Author + information
- Justin Heizer1,
- Laura Divoky2,
- Jeremy Rier3,
- Amy Wahlquist2,
- Ashley Waring2,
- Shawn Shaji2,
- Sheldon Litwin2,
- Michael Gold2,
- Valerian Fernandes2 and
- Christopher Nielsen2
Alcohol septal ablation (ASA) for hypertrophic obstructive cardiomyopathy (HOCM) has evolved since its inception in 1994, and the need for permanent pacemaker (PPM) has decreased. Left bundle branch block (LBBB) is a known risk factor for complete heart block (CHB) after ASA. Other electrocardiographic (ECG) predictors of CHB are not well established.
The study included 673 consecutive procedures on 593 patients. Patients with prior devices (n=136) or missing ECGs (n=10) were excluded; total N=527. ECGs were obtained pre-ASA and within 48 hours post-ASA, and >20 ECG features were interpreted. Primary outcomes were the development of CHB and the need for PPM. Secondary outcome was late CHB, developing >24 hours post-ASA. Data were analyzed using multivariate logistic regression.
Fifty-four patients (10%) required PPM. Forty-six patients (8%) developed CHB requiring PPM. Eight patients had other indications for PPM, including positive EP study, symptomatic bradycardia, or prior LBBB with transient CHB. Table 1 demonstrates ECG features associated with need for PPM. These included prior LBBB and new post-ASA LBBB, left axis deviation (LAD), PR lengthening >40 ms, and QRS duration >140 ms. PPM was required in 48% (11/23) of patients with prior LBBB, 40% (4/10) with new LBBB, 24% (13/54) with new LAD, 25% (9/36) with PR lengthening >40 ms, and 18.5% (37/200) with post-procedure QRS duration >140 ms. Post-ASA RBBB was common (63%), but was not predictive of need for PPM. Twenty patients had late CHB, none of whom had pre- or post-ASA LBBB. Predictors of late CHB included prior LVH, new LAD, PR lengthening >40 ms, and QRS duration >140 ms.
|Predictor||Odds Ratio (OR)||95% Confidence Interval of OR||P value|
|Pre-procedure||LBBB||9.828||4.093 - 23.594||<0.001|
|Post-procedure||New LBBB||7.032||1.666 - 29.69||0.008|
|New LAD||5.197||2.178 - 12.398||<0.001|
|PR lengthening >40 ms||3.469||1.217 - 9.882||0.02|
|QRS duration >140 ms||3.243||1.493 - 7.047||0.003|
|New RBBB||1.612||0.839 - 3.097||0.20|
ECGs before and after ASA are helpful in determining who will require PPM or develop late heart block. Major ECG predictors of CHB and PPM include LBBB (before or after ASA), new LAD, PR lengthening >40 ms, and post-ASA QRS duration >140 ms.
STRUCTURAL: Alcohol Septal Ablation/HOCM