p.31 抽出テキスト
Kusumoto et al 2018 Bradycardia Clinical Practice Guidelines August 20, 2019 Circulation. 2019;140:e382–e482. DOI: 10.1161/CIR.0000000000000628 e412 CLINICAL STATEMENTS AND GUIDELINES 5.4 CHRONIC THERAPY/ MANAGEMENT OF BRADYCARDIA ATTRIBUTABLE TO SND 5.4.1 General Principles of Chronic Therapy/ Management of Bradycardia Attributable to SND Recommendations for General Principles of Chronic Therapy/ Management of Bradycardia Attributable to SND Referenced studies that support recommendations are summarized in Online Data Supplements 22 and 23. COR LOE Recommendations III: Harm C-LD 1. In asymptomatic individuals with sinus bradycardia or sinus pauses that are secondary to physiologically elevated parasympathetic tone, permanent pacing should not be performed.S5.4.1-1–S5.4.1-7 III: Harm C-LD 2. In patients with sleep-related sinus bradycardia or transient sinus pauses occurring during sleep, permanent pacing should not be performed unless other indications for pacing are present.S5.4.1-1–S5.4.1-7 III: Harm C-LD 3. In patients with asymptomatic SND, or in those in whom the symptoms have been documented to occur in the absence of bradycardia or chronotropic incompetence, permanent pacing should not be performed.S5.4.1-5–S5.4.1-7 Synopsis The goal of anti-bradycardia therapy in SND is to increase the heart rate so that cardiac output is normalized, and the perfusion of brain and other end organs is maintained to meet physiologic demand. Because there is no established minimum heart rate below which treatment is indicated, identifying temporal correlation between symptoms and bradycardia is important when deciding on the necessity of therapy. Healthy young individuals, particularly athletes, have sinus bradycardia that is not associated with symptoms.S5.4.1-8 In some patients presenting with symptomatic bradycardia, a reversible extrinsic cause may be identifiable such as metabolic abnormality, endocrine dysfunction, infection, or overmedication (discussed in Section 5.4.2.). For other patients with symptomatic sinus bradycardia attributable to an intrinsic pathology of sinus node, permanent pacing may be necessary. Complications associated with PPM implantation range from 3% to 7% and there are significant long-term implications for pacing systems that use transvenous leads.S5.4.1-5–S5.4.1-7 Recommendation-Specific Supportive Text 1. Young individuals, especially well-conditioned athletes, have dominant parasympathetic tone at rest associated with resting sinus rates that can be well below 40 bpm.S5.4.1-1–S5.4.1-4 Sinus bradycardia is also seen in other states of heightened vagal tone such as during sleep or deep rest. In almost all cases, patients are completely asymptomatic and anti-bradycardia therapy is not indicated and the patient should be reassured. Although PPM implantation is a relatively low risk cardiac procedure, procedural complications and death directly related to implant can occur, and implanted leads have long-term management implications.S5.4.1-5–S5.4.1-7,S5.4.1-9 2. Parasympathetic tone is more dominant sympathetic tone during rest and sleep. Significant sinus bradycardia (rates <40 bpm) or pauses (>5 seconds) are common during such periods and have been observed across a wide age range.S5.4.1-1–S5.4.1-4 High vagal tone can also affect the atrioventricular node and cause transient and varying degrees of conduction abnormality that is asymptomatic in nearly all cases. Clinically relevant scenarios are often encountered in hospital settings where patients are monitored continuously on telemetry or at home with the rise of wearable home monitoring systems. Nocturnal sinus bradycardia or pause is a relatively common phenomenon in such settings. With the understanding of the physiologic (not pathologic) basis of bradycardia in such circumstances, antibradycardia therapy can be avoided. Although PPM implantation is a relatively low risk cardiac procedure, procedural complications and death directly related to implant can occur, and implanted leads have long-term management implications.S5.4.1-5–S5.4.1-7,S5.4.1-9 3. SND commonly manifests as sinus bradycardia or recurrent sinus pauses. Because SND is not a life-threatening condition, the benefit of permanent cardiac pacing is essentially symptom relief and quality of life (QOL) improvement. For this reason, asymptomatic or minimally symptomatic patients have no indication for permanent pacing even if they were to have electrophysiologic evidence of SND (eg, detected on ambulatory electrocardiographic monitoring or at EPS) because permanent pacing is associated with surgical risk and long-term consequences.S5.4.1-7 In some patients, symptoms suggestive of bradycardia are documented to occur in the absence of bradycardia. In these patients, permanent pacing has no clinical benefit and should not be performed. Although PPM implantation is a relatively low risk cardiac procedure, procedural complications and death directly related to implant can occur, and implanted leads have long-term management implications.S5.4.1-5–S5.4.1-7,S5.4.1-9 Downloaded from http://ahajournals.org by on October 7, 2026