Alcohol-induced right bundle branch block is associated with a benign outcome in HOCM after alcohol septum ablation
Dennis Lawin1, Thorsten Lawrenz1,2, Kristin Radke1
1Department of Cardiology and Intensive Care Medicine, Klinikum Bielefeld gemGmbH, Teutoburger Straße 50, 33604, Bielefeld, Germany.
Insights
Alcohol septum ablation (ASA) effectively reduces left ventricular outflow tract gradient in hypertrophic obstructive cardiomyopathy. ASA-induced right bundle branch block (RBBB) is linked to greater ethanol infusion and CK release but does not worsen clinical outcomes.
Area of Science:
- Cardiology
- Interventional Cardiology
- Cardiac Electrophysiology
Background:
- Alcohol septum ablation (ASA) is a recognized treatment for hypertrophic obstructive cardiomyopathy (HOCM).
- The study investigates the clinical and hemodynamic consequences of bundle branch block (BBB) induced by ASA.
Purpose of the Study:
- To evaluate the impact of ASA-induced bundle branch block (BBB) on clinical and hemodynamic parameters in HOCM patients.
- To assess the relationship between ASA-induced right bundle branch block (RBBB) and procedural factors like ethanol volume and CK release.
- To determine if ASA-induced BBB affects long-term clinical outcomes or the need for pacemaker implantation.
Main Methods:
- Retrospective analysis of 98 HOCM patients undergoing ASA.
- Clinical and hemodynamic assessments at baseline, early post-procedure, and during chronic follow-up.
- Evaluation of left ventricular outflow tract gradient (LVOTG), interventricular septal diameter, 6-minute walk test (6-MWT), and NYHA class.
Main Results:
- ASA significantly reduced LVOTG and interventricular septal diameter.
- Early RBBB occurred in 44.9% and chronic RBBB in 32.7% of patients; LBBB was less frequent.
- Chronic RBBB was associated with greater exercise-induced LVOTG reduction, higher ethanol volume, and elevated CK release, but did not impact 6-MWT or NYHA class.
Conclusions:
- ASA-induced RBBB correlates with increased ethanol volume and CK release but does not adversely affect clinical outcomes or pacemaker requirements.
- RBBB following ASA is associated with enhanced reduction in exercise-induced LVOTG during long-term follow-up.
- LBBB did not demonstrate a significant impact on the evaluated clinical or hemodynamic parameters.
Introduction:
Alcohol septum ablation (ASA) is a treatment option for hypertrophic obstructive cardiomyopathy (HOCM). We examined the impact of ASA-induced bundle branch block (BBB) on clinical and hemodynamic features.
Methods And Results:
We retrospectively analysed 98 HOCM patients with regard to ASA-induced BBB. Clinical examination was performed at baseline, early after ASA and at chronic follow-up (FU). ASA reduced left ventricular outflow tract gradient (LVOTG) during chronic FU (69.2 ± 41.6 pre vs. 31.8 ± 30.3 mmHg post ASA; p < 0.05) and interventricular septal diameter (21.7 ± 3.4 pre vs. 18.7 ± 5.0 mm post ASA; p < 0.05). ASA-induced early right BBB (RBBB) until discharge was observed in 44.9% and chronic RBBB at FU in 32.7%. Left BBB (LBBB) occurred in 13.3% early after ASA and in only 4.1% at chronic FU. Chronic RBBB was associated with more pronounced exercise-induced LVOTG reduction (102.1 ± 55.2 with vs. 73.6 ± 60.0 mmHg without; p < 0.05). 6-min-walk-test (6-MWT) and NYHA class were not affected by RBBB. LBBB had no influence on LVOTG, 6-MWT and symptoms. More ethanol was injected in patients with early RBBB (1.1 ± 0.4 vs. 0.8 ± 0.3 ml without; p < 0.05), who also showed higher mean CK release (827 ± 341 vs. 583 ± 279 U/l without; p < 0.05). Pacemaker implantation during FU was necessary in 11.5% of patients with early RBBB, 3.1% with chronic RBBB, 7.7% with early LBBB and 0% with chronic LBBB (p = n.s. for BBB vs. no BBB).
Conclusion:
ASA-induced RBBB is associated with a higher volume of infused ethanol and higher maximum CK release. RBBB does not adversely affect the clinical outcome or need for pacemaker implantation but was associated with higher exercise-induced LVOTG reduction during chronic FU.
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