• Journal of Chest Surgery
• /
• v.47 no.4
• /
• pp.367-372
• /
• 2014

Background: We compared the mid-term results of the Cox maze IV procedure using argon-based cryoablation with a procedure using $N_2O$-based cryoablation. Methods: From May 2006 to June 2012, 138 patients (mean age, $58.2{\pm}11.0$ years) underwent the Cox maze IV procedure. Eighty-five patients underwent the maze procedure using an $N_2O$-based cryoprobe (group N), and 53 patients underwent the maze procedure using an argon-based cryoprobe (group A). Bipolar radiofrequency ablation was concomitantly used in 131 patients. The presence of atrial fibrillation immediately, 6 months, 1 year, and 2 years after surgery was compared. Results: Early mortality occurred in 6 patients (4.3%). There were no differences in early mortality or postoperative complications between the two groups. Nineteen of 115 patients (16.5%) remained in atrial fibrillation at postoperative 12 months (14 of 80 patients (17.5%) in group N and 5 of 35 patients (14.3%) in group A, p=0.669). There were no differences in the number of patients who remained in atrial fibrillation at any of the time periods except in the immediate postoperative period. A multivariable analysis revealed that the energy source of cryoablation was not associated with the presence of atrial fibrillation at 1 year (p=0.862) and that a fine F wave (<0.1 mV) was the only risk factor predicting the presence of atrial fibrillation at 1 year (p<0.001, odds ratio=20.287). Conclusion: The Cox maze IV procedure using an argon-based cryoprobe was safe and effective compared with the maze procedure using an $N_2O$-based cryoprobe in terms of operative outcomes and the restoration of sinus rhythm for up to 2 years after surgery.

• Journal of Chest Surgery
• /
• v.35 no.1
• /
• pp.48-51
• /
• 2002

The conversion of failing Fontan circuit to total cavopulmonary connection(TCPC) is recommended as a therapeutic option in patients with late Fontan complications such as atrial arrhythmia, atrial enlargement, pulmonary venous obstruction, and ventricular dysfunction. Combined TCPC with extracardiac conduit and cryoablation of arrhythmia circuit is preferred for treatment of failing Fontan coulection with atrial lachyarrhythrnia. We report a case of conversion of atriopulmonary connection to extracardiac conduit Fontan and cryoablation of atrial arrhythmia circuit in a patient with tricuspid atresia, who also had ectopic atrial tachycardia, right atrial thrombi, pulmonary venous obstruction, and ventricular dysfunction. This patient and the parents were Jehovah's Witnesses; therefore, the patient underwent the procedure without blood transfusion.

• Journal of Chest Surgery
• /
• v.30 no.5
• /
• pp.493-500
• /
• 1997

We performed this study to evaluate hepatic venous drainage in atrial isomerism by MR and the clinical significance of anomalous hepatic venous return in total cavopulmonary shunt operation. Numbers and locations of hepatic veins in twenty-two patients with isomerism(thirteen with right isomerism and nine with left isom rism) were evaluated by MR. Operative procedure of hepatic veins and postoperative arterial oxygen saturation were compared with hepatic vein connection in six patients after total cavopulmonary shunt operation. Among nine patients with left isomerism, hepatic venous return was totally anomalous via a single opening in eight, and via two separate openings in one. Among thirteen patients with right isomerism, partial anomalous hepatic venous connection directly to the atrium was seen in four. One showed total anomalous hepatic venous connection to atrium through one opening. Total cavopulmonary shunt operation was performed in 6 patients. Hepatic veins were connected to pulmonary arteries in four patients who had one atrial opening of hepatic vein andlor IVC, or two ipsilateral atrial opening of hepatic veins and IVC. In conclusion, hepatic vein drainage to atrium is variable in atrial isomerism. MR is useful for evaluation of hepatic vein drainage in atrial isomerism and surgical pla ning.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.49 no.3
• /
• pp.38-46
• /
• 2012

Atrial fibrillation is needed to be detected at paroxysmal stage and to be treated. But, paroxysmal atrial fibrillation ECG is hardly obtained with 12-lead electrocardiographs but Holter systems. Presently, the averaged beat subtraction(ABS) method is solely used to estimate atrial fibrillatory waves even with somewhat large residual error. As an alternative, in this study, we suggested an ESAF(event-synchronous adaptive filter) based algorithm, in which the AF ECG was treated as a primary input and event-synchronous impulse train(ESIT) as a reference. And, ESIT was generated so to be synchronized with the ventricular activity by detecting QRS complex. We tested proposed algorithm with simulated AF ECGs and real AF ECGs. As results, even with low computational cost, this ESAF based algorithm showed better performance than the ABS method and comparable performance to algorithm based on PCA(principal component analysis) or SVD(singular value decomposition). We also proposed an expanded version of ESAF for some AF ECGs with multi-morphologic ventricular activities and this also showed reasonable performance. Ultimately, with Holter systems including our proposed algorithm, atrial activity signal can be precisely estimated in real-time so that it will be possible to calculate atrial fibrillatory rate and to evaluate the effect of anti-arrhythmic drugs.

• Journal of Chest Surgery
• /
• v.31 no.7
• /
• pp.668-673
• /
• 1998

During the past several years, the maze operation has become the most effective method of treatment for chronic atrial fibrillation. When the maze procedure is done concomittantly with other cardiac operations, surgeons, in their initial experiences, may be concerned about the additional operative risks and uncertainty of the results. We performed the Cox-maze III procedure in six cases of chronic atrial fibrillation associated with mitral, mitral & aortic, or coronary arterial disease. Maze III procedure was done with open mitral commissurotomy(3 cases), mitral valve replacement(1 case), aortic and mitral valve replacement(1 case), and two-vessel coronary bypass graft(1 case). In spite of rather prolonged aortic cross clamp time, cardiac recovery was uneventful in all cases. No cases required reexploration for postoperative bleeding. All patients showed regular sinus rhythms immediate or between 2 and 20 days postoperateratively. Transient postoperative supraventricular arrhythmarias were easily controlled by various antiarrhythmic agents. In follow up evaluations, all cases showed regular sinus rhythm on ECG and the right and left atrial transport function was confirmed by Doppler echocardiography in all except one. Though our experience was limited in case number, the Cox-maze III procedure was effective in controlling the chronic atrial fibrillation without serious additional operative risks.

• Clinical and Experimental Pediatrics
• /
• v.46 no.1
• /
• pp.51-55
• /
• 2003

Purpose : We intended to find out the role of transesophageal atrial pacing in evaluation of infants and children with palpitation of unknown origin. Methods : We tried transesophageal atrial pacing study in 69 infants and children with palpitation, in whom tachycardia wasn't documented in electrocardiogram and reviewed retrospectively the records of transesophageal pacing and medical records of theses patients to find out the induction rate of tachycardia by transesophageal atrial pacing and the possible mechanism of tachycardia if induced. Results : In 70.1% infants and children with palpitation, tachycardia was induced, so we could conclude that tachycaridia was the cause of palpitation in these cases. In most cases, tachycardia was induced by rapid atrial pacing, and in 21% by using isoproterenol. Tachycardia induction rate was higher in <6-year-old children than ${\geq}6$-year-old children(P<0.05). In cases of the induced, we reviewed the mechanism of tachycardia. Of these induced tachycardias, 53.2% is atrioventricular reentry tachycardia, 34.0% were atrioventricular nodal reentry tachycardia, and 12.8% were idiopathic left ventricular tachycardia. Invasive electrophysiologic study was done to 10 patients of those induced. The results of electrophysiologic study and transesophageal pacing and recording were the same except for one patient. Conclusion : Transesophageal atrial pacing and recording is a less invasive, safe and useful method to find out the cause of palpitation and the mechanism of tachycardia in infants and children.

• Journal of Biomedical Engineering Research
• /
• v.23 no.1
• /
• pp.1-8
• /
• 2002

Atrial fibrillation(AF). chronic or paroxysmal is the most frequent arrhythmia in human subjects Duration of P wave in signal-averaged electrocardiography(SAECG) reflects intra-atrial conduction time and therefore. could be used as an electrophysiological marker for atrial conduction chance at the earthy stave. So we apply the analysis method using SAECG to diagnose Paroxysmal atrial fibrillation(PAF) . Subjects Participated for the study consisted of two groups: a control group(n=34) of normal healthy volunteers and a group of AF Patients(n=38) with a documented history of PAF but no other history of cardiac disease. We evaluated the effect of several filtering and determination methods to find the starting and ending feints of the P wavy on its duration. To increase the measurement reliability of P wave duration. the automatic detection method was proposed. Also. to increase the detection rate for PAF risk, the decision threshold value was optimized using receiver operation characteristics(ROC) curve. Results showed that the highest statistical difference (p〈0.001) of the P wane duration between controls and subjects was obtained at the Processing condition, using absolute threshold vague(8.75 $\mu N$) , a least mean square(LMS) high pass filter and 30 Hz cutoff frequency. The most outstanding difference(sensitivity 88 % specificity 64.4 %) between controls and subjects was obtained at the decision threshold value of 112 ms.

• Journal of the Korean Society of Radiology
• /
• v.81 no.2
• /
• pp.272-289
• /
• 2020

Current advances in CT techniques allow thorough evaluation of the beating heart. The strengths of cardiac CT relative to echocardiography and magnetic resonance imaging are its high availability in most institutions, rapid production of high-quality images, and outstanding delineation of the anatomy. For many normal variants and pathologic conditions, such as thrombi, masses, and congenital abnormalities of the left atrium, CT findings are sufficient to make a presumptive diagnosis. Assessments of the left atrium and left atrial appendage are particularly important for the management of atrial fibrillation, as various catheter-based procedures are aimed at the mechanical and electrical isolation of these structures. CT offers information crucial to a successful catheter-based procedure or surgery. Therefore, a comprehensive review of the geometry (shape, size, and relative position), along with various CT imaging features of pathologic states, should be provided in radiology reports to be of clinical value.

• Korean Circulation Journal
• /
• v.52 no.7
• /
• pp.513-526
• /
• 2022

Background and Objectives: Atrial tachycardias (ATs) from noncoronary aortic cusp (NCC) uncovered after radiofrequency ablation for atrial fibrillation (AF) are rarely reported. This study was conducted to investigate the prevalence and clinical characteristics of NCC ATs detected during AF ablation and compare their characteristics with de novo NCC ATs without AF. Methods: Consecutive patients who underwent radiofrequency catheter ablation for AF were reviewed from the multicenter AF ablation registry of 11 tertiary hospitals. The clinical and electrophysiological characteristics of NCC AT newly detected during AF ablation were compared with its comparators (de novo NCC AT ablation cases without AF). Results: Among 10,178 AF cases, including 1,301 redo ablation cases, 8 (0.08%) NCC AT cases were discovered after pulmonary vein isolation (PVI; 0.07% in first ablation and 0.15% in redo ablation cases). All ATs were reproducibly inducible spontaneously or with programmed atrial stimulation without isoproterenol infusion. The P-wave morphological features of tachycardia were variable depending on the case, and most cases exhibited 1:1 atrioventricular conduction. AF recurrence rate after PVI and NCC AT successful ablation was 12.5% (1 of 8). Tachycardia cycle length was shorter than that of 17 de novo ATs from NCC (303 versus 378, p=0.012). No AV block occurred during and after successful AT ablation. Conclusions: Uncommon NCC ATs (0.08% in AF ablation cases) uncovered after PVI, showing different characteristics compared to de-novo NCC ATs, should be suspected irrespective of P-wave morphologies when AT shows broad propagation from the anterior interatrial septum.

• Journal of Chest Surgery
• /
• v.28 no.3
• /
• pp.316-319
• /
• 1995

Systemic emboli occur in approximately one-third of patients with cardiac myxoma. Embolization is common because of the friability of the tumor and intracardiac location. Embolic episodes in young patients with normal sinus rhythm should arouse suspicions of cardiac myxoma in the absence of active endocarditis. We present one case of 17 years old girl having saddle embolism combined with left atrial myxoma. We planned staged operation. First, the emergency thromboembolectomy of aortic bifurcation was performed through bilateral transfemoral approach with use of Forgaty catheter. One week later, the extirpation of myxoma was successfully done with ECC.