Management of monomorphic ventricular tachycardia electrical storm in structural heart disease

The conversion of electroanatomic maps for compatibility with treatment planning systems in cardiac radioablation target volume definition

BACKGROUND

Cardiac radioablation (CRA) is a new and promising treatment modality for patients with ventricular tachycardia refractory to standard-of-care treatment. Electroanatomic maps are used to define radiation target volumes; however, there is currently no native method to import electroanatomic maps into the treatment planning system (TPS).

PURPOSE

To develop Edico, a semi-automated tool to enable electroanatomic map import into a TPS, by converting electroanatomic maps to a Digital Imaging and COmmunications in Medicine (DICOM) standard. The overall aim is to facilitate target volume delineation and improve workflow efficiency in treating patients.

METHODS

Edico imports voltage and spatial data from electroanatomic maps and sorts these into voxels to be exported in a DICOM format, with each voxel containing the average voltage value of the data that falls within it. Three different rectangular electroanatomic maps were created and processed using Edico to ensure that expected features are maintained through processing. A sensitivity analysis of voxel size was completed using 19 different electroanatomic maps processed at five different sets of voxel dimensions, for a total of 95 resulting voxelized datasets. The coefficient of variation in each populated voxel in the datasets was analyzed to determine which voxel sizes are necessary to ensure that data loss is kept to a minimum throughout processing, despite averaging. Five electroanatomic maps were used to re-contour clinical target volumes and planning target volumes for previously-treated patients with their electroanatomic maps now directly registered to their planning computed tomography (CT) scans.

RESULTS

All three rectangular test electroanatomic maps were processed as expected. All tested voxel sizes resulted in low coefficients of variation overall, with the exception of the largest voxel size of 1.8 × 1.8 × 8 mm. When using Edico, a user should choose voxel dimensions similar to or smaller than those of a planning CT. Of five pairs of clinical and planning target volumes from previously treated patients, adjustments were made to four (80%), retrospectively, using the electroanatomic maps generated using Edico, registered to the patients' planning CTs.

CONCLUSIONS

Edico provides a reliable solution for electroanatomic map import into a TPS and facilitates clinical and planning target volume identification in CRA.

Successful Rescue of Ventricular Fibrillation Electrical Storm Secondary to Acute Myocardial Infarction in a Patient Presenting to a District General Hospital: A Case Report

Ventricular arrhythmia is a critical and challenging cardiovascular complication of myocardial infarction (MI). An electrical storm (ES), characterised by three or more episodes of sustained ventricular arrhythmia within 24 hours, poses a significant life-threatening risk. Standard management includes advanced life support (ALS) protocols and specialised pharmacological interventions. We present the case of a 43-year-old female who presented to the emergency department (ED) following an out-of-hospital ventricular fibrillation (OOHVF) arrest, with the return of spontaneous circulation (ROSC) achieved after multiple defibrillation shocks. Electrocardiography (ECG) revealed anterior ST-segment elevation MI (STEMI) involving the left anterior descending (LAD) artery. During her ED stay, she experienced recurrent ventricular fibrillation (VF) arrests requiring repeated defibrillation, adrenaline, amiodarone, and thrombolysis with alteplase. She was subsequently intubated and transferred to a primary percutaneous coronary intervention (PPCI) centre with intensive care support. Angiography confirmed a 100% occlusion of the LAD, which was successfully treated with stenting. The patient was admitted to the intensive care unit (ICU) and later discharged with full neurological recovery, on secondary prevention and heart failure therapy, with follow-up planned. This case underscores the complexity of managing electrical storms in MI, particularly in non-PPCI centres. It emphasises the importance of thrombolysis as an early reperfusion strategy in STEMI, especially when PPCI is not immediately available.

Pulsed ventricular tachycardia: a case study

Ventricular tachycardia (VT) is an arrhythmia that originates from the ventricles of the heart and presents as a wide and prolonged QRS complex on the electrocardiograph of greater than 120 milliseconds, with a heart rate of over 100 beats per minute. VT can occur as a pulsed or pulseless rhythm. Pulseless VT occurs when the ventricles cannot effectively pump blood out of the heart, therefore resulting in no cardiac output. Pulsed VT can manifest with the patient presenting asymptomatically, or with symptoms of reduced cardiac output resulting from poor ventricular filling. There is the potential for the patient to quickly become haemodynamically unstable if not treated. This article discusses a case of pulsed VT, diagnosed and treated out of hours in an acute hospital.

Quelling the Storm: A Review of the Management of Electrical Storm

Heightened sympathetic input to the myocardium potentiates cardiac electrical instability and may herald an electrical storm. An electrical storm is characterized by 3 or more episodes of ventricular tachycardia, ventricular fibrillation, or appropriate internal cardiac defibrillator shocks within 24 hours. Management of electrical storms is resource-intensive and inevitably requires careful coordination between multiple subspecialties. Anesthesiologists have an important role in acute, subacute, and long-term management. Identifying the phase of an electrical storm and understanding the characteristics of each morphology may help the anesthesiologist anticipate the management approach. In the acute phase, management of an electrical storm is aimed at providing advanced cardiac life support and identifying reversible causes. After initial stabilization, subacute management focuses on dampening the sympathetic surge with sedation, thoracic epidural, or stellate ganglion blockade. Definitive long-term management with surgical sympathectomy or catheter ablation also may be warranted. Our objective is to provide an overview of electrical storms and the anesthesiologist's role in management.

Electrical Storm Due to Active Myocardial Ischemia in the Right Coronary Artery Territory – Case Report

Electrical storm is defined by at least three episodes of sustained ventricular tachyarrhythmias or appropriate shocks given by implantable cardiac defibrillator devices (ICD), occurring within a period of 24 hours. In the present manuscript, we present the case of a 69-year-old female patient with previous aortocoronary bypass, who was admitted from the Emergency Department after presenting several episodes of syncope in prehospital settings and presented 4 episodes of sustained ventricular tachycardia which required electrical cardioversion. The arrhythmia disappeared after percutaneous revascularization of a chronic occlusion in the right coronary artery. In this case, the implantation of an ICD was avoided, as a reversible cause of ES has been identified and treated.