We present the case of an 85-year-old man with a history of anterior myocardial infarction, heart failure with reduced ejection fraction (35%), NYHA Class II symptoms, atypical left bundle branch block (QRS 144 ms, Figure 1A), and paroxysmal atrioventricular block. The CRT-D implantation was attempted based on the patient’s clinical profile. However, conventional biventricular pacing failed due to the absence of suitable coronary sinus branches. As a result, left bundle branch area pacing (LBBAP) was performed as a bailout strategy. A QRS narrowing to 128 ms was obtained (Figure 1B, indicating left posterior fascicular capture), with subsequent clinical improvement. Eight months later, the patient was admitted to the emergency room (ER) with acute chest pain. A 12-lead electrocardiogram (ECG) was promptly obtained (Figure 1C), which—despite ongoing ventricular pacing—clearly demonstrated inferior ST-segment elevation. Therefore, before troponin results were available, an urgent coronary angiogram was performed, confirming the diagnosis of STEMI (Figure 1D, showing proximal right coronary artery occlusion along with CRT-D leads). Following primary percutaneous coronary intervention and reperfusion, resolution of ST-segment elevation was observed (Figure 1E).
Figure 1.
(A) Baseline electrocardiogram showing QRS duration of 144 ms. (B) Electrocardiogram post-left bundle branch area pacing showing QRS duration of 128 ms (left ventricular activation delay 68 ms; Rr′ 42 ms; capture threshold 0.6 V × 0.5 ms). (C) Electrocardiogram during pacing, suggestive of inferior ST-segment elevation myocardial infarction. (D) Coronary angiography showing acute thrombotic occlusion of the proximal right coronary artery. (E) Electrocardiogram showing resolution of ST-segment elevation in the inferior leads during pacing after stent implantation.
Left bundle branch area pacing is increasingly adopted for bradycardia pacing and as an alternative to biventricular CRT.1,2 As previously reported for permanent His bundle pacing, it preserves a more physiological ventricular depolarization pattern, resulting in a narrower QRS and correction of intraventricular conduction disturbances. Consequently, myocardial repolarization is less altered compared with conventional myocardial pacing, potentially allowing recognition of ischaemic patterns on ECG. This was recently demonstrated by Deluca et al.3 in a dual-chamber pacemaker recipient.
To our knowledge, this is the first report of a STEMI diagnosis and primary revascularization in a patient with LBBAP-based CRT, based solely on ER ECG findings.
Acknowledgements
The authors thank the medical and nursing staff for their constant support of their research.
Consent: The authors confirm that the patient provided written informed consent for the publication of anonymized medical records and images.
Funding: None declared.
Contributor Information
Alessio Cucco, Department of Thoracic and Cardiovascular Diseases, Maggiore della Carità Hospital, C.so Mazzini 18, 28100 Novara, Italy; Department of Translational Medicine, University of Eastern Piedmont, Via Solaroli 17, 28100 Novara, Italy.
Gabriele Dell’Era, Department of Thoracic and Cardiovascular Diseases, Maggiore della Carità Hospital, C.so Mazzini 18, 28100 Novara, Italy.
Domenico D’Amario, Department of Thoracic and Cardiovascular Diseases, Maggiore della Carità Hospital, C.so Mazzini 18, 28100 Novara, Italy; Department of Translational Medicine, University of Eastern Piedmont, Via Solaroli 17, 28100 Novara, Italy.
Davide La Grotteria, Department of Thoracic and Cardiovascular Diseases, Maggiore della Carità Hospital, C.so Mazzini 18, 28100 Novara, Italy; Department of Translational Medicine, University of Eastern Piedmont, Via Solaroli 17, 28100 Novara, Italy.
Giuseppe Patti, Department of Thoracic and Cardiovascular Diseases, Maggiore della Carità Hospital, C.so Mazzini 18, 28100 Novara, Italy; Department of Translational Medicine, University of Eastern Piedmont, Via Solaroli 17, 28100 Novara, Italy.
Data availability
The data related to this article will be available upon reasonable request with the corresponding author.
References
- 1. Glikson M, Burri H, Abdin A, Cano O, Curila K, De Pooter J, et al. European Society of Cardiology (ESC) clinical consensus statement on indications for conduction system pacing, with special contribution of the European Heart Rhythm Association of the ESC and endorsed by the Asia Pacific Heart Rhythm Society, the Canadian Heart Rhythm Society, the Heart Rhythm Society, and the Latin American Heart Rhythm Society. Europace 2025;27:euaf050. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2. Burri H, Jastrzebski M, Cano Ó, Čurila K, de Pooter J, Huang W, et al. EHRA clinical consensus statement on conduction system pacing implantation: executive summary. Endorsed by the Asia-Pacific Heart Rhythm Society (APHRS), Canadian Heart Rhythm Society (CHRS) and Latin-American Heart Rhythm Society (LAHRS). Europace 2023;25:1237–1248. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3. Deluca F, Marcantoni L, Pastore G, Valenza S, Porcelli G, Zanon F. Acute myocardial infarction in a patient with permanent left bundle branch pacing. J Electrocardiol 2024;87:153804. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The data related to this article will be available upon reasonable request with the corresponding author.