Cardiac muscle lesions associated with chronic administration of methamphetamine in rats

Loneliness, Methamphetamine Use, and Cardiovascular Risk Factors Among Sexual Minority Men in the COVID-19 Era

BACKGROUND

Important gaps exist in our understanding of loneliness and biobehavioral outcomes among sexual minority men (SMM), such as faster HIV disease progression. At the same time, SMM who use methamphetamine are approximately one-third more likely than non-users to develop cardiovascular disease. This study examined associations of loneliness, stimulant use, and cardiovascular risk in SMM with and without HIV.

METHOD

Participants were enrolled from August 2020 to February 2022 in a 6-month prospective cohort study. The study leveraged self-report baseline data from 103 SMM, with a subset of 56 SMM that provided a blood sample to measure markers of cardiovascular risk.

RESULTS

Loneliness showed negative bivariate associations with total cholesterol and LDL cholesterol in the cardiometabolic subsample (n = 56). SMM with methamphetamine use (t(101) = 2.03, p < .05; d = .42) and those that screened positive for a stimulant use disorder (t(101) = 2.07, p < .05; d = .46) had significantly higher mean loneliness scores. In linear regression analyses, negative associations of loneliness with LDL and total cholesterol were observed only among SMM who used methamphetamine.

CONCLUSION

We observed lower cholesterol in SMM reporting loneliness and methamphetamine use. Thus, in addition to the observed associations of loneliness with cholesterol, there are important medical consequences of methamphetamine use including cardiovascular risk, higher HIV acquisition risk and progression, as well as stimulant overdose death. This cross-sectional study underscores the need for clinical research to develop and test interventions targeting loneliness among SMM with stimulant use disorders.

Vanillic acid alleviates methamphetamine-induced mitochondrial toxicity in cardiac mitochondria via antioxidant activity and inhibition of MPT Pore opening: an in-vitro study

BACKGROUND

Methamphetamine is widely abused in all parts of the world. It has been reported that short-term and long-term methamphetamine exposure could damage the dopaminergic system and induce cardiomyopathy and cardiotoxicity via mitochondrial dysfunction and oxidative stress. Vanillic acid (VA), a phenolic acid compound derived from plants, is known for its antioxidant and mitochondrial protection properties.

METHODS

In the current study we used VA for attenuating of Methamphetamine-induced mitochondrial toxicity in cardiac mitochondria. Isolated mitochondria obtained from rat heart were grouped as: control, methamphetamine (250 µM), VA (10, 50 and 100 µM) was cotreated with methamphetamine (250 µM) and VA (100 µM) alone. After 60 min, mitochondrial fraction including: succinate dehydrogenases (SDH) activity, mitochondrial membrane potential (MMP), mitochondrial swelling, mitochondrial glutathione (GSH), reactive oxygen species (ROS) and lipid peroxidation (LPO) were evaluated.

RESULTS

Methamphetamine exposure significantly disrupted mitochondrial function and induced ROS formation, lipid peroxidation, GSH depletion, MMP collapse and mitochondrial swelling, while VA significantly increased SDH activity as indicator of mitochondrial toxicity and dysfunction. VA also significantly decreased ROS formation, lipid peroxidation, mitochondrial swelling, MMP collapse and depletion of GSH in cardiac mitochondria in the presence of methamphetamine.

CONCLUSION

These findings suggested that VA is able to reduce methamphetamine-induced mitochondrial dysfunction and oxidative stress. Our results demonstrate that VA could potentially serve as a promising and accessible cardioprotective agent against methamphetamine-induced cardiotoxicity, via antioxidant and mitochondrial protection properties.

Dilated Cardiomyopathy: Beware of Diet Drugs Slimming the Heart

There have been rare reports of dilated cardiomyopathy from chronic use of phentermine/topiramate, although very limited data are available. Phentermine is an atypical amphetamine analog that has been contraindicated in patients with a history of cardiovascular disease. We present a case of nonischemic dilated cardiomyopathy in the setting of chronic phentermine/topiramate use, which is the most likely cause of her dilated cardiomyopathy.

Methamphetamine induces cardiomyopathy through GATA4/NF-κB/SASP axis-mediated cellular senescence

With the world pandemic of methamphetamine (METH), METH-associated cardiomyopathy (MAC) has become a widespread epidemic and is also recognized as a cause of heart failure in young people. The mechanism of occurrence and development of MAC is not clear. In this study, firstly, the animal model was evaluated by echocardiography and myocardial pathological staining. The results revealed that the animal model exhibited cardiac injury consistent with clinical alterations of MAC, and the mice developed cardiac hypertrophy and fibrosis remodeling, which led to systolic dysfunction and left ventricular ejection fraction (%LVEF) < 40%. The expression of cellular senescence marker proteins (p16 and p21) and senescence-associated secretory phenotype (SASP) was significantly increased in mouse myocardial tissue. Secondly, mRNA sequencing analysis of cardiac tissues revealed the key molecule GATA4, and Western blot, qPCR and immunofluorescence results showed that the expression level of GATA4 was significantly increased after METH exposure. Finally, knockdown of GATA4 expression in H9C2 cells in vitro significantly attenuated METH-induced cardiomyocyte senescence. Consequently, METH causes cardiomyopathy through cellular senescence mediated by the GATA4/NF-κB/SASP axis, which is a feasible target for the treatment of MAC.

Cardiovascular magnetic resonance imaging characteristics in patients with methamphetamine-associated cardiomyopathy

BACKGROUND

Methamphetamine-associated cardiomyopathy (MA-CMP) is an increasingly recognised aetiology of cardiomyopathy. Cardiovascular magnetic resonance (CMR) is a specialised cardiac imaging modality commonly used in assessment of cardiomyopathy. We aimed to identify specific CMR features associated with MA-CMP.

METHODS

A retrospective cohort study of CMR scans was performed in a single centre between January 2015 and December 2020. Thirty patients with MA-CMP who had undergone CMR were identified. MA-CMP was defined as those with a history of significant methamphetamine use hospitalised with acute decompensated heart failure (other causes of cardiomyopathy excluded). A retrospective analysis of index admission CMRs was performed. All studies were performed on a 1.5 T CMR scanner.

RESULTS

The mean age of MA-CMP patients was 43.7 ± 7.5 years, and 86.7% were male. The mean left ventricular (LV) volume obtained in this cohort was consistent with severe LV dilatation (LV end-diastolic volume (334 ± 99 ml); LV end-systolic volume: 269 ± 98 ml), whilst the right ventricular (RV) volume indicated moderate-to-severe dilatation (RV end-diastolic volume: 272 ± 91 ml; RV end-systolic volume: 173 ± 82 ml). Mean LV ejection fraction (20.9 ± 9.2%) indicated severe LV dysfunction, with moderate-to-severe RV dysfunction also detected (RV ejection fraction: 29.4 ± 13.4%). 22 patients (73.3%) had myocardial late gadolinium enhancement (LGE), of which 59.1% were located in the mid-wall, with all of these involving the interventricular septum. 22.7% displayed localised regions of sub-endocardial LGE in a variety of locations, and 18.2% had transmural regions of LGE that were located in the inferior and inferolateral segments. 6 patients (20%) had intracardiac thrombus (4 LV, 2 both LV and RV).

CONCLUSION

MA-CMP was associated with severe biventricular dilatation and dysfunction, with a high prevalence of intraventricular thrombus. This cohort study highlights that MA-CMP patients have a high prevalence of CMR findings.

Mitochondrial dysfunction and autophagy activation are associated with cardiomyopathy developed by extended methamphetamine self-administration in rats

The recent rise in illicit use of methamphetamine (METH), a highly addictive psychostimulant, is a huge health care burden due to its central and peripheral toxic effects. Mounting clinical studies have noted that METH use in humans is associated with the development of cardiomyopathy; however, preclinical studies and animal models to dissect detailed molecular mechanisms of METH-associated cardiomyopathy development are scarce. The present study utilized a unique very long-access binge and crash procedure of METH self-administration to characterize the sequelae of pathological alterations that occur with METH-associated cardiomyopathy. Rats were allowed to intravenously self-administer METH for 96 h continuous weekly sessions over 8 weeks. Cardiac function, histochemistry, ultrastructure, and biochemical experiments were performed 24 h after the cessation of drug administration. Voluntary METH self-administration induced pathological cardiac remodeling as indicated by cardiomyocyte hypertrophy, myocyte disarray, interstitial and perivascular fibrosis accompanied by compromised cardiac systolic function. Ultrastructural examination and native gel electrophoresis revealed altered mitochondrial morphology and reduced mitochondrial oxidative phosphorylation (OXPHOS) supercomplexes (SCs) stability and assembly in METH exposed hearts. Redox-sensitive assays revealed significantly attenuated mitochondrial respiratory complex activities with a compensatory increase in pyruvate dehydrogenase (PDH) activity reminiscent of metabolic remodeling. Increased autophagy flux and increased mitochondrial antioxidant protein level was observed in METH exposed heart. Treatment with mitoTEMPO reduced the autophagy level indicating the involvement of mitochondrial dysfunction in the adaptive activation of autophagy in METH exposed hearts. Altogether, we have reported a novel METH-associated cardiomyopathy model using voluntary drug seeking behavior. Our studies indicated that METH self-administration profoundly affects mitochondrial ultrastructure, OXPHOS SCs assembly and redox activity accompanied by increased PDH activity that may underlie observed cardiac dysfunction.

Methamphetamine Use: A Narrative Review of Adverse Effects and Related Toxicities

Methamphetamine has been labeled "America's most dangerous drug" and has received significant public health attention. Stimulant addiction and tolerance are heavily documented in the literature; increasingly larger doses maintain euphoria in short time periods to withstand stimulant tolerance. Stimulant deaths are high in the United States and abroad. Between 2013 and 2019, deaths related to methamphetamine use quadrupled from 3,616 to 16,127. Methamphetamine use increased four-fold from 2015 to 2016. Due to this increase in methamphetamine use and its associated medical complications, the mortality rate associated with methamphetamine use has doubled over the past ten years. Cardiopulmonary symptoms include chest pain, palpitations, and shortness of breath. Methamphetamine-related myocardial infarction can also occur. Central nervous system symptoms include agitation, anxiety, delusions, hallucinations, and seizures. Methamphetamine-induced psychosis may unmask underlying psychiatric disorders. It can also cause cerebral vasculitis, which elicits cortical blindness and ischemic strokes. Methamphetamine-induced neurotoxicity in serotonergic systems is more diffuse, involving the striatum, hippocampus, septum, amygdala, and hypothalamus leading to mood changes, psychosis, and memory impairment. This narrative review will aim to highlight the adverse effects as well as the toxicity that can occur with methamphetamine use.

Methamphetamine-Associated Cardiomyopathy: Addressing the Clinical Challenges

The growth in methamphetamine usage worldwide continues to present increasing societal and health care challenges. With the escalation of its usage in a variety of social demographics, the entity of methamphetamine-associated cardiomyopathy (MA-CMP) has emerged. This entity is increasingly responsible for an important proportion of heart failure burden in both admissions to hospital and in those individuals requiring chronic heart failure care. MA-CMP poses some unique challenges including its recognition, particularly in younger patients presenting with new-onset heart failure, its severity at presentation and complications as well as management options. The challenging nature of methamphetamine addiction and the necessity to achieve abstinence is a fundamental aspect of management of this condition. As methamphetamine use continues at high levels in Australia, the burden of MA-CMP will inevitably increase and, therefore, all clinicians responsible for heart failure management require an awareness of this disease entity and the specific clinical challenges of its care.

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.

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.

Supraventricular tachycardia with the use of phentermine: case report and review of literature

Case: A 34-year-old woman with no significant past medical history presented to the hospital with sudden onset of palpitations with associated dyspnea and chest discomfort. She denied any similar previous episodes. Initial electrocardiogram (EKG) was consistent with a short R-P interval supraventricular tachycardia (SVT). Her transthoracic echocardiogram (TTE) revealed no structural abnormalities, TSH levels were normal, and urine drug screen was negative for any recreational drugs. However, the patient had been taking phentermine for weight loss.Discussion: The exact mechanism is not clear; however, we postulate that the sympathomimetic effects of phentermine likely contribute to SVT induction through enhanced AV nodal conduction or increased atrial ectopy. Conclusions: The only medication she was taking at home was phentermine, and the palpitations did not recur after discontinuation of the drug during follow-up. It is important to collect a thorough medication history when patients present with AV nodal reentrant tachycardia (AVNRT) or other SVT.

Methamphetamine induces cardiomyopathy by Sigmar1 inhibition-dependent impairment of mitochondrial dynamics and function

Methamphetamine-associated cardiomyopathy is the leading cause of death linked with illicit drug use. Here we show that Sigmar1 is a therapeutic target for methamphetamine-associated cardiomyopathy and defined the molecular mechanisms using autopsy samples of human hearts, and a mouse model of "binge and crash" methamphetamine administration. Sigmar1 expression is significantly decreased in the hearts of human methamphetamine users and those of "binge and crash" methamphetamine-treated mice. The hearts of methamphetamine users also show signs of cardiomyopathy, including cellular injury, fibrosis, and enlargement of the heart. In addition, mice expose to "binge and crash" methamphetamine develop cardiac hypertrophy, fibrotic remodeling, and mitochondrial dysfunction leading to contractile dysfunction. Methamphetamine treatment inhibits Sigmar1, resulting in inactivation of the cAMP response element-binding protein (CREB), decreased expression of mitochondrial fission 1 protein (FIS1), and ultimately alteration of mitochondrial dynamics and function. Therefore, Sigmar1 is a viable therapeutic agent for protection against methamphetamine-associated cardiomyopathy.

Exposure to methamphetamine exacerbates motor activities and alters circular RNA profile of cerebellum

Methamphetamine (METH) is a psychostimulant drug that acts on monoaminergic systems in the brain. There are several lines of evidence indicating the devastating effects of addictive drugs on the cerebellum. Moreover, it was shown that circular RNAs (circRNAs) have an important role in neurodegenerative disorders. Herein, we explored the effects of METH on neuronal degeneration, motor coordination and muscle activity. We also inspected METH-mediated changes in circRNA expression profiling in the cerebellum. Accordingly, exposure to METH triggered destructive effects on the coordination of movement of rats along with disturbed muscle activity. The fluorescent staining exhibited a significant increase in neurodegeneration in the cerebellum under the influence of METH. Besides, the number of calbindin positive Purkinje cells noticeably declined in METH-treated group compared with the control. In this regard, we identified and characterized differentially expressed (DE) circRNAs in the cerebellum under METH treatment, mainly located in dendritic spines. Moreover, based on feature and function analyzes of host genes of DE circRNAs, a large number of these genes were essentially involved in cell growth, death, inflammation and oxidative metabolism. Taken together, this data might imply the potential involvement of circRNAs in METH neurotoxicity as well as motor activity deficits.

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.

Methamphetamine-related cardiovascular diseases

Aims

Abuse of crystal methamphetamine (MA) poses a growing problem for health services worldwide. This review summarizes the current literature on the effects of MA on the cardiovascular system.

Methods and results

This article is a presentation of a case report and review of the current literature. In Europe, especially the eastern countries and the eastern states of Germany are affected. MA increases the concentration of catecholamines in the synaptic gap leading to euphoria, alertness, and hunger suppression as well as psychiatric and gastrointestinal complications. MA consumption is associated with hypertension, acute and chronic myocardial toxicity, stroke, coronary artery disease, and sudden cardiac death. Although many aspects of the underlying pathophysiology remain unknown, catecholamine‐mediated pathologies appear to play an important role. The duration of MA consumption is the most important determinant for the prognosis.

Conclusions

Awareness is needed as cardiac complications are important causes of morbidity and mortality in patients with MA consumption. Drug abstinence is the mainstay of therapy, cardiac and other complications should be treated according to the respective guidelines. Incompliance to therapy and frequent relapses are the main challenges for successful treatment. Further research is required to improve the understanding of this rapidly increasing cardiomyopathy.

Methamphetamine Use and Cardiovascular Disease

While the opioid epidemic has garnered significant attention, the use of methamphetamines is growing worldwide independent of wealth or region. Following overdose and accidents, the leading cause of death in methamphetamine users is cardiovascular disease, because of significant effects of methamphetamine on vasoconstriction, pulmonary hypertension, atherosclerotic plaque formation, cardiac arrhythmias, and cardiomyopathy. In this review, we examine the current literature on methamphetamine-induced changes in cardiovascular health, discuss the potential mechanisms regulating these varied effects, and highlight our deficiencies in understanding how to treat methamphetamine-associated cardiovascular dysfunction.

Point-of-Care Ultrasound Identifies Decompensated Heart Failure in a Young Male with Methamphetamine-Associated Cardiomyopathy Presenting in Severe Sepsis to the Emergency Department

We describe a case of a young male who presents to the emergency department with severe sepsis and decompensated heart failure with underlying Methamphetamine-Associated Cardiomyopathy that was previously undiagnosed. This presentation is unique because Methamphetamine-Associated Cardiomyopathy is an uncommonly reported condition that presented in a complex clinical scenario of severe sepsis and decompensated congestive heart failure. We discuss how we used point-of-care ultrasound (POCUS) in this case to identify an unsuspected disease process and how it changed our initial resuscitation strategy and management. Emergency physicians can utilize point-of-care ultrasound (POCUS) to help identify these high-risk patients in the emergency department and guide appropriate resuscitation. Methamphetamine-Associated Cardiomyopathy (MAC) is an infrequently described complication of methamphetamine abuse, most commonly presented as a nonischemic dilated cardiomyopathy. With the rise in methamphetamine abuse in the United States, complications from methamphetamine use are more commonly presenting to the emergency department. Proper education and rehabilitation, with a goal of abstinence from amphetamine use, may allow patients to potentially regain normal cardiac function. Since the majority of patients present late with severe cardiac dysfunction, early detection is essential amongst critically ill patients since recognition may significantly influence ED management.

Findings on 3D speckle tracking echocardiography in asymptomatic methamphetamine abusers

To detect potential cardiac abnormalities in asymptomatic methamphetamine abusers using three-dimensional speckle tracking echocardiography (3D STE). Fifty-three male methamphetamine abusers, free of cardiac symptoms/signs, were enrolled in this study. A control group of 53 age-matched male normal subjects was studied for comparison. Standard 3D, flow and tissue Doppler echo with measurements of left ventricular end-diastolic volume (LVEDV), end-systolic volume (LVESV), ejection fraction (LVEF), the ratio of the early to late diastolic transmitral filling velocity (E/A), the ratio of the early diastolic transmitral filling velocity to the early diastolic septal tissue velocity (E/E') and 3D STE with measurements of global area strain (GAS), global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS) were performed, respectively. These echocardiographic parameters were compared between methamphetamine abusers and normal subjects, and receiver operating characteristic curve (ROC) analysis was done to differentiating methamphetamine abusers from normal subjects. LVESV, LVEDV, LVEF, E/A, E/E' ratios and GRS were not significantly different between methamphetamine abusers and normal subjects (p > 0.05). However, GAS, GLS and GCS were significantly less in methamphetamine abusers than in normal subjects (p < 0.05). The areas under ROC (AUC) for GAS were greatest among all the 3D STE derived LV global strains (GAS vs. GLS, GCS and GRS, 0.95 vs. 0.76, 0.69 and 0.61, respectively). The cutoff value with - 30.3% of GAS had sensitivity of 91.8%, specificity of 91.6% and accuracy of 91.3% for differentiating methamphetamine abusers from normal subjects. The potential myocardial function abnormalities can be detected by 3D STE in asymptomatic methamphetamine abusers, and GAS is a good indicator for indentifying methamphetamine abusers from normal population, which can be used to screening and monitor methamphetamine abuse, detect subclinical LV dysfunction, predict potential methamphetamine-related cardiotoxicity, and to initiate early cardioprotective therapy before the onset of overt heart failure in time.

Risks associated with use of stimulant medications in patients with obstructive sleep apnea and cardiomyopathy: a case-control study

OBJECTIVES

Stimulant medications are indicated in patients with obstructive sleep apnea (OSA) who experience sleepiness despite optimal control of sleep-disordered breathing. The safety of stimulant medications in patients with OSA and co-morbid cardiomyopathy is unknown. We performed a case-control study to assess cardiovascular outcomes and mortality risk associated with stimulant use in this group of patients.

METHODS

A total of 162 subjects with OSA and cardiomyopathy were identified. Subjects who used stimulant medications for ≥1 month were designated as cases. Age-and-sex-matched controls not taking these medications were randomly chosen from the same cohort. Outcomes assessed were mortality, implantable cardioverter-defibrillator (ICD) and pacemaker insertion.

RESULTS

Twenty-two cases and 44 controls were included in the analyses. Mean age was 62.6 ± 15 years, 72% were male. Median duration of medication use was 27 months (range 1-98). There were four deaths among cases versus eight among controls. Four cases had a pacemaker and six had an ICD inserted, compared to six and eight respectively in the control group. Age (p = 0.01) and positive airway pressure (PAP) compliance (p = 0.01), but not stimulant medication use (p = 1.00) were associated with mortality on univariate analysis. In multiple logistic regression analyses accounting for body mass index, apnea-hypopnea index/respiratory disturbance index, PAP compliance, ejection fraction and duration of follow up, use of stimulant medication was not associated with mortality (p = 0.50), pacemaker (p = 0.20) or ICD (p = 0.90) implantation.

CONCLUSIONS

Stimulant medications were not associated with elevated risk of mortality, pacemaker or ICD implantation in this case-control study, even after accounting for multiple confounders.

Methamphetamine and HIV-Tat alter murine cardiac DNA methylation and gene expression

This study addresses the individual and combined effects of HIV-1 and methamphetamine (N-methyl-1-phenylpropan-2-amine, METH) on cardiac dysfunction in a transgenic mouse model of HIV/AIDS. METH is abused epidemically and is frequently associated with acquisition of HIV-1 infection or AIDS. We employed microarrays to identify mRNA differences in cardiac left ventricle (LV) gene expression following METH administration (10d, 3mg/kg/d, subcutaneously) in C57Bl/6 wild-type littermates (WT) and Tat-expressing transgenic (TG) mice. Arrays identified 880 differentially expressed genes (expression fold change>1.5, p<0.05) following METH exposure, Tat expression, or both. Using pathway enrichment analysis, mRNAs encoding polypeptides for calcium signaling and contractility were altered in the LV samples. Correlative DNA methylation analysis revealed significant LV DNA methylation changes following METH exposure and Tat expression. By combining these data sets, 38 gene promoters (27 related to METH, 11 related to Tat) exhibited differences by both methods of analysis. Among those, only the promoter for CACNA1C that encodes L-type calcium channel Cav1.2 displayed DNA methylation changes concordant with its gene expression change. Quantitative PCR verified that Cav1.2 LV mRNA abundance doubled following METH. Correlative immunoblots specific for Cav1.2 revealed a 3.5-fold increase in protein abundance in METH LVs. Data implicate Cav1.2 in calcium dysregulation and hypercontractility in the murine LV exposed to METH. They suggest a pathogenetic role for METH exposure to promote LV dysfunction that outweighs Tat-induced effects.

Effect of methamphetamine dependence on heart rate variability

Methamphetamine (METH) is an increasing popular and highly addictive stimulant associated with autonomic nervous system (ANS) dysfunction, cardiovascular pathology and neurotoxicity. Heart rate variability (HRV) has been used to assess autonomic function and predict mortality in cardiac disorders and drug intoxication, but has not been characterized in METH use. We recorded HRV in a sample of currently abstinent individuals with a history of METH dependence compared to age- and gender-matched drug-free comparison subjects. HRV was assessed using time domain, frequency domain, and non-linear entropic analyses in 17 previously METH-dependent and 21 drug-free comparison individuals during a 5 minute rest period. The METH-dependent group demonstrated significant reduction in HRV, reduced parasympathetic activity, and diminished heartbeat complexity relative to comparison participants. More recent METH use was associated with increased sympathetic tone. Chronic METH exposure may be associated with decreased HRV, impaired vagal function, and reduction in heart rate complexity as assessed by multiple methods of analysis. We discuss and review evidence that impaired HRV may be related to the cardiotoxic or neurotoxic effects of prolonged METH use.

Association of khat chewing with increased risk of stroke and death in patients presenting with acute coronary syndrome

OBJECTIVE

To evaluate the prevalence and significance of khat chewing in patients with acute coronary syndrome (ACS).

PATIENTS AND METHODS

From January 29, 2007, through July 29, 2007, 8176 consecutive patients presenting with ACS were enrolled in a prospective, multicenter study from 6 adjacent Middle Eastern countries.

RESULTS

Of the 8176 study patients, 7242 (88.6%) were non-khat chewers, and 934 (11.4%) were khat chewers, mainly of Yemeni origin. Khat chewers were older (57 vs 56 years; P=.01) and more likely to be men (85.7% vs 74.5%) compared with non-khat chewers. Non-khat chewers were more likely to have diabetes mellitus, hypertension, dyslipidemia, obesity, and prior history of coronary artery disease and revascularization. Cigarette smoking was more prevalent in khat chewers, and they were more likely to present greater than 12 hours after onset of symptoms compared with non-khat chewers. At admission, khat chewers had higher heart rate, Killip class, and Global Registry of Acute Coronary Events risk scores. Khat chewers had a significantly higher risk of cardiogenic shock, stroke, and mortality. After adjustment of baseline variables, khat chewing was an independent risk factor for in-hospital mortality (odds ratio, 1.9; 95% confidence interval, 1.3-2.7; P<.001) and stroke (odds ratio, 2.7; 95% confidence interval, 1.3-5.9; P=.01).

CONCLUSION

In this large cohort of patients with ACS, khat chewing was prevalent and was associated with increased risk of stroke and death. In the context of increasing global migration, a greater awareness of potential widespread practices is essential.

A comparison of echocardiographic findings in young adults with cardiomyopathy: with and without a history of methamphetamine abuse

BACKGROUND

Methamphetamine is currently the most widespread illegal stimulant abused in the United States. No previous reports comparing echocardiographic findings of cardiomyopathy with and without a history of methamphetamine abuse are available.

METHODS

We performed a single institution retrospective review of medical records and analyses of echocardiographic findings in patients < or = 45 years of age hospitalized between 2001 and 2004 who were discharged with a diagnosis of cardiomyopathy or heart failure. After exclusion of patients with coronary artery disease or severe cardiac valvular disease, the remaining patients were divided into 2 groups based on their abuse or non abuse of methamphetamine, as determined by the documented history in the medical records or urine toxicology testing.

RESULTS

Among a total of 59 patients, 28 (47%) had a history of methamphetamine abuse or positive urine toxicology. Both methamphetamine abusers and non-abusers were predominately male (64.3% vs 64.5%, P = .99), and had a high prevalence of obesity (55.6% vs 73.3%, P = .16). Bivariate analysis revealed significant differences between the methamphetamine abusers and non-abusers in left atrium volume (119.7 +/- 55.4 ml vs 85.8 +/- 33.5 ml, P = .008), left ventricular end-diastolic volume (201.9 +/- 71.4 ml vs 156.6 +/- 63.1 ml, P = .01), left ventricular end-systolic volume (136.0 +/- 53.7 ml vs 92.3 +/- 55.8 ml, P = .004), right ventricular dimension (26.3 +/- 6.0 mm vs 21.3 +/- 6.0 mm, P = .007), and quantified left ventricular ejection fraction (32.9% +/- 11.3% vs 44.6% +/- 17.8%, P = .004).

CONCLUSIONS

We found a high prevalence of methamphetamine abuse in our study population. Methamphetamine abusers had echocardiographic findings of more severe dilated cardiomyopathy compared with non-abusers.

Oxidative stress contributes to methamphetamine-induced left ventricular dysfunction

AIMS

Our aim was to test the hypothesis that the repeated, binge administration of methamphetamine would produce oxidative stress in the myocardium leading to structural remodeling and impaired left ventricular function.

METHODS AND RESULTS

Echocardiography and Millar pressure-volume catheters were used to monitor left ventricular structure and function in rats subjected to four methamphetamine binges (3 mg/kg, iv for 4 days, separated by a 10-day drug-free period). Hearts from treated and control rats were used for histological or proteomic analysis. When compared with saline treatment, four methamphetamine binges produced eccentric left ventricular hypertrophy. The drug also significantly impaired systolic function (decreased fractional shortening, ejection fraction, and adjusted maximal power) and produced significant diastolic dysfunction (increased -dP/dt and tau). Dihydroethedium staining showed that methamphetamine significantly increased (285%) the levels of reactive oxygen species in the left ventricle. Treatment with methamphetamine also resulted in the tyrosine nitration of myofilament (desmin, myosin light chain) and mitochondrial (ATP synthase, NADH dehydrogenase, cytochrome c oxidase, prohibitin) proteins. Treatment with the superoxide dismutase mimetic, tempol in the drinking water prevented methamphetamine-induced left ventricular dilation and systolic dysfunction; however, tempol (2.5 mM) did not prevent the diastolic dysfunction. Tempol significantly reduced, but did not eliminate dihydroethedium staining in the left ventricle, nor did it prevent the tyrosine nitration of mitochondrial and contractile proteins.

CONCLUSION

This study shows that oxidative stress plays a significant role in mediating methamphetamine-induced eccentric left ventricular dilation and systolic dysfunction.

Recovery of methamphetamine associated cardiomyopathy predicted by late gadolinium enhanced cardiovascular magnetic resonance

Methamphetamine is known to cause a cardiomyopathy which may be reversible with appropriate medical therapy and cessation of use. Late gadolinium enhancement cardiovascular magnetic resonance (CMR) has been shown to identify fibrosis in ischemic and non-ischemic cardiomyopathies. We present a case of severe methamphetamine-associated cardiomyopathy in which cardiac function recovered after 6 months. Evaluation by CMR using late gadolinium enhancement was notable for an absence of enhancement, suggesting an absence of irreversible myocyte injury and a good prognosis. CMR may be useful to predict recovery in toxin-associated non-ischemic cardiomyopathies.

Acute methamphetamine exposure inhibits cardiac contractile function

Methamphetamine, a commonly seen substance of abuse, has been reported to exert detrimental effect on bodily function including the cardiovascular system although its mechanism of action is poorly understood. This study was designed to examine the direct impact of methamphetamine on isolated whole heart and single cardiomyocyte contractile function. Murine hearts and isolated cardiomyocytes from adult FVB mice were exposed to various concentrations of methamphetamine for 30min prior to the assessment of mechanical function using a Langendroff apparatus and an IonOptix Myocam system, respectively. Cardiac contractile properties analyzed included maximal velocity of left ventricular pressure development and decline (+/-dP/dt), peak shortening amplitude (PS), maximal velocity of shortening/relengthening (+/-dLdt), time-to-PS (TPS), time-to-90% relengthening (TR(90)), resting and electrically stimulated increase of intracellular Ca(2+) as well as intracellular Ca(2+) decay. Our results revealed that acute methamphetamine exposure depressed +/-dP/dt, PS and rise of intracellular Ca(2+) without affecting +/-dLdt, TPS, TR(90), resting intracellular Ca(2+) and intracellular Ca(2+) decay. Furthermore, methamphetamine nullified the adrenergic agonist norepinephrine-elicited positive cardiomyocyte contractile response, including elevated PS, +/-dLdt and shortened TR(90) without affecting TPS. Western blot analysis showed unchanged expression of sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA2a) and phospholamban, associated with upregulated Na(+)-Ca(2+) exchanger levels following acute methamphetamine exposure. In addition, methamphetamine promoted overt cardiomyocyte protein damage evaluated by carbonyl formation. Taken together, these results demonstrate direct cardiac depressant effect of methamphetamine in myocardium and isolated cardiomyocytes, possibly associated with protein damage and dampened adrenergic response.

Drugs of abuse that mediate advanced glycation end product formation: a chemical link to disease pathology

Nicotine and methamphetamine are frequently abused in modern society, despite the increasing evidence of their addictive, neuropharmacological, and toxic effects. Tobacco, the most widely abused substance, is the leading cause of preventable death in the United States, killing nearly half a million Americans annually. A methamphetamine epidemic has also spread during the past decade; severe neurotoxicity and addictiveness contribute to the drug's notoriety. Although the majority of research on these two drugs is of pharmacological and neurobiological motivation, further study of these molecules from a chemical perspective may provide novel mechanistic insight into either their addictive potential or their pathological effects. For example, nicotine and methamphetamine share a common structural feature, a secondary amine, suggesting that these molecules could possess similar (or analogous) in vivo reactivity. Discoveries concerning the synthetic requirements for aqueous aldol catalysis and the feasibility of the enamine mechanism under physiological conditions have given rise to the hypothesis that ingested molecules, such as abused drugs, could participate in reactions utilizing an enamine intermediate in vivo. The chemical reactivity of exogenous drugs with amine functionalities was initially examined in the context of the Maillard reaction, or nonenzymatic browning. The heating of reducing sugars with amino acids yields a brown solution; studies of this reaction were originally applied to food chemistry for the production of distinct flavors and aromas. Further research has since revealed numerous instances in which the in vivo production of advanced glycation end products (AGEs) through the Maillard reaction contribute to the pathology of disease states. Specifically, the modification of long-lived proteins by glycation and glycoxidation and the accumulation of these AGEs compromise the original function of such proteins and change the mechanical properties of affected tissue. In this Account, we summarize our investigations into the capacity for exogenous compounds to initiate the Maillard reaction and the corresponding physiological and immunological impact of the drug-conjugated AGEs that form. Many of the pathological components of diabetes, atherosclerosis, cancer, macular degeneration, Alzheimer's disease, and even the normal aging process are attributable to AGEs and their potential for aggregate formation in the vasculature. A deeper understanding of AGEs, and particularly glycated proteins, will provide fundamental mechanistic insight into disease origins.

Myocardial lesions after long-term administration of methamphetamine in rats

OBJECTIVE

To demonstrate the myocardial lesion associated with long-term administration of methamphetamine in rats.

METHODS

The experimental models of intoxication of methamphetamine were established in Sprague-Dawley rats. Methamphetamine hydrochloride (3 mg x kg(-1) x d(-1)) was subcutaneously injected to rats in methamphetamine-treated group (n = 16), and normal saline at the same dose was injected to rats in control group (n = 16). After 1 week and 8 weeks of injection, 8 rats in each group were sacrificed and their hearts were examined with light microscopy and electron microscopy, respectively.

RESULTS

After 1 week of methamphetamine exposure, foci of contraction band and cellular degeneration were present in subendocardial myocardium. Cellular degeneration, myocytolysis, and contraction band necrosis became prominent and extensive in methamphetamine-treated rats after 8 weeks. Hypertrophy, intracellular vacuolization, and fibrosis were also observed. The ultrastructural feature showed marked swelling and degeneration of mitochondria, enlargement of sarcoplasmic reticulum, and dissolution of myofilaments. No obvious cardiac myocyte lesions were observed in rats of control group.

CONCLUSION

Methamphetamine abuse daily for a long time may result in an increased risk of cardiovascular lesions similar to cardiomyopathy.

Managing young people with Type 1 diabetes in a 'rave' new world: metabolic complications of substance abuse in Type 1 diabetes

The taxing transition from adolescence towards adulthood intensifies the impact of a chronic illness such as Type 1 diabetes. It is not uncommon for young people with Type 1 diabetes to use recreational drugs for emotional relief to escape the day-to-day burden of chronic disease. Despite increasing use, especially in the setting of 'rave' parties, there is professional lack of understanding of the impact of recreational drug use on glycaemia and metabolic complications. The current review describes the prevalence of substance abuse in Type 1 diabetes and the acute impact of designer drugs on its management. We propose a practical approach to improve care of young people with Type 1 diabetes using designer drugs.

Cardiac arrest in the setting of diet pill consumption

The obesity epidemic currently plaguing the United States has spurred the development of a vast number of drugs to assist in the battle against obesity and its associated complications. The need to loose weight often causes patients to loose sight of or even ignore the serious side effects of some of the most widely used weight-loss medications. Here we present the case of ventricular tachycardia/fibrillation arrest in an otherwise healthy 48-year-old woman who was taking no medications other than phentermine, a common appetite suppressant that functions as a central nervous system stimulant through activation of the noradrenergic pathway of the sympathetic nervous system.

Methamphetamine-related fatalities in Australia: demographics, circumstances, toxicology and major organ pathology

AIM

To examine the demographic characteristics, circumstances of death, toxicological results and major organ pathology of methamphetamine-related deaths in Australia.

DESIGN

Retrospective review of coronial files.

SETTING

Australia.

METHODS

Cases in which methamphetamine was listed as a cause of death were identified from the National Coronial Information System (NCIS).

FINDINGS

A total of 371 cases were identified. The mean age of decedents was 32.7 years; 77% were male and 35% were employed. Route of administration was predominantly by injection (89%). Drugs other than methamphetamine were detected in 89% of cases, most commonly benzodiazepines (41%) and morphine (36%). The median blood methamphetamine concentration was 0.2 mg/l (range 0.02-15.0 mg/l). Deaths were overwhelmingly accidental, with 14% determined to be suicides, and occurred in a private home (71%). Cardiovascular pathology, typically coronary artery atherosclerosis, was detected in 54% of decedents. Cerebrovascular pathology, most commonly cerebral haemorrhage and hypoxia, was present in 20% of cases.

CONCLUSIONS

Methamphetamine has contributed to a substantial number of deaths in Australia. Users need to be informed of the potential harms of methamphetamine use, particularly those associated with the cardiotoxicity of methamphetamine and the use of methamphetamine in conjunction with other drugs.

Methamphetamine and cardiovascular pathology: a review of the evidence

AIMS

To examine the literature pertaining to the cardiovascular effects of methamphetamine and discuss the implications for methamphetamine users.

METHODS

Relevant literature was identified through comprehensive MEDLINE and EMBASE searches.

FINDINGS AND CONCLUSIONS

There is sufficient clinical and experimental evidence to suggest that methamphetamine can have adverse and potentially fatal effects on the cardiovascular system. The existing literature suggests that: (1) methamphetamine users are at elevated risk of cardiac pathology; (2) risk is not likely to be limited to the duration of their methamphetamine use, because of the chronic pathology associated with methamphetamine use; (3) the risk of cardiac pathology is greatest among chronic methamphetamine users; (4) pre-existing cardiac pathology, due to methamphetamine use or other factors, increases the risk of an acute cardiac event; and (5) methamphetamine use is likely to exacerbate the risk of cardiac pathology from other causes, and may therefore lead to premature mortality.

Self-vaccination by methamphetamine glycation products chemically links chronic drug abuse and cardiovascular disease

Methamphetamine abuse is spreading rapidly throughout the United States and is characterized by significant health consequences. The powerfully rewarding effects of methamphetamine are attributed to multiple neuropharmacological actions such as its ability to block plasma membrane transporters of all monoamines, reduce dopamine transporter expression, and inhibit monoamine oxidase activity while increasing tyrosine hydroxylase activity. However, subsequent neuroreceptor changes including monoamine deficits complement this striking increase in monoamine release. Chronic methamphetamine abuse, as studied via self-administration paradigms in rodents, causes progressive dopaminergic neurotoxicity, a neuroanatomical change accompanied by increasing drug tolerance and escalating intake, two behavioral parameters of addiction. We have recently proposed that methamphetamine covalently glycates endogenous proteins. Such an event spurs antibody production against these immunoconjugates, possibly leading to drug sequestration by antibody binding of drug. Here we demonstrate that this drug-dependent glycation mechanism is operative in vivo through the dose-dependent detection of antibodies against methamphetamine-derived advanced glycation end products in rats chronically self-administering methamphetamine. Furthermore, increased levels of proinflammatory cytokines, evidence of potent immunoactivation, were also detected. Given the known role of advanced glycation end products in the alteration of protein function in vivo and the participation of these molecules in various diseases, methamphetamine-derived advanced glycation end products provide an unrecognized molecular mechanism for the development of vasculitis and other cardiovascular maladies reported with high incidence in chronic methamphetamine users.

The association of methamphetamine use and cardiomyopathy in young patients

PURPOSE

Methamphetamine is the most widespread illegally used stimulant in the United States. Previously published case reports and series suggest a potential association between methamphetamine exposure and cardiomyopathy. The objective of this study is to demonstrate an association between methamphetamine use and cardiomyopathy.

SUBJECT AND METHODS

Case-control study based on chart review of discharges from a tertiary care medical center from January 2001 to June 2004. Patients were < or =45 years old. Cases included patients with a discharge diagnosis of either cardiomyopathy or heart failure. Controls included hospitalized patients who had an echocardiographic assessment of left ventricular function with ejection fraction > or =55% and no wall motion abnormalities.

RESULTS

One hundred and seven cases and 114 controls were identified. Both groups had similar gender distribution, length of hospital stay, rates of health insurance, prevalence of coronary artery disease, diabetes mellitus, hypertension, cigarette smoking, alcohol abuse, and marijuana and cocaine use. Cases were older than controls (mean age: 38 vs 35 years; P=.008), had higher body mass index (BMI) (mean BMI: 37 vs 30 kg/m2; P<.001), and higher prevalence of renal failure (13% vs 4.4%; P=.03). Methamphetamine users had a 3.7-fold increased odds ratio [95% confidence interval, 1.8-7.8] for cardiomyopathy, adjusting for age, body mass index, and renal failure.

CONCLUSIONS

Methamphetamine use was associated with cardiomyopathy in young patients.

Fatal amphetamine-associated cardiotoxicity and its medicolegal implications

Amphetamines are popular drugs of abuse, particularly among youngsters and at dance scenes. Cardiotoxicity (manifested as cardiomyopathy, acute myocardial infarction/necrosis, heart failure, or arrhythmia) after the recreational (mis)use of amphetamine and its synthetic derivatives has been documented but is rather rare. Amphetamine-related cardiac fatalities are even more rare. We present 6 cases of young persons who died unexpected after the chronic abuse of amphetamines. Death was not attributed to a lethal intoxication but to an acute myocardial necrosis, a right ventricle rupture, a cardiomyopathy, or an arrhythmia. Two of the deceased persons presented prior to their death to the emergency department, but their complaints were not considered (probably due to their young age) to be of cardiac origin. One case was a sport-related fatality where medical screening failed to identify the underlying cardiac pathology or the amphetamine abuse, and 1 case was a so-called idiopathic dilated cardiomyopathy where substance abuse was not considered by the treating physician. We think that amphetamine-associated cardiotoxicity is a rare but probably genuine entity that should be considered both in forensic and clinical/emergency medicine because of its potential medicolegal implications.

Determination of histopathologic risk factors for postoperative atrial fibrillation in cardiac surgery

BACKGROUND

Postoperative atrial fibrillation is one of the most common complications after coronary artery bypass grafting. This study aimed to identify preoperative histopathologic risk factors for the development of postoperative atrial fibrillation.

METHODS

One hundred elective coronary artery bypass grafting patients were enrolled into the study. Right atrial tissue from all patients was sampled before cardiopulmonary bypass. Patients were monitored for the occurrence of the postoperative atrial fibrillation. Right atrial tissue samples from the atrial fibrillation group were compared with samples belonging to the patients who remained in sinus rhythm postoperatively. Evaluation for atrial histopathology and myocyte apoptosis included light microscopic and immunohistochemical studies.

RESULTS

Fourteen of 100 patients (14%) developed postoperative atrial fibrillation. On univariate analysis, the only predictor for the development of postoperative atrial fibrillation was chronic obstructive pulmonary disease (p = 0.014). Histologically, larger sized myolytic vacuoles were more common in patients who developed postoperative atrial fibrillation (p = 0.001). The percentage of apoptotic myocytes in each specimen was significantly higher in patients with atrial fibrillation (p = 0.000). Most of the specimens with positive apoptotic staining were also severely myolytic in patients with postoperative atrial fibrillation.

CONCLUSIONS

Our results suggest that degree of myolysis and increased apoptotic pattern in right atrial myocardium are significant predictors for the development of postoperative atrial fibrillation. The improvement of preoperative metabolic status of the myocardial cells may reduce the incidence of this common complication.

Changes in renal function and oxidative damage in methamphetamine-treated rat

In this study, we observed renal damage and peroxidative injury as the acute or sub-acute effect of methamphetamine (MA) to determine whether MA intoxication can be diagnosed from immunohistochemical changes in the kidney. In addition, renal function was investigated in relation to the immunohistochemical changes. A single administration of MA (group I) (50mg/kg/ (i.p.)) and repeated administration (group II) (10mg/kg/day (i.p.) for 5 days) were designed as an acute model and a sub-acute or chronic model. Immunohistochemically, cell damage markers were observed. Then, renal function markers and minerals in blood were measured. Myoglobin and creatinine phosphokinase (CPK) in blood were also analyzed. In group I, ubiquitin immunoreactivity was enhanced only in the renal tubules. Creatinine increased, while K, Ca, and P decreased (P<0.01). CPK increased significantly (P<0.01). Therefore, it was suspected that MA might induce renal dysfunction with renal tubule damage. This damage might be related to leakage of CPK from muscle. In group II, 8-hydroxy-2'-deoxyguanosine (8-OH-dG) increased immunohistochemically and quantitatively (P<0.01). It was considered that oxidative DNA damage might be induced by repeated administration. It was considered that this study offers basic information for the evaluation of pathological changes in the kidney in MA-related autopsy cases.

Maternal methamphetamine administration during pregnancy influences on fetal rat heart development

Methamphetamine (MAP) is one of the most abused drugs in Japan. The rate of MAP abuse by young women has recently reached more than 50 percent in adolescents. A major health concern is that these women will continue to use MAP during pregnancy. The purpose of this study was to investigate whether MAP administered to the mother during pregnancy would change the expression of alpha- and beta- myosin heavy chain (MHC) mRNA in rat neonatal hearts, as detected by quantitative RT-PCR. In addition, morphological changes in the rat neonatal ventricles were examined. Pregnant rats were injected intraperitoneally with MAP (1 mg/kg/day) starting at day 0 of gestation and ending at day 21. There was a significant increase in alpha-MHC mRNA expression in the neonatal ventricular muscle in the experimental group compared with the control at postnatal day (P) 0 and 5. alpha-MHC mRNA expression in both groups was similar after P9. beta-MHC mRNA expression was similar in both groups at P0. Postnatal beta-MHC mRNA expression decreased rapidly, but significant alteration was not detected. Neonatal rats at P0 exhibited some cardiac changes, including hypertrophy, degeneration, and disarrangement of myofibers, but these lesions disappeared by P14. We conclude that chronic maternal administration of MAP changes the alpha- and beta-MHC mRNA expression pattern in fetal and neonatal hearts, correlating with abnormal development, plasma level of hormones, and myocardial damage. At the same time, it is indicated that neonatal cardiomyocytes have reversibility.

Heart disease, methamphetamine and AIDS

Methamphetamine (MA) not only affects the nervous system but also has cardiac toxicity and immunosuppressive properties. This manuscript will provide support that there is a relationship between MA use and heart disease as well as immune dysfunction. The cardiovascular manifestations of acute MA use include tachycardia, atrioventricular arrhythmias, myocardial ischemia, myocardial ischemia and hypertension, resulting in cardiac lesions. Chronic use of MA causes cardiomyopathy including cellular infiltration, myocardial hypertrophy, myocardium rupture and fibrosis. The increased catecholamine levels are responsible for the cardiac lesions induced by MA. The additional problem with MA use is its potential to disrupt the immune system function leading to suppression of mitogen-stimulated lymphocyte, a reduction in circulating lymphocyte numbers and alternation T-lymphocyte cytokine secretion as well as B cell proinflammatory cytokine secretion. Concomitant MA use and Human Immunodeficiency Virus (HIV) infection not only enhances immunosuppression associated with HIV but also increases the heart disease occurrence with a coincidentally complication of AIDS or AIDS medications.

Brain and heart specific alteration of methamphetamine (MAP) distribution in MAP-sensitized rat

The repeated administration of methamphetamine (MAP) causes behavioral sensitization in animals. We previously reported that the high accumulation of MAP was observed in the MAP-sensitized animal brain, which suggested that this phenomenon is an important factor in the development or expression of behavioral sensitization. The purpose of the present study is to elucidate the MAP distribution in the MAP-sensitized rat using gas chromatography/mass spectrometry (GC/MS). As a result, the MAP distribution in the heart at 10 min when showing a high accumulation of MAP in the MAP-sensitized rat brain was significantly higher than that of the control rat, whereas no significant differences in the liver, kidney, abdominal muscle, femoral muscle and blood were observed. In the brain and heart, there was no different distribution at 1 min, reflecting only the influx process from blood to brain and heart. On the contrary, there was the significant difference at 10 min, reflecting both the influx and efflux process, suggesting that the efflux process of MAP from brain or heart to blood may be slow due to MAP sensitization. In conclusion, it was clear that the brain and heart specific alteration of the MAP distribution occurred in the MAP sensitization. It was considered that the high accumulation of MAP in the MAP-sensitized rat brain may be related to the expression of behavioral sensitization and that the delayed efflux of MAP in the MAP-sensitized rat heart may be connected with the cardiac toxicity.

Crystal Methamphetamine‐Associated Cardiomyopathy: Tip of the Iceberg?

BACKGROUND

Crystal methamphetamine has become a drug of widespread use. Previous reports describe myocardial infarction, pulmonary edema, and aortic dissection related to methamphetamine use. Cardiomyopathy due to methamphetamine exposure has been rarely described.

METHODS

We identified 1640 patients admitted in a 4-yr period with a primary or secondary diagnosis of cardiomyopathy. We excluded patients with known cause of cardiomyopathy other than substance abuse. We found 120 patients had a diagnosis of substance abuse, including 21 patients with methamphetamine use. We retrospectively reviewed the medical records of these 21 crystal methamphetamine users.

RESULTS

Nineteen (84%) underwent echocardiography with consistent findings of dilated cardiomyopathy and global ventricular dysfunction. Of five who had a nuclear myocardial perfusion study, none had evidence of ischemia or infarct. Of six who underwent cardiac catheterization, only one had evidence of coronary stenosis.

CONCLUSION

Methamphetamine use appears to produce cardiomyopathy in some users. The pathogenesis is probably similar to that of cocaine and catecholamine-induced cardiomyopathy. Cellular, animal, and clinical data support the link between methamphetamine exposure and myocardial pathology.

Immunohistochemical study of myoglobin and oxidative injury-related markers in the kidney of methamphetamine abusers

It is known that methamphetamine (MA) causes rhabdomyolysis, myoglobinuria, and acute renal failure. We conducted an immunohistochemical study on the kidney of 22 forensic autopsy cases in which MA had been detected. Myoglobin was positive in 17 cases. The concentration of the blood MA in the myoglobin-positive cases (8.39+/-3.43 micromol/dl) was higher than -negative cases (0.198+/-0.076 micromol/dl). And, the 70 kDa heat shock protein (HSP70), 8-hydroxy-2'-deoxyguanosine (8-OH-dG), 4-hydroxy-2-nonenal (4-HNE), and Cu/Zn superoxide dismutase (SOD) were also stained positively in five, ten, 11, nine cases of examined, respectively. In addition, 80% of HSP70-positive cases were myoglobin-positive. Myoglobin was also observed in 60% of 8-OH-dG-positive, in 82% of 4-HNE-positive, and in 78% of SOD-positive cases, respectively. Therefore, myoglobin rather than MA itself might induce oxidative damage. From these results, it was considered that MA abuse had caused the skeletal muscle damage before death. In forensic autopsy cases of drug abusers, the antemortem situation is not often known. The present research suggested that in addition to the measurement of the concentration of MA, immunohistochemical staining of myoglobin, HSP70, 8-OH-dG, 4-HNE, and SOD offers important information for the diagnosis of MA poisoning.