This diagnostic image displays three segments of intracardiac electrogram (EGM) tracings and surface ECG leads, likely recorded from an Implantable Cardioverter Defibrillator (ICD). The primary tracing, labeled 'RV Tip to RV Ring,' illustrates cardiac electrical activity during an episode of non-sustained ventricular tachycardia (NSVT) and frequent premature ventricular contractions (PVCs). Red arrows highlight specific PVCs characterized by wide QRS morphology. The lower portion of each strip includes digital marker annotations common in cardiac rhythm management devices: 'S' (Sensing), 'F' (Fibrillation detection), and 'V' (Ventricular event). The label 'WV' indicates the application of a wavelet discrimination algorithm used to differentiate supraventricular tachycardia from ventricular tachycardia to prevent inappropriate therapy. Numerical values represent R-R and V-V intervals in milliseconds. The segments demonstrate a lead integrity alert (LIA) triggered by rapid R-R intervals (<220 ms) and T-wave oversensing (TWOS) leading to short V-V intervals (<140 ms). The clinical relevance of this image is to demonstrate device-based arrhythmia detection, the use of discrimination algorithms, and the identification of potential sensing artifacts like TWOS in cardiology.

Diagnostic electrocardiographic (ECG) tracings from an implantable cardioverter-defibrillator (ICD) divided into four sequential panels illustrating the management of ventricular arrhythmias. The top row of each panel shows the ventricular intracardiac electrogram (EGM) in red (labeled 'V'), while the bottom row shows the 'Shock' channel in green. The sequence begins (top-left) with a baseline rhythm that transitions into a monomorphic ventricular tachycardia (VT), characterized by a sudden increase in frequency and regular, high-amplitude sharp peaks. The second and third panels (top-right, bottom-left) demonstrate the persistence of this high-frequency ventricular rhythm with associated markers indicating detection. In the final panel (bottom-right), a vertical green marker denotes the delivery of a high-energy defibrillation shock. Following the shock, there is an immediate termination of the tachycardia, evidenced by an abrupt change in the red waveform back to a lower frequency, lower amplitude, and more regular morphology, indicating successful restoration of a stable rhythm. Annotations at the bottom of the strips provide cycle length intervals in milliseconds, confirming the rate changes from VT to a non-tachycardic state.

This composite educational image illustrates the management of refractory tachycardia-induced cardiomyopathy. Panel A presents a 12-lead electrocardiogram (ECG) showing atrial fibrillation with a rapid ventricular response (tachyarrhythmia). The tracing is characterized by absent P waves, irregular R-R intervals, and narrow QRS complexes at a rate of approximately 175 bpm. Panel B displays a follow-up ECG after an 'ablate and pace' intervention, specifically showing a more controlled rhythm resulting from atrioventricular (AV) node ablation and subsequent His bundle pacing (HBP). Panel C is a fluoroscopic angiogram in a post-procedural state, depicting the anatomical placement of cardiac pacing leads. Key landmarks include the atrial lead positioned superiorly, the HBP lead situated in the region of the His bundle, and a backup right ventricular (RV) lead. A large, radiopaque extracorporeal membrane oxygenation (ECMO) cannula is visible in the background, crossing the cardiac silhouette. This content demonstrates advanced electrophysiological strategies and mechanical circulatory support in the context of cardiogenic shock and refractory arrhythmia.

This composite figure illustrates a multidisciplinary approach to managing ventricular tachycardia (VT) via transapical access. Panel A presents a 12-lead electrocardiogram (ECG) tracing showing a wide-complex tachycardia consistent with VT. Panel B is a transthoracic echocardiogram demonstrating an aneurysmal left ventricular (LV) apex. Panel C provides a clinical photograph of a surgical transapical incision in the left thorax, showing stay sutures and surgical instruments utilized for sheath insertion. Panel D displays a fluoroscopic image showing the placement of an ablation catheter within the LV cavity, positioned to avoid contact with metallic prosthetic valves. Panel E contains electrophysiology study (EPS) tracings, including surface leads and intracardiac electrograms (RV-D and ABL-D), showing the termination of VT during radiofrequency (RF) ablation. Panel F exhibits a 3D electroanatomical voltage map of the LV aneurysm and epicardium; purple areas indicate low-voltage scar tissue, while color-coded points signify ablation sites. This collection highlights the integration of cardiac imaging, surgery, and electrophysiology for complex arrhythmia management.