Related Experiment Videos
[Long-term variability in unsustained ventricular arrhythmias: pharmacologic and pro-arrhythmic effect]
F Gaita1, E Richiardi, M Bobbio
1Cattedra di Cardiologia, Università degli Studi di Torino.
Giornale Italiano Di Cardiologia
|October 1, 1989
Summary
Short-term criteria for evaluating antiarrhythmic drug efficacy are unreliable long-term. Spontaneous reductions or increases in premature ventricular complexes mimic drug effects, affecting nearly 50% of patients.
Area of Science:
- Cardiology
- Electrophysiology
- Clinical Trials
Context:
- Established short-term criteria for antiarrhythmic treatment efficacy include a 72% reduction in premature ventricular complexes (PVCs) and 65-75% reduction in pairs/repetitive forms.
- Conversely, a three-to-tenfold increase in PVC frequency is considered a proarrhythmic effect.
- Long-term variability of ventricular arrhythmias requires re-evaluation of these criteria.
Purpose:
- To assess the long-term applicability of established short-term criteria for evaluating antiarrhythmic treatment efficacy and proarrhythmic effects.
- To determine if spontaneous variations in ventricular arrhythmias over 24 months can be misinterpreted as therapeutic or proarrhythmic outcomes.
Summary:
- Twenty-eight healthy subjects and 21 patients with stable ischemic heart disease, all with >30 PVCs/hour, were monitored for 24 months.
- Spontaneous PVC reduction (>72%) mimicking therapeutic effects occurred in ~50% of patients.
- Spontaneous PVC increase mimicking proarrhythmic effects occurred in ~10% of patients, irrespective of underlying heart disease.
Impact:
- Current short-term criteria for judging antiarrhythmic drug efficacy and proarrhythmic effects are not reliable for long-term assessment.
- Spontaneous arrhythmia variability can lead to misinterpretation of treatment outcomes.
- This study highlights the need for revised long-term evaluation strategies for antiarrhythmic therapies.