What is the clinical evidence from this study?

Study design: Observational. Population: Myxomatous mitral valve prolapse (MVP) and mitral-annular disjunction (Barlow disease) with ventricular arrhythmias (n=23). Intervention: Electro-anatomical mapping (EAM) and programmed ventricular stimulation (PES). Primary outcome: Electrophysiological substrate (low-voltage areas) and ventricular arrhythmia inducibility.

October 20, 2021

Characterization of the electrophysiological substrate in patients with Barlow's disease

Key Result

Electro-anatomical mapping detected large unipolar low-voltage areas (<8.3 mV) in the basal inferolateral LV region in 73% of patients with Barlow's disease and ventricular arrhythmias.

Study Design

Type

Observational (n=23)

Structured PICO

Population

23 patients with myxomatous mitral valve prolapse (MVP) and mitral-annular disjunction (Barlow disease phenotype) with ventricular arrhythmias (VA), including 5 with syncope and 4 with a history of sudden cardiac death (SCD).

Intervention

Electro-anatomical mapping (EAM), programmed ventricular stimulation (PES), and cardiac magnetic resonance (CMR)

Outcome

Electrophysiological parameters (unipolar and bipolar low-voltage areas) and their correlation with VA patterns, ECG inferior negative T wave (nTW), and late gadolinium enhancement (LGE)surrogate

Low unipolar voltage areas in the basal inferolateral LV region and papillary muscles represent a potential electrophysiological substrate for ventricular arrhythmias and sudden cardiac death in patients with Barlow's disease.

Abstract

Abstract Background Myxomatous mitral valve prolapse (MVP) and mitral‐annular disjunction (Barlow disease) are at‐risk for ventricular arrhythmias (VA). Fibrosis involving the papillary muscles and/or the infero‐basal left ventricular (LV) wall was reported at autopsy in sudden cardiac death (SCD) patients with MVP. Objectives We investigated the electrophysiological substrate subtending VA in MVP patients with Barlow disease phenotype. Methods Twenty‐three patients with VA were enrolled, including five with syncope and four with a history of SCD. Unipolar (Uni < 8.3 mV) and bipolar (Bi < 1.5 mV) low‐voltage areas were analyzed with electro‐anatomical mapping (EAM), and VA inducibility was evaluated with programmed ventricular stimulation (PES). Electrophysiological parameters were correlated with VA patterns, electrocardiogram (ECG) inferior negative T wave (nTW), and late gadolinium enhancement (LGE) assessed by cardiac magnetic resonance. Results Premature ventricular complex (PVC) burden was 12 061.9 ± 12 994.6/24 h with a papillary‐muscle type (PM‐PVC) in 18 patients (68%). Twelve‐lead ECG showed nTW in 12 patients (43.5%). A large Uni less than 8.3 mV area (62.4 ± 45.5 cm 2 ) was detected in the basal infero‐lateral LV region in 12 (73%) patients, and in the papillary muscles (2.2 ± 2.9 cm 2 ) in 5 (30%) of 15 patients undergoing EAM. A concomitant Bi less than 1.5 mV area (5.0 ± 1.0 cm 2 ) was identified in two patients. A history of SCD, and the presence of nTW, and LGE were associated with a greater Uni less than 8.3 mV extension: (32.8 ± 3.1 cm 2 vs. 9.2 ± 8.7 cm 2 ), nTW (20.1 ± 11.0 vs. 4.1 ± 3.8 cm 2 ), and LGE (19.2 ± 11.7 cm 2 vs. 1.0 ± 2.0 cm 2 , p = .013), respectively. All patients with PM‐PVC had a Uni less than 8.3 mV area. Sustained VA (ventricular tachycardia 2 and VF 2) were induced by PES only in four patients (one with resuscitated SCD). Conclusions Low unipolar low voltage areas can be identified with EAM in the basal inferolateral LV region and in the papillary muscles as a potential electrophysiological substrate for VA and SCD in patients with MVP and Barlow disease phenotype.

Bookmark