Brugada syndrome (BrS) is an inherited proarrhythmic disorder, and its symptoms are caused by a variety of factors in addition to myocardial ionic channel abnormalities. If abnormalities suggestive of BrS are found through a preoperative electrocardiogram, it is necessary to consult a cardiologist to discuss diagnosis and arrhythmia prevention. During surgery, it is necessary to refrain from using drugs that inhibit sodium channels as much as possible, and to monitor for the occurrence of arrhythmia.

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  Mechanical properties of pulmonary circulation are described by the static (non-pulsatile) and dynamic (pulsatile) characteristic of vasculature. The former is given by pulmonary vascular resistance (PVR), and the latter is represented by pulmonary artery (PA) impedance. In clinical practice, PVR, given by pressure difference divided by cardiac output, is the simplest and widely-used parameter, but it captures only non-pulsatile properties and ignores pulsatile state. On the other hand, PA impedance provides the pulsatile relationship between PA flow and pressure in the frequency domain. PA impedance contributes to a better description of vascular mechanics under pulsatile flow; however, the interpretation is difficult for clinical application. With the use of arterial models, for example, Windkessel model, which contain . parameters with physiological meanings, PA impedance can be interpreted more straightforwardly. PA impedance with arterial models can provide more insight into arterial compliance, the mechanics of the proximal PA (characteristic impedance), blood iner tance, and wave ref lect ion phenomenon. Furthermore, the pathological change of pulmonary vasculature in pulmonary hypertension (PH) can be assessed by PA impedance. Toward a bet ter description of pulmonary circulation, this review article explains 1) the physiological concept of PA impedance, 2) animal experiments in PH models, and 3) clinical studies in patients with PH.

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  A 68-year-old female patient was admitted with the history of hereditary hemorrhagic telangiectasia （HHT）. She was diagnosed with pulmona ry arteriovenous malformations （PAVM） by the chest CT scan, and she was suffered from shortness of breath after local anesthesia with Xylocaine 2% with adrenalin 1:80,000 for the dental treatment at our hospital. Dental procedures were performed using Citanest-Octapressin Cartridge （prilocaine 3% with 0.054 IU Felypressin） to prevent shortness of breath. Reportedly, patients with HHT would also suffer from PAVM at the rate of about 50%. Moreover, the patients with HHT which merged with PAVM have cerebral infarction and a stroke prognosis rate of 9–41%. Not evaluating for PAVM in the dental treatments might cause a brain abscess, air embolization, and/or shortness of breath. As for the dental treatment, blood circulation mostly remains unaffected. However, this treatment sometimes affects the systemic circulation; thus, circulation control is necessary.

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  Vagus nerve stimulation (VNS) is used to treat drug-resistant epilepsy. We report a case of intraoperative severe bradycardia and cardiac arrest during a second VNS implantation. No cases of bradycardia during the second VNS implantation have been reported.
  The patient underwent the first VNS implantation before and experienced no intraoperative bradycardia. A mechanical error of the VNS was discovered, and the second operation was scheduled. General anesthesia was scheduled with supporting by a prophylactic pacing defibrillator to manage bradycardia during VNS. After exchanging the electrodes on the left vagus nerve, test stimulations were performed. We observed an increase in the PR interval on the electrocardiogram (ECG) during the test stimulation and severe bradycardia with cardiac arrest during the main stimulation, which required shortterm chest compressions and percutaneous pacing. After discontinuing stimulation, the pulse rate recovered immediately. We conclude that continuous ECG monitoring intraoperative is crucial, even if the first VNS implantation was uneventful.

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  Absent pulmonary valve syndrome (APVS) is a rare entity of congenital cardiac anomaly, and is often associated with tetralogy of Fallot. APVS associated with functional single ventricle (fSV) is even rarer. Respiratory tract compression due to pulmonary artery dilation is a severe complication for patients with APVS. fSV patients cannot tolerate worsening respiratory status due to respiratory tract compression, since maintaining good respiratory status is essential for Fontan circulation. We present a case with an APVSfSV patient with severe respiratory tract compression symptoms who improved after cardiac surgery, including bilateral pulmonary artery angioplasty and pulmonary blood flow reconstruction using Blalock-Taussig shunt.

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