Related Experiment Video
Updated: Jul 16, 2026
Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
Delayed electrocardiographic changes after percutaneous transluminal septal myocardial ablation in hypertrophic
Hangyuan Guo1, Ping Wang, Yangbo Xing
1Department of Cardiology, Shaoxing People's Hospital, The First Affiliated Hospital of Shaoxing, University of China, Shaoxing, Zhejiang, China. ghangyuan@hotmail.com <ghangyuan@hotmail.com>
Insights
Percutaneous transluminal septal myocardial ablation (PTSMA) for hypertrophic obstructive cardiomyopathy (HOCM) causes significant delayed ECG changes, including prolonged QRS duration and QT interval. Long-term follow-up is needed to assess the therapeutic significance of these findings.
Area of Science:
- Cardiology
- Interventional Cardiology
- Electrophysiology
Background:
- Hypertrophic obstructive cardiomyopathy (HOCM) is a complex condition requiring effective treatment strategies.
- Percutaneous transluminal septal myocardial ablation (PTSMA) is an interventional procedure used to manage HOCM.
- Understanding the long-term electrocardiographic (ECG) sequelae of PTSMA is crucial for patient management.
Purpose of the Study:
- To investigate the delayed ECG changes, specifically Q-T interval, corrected Q-T dispersion, and heart rate variability (HRV), three years after PTSMA in HOCM patients.
- To assess the persistence and significance of these ECG alterations post-procedure.
Main Methods:
- A cohort of 26 symptomatic HOCM patients underwent PTSMA using alcohol ablation of the hypertrophied interventricular septum.
- 24-hour Holter ECG monitoring was performed at baseline, 3 days, and 3 years post-procedure.
- Analysis included PR interval, QRS duration, QT interval, corrected QT dispersion, JT interval, corrected JT dispersion, and various HRV parameters.
Main Results:
- PTSMA led to significant and persistent QRS prolongation and new-onset right bundle branch block in most patients after 3 years.
- Persistent QT interval prolongation was observed, while corrected QT dispersion was transiently prolonged.
- Heart rate variability (time and frequency domain) significantly increased 3 days and 3 years post-PTSMA, indicating altered autonomic function.
Conclusions:
- PTSMA in HOCM patients induces significant and lasting electrocardiographic changes.
- Key findings include persistent QRS and QT prolongation, and altered HRV, suggesting potential long-term electrophysiological impact.
- Further long-term studies with larger cohorts are necessary to fully elucidate the therapeutic implications of these ECG changes.
Objectives:
This work aimed to study the delayed electrocardiographic changes, including Q-T interval, corrected Q-T dispersion, and heart rate variability (HRV) 3 years after percutaneous transluminal septal myocardial ablation (PTSMA), in symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM).
Methods:
In 26 patients (11 women, 15 men; average age, 37.4 +/- 11.2 years) with symptomatic and medically refractory HOCM, 1.4 +/- 0.5 septal branches were occluded with an injection of 3.8 +/- 1.3 mL of alcohol (95%) to ablate the hypertrophied interventricular septum. Baseline and 3 days and 3 years postprocedure 24-hour Holter electrocardiographic findings were determined.
Results:
One patient developed complete atrioventricular block requiring permanent pacing. The PR interval was significantly prolonged 3 days after ablation, but recovered 3 years postprocedure. Three days after the procedure, all patients developed right bundle branch block, which was present in 24 patients after 3 years. The QRS duration was significantly prolonged 3 days after ablation and during 3 years of follow-up. There was significant and persistent prolongation of QT interval and transient prolongation of corrected QT dispersion 3 days after ablation and returned to preablation values 3 years postprocedure, but JT interval and corrected JT dispersion were not significantly changed after PTSMA. Heart rate variability data (time domain and frequency domain) 3 days and 3 years after PTSMA, including low frequency, high frequency, root mean squared successive difference interval, and the percent of sinus cycles differing from the preceding cycle by more than 50 milliseconds, significantly increased compared to that before the procedure. Low frequency/high frequency, SD of all normal-to-normal intervals, and SD of 5-minute average normal-to-normal intervals were not significantly changed after PTSMA.
Conclusions:
Percutaneous transluminal septal myocardial ablation for HOCM induces significant delayed electrocardiographic changes in most patients. The changes include QRS prolongation, new right bundle branch block, persistent QT prolongation, transient QT dispersion and PR prolongation, and changes in HRV data. Electrocardiographic long-term follow-up of a larger series of patients is required to determine the conclusive therapeutic significance.
