What test or finding helps stratify risk for sudden death in tachyarrhythmia patients?

• A. Single ECG morphology alone.
• B. LV function assessment alone.
• C. Integrated assessment including ECG morphology, LV function, age, and comorbidities; EP studies can aid risk stratification.
• D. Genetic testing only.

Answer: (C)

Risk stratification for sudden death in tachyarrhythmia patients hinges on an integrated view that combines multiple pieces of information rather than relying on any single test. The ECG morphology during a tachyarrhythmia helps identify where the rhythm is coming from and the likely circuit, but on its own it doesn’t tell you how dangerous the rhythm will be for that patient. Left ventricular function adds another dimension by showing how well the heart can tolerate rapid rhythms and the overall substrate for arrhythmia; poorer function generally signals higher risk. Age and comorbidities such as coronary disease or other organ dysfunction shape overall prognosis and treatment benefit. Electrophysiology studies can offer additional insight by testing whether dangerous arrhythmias can be induced, which helps refine risk in the right clinical context and can influence decisions about therapies like ICD implantation or ablation. Relying on a single element—for example, LV function alone, genetic testing alone, or ECG features alone—misses how these factors interact to determine true risk.