewed all the relevant information from inception up to July 2022 regarding the risks of sertraline use in cardiovascular diseases, particularly with a focus on post-myocardial infarction depression, and gathered around 500 articles in our research and narrowed it down to 37 relevant articles. The database used was PubMed and the keywords used are sertraline, arrhythmia, major depression, post-myocardial infarction, and ventricular tachycardia. We carefully screened all relevant articles and found articles supporting and refuting the effects of sertraline in increasing cardiovascular morbidity and mortality. We concluded that there is a significant variability due to confounding factors affecting individual cases. Overall, sertraline has no increased risk in comparison with other antidepressants and a comparatively preferable safety profile to other SSRIs like citalopram in general cases. Any patient with a high risk of arrhythmias due to any etiology should receive a screening ECG before sertraline prescription for baseline QT interval and genotyping for any serotonin transporter/receptor variations. Patients should also be periodically monitored for drug-drug interactions while on therapy. We encourage further research, including randomized clinical trials and post-marketing surveillance regarding the use of sertraline in high-risk cases.

Risk and Protective Factors for Sudden Cardiac Death: An Umbrella Review of Meta-Analyses

Background

Sudden cardiac death (SCD) is a global public health issue, accounting for 10–20% of deaths in industrialized countries. Identification of modifiable risk factors may reduce SCD incidence.

Methods

This umbrella review systematically evaluates published meta-analyses of observational and randomized controlled trials (RCT) for the association of modifiable risk and protective factors of SCD.

Results

Fifty-five meta-analyses were included in the final analysis, of which 31 analyzed observational studies and 24 analyzed RCTs. Five associations of meta-analyses of observational studies presented convincing evidence, including three risk factors [diabetes mellitus (DM), smoking, and early repolarization pattern (ERP)] and two protective factors [implanted cardiac defibrillator (ICD) and physical activity]. Meta-analyses of RCTs identified five protective factors with a high level of evidence: ICDs, mineralocorticoid receptor antagonist (MRA), beta-blockers, and sodium-glucose cotransporter-2 (SGLT-2) inhibitors in patients with HF. On the contrary, other established, significant protective agents [i.e., amiodarone and statins along with angiotensin-converting enzyme (ACE) inhibitors in heart failure (HF)], did not show credibility. Likewise, risk factors as left ventricular ejection fraction in HF, and left ventricular hypertrophy, non-sustain ventricular tachycardia, history of syncope or aborted SCD in pediatric patients with hypertrophic cardiomyopathy, presented weak or no evidence.

Conclusions

Lifestyle risk factors (physical activity, smoking), comorbidities like DM, and electrocardiographic features like ERP constitute modifiable risk factors of SCD. Alternatively, the use of MRA, beta-blockers, SGLT-2 inhibitors, and ICD in patients with HF are credible protective factors. Further investigation targeted in specific populations will be important for reducing the burden of SCD.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020216363, PROSPERO CRD42020216363.

Block of Voltage-Gated Sodium Channels by Atomoxetine in a State- and Use-dependent Manner

Atomoxetine, a neuroactive drug, is approved for the treatment of attention-deficit/hyperactivity disorder (ADHD). It is primarily known as a high affinity blocker of the noradrenaline transporter, whereby its application leads to an increased level of the corresponding neurotransmitter in different brain regions. However, the concentrations used to obtain clinical effects are much higher than those which are required to block the transporter system. Thus, off-target effects are likely to occur. In this way, we previously identified atomoxetine as blocker of NMDA receptors. As many psychotropic drugs give rise to sudden death of cardiac origin, we now tested the hypothesis whether atomoxetine also interacts with voltage-gated sodium channels of heart muscle type in clinically relevant concentrations. Electrophysiological experiments were performed by means of the patch-clamp technique at human heart muscle sodium channels (hNav1.5) heterogeneously expressed in human embryonic kidney cells. Atomoxetine inhibited sodium channels in a state- and use-dependent manner. Atomoxetine had only a weak affinity for the resting state of the hNav1.5 (Kr: ∼ 120 µM). The efficacy of atomoxetine strongly increased with membrane depolarization, indicating that the inactivated state is an important target. A hallmark of this drug was its slow interaction. By use of different experimental settings, we concluded that the interaction occurs with the slow inactivated state as well as by slow kinetics with the fast-inactivated state. Half-maximal effective concentrations (2–3 µM) were well within the concentration range found in plasma of treated patients. Atomoxetine also interacted with the open channel. However, the interaction was not fast enough to accelerate the time constant of fast inactivation. Nevertheless, when using the inactivation-deficient hNav1.5_I408W_L409C_A410W mutant, we found that the persistent late current was blocked half maximal at about 3 µM atomoxetine. The interaction most probably occurred via the local anesthetic binding site. Atomoxetine inhibited sodium channels at a similar concentration as it is used for the treatment of ADHD. Due to its slow interaction and by inhibiting the late current, it potentially exerts antiarrhythmic properties.

Effect of the antipsychotic drug haloperidol on arrhythmias during acute myocardial infarction in a porcine model

Patients receiving psychiatric medication, like the antipsychotic drug haloperidol, are at an increased risk of sudden cardiac death (SCD). Haloperidol blocks the cardiac rapidly-activating delayed rectifier potassium current, thereby increasing electrical dispersion of repolarization which can potentially lead to arrhythmias. Whether these patients are also at a higher risk to develop SCD during an acute myocardial infarction (AMI) is unknown. AMI locally shortens action potential duration, which might further increase repolarization dispersion and increase the risk of arrhythmia in the presence of haloperidol compared to without. Our aim was to test whether treatment with haloperidol implies an increased risk of SCD when eventually experiencing AMI. Twenty-eight female Danish Landrace pigs were randomized into three groups: low dose haloperidol (0.1 mg/kg), high dose (1.0 mg/kg) or vehicle-control group. One hour after haloperidol/vehicle infusion, AMI was induced by balloon-occlusion of the mid-left anterior descending coronary artery and maintained for 120 min, followed by 60 min of reperfusion. VF occurred during occlusion in 7/11 pigs in the control group, 3/11 in the low dose (p = 0.198) and 2/6 in the high dose group (p = 0.335). High dose haloperidol significantly prolonged QT, and reduced heart rate, vascular resistance and blood pressure before and during AMI. Premature ventricular contractions in phase 1b during AMI were reduced with high dose haloperidol. AMI-induced arrhythmia was not aggravated in pigs with haloperidol treatment. Our results do not suggest that AMI is contributing to the excess mortality in patients treated with antipsychotic drugs seen in epidemiological studies.

Sudden cardiac death caused by myocarditis in persons aged 1-49 years: a nationwide study of 14 294 deaths in Denmark

Myocarditis is associated with an increased risk of sudden cardiac death (SCD) in the young. However, information on nationwide burden of SCD caused by myocarditis (SCD-myocarditis) is sparse. For this study all deaths among persons in Denmark aged 1–35 years in 2000–2009 and 36–49 years in 2007–2009 (27.1 million person-years) were included. Autopsy reports, death certificates, discharge summaries, and nationwide registries were used to identify all cases of SCD-myocarditis. In the 10-year study period, there were 14 294 deaths, of which we identified 1 363 (10%) SCD. Among autopsied SCD (n = 753, 55%), cause of death was myocarditis in 42 (6%) cases corresponding to an SCD-myocarditis incidence of 0.16 (95%CI: 0.11–0.21) per 100 000 person-years. Males had significantly higher incidence rates of SCD-myocarditis compared to females with an incidence rate ratio of 2.2 (95%CI: 1.1–4.1). Myocarditis was not registered as cause of death in any of the non-autopsied SCD (n = 610, 45%). In conclusion, after nationwide unselected inclusion of 14 294 deaths, we found that 6% of all autopsied SCD was caused by myocarditis. No cases of SCD-myocarditis were reported in the non-autopsied SCD, which could reflect underdiagnosing of myocarditis in non-autopsied SCD. Furthermore, our data suggest a female protection towards SCD-myocarditis.

Anorexia nervosa and heart disease: a systematic review

Anorexia nervosa (AN) is an eating disorder that most frequently afflicts females in adolescence. In these subjects, cardiovascular complications are the main cause of morbidity and mortality. Aim of this review is to analyze the hemodynamic, pro-arrhythmic and structural changes occurring during all phases of this illness, including re-feeding. A systematic literature search was performed on studies in the MEDLINE database, from its inception until September 2017, with PUBMED interface focusing on AN and cardiovascular disease. This review demonstrated that the most common cardiac abnormalities in AN are bradycardia and QT interval prolongation, which may occasionally degenerate into ventricular arrhythmias such as Torsades des Pointes or ventricular fibrillation. As these arrhythmias may be the substrate of sudden cardiac death (SCD), they require cardiac monitoring in hospital. In addition, reduced cardiac mass, with smaller volumes and decreased cardiac output, may be found. Furthermore, mitral prolapse and a mild pericardial effusion may occur, the latter due to protein deficiency and low levels of thyroid hormone. In anorectic patients, some cases of hypercholesterolemia may be present; however, conclusive evidence that AN is an atherogenic condition is still lacking, although a few cases of myocardial infarction have been reported. Finally, refeeding syndrome (RFS), which occurs during the first days of refeeding, may engender a critically increased risk of acute, life-threatening cardiac complications.

Associations between the use of specific psychotropic drugs and all-cause mortality among older adults in Germany: Results of the mortality follow-up of the German National Health Interview and Examination Survey 1998

BACKGROUND

Use of psychotropic drugs is common among older adults. Population-based studies on the associations of psychotropic drug use with mortality are sparse.

OBJECTIVES

To investigate the associations between the use of specific psychotropic drug groups (opioids, antipsychotics, antidepressants and benzodiazepines) and all-cause mortality among community-dwelling older adults in Germany.

METHODS

Participants of the German National Health Interview and Examination Survey 1998 were followed up for mortality from 1997 to 2011. Persons aged 60-79 years with complete data on psychotropic drug use at baseline and on mortality follow-up were considered as study population (N = 1,563). Associations between the use of opioids, antipsychotics, antidepressants and benzodiazepines and all-cause mortality were examined by Cox proportional hazards models adjusted for sociodemographics (sex, age, community size, region, socioeconomic status), life style (smoking, sports, risky alcohol drinking) and health conditions (obesity, disability, history of cardiovascular diseases, diabetes, hyperlipidemia, hypertension, any cancers, any mental disorders) at baseline.

RESULTS

After a median follow-up of 11.4 years, 21, 18, 23 and 26 deaths were documented among those who used at baseline opioids (n = 39), antipsychotics (n = 30), antidepressants (n = 53) and benzodiazepines (n = 54) with an unadjusted mortality rate (MR) of 57.7, 59.1, 44.6 and 53.7 per 1000 person-years, respectively. Meanwhile, 400 deaths were documented among 1,406 nonusers of any of the above mentioned psychotropic drugs with a MR of 26.7 per 1000 person-years. The age and sex adjusted mortality rate ratios in comparison with nonusers were 2.20 (95% confidence intervals 1.42-3.41), 1.66(1.03-2.70), 1.56(1.06-2.28), and 1.57(1.07-2.31) for the use of opioids, antipsychotics, antidepressants and benzodiazepines, respectively. In the fully adjusted Cox models, use of opioids (hazardous ratio 2.04, 95% confidence intervals 1.07-3.89), antipsychotics (2.15, 1.11-4.15) and benzodiazepines (1.76, 1.09-2.82), but not antidepressants, were significantly associated with an increased risk of mortality.

CONCLUSIONS

Use of opioids, antipsychotics, benzodiazepines is significantly associated with an increased risk of all-cause mortality among community-dwelling older adults in Germany. Clinicians should be careful in prescribing these psychotropic drugs to older adults while patients already under psychotropic therapy should well balance the risks and benefits of drug use. Further studies with a larger sample size and information on specific indications for psychotropic drug use and mental comorbidities are required to confirm the findings of the present study.

Drug-induced life-threatening arrhythmias and sudden cardiac death: A clinical perspective of long QT, short QT and Brugada syndromes

Sudden cardiac death is a major public health challenge, which can be caused by genetic or acquired structural or electrophysiological abnormalities. These abnormalities include hereditary channelopathies: long QT, short QT and Brugada syndromes. These syndromes are a notable concern, particularly in young people, due to their high propensity for severe ventricular arrhythmias and sudden cardiac death. Current evidence suggests the involvement of an increasing number of drugs in acquired forms of long QT and Brugada syndromes. However, drug-induced short QT syndrome is still a rarely reported condition. Therefore, there has been speculation on its clinical significance, since few fatal arrhythmias and sudden cardiac death cases have been described so far. Drug-induced proarrhythmia is a growing challenge for physicians, regulatory agencies and the pharmaceutical industry. Physicians should weigh the risks of potentially fatal outcomes against the therapeutic benefits, when making decisions about drug prescriptions. Growing concerns about its safety and the need for more accurate predictive models for drug-induced fatal outcomes justify further research in these fields. The aim of this article is to comprehensively and critically review the recently published evidence with regard to drug-induced life-threatening arrhythmias and sudden cardiac death. This article will take into account the provision of data to physicians that are useful in the identification of the culprit drugs, and thus, contribute to the prompt recognition and management of these serious clinical conditions.

Noncompaction and Dilated Cardiomyopathy in a Patient with Schizophrenia

Objectives. Psychosis and left ventricular hypertrabeculation (or noncompaction) (LVHT) have not been described in the same patient. Here we report a patient with a long-term history of schizophrenia who was later diagnosed with dilated cardiomyopathy (dCMP) and LVHT. Case Report. A 47-year-old Caucasian male developed nondifferentiated schizophrenia at the age of 26 y. Since the age of 33 y he was regularly drinking alcohol. At the age of 47 y he developed heart failure. Transthoracic echocardiography showed an enlarged left ventricle, reduced systolic function, and surprisingly LVHT in the apical segment. Additionally, the left atrium was enlarged, the right ventricular cavities were mildly enlarged, and there were pulmonary hypertension and a small pericardial effusion. Cardiac MRI confirmed the echocardiographic findings. Since coronary angiography was normal, dilated cardiomyopathy was additionally diagnosed. Since he was taking clozapine during years, dilated cardiomyopathy could be due to not only alcohol consumption but also the long-term neuroleptic medication. Conclusions. LVHT may be associated with nondifferentiated psychosis. Management of LVHT is challenging in patients with psychosis due to poor compliance and adherence of these patients. Patients with LVHT and psychosis need particular attention since they usually take cardiotoxic drugs for a long time, which may further deteriorate the prognosis of LVHT.

Cardiovascular side effects of psychopharmacologic therapy

WHO defined in 1976 psychopharmaca as drugs affecting psychological functions, behaviour and self-perception. Psychopharmacology is the study of pharmacological agents that affect mental and emotional functions. Creative approach to psychopharmacotherapy reflects a transdisciplinary, integrative and person-centered psychiatry. Psychiatric disorders often occur in cardiac patients and can affect the clinical presentation and morbidity. Cardiovascular (CV) side effects (SE) caused by psychopharmaceutic agents require comprehensive attention. Therapeutic approach can increase placebo and decrease nocebo reactions. The main purpose of this review is to comprehend CV SE of psychotropic drugs (PD). Critical overview of CV SE of PD will be presented in this review. Search was directed but not limited to CV effects of psychopharmacological substances, namely antipsychotics, anxiolytics, hypnotics, sedatives, antidepressants and stimulants. Literature review was performed and data identified by searches of Medline and PubMed for period from 2004 to 2015. Only full articles and abstracts published in English were included. SE of PD are organized according to the following types of CV effects: cardiac and circulatory effects, abnormalities of cardiac repolarisation and arrhythmias and heart muscle disease. There is wide spectrum and various CV effects of PD. Results of this review are based on literature research. The reviewed data came largely from prevalence studies, case reports, and cross-sectional studies. Psychopharmacotherapy of psychiatric disorders is complex and when concomitantly present with CV disease, presentation of drug SEs can significantly contribute to illness course. Further development of creative psychopharmacotherapy is required to deal with CV effects of PD.

Determinants of torsades de pointes in older patients with drug-associated long QT syndrome: a case-control study

OBJECTIVE

Many elderly patients are routinely exposed to drugs that may prolong the cardiac QT interval and cause Torsades de pointes (TdP). However, predictors of TdP in patients with drug-associated long QT syndrome (LQTS) are not fully understood, especially in the geriatric population. The objective of this study was to identify risk factors of TdP in elderly patients with drug-associated LQTS.

METHODS

In this retrospective, case-control study, documented reports of drug-associated LQTS plus TdP (n = 125) and LQTS without TdP (n = 81) in patients ≥65 years of age were retrieved from the French Pharmacovigilance Database over a 10-year period. Available clinical, biological, and drug therapy data were compared in the two groups and logistic regression was performed to identify significant predictors of TdP.

RESULTS

The uncorrected QT interval was significantly longer in patients with TdP than in patients without TdP (577 ± 79 vs. 519 ± 68 ms; p = 0.0001). The number of drugs with a known risk of TdP administered to each patient was not a predictor of arrhythmia, nor was female gender. Logistic regression analysis identified the uncorrected QT interval as the only significant predictor of TdP. The receiver operating characteristic curve analysis was characterized by an area under the curve of 0.77 (95 % confidence interval 0.64-0.88) and a QT cutoff of 550 ms.

CONCLUSION

The uncorrected QT interval was significantly associated with the probability of TdP in elderly patients with acquired, drug-associated LQTS.

Fluoxetine blocks Nav1.5 channels via a mechanism similar to that of class 1 antiarrhythmics

The voltage-gated Nav1.5 channel is essential for the propagation of action potentials in the heart. Malfunctions of this channel are known to cause hereditary diseases. It is a prime target for class 1 antiarrhythmic drugs and a number of antidepressants. Our study investigated the Nav1.5 blocking properties of fluoxetine, a selective serotonin reuptake inhibitor. Nav1.5 channels were expressed in HEK-293 cells, and Na(+) currents were recorded using the patch-clamp technique. Dose-response curves of racemic fluoxetine (IC50 = 39 μM) and its optical isomers had a similar IC50 [40 and 47 μM for the (+) and (-) isomers, respectively]. Norfluoxetine, a fluoxetine metabolite, had a higher affinity than fluoxetine, with an IC50 of 29 μM. Fluoxetine inhibited currents in a frequency-dependent manner, shifted steady-state inactivation to more hyperpolarized potentials, and slowed the recovery of Nav1.5 from inactivation. Mutating a phenylalanine (F1760) and a tyrosine (Y1767) in the S6 segment of domain (D) IV (DIVS6) significantly reduced the affinity of fluoxetine and its frequency-dependent inhibition. We used a noninactivating Nav1.5 mutant to show that fluoxetine displays open-channel block behavior. The molecular model of fluoxetine in Nav1.5 was in agreement with mutational experiments in which F1760 and Y1767 were found to be the key residues in binding fluoxetine. We concluded that fluoxetine blocks Nav1.5 by binding to the class 1 antiarrhythmic site. The blocking of cardiac Na(+) channels should be taken into consideration when prescribing fluoxetine alone or in association with other drugs that may be cardiotoxic or for patients with conduction disorders.

Brugada syndrome ECG is highly prevalent in schizophrenia

BACKGROUND

The causes of increased risk of sudden cardiac death in schizophrenia are not resolved. We aimed to establish (1) whether ECG markers of sudden cardiac death risk, in particular Brugada-ECG pattern, are more prevalent among patients with schizophrenia, and (2) whether increased prevalence of these ECG markers in schizophrenia is explained by confounding factors, notably sodium channel-blocking medication.

METHODS AND RESULTS

In a cross-sectional study, we analyzed ECGs of a cohort of 275 patients with schizophrenia, along with medication use. We determined whether Brugada-ECG was present and assessed standard ECG measures (heart rate, PQ-, QRS-, and QT-intervals). We compared the findings with nonschizophrenic individuals of comparable age (the Netherlands Study of Depression and Anxiety [NESDA] cohort; N=179) and, to account for assumed increased aging rate in schizophrenia, with individuals 20 years older (Hoorn cohort; n=1168), using multivariate regression models. Brugada-ECG was significantly more prevalent in the schizophrenia cohort (11.6%) compared with NESDA controls (1.1%) or Hoorn controls (2.4%). Moreover, patients with schizophrenia had longer QT-intervals (410.9 versus 393.1 and 401.9 ms; both P<0.05), increased proportion of mild or severe QTc prolongation (13.1% and 5.8% versus 3.4% and 0.0% [NESDA], versus 5.1 and 2.8% [Hoorn]), and higher heart rates (80.8 versus 61.7 and 68.0 beats per minute; both P<0.05). The prevalence of Brugada-ECG was still increased (9.6%) when patients with schizophrenia without sodium channel-blocking medication were compared with either of the control cohorts.

CONCLUSIONS

Brugada-ECG has increased prevalence among patients with schizophrenia. This association is not explained by the use of sodium channel-blocking medication.

Molecular analysis of potassium ion channel genes in sudden death cases among patients administered psychotropic drug therapy: are polymorphisms in LQT genes a potential risk factor?

Psychotropic drugs can pose the risk of acquired long QT syndrome (LQTS). Unexpected autopsy-negative sudden death in patients taking psychotropic drugs may be associated with prolonged QT intervals and life-threatening arrhythmias. We analyzed genes that encode for cardiac ion channels and potentially associated with LQTS, examining specifically the potassium channel genes KCNQ1 and KCNH2 in 10 cases of sudden death involving patients administered psychotropic medication in which autopsy findings identified no clear cause of death. We amplified and sequenced all exons of KCNQ1 and KCNH2, identifying G643S, missense polymorphism in KCNQ1, in 6 of the 10 cases. A study analysis indicated that only 11% of 381 healthy Japanese individuals carry this polymorphism. Reports of previous functional analyses indicate that the G643S polymorphism in the KCNQ1 potassium channel protein causes mild I(Ks) channel dysfunction. Our present study suggests that administering psychotropic drug therapy to individuals carrying the G643S polymorphism may heighten the risk of prolonged QT intervals and life-threatening arrhythmias. Thus, screening for the G643S polymorphism before prescribing psychotropic drugs may help reduce the risk of unexpected sudden death.

Antipsychotics and the Risks of Sudden Cardiac Death and All-Cause Death: Cohort Studies in Medicaid and Dually-Eligible Medicaid-Medicare Beneficiaries of Five States

CONTEXT

Antipsychotic drugs have been linked to QT-interval prolongation, a presumed marker of cardiac risk, and torsade de pointes.

OBJECTIVE

To examine the associations between antipsychotics and 1) outpatient-originated sudden cardiac death and ventricular arrhythmia (SD/VA) and 2) all-cause death.

DESIGN

Two retrospective cohort studies.

SETTING

Medicaid programs of California, Florida, New York, Ohio and Pennsylvania.

PATIENTS

Incident antipsychotic users aged 30-75 years.

MAIN OUTCOME MEASURES

1) Incident, first-listed emergency department or principal inpatient SD/VA diagnoses; and 2) death reported in the Social Security Administration Death Master File.

RESULTS

Among 459,614 incident antipsychotic users, the incidences of SD/VA and death were 3.4 and 35.1 per 1,000 person-years, respectively. Compared to olanzapine as the referent, adjusted hazard ratios (HRs) for SD/VA were 2.06 (95% CI, 1.20-3.53) for chlorpromazine, 1.72 (1.28-2.31) for haloperidol, and 0.73 (0.57-0.93) for quetiapine. Adjusted HRs for perphenazine and risperidone were consistent with unity. In a subanalysis limited to first prescription exposures, HRs for chlorpromazine and haloperidol were further elevated (2.54 [1.07-5.99] and 2.68 [1.59-4.53], respectively), with the latter exhibiting a dose-response relationship. Results for death were similar.

CONCLUSIONS

Haloperidol and chlorpromazine had less favorable cardiac safety profiles than olanzapine. Among atypical agents, risperidone had a similar cardiac safety profile to olanzapine, whereas quetiapine was associated with 30% and 20% lower risks of SD/VA and death, respectively, compared to olanzapine. These measured risks do not correlate well with average QT prolongation, further supporting the notion that average QT prolongation may be a poor surrogate of antipsychotic arrhythmogenicity.

A research method for detecting transient myocardial ischemia in patients with suspected acute coronary syndrome using continuous ST-segment analysis

Each year, an estimated 785,000 Americans will have a new coronary attack, or acute coronary syndrome (ACS). The pathophysiology of ACS involves rupture of an atherosclerotic plaque; hence, treatment is aimed at plaque stabilization in order to prevent cellular death. However, there is considerable debate among clinicians, about which treatment pathway is best: early invasive using percutaneous coronary intervention (PCI/stent) when indicated or a conservative approach (i.e., medication only with PCI/stent if recurrent symptoms occur).

There are three types of ACS: ST elevation myocardial infarction (STEMI), non-ST elevation MI (NSTEMI), and unstable angina (UA). Among the three types, NSTEMI/UA is nearly four times as common as STEMI. Treatment decisions for NSTEMI/UA are based largely on symptoms and resting or exercise electrocardiograms (ECG). However, because of the dynamic and unpredictable nature of the atherosclerotic plaque, these methods often under detect myocardial ischemia because symptoms are unreliable, and/or continuous ECG monitoring was not utilized.

Continuous 12-lead ECG monitoring, which is both inexpensive and non-invasive, can identify transient episodes of myocardial ischemia, a precursor to MI, even when asymptomatic. However, continuous 12-lead ECG monitoring is not usual hospital practice; rather, only two leads are typically monitored. Information obtained with 12-lead ECG monitoring might provide useful information for deciding the best ACS treatment.

Purpose. Therefore, using 12-lead ECG monitoring, the COMPARE Study (electroCardiographic evaluatiOn of ischeMia comParing invAsive to phaRmacological trEatment) was designed to assess the frequency and clinical consequences of transient myocardial ischemia, in patients with NSTEMI/UA treated with either early invasive PCI/stent or those managed conservatively (medications or PCI/stent following recurrent symptoms). The purpose of this manuscript is to describe the methodology used in the COMPARE Study.

Method. Permission to proceed with this study was obtained from the Institutional Review Board of the hospital and the university. Research nurses identify hospitalized patients from the emergency department and telemetry unit with suspected ACS. Once consented, a 12-lead ECG Holter monitor is applied, and remains in place during the patient's entire hospital stay. Patients are also maintained on the routine bedside ECG monitoring system per hospital protocol. Off-line ECG analysis is done using sophisticated software and careful human oversight.