Is an Abnormal ECG Just the Tip of the ICE-berg? Examining the Utility of Electrocardiography in Detecting Methamphetamine-Induced Cardiac Pathology

Methamphetamine-associated cardiomyopathy: an addiction medicine perspective

Methamphetamine-associated cardiomyopathy (MaCM) is an increasingly recognised serious complication from methamphetamine (MA) use. It is characterised as the development of otherwise unexplained heart failure in the context of MA use. MaCM predominantly affects a young and vulnerable population with high morbidity and mortality. It is the second leading cause of mortality in patients with MA use disorder (MUD). Our understanding of MaCM pathogenesis is based on observational cohorts and autopsy studies. Currently, the treatment of MaCM is predicated on abstinence. Medical therapies offer some benefit to a minority of patients; however, without abstinence, medical therapies are often ineffective. Abstinence is difficult for most patients to achieve; all clinicians require an understanding of MaCM and how to educate patients on the risks of ongoing use. Where available, referral to addiction medicine specialists to assist with treatment of MUD is recommended. This review aims to: (i) explain the proposed pathologic mechanisms of MaCM; (ii) summarise recent recommendations of the screening and treatment of MaCM; and (iii) highlight the role of addiction medicine in the management of patient with MaCM.

The effects of methamphetamine on electrocardiographic parameters in male patients

OBJECTIVE

We aimed to compare the electrocardiographic parameters in patients with methamphetamine use to healthy controls.

METHODS

The study is a cross-sectional case-control study. Sixty-eight patients diagnosed with methamphetamine use disorder (MUD) according to DSM-5 criteria and 65 subjects in healthy control group who can match the patient group with demographic data were included in the study. Heart rate, P wave dispersion, QT dispersion, QTc and Tp-e/QTc ratios were calculated in the ECGs of all participants.

RESULTS

The mean age of the patients was 25.60 ± 5.70 and of the control group was 27.43 ± 6.10 (p = 0.076). There was no statistically significant difference between the blood pressure, body mass index, HDL-LDL-total cholesterol and triglyceride values of the participants (p > 0.05). Although QT dispersion was 13.68 ± 9.12 in patients with methamphetamine use disorder, it was calculated as 9.08 ± 7.85 in the control group (p = 0.002). Finally, the Tp-e/QTc ratio of the patients was higher than the healthy controls (p = 0.014).

CONCLUSION

In our study, we found a significant deterioration in QT dispersion and Tp-e/QTc ratio in the MUD group. Therefore, it should be kept in mind that there is a risk of malignant arrhythmia in this patient group and care should be taken in terms of arrhythmic events during follow-up in this patient group.Key pointsPatients with methamphetamine use showed significant deterioration in QTd and Tp-e/QTcMethamphetamine users have prolonged Tp-e/QTc ratio and QTdCaution should be exercised in terms of arrhythmic events in methamphetamine users.

Cardiovascular disease associated with methamphetamine use: a review

Methamphetamine abuse is a global epidemic associated with a wide-ranging array of adverse effects on the cardiovascular system including dilated cardiomyopathy, malignant and benign arrhythmias, coronary vasospasm, and atherosclerotic coronary artery disease. While the acute behavioral manifestations of amphetamine abuse are the most easily clinically identified, cardiovascular toxicity is common in this patient population and should be considered in this setting due to its high morbidity and mortality. The specific mechanisms for amphetamine cardiotoxicity have not been fully established, but new research implicates activation of several cellular targets including Sigma-1 receptors and trace amine-associated receptor 1 (TAAR1) leading to a myriad of negative downstream effects including increased reactive oxygenating species (ROS), mitochondrial dysfunction, and modulations of intracellular calcium. Additional pathologic effects are mediated by increased circulating catecholamines, which when chronically activated have well-established adverse effects on the cardiovascular system. In this article, we present a case report followed by a current review of the epidemiology, pathophysiology, diagnosis, and treatment modalities of amphetamine-induced cardiovascular disease.

Methadone Blockade of Cardiac Inward Rectifier K+ Current Augments Membrane Instability and Amplifies U Waves on Surface ECGs: A Translational Study

Background Methadone is associated with a disproportionate risk of sudden death and ventricular tachyarrhythmia despite only modest inhibition of delayed rectifier K⁺ current (I_Kr)_, the principal mechanism of drug-associated arrhythmia. Congenital defects of inward rectifier K⁺ current (I_K1) have been linked to increased U-wave amplitude on ECG and fatal arrhythmia. We hypothesized that methadone may also be a potent inhibitor of I_K1, contributing to delayed repolarization and manifesting on surface ECGs as augmented U-wave integrals. Methods and Results Using a whole-cell voltage clamp, methadone inhibited both recombinant and native I_K1 with a half-maximal inhibitory concentration IC50) of 1.5 μmol/L, similar to that observed for I_Kr block (half-maximal inhibitory concentration of 2.9 μmol/L). Methadone modestly increased the action potential duration at 90% repolarization and slowed terminal repolarization at low concentrations. At higher concentrations, action potential duration at 90% repolarization lengthening was abolished, but its effect on terminal repolarization rose steadily and correlated with increased fluctuations of diastolic membrane potential. In parallel, patient ECGs were analyzed before and after methadone initiation, with 68% of patients having a markedly increased U-wave integral compared with premethadone (lead V3; mean +38%±15%, P=0.016), along with increased QT and T_Peak to T_End intervals, likely reflective of I_Kr block. Conclusions Methadone is a potent I_K1 inhibitor that causes augmentation of U waves on surface ECG. We propose that increased membrane instability resulting from I_K1 block may better explain methadone's arrhythmia risk beyond I_Kr inhibition alone. Drug-induced augmentation of U waves may represent evidence of blockade of multiple repolarizing ion channels, and evaluation of the effect of that agent on I_K1 may be warranted.

A Comprehensive Approach to Managing Methamphetamine-Associated Cardiomyopathy

Methamphetamines are illicit drugs of the amphetamine-type stimulant class that have been increasing in popularity, availability, and purity in recent decades. As a result, rates of methamphetamine-associated cardiomyopathy (MAC) are rising globally. MAC is associated with high rates of sudden cardiac arrest, late presentation, and poor outcomes. This review discusses the medical management of MAC, including anticipated challenges specific to methamphetamine users. Not only are patients with MAC more likely to present at a younger age and with multisystem disease than patients with cardiomyopathy of other etiologies, but there may also be significant behavioral, psychosocial, financial, and system-based challenges to providing the best medical care. An individualized treatment plan that emphasizes methamphetamine abstinence as the foundation of therapy, as well as introducing optimal heart failure therapy and providing multidisciplinary support is likely to result in optimal outcomes. Given the potential reversibility of MAC, institution of guideline-directed heart failure therapy and patient support for adherence to therapy and abstinence from methamphetamines should be energetically pursued.

Amphetamine-induced cardiomyopathy complicated by embolic stroke: a case report

Background

Amphetamine use causes cardiomyopathy via catecholamine-mediated effects such as tachycardia, hypertension, vasoconstriction, and direct cardio-toxic effects. Traditionally, an increased risk of haemorrhagic stroke is associated with amphetamine use. However, up to one-third of stimulant-associated cardiomyopathy patients have left ventricular (LV) thrombus formation leading to an increased risk of systemic embolization. We report a case of amphetamine-induced cardiomyopathy complicated by embolic stroke secondary to LV thrombus.

Case summary

A 38-year-old man with 6-month history of sustained amphetamine use presented to the emergency department with left-sided weakness, facial droop, and dysarthria. Angiography confirmed right middle cerebral artery thrombus. Prompt mechanical thrombectomy yielded full neurological recovery. Dyspnoea prompted transthoracic echocardiography showing dilated cardiomyopathy with an ejection fraction of 5% and LV thrombus. Anticoagulation was initiated with warfarin as well as pharmacological therapy for heart failure with reduced ejection fraction including bisoprolol, spironolactone, loop diuretic, and sacubitril/valsartan. He was discharged successfully following resolution of ventricular thrombus and medical management of heart failure. Clinical recovery was hampered by psychosocial factors resulting in non-adherence to medical therapy and continued amphetamine use.

Conclusion

Sustained amphetamine use can result in severe dilated cardiomyopathy with LV thrombus formation and embolic complications such as ischaemic stroke. Avoidance of amphetamines in conjunction with guideline-directed pharmacological management are key components of therapy. However, psychosocial factors can exert significant influence on recovery.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

Stimulant Drugs of Abuse and Cardiac Arrhythmias

Nonmedical use of prescription and nonprescription drugs is a worldwide epidemic, rapidly growing in magnitude with deaths because of overdose and chronic use. A vast majority of these drugs are stimulants that have various effects on the cardiovascular system including the cardiac rhythm. Drugs, like cocaine and methamphetamine, have measured effects on the conduction system and through several direct and indirect pathways, utilizing multiple second messenger systems, change the structural and electrical substrate of the heart, thereby promoting cardiac dysrhythmias. Substituted amphetamines and cocaine affect the expression and activation kinetics of multiple ion channels and calcium signaling proteins resulting in EKG changes, and atrial and ventricular brady and tachyarrhythmias. Preexisting conditions cause substrate changes in the heart, which decrease the threshold for such drug-induced cardiac arrhythmias. The treatment of cardiac arrhythmias in patients who take drugs of abuse may be specialized and will require an understanding of the unique underlying mechanisms and necessitates a multidisciplinary approach. The use of primary or secondary prevention defibrillators in drug abusers with chronic systolic heart failure is both sensitive and controversial. This review provides a broad overview of cardiac arrhythmias associated with stimulant substance abuse and their management.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

Neurobiology, Clinical Presentation, and Treatment of Methamphetamine Use Disorder: A Review

IMPORTANCE

The prevalence of and mortality associated with methamphetamine use has doubled during the past 10 years. There is evidence suggesting that methamphetamine use disorder could be the next substance use crisis in the United States and possibly worldwide.

OBSERVATION

The neurobiology of methamphetamine use disorder extends beyond the acute effect of the drug as a monoaminergic modulator and includes intracellular pathways focused on oxidative stress, neurotoxic and excitotoxic effects, and neuroinflammation. Similarly, the clinical picture extends beyond the acute psychostimulatory symptoms to include complex cardiovascular and cerebrovascular signs and symptoms that need to be identified by the clinician. Although there are no pharmacologic treatments for methamphetamine use disorder, cognitive behavioral therapy, behavioral activation, and contingency management show modest effectiveness.

CONCLUSIONS AND RELEVANCE

There is a need to better understand the complex neurobiology of methamphetamine use disorder and to develop interventions aimed at novel biological targets. Parsing the disorder into different processes (eg, craving or mood-associated alterations) and targeting the neural systems and biological pathways underlying these processes may lead to greater success in identifying disease-modifying interventions. Finally, mental health professionals need to be trained in recognizing early cardiovascular and cerebrovascular warning signs to mitigate the mortality associated with methamphetamine use disorder.

The Cardiac Conduction and Contractility Complications of Methamphetamine Use and the Relationship to Psychiatric Comorbidity: A Systematic Review

Background:

Methamphetamine has the potential to produce more severe short and long term effects than typical amphetamines due to the drug’s increased purity. The cardiovascular consequences compromise a large proportion of the drug’s mortality. Previous reviews have not examined these complications in relation to psychiatric patients who have high rates of substance use and physical comorbidity.

Methods:

Ovid Medline, Embase, Emcare, PsycINFO, CINAHL, and Cochrane were systematically searched in English until November 2017. Data were coded according to study design, sample size, demographics, medical and psychiatric comorbidity, electrocardiograph abnormalities, echocardiograph parameters, illness severity, treatment, and outcome on follow up.

Results:

The 11 included studies were predominantly case series conducted in the USA. Males were more likely to use methamphetamine and be associated with global systolic dysfunction. The mean age was lower for those with methamphetamine-related cardiovascular complications. QTc interval prolongation was the most frequent electrocardiograph abnormality. Continued methamphetamine use was associated with persistently impaired ventricular function, whilst discontinuation led to remodeling and improved ejection fraction. Only one study referenced psychiatric comorbidity or dual diagnosis.

Conclusion:

This review describes the range of variables related to methamphetamine associated arrhythmias and cardiomyopathies. Early detection of methamphetamine use and the subsequent cardiac complications is important, especially in a psychiatric cohort where physical illness is more commonly neglected. The monitoring of electrocardiographs in methamphetamine users is also crucial. Future research is needed to allow for appropriate recommendations in managing the harmful impacts of methamphetamine use in this population.

Clinical Characteristics and Management of Methamphetamine-Associated Cardiomyopathy: State-of-the-Art Review

Methamphetamine‐associated cardiomyopathy (MACM) is an increasingly recognized disease entity in the context of a rapidly spreading methamphetamine epidemic. MACM may afflict individuals with a wide range of ages and socioeconomic backgrounds. Presentations can vary greatly and may involve several complications unique to the disease. Given the public health significance of this disease, there is a relative dearth of consensus material to guide clinicians in understanding, diagnosing, and managing MACM. This review therefore aims to: (1) describe pathologic mechanisms of methamphetamine as they pertain to the development, progression, and prognosis of MACM, and the potential to recover cardiac function; (2) summarize existing data from epidemiologic studies and case series in an effort to improve recognition and diagnosis of the disease; (3) guide short‐ and long‐term management of MACM with special attention to expected or potential sequelae of the disease; and (4) highlight pivotal unanswered questions in need of urgent investigation from a public health perspective.

Effects of drug abuse, smoking and alcohol on donor hearts and lungs

Potential heart and lung donors with a history of illicit drugs and/or smoking and alcohol are frequently offered, though there is no clear guidance on when it is safe to use these organs. A review of the literature on effects of drugs, alcohol and smoking on donor outcomes, and the effects of these on the intact heart and lung was undertaken. There has been a marked increase in deaths from opioid abuse in many developed countries, though recent evidence suggests that outcomes after cardiothoracic transplantation are equivalent to nonopioid donor causes of death. For donor smoking, there is an increased risk with lung transplantation; however, that risk is less when compared to further waiting on the transplant list for a nonsmoking alternative. Heavy alcohol consumption does not adversely affect heart transplantation, and there is no clear evidence of adverse outcomes after lung transplantation. There are no overall effects of cannabis or cocaine on survival after heart or lung transplantation. In all these cases, careful donor assessment can establish if a particular organ can be used. In most cases, use of drugs requires careful assessment, but is not in of itself a contraindication to cardiothoracic transplantation.