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A Simple Predictive Marker in Cardiac Resynchronization Therapy Recipients: Prominent S-Wave in Right Precordial
Naoya Kataoka1, Teruhiko Imamura1, Takahisa Koi1
1Department of Internal Medicine, University of Toyama, Sugitani, Toyama 930-0194, Japan.
Insights
A prominent S-wave in right precordial leads on an electrocardiogram can predict which patients will respond to cardiac resynchronization therapy (CRT). This finding may improve patient selection for CRT, enhancing treatment outcomes.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Diagnostics
Background:
- Current criteria for cardiac resynchronization therapy (CRT) patient selection are insufficient.
- QRS amplitude on electrocardiograms (ECG) may indicate myocardial disturbance and aid CRT selection.
Purpose of the Study:
- To evaluate baseline ECG parameters, specifically QRS amplitudes, for predicting CRT response.
- To identify novel ECG predictors for optimizing patient selection for CRT.
Main Methods:
- Measured baseline R-wave and S-wave amplitudes in right (V1-V3) and left (V4-V6) precordial leads.
- Defined CRT response as a ≥15% decrease in left ventricular end-systolic volume at 6-month follow-up.
- Analyzed the association between ECG parameters and CRT response using logistic regression.
Main Results:
- 53% of 47 patients met the criteria for CRT response.
- Higher S-wave amplitude in right precordial leads (≥1.44 mV) independently predicted CRT response (OR: 2.181, p=0.030).
- This S-wave amplitude cutoff also predicted reduced heart failure readmission and need for defibrillation.
Conclusions:
- A prominent S-wave in right precordial leads is a promising predictor of CRT response.
- This ECG marker may identify patients likely to achieve left ventricular reverse remodeling and better clinical outcomes.
- Utilizing S-wave amplitude could enhance patient selection for cardiac resynchronization therapy.
Abstract:
Background and objectives: Current guidelines criteria do not satisfactorily discriminate responders to cardiac resynchronization therapy (CRT). QRS amplitude is an established index to recognize the severity of myocardial disturbance and might be a key to optimal patient selection for CRT. Materials and Methods: (1) Initial R-wave amplitude, (2) S-wave amplitude, and (3) a summation of maximal R- or R'-wave amplitude and S-wave amplitude were measured at baseline. These parameters were averaged according to right (V1 to V3) or left (V4 to V6) precordial leads. The impact of these parameters on response to CRT, which was defined as a decrease in left ventricular end-systolic volume ≥15% at six-month follow-up, was investigated. Results: Among 47 patients (71 years old, 28 men) who received guideline-indicated CRT implantation, 25 (53%) achieved the definition of CRT responder. Among baseline electrocardiogram parameters, only the higher S-wave amplitude in right precordial leads was an independent predictor of CRT responders (odds ratio: 2.181, 95% confidence interval: 1.078-4.414, p = 0.030) at a cutoff of 1.44 mV. The cutoff was independently associated with cumulative incidence of heart failure readmission and appropriate electrical defibrillation following CRT implantation (p < 0.05, respectively). Conclusions: Prominent S-wave in right precordial leads might be a promising index to predict left ventricular reverse remodeling and greater clinical outcomes following CRT implantation.
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