T Wave Safety Margin during the Process of ICD Implantation As a Novel Predictor of T Wave Oversensing

A review of local anesthetic-induced heart toxicity using human induced pluripotent stem cell-derived cardiomyocytes

Local anesthetic (LA) cardiotoxicity is one of the main health problems in anesthesiology and pain management. This study reviewed the reported LA-induced cardiac toxicity types, risk factors, management, and mechanisms, with attention to the use of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in heart toxicity research. Important scientific databases were searched to find relevant articles. We briefly assessed the reported cardiotoxic effects of different types of LA drugs, including ester- and amide-linked LA agents. Furthermore, cardiotoxic effects and clinical manifestations, strategies for preventing and managing LA-induced cardiotoxic effects, pharmacokinetics, pharmacodynamics, and sodium channel dynamics regarding individual variability and genetic influences were discussed in this review. The applications and importance of hiPSC-CMs cellular model for evaluating the cardiotoxic effects of LA drugs were discussed in detail. This review also explored hiPSC-CMs' potential in risk assessment, drug screening, and developing targeted therapies. The main mechanisms underlying LA-induced cardiotoxicity included perturbation in sodium channels, ROS production, and disorders in the immune system response due to the presence of LA drugs. Furthermore, drug-specific characteristics including pharmacokinetics and pharmacodynamics are important determinants after LA drug injection. In addition, individual patient factors such as age, comorbidities, and genetic variability emphasize the need for a personalized approach to mitigate risks and enhance patient safety. The strategies outlined for the prevention and management of LA cardiotoxicity underscore the importance of careful dosing, continuous monitoring, and the immediate availability of resuscitation equipment. This comprehensive review can be used to guide future investigations into better understanding LA cardiac toxicities and improving patient safety.

Implantable cardioverter defibrillator replacement guided by T wave safety margin in a short QT syndrome patient

We report implantable cardioverter defibrillator (ICD) generator replacement guided by T wave safety margin (TWSM) in a short QT syndrome patient with T wave oversensing (TWOS). During the procedure of generator replacement, the feature of ventricular sensing in four different ICDs was compared in the patient. The four ICDs showed different R and T wave amplitudes. Though R/T ratio is not the highest, Vitality ICD showed the highest TWSM and was implanted as replacing generator. During 20-month follow-up, the patient has been symptom-free with no T-wave oversensing episode. This case illustrates a method to evaluate the risk of TWOS before ICD implantation in patients with high risk of TWOS.