Images in cardiovascular medicine. Tricyclic cardiotoxicity treated with sodium bicarbonate

Increased Dispersion of Ventricular Repolarization as an Arrhythmic Risk Marker in Drug-free Patients With Major Depressive Disorder: A Preliminary Comparative Study

OBJECTIVE

Drug-free patients with major depressive disorder (MDD) are understudied in terms of increased risk for arrhythmias. In this study, we compared changes in corrected QT interval (QTc), QTc dispersion (QTcd), Tpeak-Tend (Tp-e), Tp-e/QT ratio, corrected JT interval (JTc), and JTc dispersion (JTcd), which are considered to be among the risk factors for the emergence of ventricular arrhythmias in patients with MDD.

METHODS

The study involved 50 patients with MDD who had been free of psychotropic medications for at least 1 month and 52 age-matched and sex-matched healthy controls. Illness-related characteristics, including duration of illness and Beck Depression Inventory scores, were recorded. Electrocardiography recordings made under a standardized procedure were performed for all participants, and arrhythmia risk markers were calculated from the electrocardiograms.

RESULTS

The patient group had significantly higher QTcd, JTc, and JTcd values compared with the controls. Among electrocardiogram markers, only Tp-e/QTc was significantly and inversely correlated with the duration of illness, while none of the markers was associated with Beck Depression Inventory scores.

CONCLUSIONS

Alterations in electrocardiogram-derived markers of ventricular arrhythmia, which can be obtained easily and inexpensively, can be evaluated for the prediction and prevention of severe cardiac conditions in patients with MDD and considered in selecting the safest antidepressant options available.

Amitriptyline accumulation in tissues after coated activated charcoal hemoperfusion-a randomized controlled animal poisoning model

Amitriptyline poisoning (AT) is a common poisoning, and AT possess the ability to promote life-threatening complications by its main action on the central nervous and cardiovascular systems. The pharmacokinetic properties might be altered at toxic levels compared to therapeutic levels. The effect of coated activated charcoal hemoperfusion (CAC-HP) on the accumulation of AT and its active metabolite nortriptyline (NT) in various tissues was studied in a non-blinded randomized controlled animal trial including 14 female Danish Land Race piglets. All piglets were poisoned with amitriptyline 7.5 mg/kg infused in 20 min, followed by orally instilled activated charcoal at 30 min after infusion cessation. The intervention group received 4 h of CAC-HP followed by a 1-h redistribution phase. At study cessation, the piglets were euthanized, and within 20 min, vitreous fluid, liver tissue, ventricle and septum of the heart, diaphragm and lipoic and brain tissues were collected. AT and NT tissue concentrations were quantified by UHPLC-MS/MS. A 4-h treatment with CAC-HP did not affect the tissue accumulation of AT in the selected organs when tested by Mann-Whitney U test (p values between 0.44 and 0.73). For NT concentrations, p values were between 0.13 and 1.00. Although not significant, an interesting finding was that data showed a tendency of increased tissue accumulation of AT and NT in the CAC-HP group compared with the control group. Coated activated charcoal hemoperfusion does not significantly alter the tissue concentration of AT and NT in the AT-poisoned piglet.

The return of an old nemesis: Survival after severe tricyclic antidepressant toxicity, a case report

Tricyclic antidepressants (TCAs) were first approved by the Food and Drug Administration (FDA) for use as antidepressants in the 1950s. Although their function as an antidepressant in the U.S. has largely been replaced by newer and safer alternatives, they are still prescribed for various conditions, including chronic pain and intractable depression. We will discuss a case of a TCA overdose presenting with generalized tonic-clonic seizures and multiple recurrent cardiac arrests. This is a case of a 34 year-old female who was brought in by Emergency Medical Services (EMS) with generalized tonic clonic seizure, status post intentional ingestion of multiple drugs. Her vital signs were: Temperature-38.8 °C, Heart Rate-140 beats per minute, Respiratory Rate (RR)-25 breaths per minute, Blood Pressure (BP)-139/77 mmHg, Oxygen Saturation (SaO2)-99% on 100% nonrebreather facemask (NRB). Her electrocardiogram (EKG) showed a widened ventricular tachyarrhythmia and she was immediately given an ampule of sodium bicarbonate. Over the span of the subsequent 2 h, she had recurrent pulseless ventricular tachycardic arrest 5 times in the emergency department (ED). After 5 days of further stabilization, the patient had a subsequent complete recovery with normal neurological function at discharge from the medical unit. In the ED it is imperative that we understand the now uncommon presentation of a TCA overdose in order to initiate immediate treatment. It is also important to understand the optimal treatment choices in patients that presents with TCA toxicity, especially arrhythmias that are refractory to initial treatment choices. Overall, severe TCA poisoning is often fatal; however, we demonstrated that with high quality resuscitative efforts, despite multiple arrests, survival to discharge with normal neurological outcome is possible.

Survival after severe amitriptyline poisoning with prolonged ventricular tachycardia and cardiac arrest

Background

Tricyclic antidepressants (TCA) are becoming one of the most frequently used substances in self poisoning. Significant morbidity and mortality associated with TCA overdose are often related to and refractory hypotension. We report the first case of survival after severe amitriptyline poisoning, leading to prolonged cardiac arrest and ventricular tachycardia (VT), resuscitated with 3 h of uninterrupted cardiac massage and Direct current (DC) shocks.

Case presentation

A 25 year old girl presented with severe amitriptyline poisoning causing pulseless VT and prolonged cardiac arrest. After 3 h of uninterrupted external cardiac massage, together with nine DC shocks and intra venous bicarbonate injections the rhythm reverted to a nodal tachycardia, initial 2D echocardiogram showed left ventricular dysfunction, which recovered to normal after 2 weeks and the patient had a complete recovery subsequently.

Conclusion

Our case highlights the importance of continued resuscitation in patients presenting with TCA poisoning and resistant arrhythmia, especially in young and otherwise healthy patients.

ST-T segment changes in patients with tricyclic antidepressant poisoning

Objective:

Tricyclic antidepressant (TCA) poisoning is among highly prevalent and potentially dangerous toxicities. ST-T changes are observed in the electrocardiogram (ECG) of most of TCA poisoned patients. We aimed to study ST-T segment changes in TCA toxicity and its probable relationship with other ECG findings.

Methods:

This retrospective study was carried out in Noor and Ali Asghar University Hospital, Isfahan (Iran) in 2012. Patients with TCA toxicity based on the patients’ history who had not consumed any cardio-active drugs and did not have a past medical history of cardiovascular disease in the recent 5 years, were randomly selected and investigated. Their demographic and medical data on admission including ECG, age, sex, type and amount of ingested TCA, poisoning severity score, QRS changes, QT interval, heart axis position and R-wave were all recorded. ST-T changes and their relation with other ECG parameters have been determined using statistical analysis.

Findings:

Medical records of 272 patients were analyzed. In symptomatic patients, ST change prevalence was 40.8% and T change prevalence was 9.5%. In asymptomatic patients, the frequency of ST and T changes were 4.8% and 0.8%, respectively (P < 0.05). The most common ST and T changes in baseline (on admission) ECG were non-significant elevation (15.4%), significant elevation (11%) in pre-cordial leads, and T-wave flattening (6.6%). A statistically significant correlation was documented between ST segment changes with QRS and R-wave in aVR. The correlation between T-wave changes and R-wave in aVR lead was also significant.

Conclusion:

ST-T changes in TCA poisoned patients are more prevalent in symptomatic patients. Obviously for a more definite conclusion, it is necessary to design a prospective study with the control group. This may facilitate a better understanding of ST-T segment changes.

Crack cocaine-induced cardiac conduction abnormalities are reversed by sodium bicarbonate infusion

We report a dramatic case of a 19-year-old man with crack cocaine overdose with important clinical complications as cardiac arrest due to ventricular fibrillation and epileptics status. During this intoxication, electrocardiographic abnormalities similar to those found in tricyclic antidepressant poisoning were observed, and they were reversed by intravenous sodium bicarbonate infusion.

Clinical use of antidepressant therapy and associated cardiovascular risk

A number of different psychotropic agents have been associated with an increased risk of cardiovascular disease, and these relationships have been difficult to interpret due to the presence of confounding factors. Recently, there has been renewed interest in the potential for certain antidepressants to cause QT prolongation, which is a predisposing factor for arrhythmia. However, the optimum means of determining QT remains contentious due to discrepancies between methods that may be readily applied in a clinical setting versus more detailed techniques during regulatory assessment. A number of different pharmacological mechanisms might explain the occurrence of adverse cardiac effects, and these differ according to the type of antidepressant agent. Emerging data indicate that citalopram exhibits a dose-effect relationship for QT prolongation. Whereas cardiotoxicity is readily apparent in the context of intentional antidepressant overdose, the occurrence of cardiac effects as a result of therapeutic administration is less certain. Pre-existing cardiac disease and other factors that independently predispose to arrhythmia are important considerations. Therefore, clinical judgment is needed to evaluate the overall risk or benefit of a particular antidepressant in any patient. Close monitoring should be considered for those at greatest risk of QT prolongation and arrhythmia.

Use of venlafaxine compared with other antidepressants and the risk of sudden cardiac death or near death: a nested case-control study

OBJECTIVE

To assess whether use of the antidepressant venlafaxine is associated with an increased risk of sudden cardiac death or near death compared with other commonly used antidepressants.

DESIGN

Population based observational study.

SETTING

We did a nested case-control analysis within a new user cohort formed using the United Kingdom General Practice Research Database.

PARTICIPANTS

New users of venlafaxine, fluoxetine, citalopram, or dosulepin on or after 1 January 1995, aged 18 to 89 years, with a diagnosis of depression or anxiety. Participants were followed-up until February 2005, or the occurrence of sudden cardiac death or near death, identified from medical records indicating non-fatal acute ventricular tachyarrhythmia, sudden death due to cardiac causes, or out of hospital deaths from acute ischaemic cardiac events. For each case, 30 controls were selected matched for age, sex, calendar time, and indication. We used conditional logistic regression to calculate the adjusted odds ratio of sudden cardiac death or near death associated with current use of venlafaxine compared with current use of fluoxetine, citalopram or dosulepin.

RESULTS

207 384 participants were followed-up for an average of 3.3 years. There were 568 cases of sudden cardiac death or near death, which were matched to 14 812 controls. The adjusted odds ratio of sudden cardiac death or near death associated with venlafaxine use was 0.66 (95% confidence interval 0.38 to 1.14) relative to fluoxetine use, whereas compared with citalopram it was 0.89 (0.50 to 1.60) and with dosulepin 0.83 (0.46 to 1.52).

CONCLUSIONS

In this large, population based study, the use of venlafaxine was not associated with an excess risk of sudden cardiac death or near death compared with fluoxetine, dosulepin, or citalopram, in patients with depression or anxiety.