• Korean Journal of Veterinary Research
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• v.57 no.1
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• pp.51-54
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• 2017

A 9-month-old intact male Maltese dog (1.52 kg) was diagnosed with a patent ductus arteriosus (PDA). Transcatheter occlusion of the PDA was performed by using the Amplatz canine duct occluder (ACDO). After occlusion, reflex bradycardia occurred and lasted for at least 15 h with normal systolic arterial pressure and slightly increased diastolic arterial pressure. The bradycardia slowly resolved, and the heart rate was normal in re-examinations after 7 and 30 days. This is the first case of reflex bradycardia after ACDO implantation, in which the bradycardia continued for a long time, even after recovery from anesthesia.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.4
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• pp.335-336
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• 2021

The oculocardiac reflex is a trigeminal-vagal reflex that manifests as cardiac arrythmias, most often bradycardia. The reflex can be triggered by manipulation of periorbital structures and unintended pressure on the bulbus oculi maxillofacial procedures. In this brief communication, we describe an unusual trigger of the oculocardiac reflex during maxillofacial surgery that resulted in severe bradycardia. This case highlights the need for careful securement of medical devices and attention to surgical technique to avoid undue pressure on draped fascial structures.

• Journal of The Korean Dental Society of Anesthesiology
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• v.12 no.3
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• pp.151-155
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• 2012

A vasovagal reaction is defined as the 'development of hypotension and bradycardia associated with the typical clinical manifestations of pallor, sweating and weakness'. The most profound degree of vasovagal reaction results in fainting or syncope. Incidence of vasovagal reactions in the local anesthetic department of a dental hospital is around 2%. The pathophysiology of the hypotension/bradycardia reflex responsible for vasovagal syncope is not completely understood. Central as well as peripheral mechanisms have been implicated in its pathogenesis: however their relative contribution is not fully elucidated. Recently, trigeminocardiac reflex, previously known as oculocardiac reflex, may serve as syncope. The management of vasovagal syncope is evolving. Non-pharmacological treatment options are a fundamental first step of all treatment pathways. In this article, we would like to review new mechanism of vasovagal syncope and hope to be of help to manage the syncopal patients.

• Journal of Veterinary Clinics
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• v.31 no.4
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• pp.350-353
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• 2014

A 13-year-old, castrated male, Shih Tzu dog with a history of acute ataxia was referred to veterinary medical teaching hospital and anesthetized for diagnostic magnetic resonance imaging of cervical intervertebral disk disease. After preanesthetic evaluation including physical examination, blood chemistry, radiography and ultrasound, the patient was premedicated with intravenous butorphanol (0.2 mg/kg). Anesthesia was induced by intravenous propofol (6 mg/kg) and maintained with isoflurane at 1.2 minimal alveolar concentrations. Because the mean arterial pressure (MAP) decreased from 70 to 58 mmHg at 70 minutes after induction, dobutamine was administered by constant rate infusion ($5{\mu}g/kg/min$) to treat hypotension. However MAP did not increase, and heart rate rapidly decreased from 100 to 55 beats per minute (bpm). To treat bradycardia, intravenous glycopyrrolate ($5{\mu}g/kg$) was administered, and heart rate increased to 165 bpm. After extubation of endotracheal tube, the patient showed normal recovery without any problems related to cardiovascular system. Unexpected dobutamine-induced bradycardia was considered as Bezold-Jarisch reflex. It is recommended that clinicians know and prepare the possibility of bradycardia during dobutamine therapy under general anesthesia.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.1
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• pp.61-65
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• 2022

Trigeminocardiac reflex (TCR) is a well-known brainstem reflex that manifests as hypotension, bradycardia, dysrhythmia, and asystole when stimulation is applied to a branch of the trigeminal nerve. Most commonly associated with ophthalmic, orbital, and neurologic surgeries, mandibular division and oral cavity variants occur far less frequently. Here, we describe a case of asystolic TCR elicited by lingual nerve stimulation. This case highlights the role of specific anesthetic medications in modulating this phenomenon and reinforces the need for early recognition and clear communication in case of its occurrence. Anesthesia providers must consider discontinuing or avoiding certain medications when clinically appropriate, even during low TCR-risk procedures.

• The Korean Journal of Pain
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• v.10 no.2
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• pp.166-169
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• 1997

Background: We have noted a high incidence of vasovagal episodes associated with use of interscalene block(ISB) for shoulder arthroscopy in the sitting position. The purpose of this retrospective study is to alert the possibility of potentially dangerous vasovagal events, describe the characteristics of this problem, and propose therapeutic devices. Methods: Results 62 patients who underwent shoulder arthroscopy in the sitting position with ISB were retrospectively analyzed. Group 1, 10 patients experienced vasovagal events characterized by sudden hypotension and bradycardia. Remaining 52 patients, Group 2, did not experience these symptoms. All patient charts were reviewed for age, sex, side of surgery, premedication, preoperative fluid and intraoperative medications. Perioperative hemodynamic changes were also compared between the two groups. Results: Vasovagal events experienced in 16% of patients(10/62) and occurred $39{\pm}18$ min after sitting position and $22{\pm}18$ min after start of operation. Number of patients who receiving anticholinergics for premedication were significantly lower in Group 1 than Group 2(2/10 vs. 28/52, p<0.05). Conclusions: Bezold-parish reflex is a potential mechanism for sudden hypotension and bradycardia which can occur during shoulder arthroscopy in sitting position. Therefore anticholinergic pretreatment and meticulous monitoring during operation are recommended to prevent B-J reflex.

• The Korean Journal of Physiology
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• v.14 no.1
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• pp.15-23
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• 1980

In an attempt to clarify the influence of lung volume and water temperature on the heart rate response during apneic face immersion in the trained athletes, 10 soccer players were studied while holding their breath as long as possible after full inspiration(TLC), full expiration(RV) or normal breath(FRC) with face immersion in water. The electrocardiogram(Lead II) was recorded before and during each manuever and compared with 20 control subjects. The results are summarized as follows; 1) Resting heart rate was significantly lower in the athletes than that of the control groups. 2) During apneic face immersion, severe bradycardia were observed in both groups and the heart rate was significantly lower in the athletes than that of the control groups. 3) The degree of the bradycardia (maximum percent reduction of heart rate, HRmax.) were inversely propotional to the lung volume and water temperature. In the above results, bradycardial response was more sensitive in the athletes than the control. It was suggested that diving bradycardia was related to the gas content in the lung and reflex from the cold receptor in the face.

• Journal of Veterinary Clinics
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• v.33 no.4
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• pp.234-236
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• 2016

A 14 kg, 9-year-old, spayed female, Cocker Spaniel was presented to the Veterinary Medical Teaching Hospital of Seoul National University with a history of head tilt and circling. Otitis externa and media were diagnosed by computerized tomography, and total ear canal ablation was performed. In preanesthetic evaluation, systemic hypertension and second-degree atrioventricular block were observed, but there was no regurgitation through the heart valves. Systemic hypertension was managed with amlodipine (0.1 mg/kg, PO, BID) for the anesthesia. The dog was premedicated with cefazolin (22 mg/kg, IV) and midazolam (0.2 mg/kg, IV). Anesthesia was induced with alfaxalone (2 mg/kg, IV) and maintained with isoflurane and 100% oxygen following intubation. During surgery, vital signs (heart rate, respiratory rate, blood pressure, end tidal carbon dioxide partial pressure and body temperature) were maintained within normal ranges, but bradycardia was observed and corrected with glycopyrrolate (5 ug/kg IV, twice). During subcuticular suture, electrohemostasis was applied at the incision line, which was close to the trigeminal nerve. In no time at all, heart rate dramatically decreased from 110 to 60 beats per minute. No additional treatment was done because mean blood pressure was maintained above 70 mmHg. The heart rate recovered according to the decrease of end tidal isoflurane concentration and there were no complications associated with the anesthesia and surgery. Sudden bradycardia after electrical stimulation around the trigeminal nerve was considered as trigeminocardiac reflex (TCR). It is recommended to be careful of bradycardia from TCR when electrocautery is used in the craniofacial area during surgery.

• The Korean Journal of Physiology
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• v.10 no.1
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• pp.49-54
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• 1976

The change of heart rates during Flack Test was observed in the pregnant women, $24{\sim}48$weeks, of gestational age, to analyze mechanical and neural regulatory factors in responses to the positive lung inflation. The results obtained were summarized as followings: 1) Endurance tine of Flack Test was 37.6 sec, in the nonpregnant women, and 25.1 sec. in the pregnant women. 2) When Flack Test was employed, heart rate was decreased in early stage of Flack Test in the pregnant women, while heart rate was increased in the nonpregnant women. 3) In the pregnant women bradycardia due to abdominal mechanical intervention in early stage of Flack Test was prominent, while tachycardia was found in the nonpregnant women. 4) During Flack Test, tachycardia due to sympathetic central reflex activation was observed immediately after bradycardia in early stage of Flack Test. 5) It may be noted that Flack Test employed in the present study is a useful model to evaluate and analyze the neural and mechanical abdominal intervention factor in response to the positive inflation of lung in pregnant women.

• Journal of Korean Neurosurgical Society
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• v.64 no.6
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• pp.957-965
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• 2021

Objective : Rapid increase in intracranial pressure (ICP) can result in hypertension, bradycardia and apnea, referred to as the Cushing phenomenon. During decompressive craniectomy (DC), rapid ICP decreases can cause changes in mean atrial blood pressure (mABP) and heart rate (HR), which may be an indicator of intact autoregulation and vasomotor reflex. Methods : A total of 82 patients who underwent DC due to traumatic brain injury (42 cases), hypertensive intracerebral hematoma (19 cases), or major infarction (21 cases) were included in this prospective study. Simultaneous ICP, mABP, and HR changes were monitored in one minute intervals during, prior to and 5-10 minutes following the DC. Results : After DC, the ICP decreased from 38.1±16.3 mmHg to 9.5±14.2 mmHg (p<0.001) and the mABP decreased from 86.4±14.5 mmHg to 72.5±11.4 mmHg (p<0.001). Conversly, overall HR was no significantly changed in HR, which was 100.1±19.7 rate/min prior to DC and 99.7±18.2 rate/min (p=0.848) after DC. Notably when the HR increased after DC, it correlated with a favorable outcome (p<0.001), however mortality was increased (p=0.032) when the HR decreased or remained unchanged. Conclusion : In this study, ICP was decreased in all patients after DC. Changes in HR were an indicator of preserved autoregulation and vasomotor reflex. The clinical outcome was improved in patients with increased HR after DC.