What is the clinical evidence from this study?

Study design: Observational. Population: Atrial fibrillation (n=38). Intervention: Sinus rhythm mapping vs. Atrial fibrillation mapping. Primary outcome: Left atrial bipolar electrogram voltage (mV) (p=<0.0005).

What question did this study set out to answer?

To assess differences in electrogram voltages and scar surface area between the atria across sinus rhythm and atrial fibrillation.

October 24, 2023Journal of Interventional Cardiac ElectrophysiologyOpen Access

Comparison of voltages between atria: differences in sinus rhythm and atrial fibrillation

Q: What are the key findings of this study?

Ultra high-density mapping revealed that paired electrograms correlate poorly between sinus rhythm and atrial fibrillation, with left atrial voltages significantly higher in sinus rhythm (0.61 mV) than in atrial fibrillation (0.31 mV).

Q: What does this research mean for the field?

Ultra high-density mapping reveals that paired electrograms correlate poorly between sinus rhythm and atrial fibrillation, with left atrial voltages significantly higher in sinus rhythm than in atrial fibrillation. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

Q: What question did this study set out to answer?

To assess differences in electrogram voltages and scar surface area between the atria across sinus rhythm and atrial fibrillation.

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Key result

Ultra high-density mapping reveals ~50% lower left atrial voltage in atrial fibrillation versus sinus rhythm.

P<0.0005
n=38

Why the study?

Ultra high-density mapping systems allow for detailed electroanatomical comparison, motivating the assessment of atrial scar determined by voltages and surface area between atria, rhythm, and AF types.

How do atrial electrogram voltages and scar surface areas compare between sinus rhythm and atrial fibrillation, and between paroxysmal and persistent AF?

Key Points

To assess differences in electrogram voltages and scar surface area between the atria across sinus rhythm and atrial fibrillation.
Recruited 38 patients undergoing catheter ablation for paroxysmal AF (sinus rhythm maps only) or persistent AF (both AF and sinus rhythm maps).
Created 96 left and right atrial maps totaling 913,480 electrograms via Rhythmia HDx ultra high-density mapping, classifying tissue as low- (≤ 0.05 mV), intermediate- (0.05–0.5 mV), or normal-voltage (> 0.5 mV).
Paired electrograms showed fair correlation in the LA (Spearman's ρ = 0.32) and weak correlation in the RA (ρ = 0.19), with significantly higher voltages in sinus rhythm than AF (LA: 0.61 mV vs 0.31 mV; RA: 0.68 mV vs 0.47 mV; p < 0.0005 for both).
Voltages were significantly higher in paroxysmal than persistent AF (LA: 1.13 mV vs 0.52 mV; RA: 0.93 mV vs 0.57 mV), while intra-patient differences between atria were minimal.
Significantly greater intermediate- and low-voltage surface areas were present during AF versus sinus rhythm in the LA (p < 0.0005) and in persistent versus paroxysmal AF (LA: p = 0.01; RA: p = 0.04).

Study Design

Type

Observational (n=38)

Multicenter

Structured PICO

How do atrial electrogram voltages and scar surface areas compare between sinus rhythm and atrial fibrillation, and between paroxysmal and persistent AF?

Population

38 patients listed for ablation for paroxysmal (PAF) or persistent AF (PeAF)

Intervention

Ultra high-density mapping using Rhythmia HDx

Outcome

Atrial scar determined by voltages and surface area between atria, rhythm and atrial fibrillation (AF) typessurrogate

Main Result

Absolute Event Rate: 0.61% vs 0.31%

p-value: p=<0.0005

Ultra high-density mapping reveals that electrogram voltages correlate poorly between sinus rhythm and AF, are generally larger in sinus rhythm, and are lower globally in persistent compared to paroxysmal AF.

Limitations

Only electrogram amplitude was considered as a marker of tissue health, excluding other indicators like fractionation.
Conventional cut-offs of 0.05 mV and 0.5 mV for dense scar and diseased atrial tissue were used, which are not histologically validated.
The study used the Orion mapping catheter, so caution is needed when extrapolating results to other catheters and mapping systems.
Variance in electrogram size may have been related to differences in contact, as maps were collected by a non-contact force sensing multipolar catheter.
The relationship between mapped voltages and arrhythmic prognosis was not investigated.

Implication

AF voltages lower than sinus rhythm; leaves open whether rhythm-specific mapping thresholds improve ablation outcomes.

Abstract

BACKGROUND: Ultra high-density mapping systems allow for comparison of atrial electroanatomical maps in unprecedented detail. Atrial scar determined by voltages and surface area between atria, rhythm and atrial fibrillation (AF) types was assessed. METHODS: Left (LA) and right atrial (RA) maps were created using Rhythmia HDx in patients listed for ablation for paroxysmal (PAF, sinus rhythm (SR) maps only) or persistent AF (PeAF, AF and SR maps). Electrograms on corresponding SR/AF maps were paired for direct comparison. Percentage surface area of scar was assigned low- (LVM, ≤ 0.05 mV), intermediate- (IVM, 0.05-0.5 mV) or normal voltage myocardium, (NVM, > 0.5 mV). RESULTS: Thirty-eight patients were recruited generating 96 maps using 913,480 electrograms. Paired SR-AF bipolar electrograms showed fair correlation in LA (Spearman's ρ = 0.32) and weak correlation in RA (ρ = 0.19) and were significantly higher in SR in both (LA: 0.61 mV (0.20-1.67) vs 0.31 mV (0.10-0.74), RA: 0.68 mV (0.19-1.88) vs 0.47 mV (0.14-1.07), p < 0.0005 both). Voltages were significantly higher in patients with PAF over PeAF, (LA: 1.13 mV (0.39-2.93) vs 0.52 mV (0.16-1.49); RA: 0.93 mV (0.24-2.46) vs 0.57 mV (0.17-1.69)). Minimal differences were seen in electrogram voltages between atria. Significantly more IVM/LVM surface areas were seen in AF over SR (LA only, p < 0005), and PeAF over PAF (LA: p = 0.01, RA: p = 0.04). There was minimal difference between atria within patients. CONCLUSIONS: Ultra high-density mapping shows paired electrograms correlate poorly between SR and AF. SR electrograms are typically (but not always) larger than those in AF. Patients with PeAF have a lower global electrogram voltage than those with PAF. Electrogram voltages are similar between atria within individual patients.

Discussion

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Published by Journal of Interventional Cardiac Electrophysiology · CC BY

Cite This Study

Bates et al. (2023) conducted an observational in Atrial fibrillation (n=38). Sinus rhythm mapping vs. Atrial fibrillation mapping was evaluated on Left atrial bipolar electrogram voltage (mV) (p=<0.0005). Ultra high-density mapping revealed that paired electrograms correlate poorly between sinus rhythm and atrial fibrillation, with left atrial voltages significantly higher in sinus rhythm (0.61 mV) than in atrial fibrillation (0.31 mV).

synapsesocial.com/papers/6a15554079ff98d0de4e764e https://doi.org/10.1007/s10840-023-01671-0

Topics

Atrial fibrillation

Left atrial appendage closure

Persistent AF management

AF ablation outcomes

Anticoagulation in AF

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Implication

AF voltages lower than sinus rhythm; leaves open whether rhythm-specific mapping thresholds improve ablation outcomes.

Comparison of voltages between atria: differences in sinus rhythm and atrial fibrillation

Key Points

Study Design

Structured PICO

Main Result

Limitations

Implication

Abstract

Discussion

Figures from the paper

Cite This Study

Topics

Comparison of voltages between atria: differences in sinus rhythm and atrial fibrillation

Key Points

Study Design

Structured PICO

Main Result

Limitations

Implication

Abstract

Discussion

Figures from the paper

Cite This Study

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Topics

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