Related Experiment Video
Updated: Sep 21, 2025
Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System
Published on: April 11, 2025
Association of QTc Interval and V4-S Wave With Appropriate ICD Therapy in Hypertrophic Cardiomyopathy
Nixiao Zhang1,2, Sijing Cheng2, Hongxia Niu2
1Department of Cardiology, Cardiovascular Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
Insights
Electrocardiogram (ECG) indicators, specifically corrected QT (QTc) interval and S wave anomalies in the V4 lead, predict implantable cardioverter-defibrillator (ICD) therapy risk in hypertrophic cardiomyopathy (HCM). Combining these ECG findings improves risk prediction for sudden cardiac death (SCD) in HCM patients.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Diagnostics
Background:
- Hypertrophic cardiomyopathy (HCM) poses a risk of sudden cardiac death (SCD) due to ventricular arrhythmias.
- Electrocardiogram (ECG) indicators may help identify patients at higher risk for life-threatening events.
Purpose of the Study:
- To investigate the association between specific ECG parameters and the risk of appropriate implantable cardioverter-defibrillator (ICD) therapy in HCM patients.
- To evaluate the predictive value of corrected QT (QTc) interval and S wave characteristics in the V4 lead for ICD therapy events.
Main Methods:
- A cohort of 149 HCM patients receiving ICDs was analyzed.
- Corrected QT (QTc) interval and S wave duration/amplitude in V4 lead were measured.
- Cox regression and ROC analyses identified independent predictors and optimal cut-off values for appropriate ICD therapy.
Main Results:
- Appropriate ICD therapy occurred in 31.5% of patients over a median follow-up of 2.9 years.
- Both QTc interval (HR 1.014) and S wave anomalies in V4 lead (HR 1.955) were independent predictors of appropriate ICD therapy.
- A combined model incorporating QTc ≥464 ms and V4 S wave anomalies significantly improved risk prediction (NRI 0.302) compared to the existing HCM-risk-SCD model.
Conclusions:
- QTc interval and V4 S wave anomalies are significant predictors of appropriate ICD therapy in HCM.
- Patients with QTc ≥464 ms and V4 S wave anomalies face the highest risk.
- Integrating these ECG markers into risk stratification models enhances prediction of SCD events in HCM.
Background:
Ventricular arrhythmias in patients with hypertrophic cardiomyopathy (HCM) may lead to sudden cardiac death (SCD). We aimed to investigate the relationship between electrocardiogram (ECG) indicators and the risk of appropriate implantable cardioverter-defibrillator (ICD) therapy in HCM.
Methods:
The HCM patients receiving ICD implantation were enrolled consecutively. QT interval correction (QTc) was calculated using Bazett's formula. Long or deep S wave in V4 lead was defined as duration time >50 ms and/or voltage amplitude >0.6 mV. The endpoint in our study was at least one ICD appropriate therapy triggered by ventricular tachyarrhythmia (VT) or ventricular fibrillation (VF), including anti-tachyarrhythmia pacing (ATP) and electrical shock.
Results:
A total of 149 patients with HCM (mean age 53 ± 14 years, male 69.8%) were studied. Appropriate ICD therapies occurred in 47 patients (31.5%) during a median follow-up of 2.9 years. Cox regression analysis showed that long or deep S wave in V4 lead [hazard ratio (HR) 1.955, 95% confidence interval (CI) 1.017-3.759, P = 0.045] and QTc interval (HR 1.014, 95% CI 1.008-1.021, P < 0.001) were independent risk factors for appropriate ICD therapy. The ROC showed that the optimal cut-off point value for the QTc interval to predict the appropriate ICD therapy was 464 ms, and the AUC was 0.658 (95% CI 0.544-0.762, P = 0.002). The AUC for S wave anomalies in V4 lead was 0.608 (95% CI 0.511-0.706, P = 0.034). We developed a new model that combined the QTc interval and S wave anomalies in V4 lead based on four patient groups. Patients with QTc ≥464 ms and long or deep V4-S wave had the highest risk of developing appropriate ICD therapy (log-rank P < 0.0001). After adding QTc interval and V4-S wave anomalies into the HCM-risk-SCD model, the prediction effect of the new model was significantly improved, and the NRI was 0.302.
Conclusions:
In this HCM cohort, QTc and S wave anomalies in V4 lead were found to be significant and strong predictors of the risk of appropriate ICD therapy. Patients with QTc ≥464 ms and long or deep S wave had the highest risk. After QTc interval and V4-S wave anomalies adding to the HCM-risk-SCD model, the prediction effect is significantly improved.
More Related Videos
12:45Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
06:57Ablation of Ischemic Ventricular Tachycardia Using a Multipolar Catheter and 3-dimensional Mapping System for High-density Electro-anatomical Reconstruction
Published on: January 31, 2019
Related Concept Videos
01:29Cardiomyopathy III: Hypertrophic Cardiomyopathy
01:25ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
01:29Cardiomyopathy V: Interprofessional Care
01:30Cardiomyopathy II: Dilated Cardiomyopathy
01:29Electrocardiogram
Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and...
01:20Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...