Alterations in heart rate following radiofrequency ablation in the treatment of reentrant supraventricular arrhythmias: relation to alterations in autonomic tone.

Abstract

To determine the relation between the creation of endocardial lesions and alterations in autonomic tone, we analyzed heart rate variability in patients undergoing radiofrequency catheter ablation for symptomatic supraventricular tachycardia. Elevated heart rates are frequently noted after radiofrequency catheter ablation for supraventricular arrhythmias. It has been postulated that this elevation may be secondary to alterations in cardiac autonomic tone. Since heart rate variability is a measure of autonomic nervous system activity, we used this technique to examine the heart rate elevation and to characterize postablation autonomic changes. Thirty-eight patients undergoing 44 radiofrequency catheter ablation procedures were included in the study. Total arrhythmic substrates treated included 34 accessory pathways and 13 AV nodes with dual physiology. Twenty-four hour ambulatory electrocardiographic recordings were obtained in a drug-free state prior to, ablation early postablation, and late postablation. Spectral and nonspectral analyses of heart rate variability were performed. Subgroup analyses were also done on specific cohorts. Subgroups included patients undergoing accessory pathway ablations, AV node modifications, and ablation of septal and nonseptal targets. To determine whether the amount of tissue damage was related to changes in heart rate variability, we analyzed the relation between the total energy delivered to the endocardium and the peak change in creatine kinase and heart rate variability. In this population, a significant transient increase in heart rate was noted following radiofrequency ablation. All time and frequency domain parameters of heart rate variability showed significant reversible decreases. These changes were independent of target site and arrhythmia substrate. There was no correlation noted between the changes in heart rate variability and either the total amount of energy applied to the endocardium or the change in creatine kinase. Increased heart rates and decreased heart rate variability occur following radiofrequency catheter ablation for supraventricular tachycardia. Clinically, the predominant effect is that of decreased parasympathetic tone. Since these transient changes are independent of arrhythmic substrate or ablation site in the atria, a rich parasympathetic innervation of the heart is proposed.

AI evidence extraction

Main findings

In 38 patients undergoing 44 radiofrequency catheter ablation procedures, heart rate increased transiently after ablation and all time- and frequency-domain heart rate variability parameters showed significant reversible decreases. These changes were reported as independent of ablation target site and arrhythmia substrate, and were not correlated with total energy applied or peak creatine kinase change; the predominant clinical effect was described as decreased parasympathetic tone.

Outcomes measured

• Heart rate
• Heart rate variability (time and frequency domain parameters)
• Autonomic tone (parasympathetic activity inferred from HRV)
• Creatine kinase change
• Relation of total energy delivered to HRV/CK changes

Limitations

• No control/comparator group described in the abstract
• Frequency, dosimetry, and exposure metrics for the radiofrequency energy are not reported in the abstract
• Timing definitions for early vs late postablation measurements are not specified in the abstract
• Clinical significance beyond transient autonomic changes is not detailed in the abstract

Suggested hubs

• other (0.2)
  Clinical electrophysiology study involving radiofrequency ablation; not clearly related to environmental/telecom EMF hubs.

{
    "study_type": "cohort",
    "exposure": {
        "band": null,
        "source": "radiofrequency catheter ablation (medical procedure)",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": null
    },
    "population": "Patients undergoing radiofrequency catheter ablation for symptomatic supraventricular tachycardia (supraventricular arrhythmias)",
    "sample_size": 38,
    "outcomes": [
        "Heart rate",
        "Heart rate variability (time and frequency domain parameters)",
        "Autonomic tone (parasympathetic activity inferred from HRV)",
        "Creatine kinase change",
        "Relation of total energy delivered to HRV/CK changes"
    ],
    "main_findings": "In 38 patients undergoing 44 radiofrequency catheter ablation procedures, heart rate increased transiently after ablation and all time- and frequency-domain heart rate variability parameters showed significant reversible decreases. These changes were reported as independent of ablation target site and arrhythmia substrate, and were not correlated with total energy applied or peak creatine kinase change; the predominant clinical effect was described as decreased parasympathetic tone.",
    "effect_direction": "harm",
    "limitations": [
        "No control/comparator group described in the abstract",
        "Frequency, dosimetry, and exposure metrics for the radiofrequency energy are not reported in the abstract",
        "Timing definitions for early vs late postablation measurements are not specified in the abstract",
        "Clinical significance beyond transient autonomic changes is not detailed in the abstract"
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "radiofrequency catheter ablation",
        "supraventricular tachycardia",
        "reentrant supraventricular arrhythmias",
        "heart rate variability",
        "autonomic tone",
        "parasympathetic tone",
        "accessory pathway",
        "AV node modification",
        "creatine kinase"
    ],
    "suggested_hubs": [
        {
            "slug": "other",
            "weight": 0.200000000000000011102230246251565404236316680908203125,
            "reason": "Clinical electrophysiology study involving radiofrequency ablation; not clearly related to environmental/telecom EMF hubs."
        }
    ]
}

Comments

Log in to comment.

No comments yet.