Sudden cardiac death Implantable cardioverter defibrillators Primary prevention Secondary prevention Arrhythmic death

Two antipsychotic drugs prolong QTc interval, may cause arrhythmias, sudden cardiac death

Posted by

0


Key takeaways:

  • More than 13% of users of quetiapine and haloperidol developed severe QT prolongation.
  • Severe QT prolongation was linked to ventricular arrhythmia and, in quetiapine users, sudden cardiac death.

The antipsychotic drugs quetiapine and haloperidol were associated with severe QT prolongation, ventricular arrhythmias and sudden cardiac death, researchers reported in HeartRhythm.

“The use of the antipsychotics quetiapine and haloperidol to treat mental disorders is widespread,” Shang-Hung Chang, MD, PhD, of the cardiovascular division, department of internal medicine, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan, said in a press release. “In an effort to enhance patient safety and optimize the management of individuals receiving these medications, we have investigated the incidences, risk factors and clinical outcomes of severe QT prolongation to provide valuable insights for health care professionals, patients and caregivers.”

ECG reading
More than 13% of users of quetiapine and haloperidol developed severe QT prolongation.

Using electronic health records from a multicenter health care hospital system in Taiwan, the researchers analyzed data from 8,832 patients administered quetiapine (mean age, 69 years; 59% men) and 2,341 administered haloperidol (mean age, 66 years; 65% men). The outcomes of interest were incidence of severe QT prolongation, defined as a posttreatment corrected QT (QTc) interval exceeding 500 milliseconds or an increase in QTc interval of more than 60 milliseconds compared with baseline, risk factors for severe QT prolongation and clinical outcomes associated with severe QT prolongation.

Severe QT prolongation

The mean increase in QTc was 18.3 milliseconds in quetiapine users and 18.9 milliseconds in haloperidol users, with 13% of the quetiapine group and 14.2% of the haloperidol group developing severe QT prolongation, according to the researchers.

In both groups, risk factors for developing severe QT prolongation included age older than 65 years (P < .001 in quetiapine group; P = .033 in haloperidol group), hypokalemia (P < .001 in quetiapine group; P = .002 in haloperidol group), hypocalcemia (P < .001 in quetiapine group; P = .008 in haloperidol group) and hypomagnesemia (P = .004 in quetiapine group; P = .04 in haloperidol group), the researchers found.

In the quetiapine group, those who developed severe QT prolongation had greater incidence of ventricular arrhythmias (3.8% vs. 1.1%; P < .001) and sudden cardiac death (2.3% vs. 0.8%; P < .001) than those who did not, but there was no difference by severe QT prolongation status in syncope and seizure, Chang and colleagues wrote.

In the haloperidol group, those who developed severe QT prolongation had greater incidence of ventricular arrhythmias (3.3% vs. 1.6%; P = .039), but there was no difference by severe QT prolongation status in sudden cardiac death (P = .414), syncope and seizure, according to the researchers.

‘Be aware of the potential risks’

“Clinicians should be aware of the potential risks associated with quetiapine use, particularly the risk of severe QT prolongation and its associated outcomes, including ventricular arrhythmias and sudden cardiac death,” Chung-Li Wang, MD, of the cardiovascular division, department of internal medicine, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan, said in the release.

In a related editorial, Clifford TeBay, BBSc (Hons), from the Mark Cowley Lidwill Research Program in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia, and Jamie I. Vandenberg, PhD, MBBS, FHRS, from the School of Clinical Medicine, Faculty of Medicine and Health, University of New South Wales in Sydney, wrote about a limitation of the study: “The age group studied was relatively old and likely included only small numbers of patients in their late teens/twenties, which is when schizophrenia is often first diagnosed and antipsychotic drug commenced. So, we cannot necessarily extrapolate the findings from the present study to this younger cohort that may have fewer comorbidities. Nevertheless, this study represents an important step forward into real-world monitoring of severe QT prolongation.”

“It would be prudent to undertake an ECG before and after commencement of an antipsychotic drug,” Vandenberg said in the release. “If it is an option, one could stop a drug causing QT prolongation and try a different antipsychotic. But if this is not practical, one should pay particular attention to reducing other risk factors, such as prescription of other drugs that may exacerbate QT prolongation, and be vigilant for hypokalemia.”

Magnets in some Apple, Microsoft products may interfere with ICDs, pacemakers

Posted by

0


Strong magnets in newer portable electronic devices like the Apple AirPods Pro charging case or Microsoft Surface Pen can interfere with pacemakers and implantable cardioverter defibrillators, researchers reported.

Corentin Féry

“We show that there is a risk of deactivating the therapy of these medical devices if some electronic objects with magnets are placed near the chest of the patients,” Corentin Féry, MSc, a research engineer at the University of Applied Sciences and Arts Northwestern Switzerland, Institute for Medical Engineering and Medical Informatics in Muttenz, Switzerland, told Healio. “The key word is caution for wearers of ICDs and pacemakers. The risk for death is real for them since a tachycardia will not be detected if a device with a strong magnet is deactivating their implant. Our tests on some everyday objects, such as the iPhone 12 Pro Max or the Microsoft Surface Pen, lead us to say that it is necessary to keep a distance of at least 1 inch between the implants and these devices. We also recommend not to carry electronic objects in a pocket close to the chest, or to fall asleep with such devices.”

Phone

Investigating magnetic strength

The researchers investigated several portable electronic devices (PEDs), including the Apple AirPods Pro and its wireless charging case, the Microsoft Surface Pen and the Apple Pencil (second generation), comparing their magnetic field strength with the iPhone 12 Pro Max. Using a magnetic mapper with 64 magnetic sensors, researchers measured the magnetic field strength of the products at various distances. The PEDs were also placed incrementally closer to five defibrillators from two representative manufacturers (Boston Scientific: Inogen, Teligen and Cognis; Medtronic: Protecta and Viva Quad) until a therapy deactivation occurred. According to the FDA, a minimal field strength of 10 G is required for CV implantable devices to trigger to magnet mode.

The findings were published in Circulation: Arrhythmia and Electrophysiology.

The researchers found the farthest point where a 10 G intensity was measured is located about 2 cm (0.78 in) from the surface for the Apple products and at 2.9 cm (1.14 in) for the Microsoft Surface Pen. Magnet reversion mode was triggered at a distance between 8 mm and 18 mm for the tested PEDs.

“Our study found that PEDs other than the iPhone 12 have magnetic susceptibility and, thus, have the potential to inhibit lifesaving therapies,” the researchers wrote.

Although the test results showed the maximum distance for a possible ICD interaction, researchers said for safety, the minimal distance is between 0.8 cm (0.31 in) for the iPhone 12 Pro Max and the Apple Pencil (second generation) and 1.8 cm (0.71 in) for the Microsoft Surface Pen and the opened charging case of the Apple AirPods Pro.

“Clinicians should warn their patients to be cautious when using electronic devices,” Féry told Healio. “Since we have not tested all electronic devices on the market, we suggest caution with any device that has magnets.”

Sven Knecht

Sven Knecht, DSc, a research engineer at the Cardiovascular Research Institute Basel at University Hospital Basel, University of Basel in Switzerland, noted that the magnet mode does deactivate the therapy but not the detection of the tachycardia.

“Furthermore, the risk of death is theoretically possible if the deactivation of the ICD by the portable electronic device occurs during a lethal, hemodynamically relevant tachycardia,” Knecht told Healio. “This likelihood might, however, be relatively low.”

More research needed

A major limitation of the study was that it was not conducted on ICDs implanted in patients, Féry said, adding the researchers need to perform in vivo tests with the electronic devices, as well as highlight the potential risk with other classes of objects, such as watches or e-cigarettes.

As Healio previously reported, the FDA issued a warning in May that certain cellphones and smartwatches containing high field strength magnets may cause some implanted medical devices, particularly cardiac devices, to suspend normal operations when in proximity to the magnet. The FDA noted at the time that many implanted medical devices such as pacemakers and ICDs are designed with a “magnet mode” to allow safe operation during certain medical procedures such as MRI. Placing certain cellphones and smartwatches too close to the implanted device can cause the device to switch into magnet mode when it is not supposed to, suspending normal operations, the agency stated.

The American Heart Association recommends keeping cellphones at least 6 inches away from ICDs or pacemakers by using it on the ear opposite from the implantation and to avoid keeping the cellphone in a front chest pocket.

N.A. Mark A. Estes

“The current study extends observations on magnetic field interactions with even more devices containing magnets,” N.A. Mark A. Estes, MD, professor of medicine and director of the Clinical Cardiac Electrophysiology Fellowship Program at the Heart and Vascular Institute of the University of Pittsburgh School of Medicine, and an AHA volunteer, said in a press release. “Patients with cardiac electronic implantable devices should be instructed to keep all electronic devices that can generate a magnetic field several inches from their pacemakers or ICDs.”

Sudden cardiac death and implantable cardioverter defibrillators: two modern epidemics?

Posted by

0


Critical analysis of the existing evidence indicates that:

  1. In patients with documented sustained ventricular arrhythmias and/or cardiac arrest, implantable cardioverter defibrillators (ICDs) confer a survival benefit. In several clinical settings this is rather transient, and might be lost when modern medical therapy including β-blockers is implemented.
  2. In patients without sustained ventricular arrhythmias or cardiac arrest, ICDs confer a significant survival benefit only in high-risk patients with ischaemic cardiomyopathy and left ventricular ejection fraction of ≤35% due to a remote myocardial infarction.
  3. Left ventricular ejection fraction alone is rather unlikely to be sufficient for effective sudden cardiac death risk prediction, due to low sensitivity and specificity.
  4. The benefits of ICDs in the elderly as well as in women are not established.
  5. With current prices, ICDs are probably cost-effective only when used in high-risk patients without associated comorbidities that limit the life expectancy to <10 years.

Recommendations by current guidelines may result in unnecessary overuse of ICD.

Source: Oxford Journal