• Journal of Chest Surgery
• /
• v.56 no.3
• /
• pp.186-193
• /
• 2023

Background: Complete surgical excision is the only curative treatment for primary cardiac tumors. For wide excision, interatrial septal reconstruction (ISR) is commonly performed. We hypothesized that ISR may increase the risk of postoperative atrial tachyarrhythmia (AT) after surgical resection of cardiac myxoma. Methods: After excluding patients with a history of cardiac surgery and concomitant procedures unrelated to tumor resection and those with AT or permanent pacemakers, we finally enrolled 272 adult patients who underwent benign cardiac tumor surgery from 1995 to 2021 at our institution. They were divided into the ISR (n=184) and non-ISR (n=88) groups. The primary outcome was postoperative new-onset AT. Results: The study cohort predominantly consisted of women (66.2%), with a mean age of 57.2±13.6 years. The incidence of postoperative new-onset AT was 15.4%. No 30-day mortality or recurrence was observed. The cardiopulmonary bypass time and aortic cross-clamping time were significantly longer in the ISR group than in the non-ISR group (p<0.001). The median duration of hospital stay of all patients was 6.0 days (interquartile range, 5.0-7.0 days), and no significant difference was observed between the 2 groups (p=0.329). ISR was not an independent predictor of new-onset AT (p=0.248). Male sex and hypertension were found to be independent predictors of new-onset AT. Conclusion: ISR was not a significant predictor of postoperative new-onset AT. ISR might be a feasible and safe procedure for surgical resection of cardiac myxoma and should be considered if needed.

• Journal of Chest Surgery
• /
• v.56 no.3
• /
• pp.194-196
• /
• 2023

• Journal of Biomedical Engineering Research
• /
• v.23 no.6
• /
• pp.477-484
• /
• 2002

A pacemaker autosense algorithm with dual thresholds. one for noise or tachyarrhythmia detection (noise threshold, NT) and the other for intrinsic beat detection (sensing threshold. ST), was developed to improve the sensing performance in single pass VDD electrograms. unipolar electrograms, or atrial fibrillation detection. When a deflection in an electrogram exceeds the NT (defined as 50% of 57), the autosense algorithm with dual thresholds checks if the deflection also exceeds the ST. If it does, the autosense algorithm calculates the signal to noise ratio (SNR) of the deflection to the highest deflection detected by NT but lower than ST during the last cardiac cycle. If the SNR 2, the autosense algorithm declares an intrinsic beat detection and calculates the next ST based on the three most recent intrinsic peaks. If the SNR $\geq$2, the autosense algorithm checks the number of deflections detected by NT during the last cardiac cycle in order to determine if it is a noise detection or tachyarrhythmia detection. Usually the autosense algorithm tries to set the 57 at 37.5% of the average of the three intrinsic beats, although it changes the percentage according to event classifications. The autosense algorithm was tested through computer simulation of atrial electrograms from 5 patients obtained during EP study, to simulate a worst sensing situation. The result showed that the ST levels for autosense algorithm tracked the electrogram amplitudes properly, providing more noise immunity whenever necessary. Also, the autosense algorithm with dual thresholds achieved sensing performance as good as the conventional fixed sensitivity method that was optimized retrospectively.

• Journal of Chest Surgery
• /
• v.51 no.2
• /
• pp.146-148
• /
• 2018

Left atrial appendage (LAA) aneurysm is a rare, pathologic condition that may lead to atrial tachyarrhythmia or thromboembolic events. A 49-year-old man presented with aggravated palpitation and dizziness. He suffered from refractory atrial fibrillation despite a previous history of radiofrequency catheter ablation. Echocardiography revealed a 57-mm LAA aneurysm. Surgical ablation was performed through a right mini-thoracotomy, and the LAA aneurysm was obliterated with a 50-mm AtriClip (Atricure Inc., Westchester, OH, USA). However, follow-up computed tomography showed residual communication, so the patient is still taking warfarin. We report that a minimally invasive strategy for treating LAA aneurysm can be considered, but incomplete closure may occur; thus, caution is needed.

• Journal of Chest Surgery
• /
• v.21 no.6
• /
• pp.1137-1144
• /
• 1988

Supraventricular tachyarrhythmias are readily characterized and understood, but the surgical procedures for their correction are complex and not easily mastered. Conversely, ventricular tachyarrhythmias are frequently difficult to characterize and localize electrophysiologically and their basic mechanisms are poorly understood. The role of the surgeon in the treatment of cardiac arrhythmia has changed dramatically during the past decade. This report is a case of 26 years old male with supraventricular tachyarrhythmia. The result of endocardial electrophysiologic study demonstrated accessory pathway connecting left atrium to left ventricle which located at left atrial free wall about 4 cm apart from the coronary sinus orifice. The accessory bundle interruption has been successfully accomplished utilizing the internal open heart technique. The operation consisted of dissection of the atrioventricular fat pad and division of all the superficial fibers going from the ventricle to the annulus. Following this, cryoablation made with cryoprobe at - 60$^\circ{C}$ for 90 seconds. The accessory pathway was successfully ablated without specific problems.

• Journal of Chest Surgery
• /
• v.21 no.6
• /
• pp.1145-1151
• /
• 1988

Supraventricular tachyarrhythmias are readily characterized and understood, but the surgical procedures for their correction are complex and not easily mastered. Conversely, ventricular tachyarrhythmias are frequently difficult to characterize and localize electrophysiologically and their basic mechanisms are poorly understood. The role of the surgeon in the treatment of cardiac arrhythmia has changed dramatically during the past decade. This report is a case of 26 years old male with supraventricular tachyarrhythmia. The result of endocardial electrophysiologic study demonstrated accessory pathway connecting left atrium to left ventricle which located at left atrial free wall about 4 cm apart from the coronary sinus orifice. The accessory bundle interruption has been successfully accomplished utilizing the internal open heart technique. The operation consisted of dissection of the atrioventricular fat pad and division of all the superficial fibers going from the ventricle to the annulus. Following this, cryoablation made with cryoprobe at - 60` for 90 seconds. The accessory pathway was successfully ablated without specific problems.

• Journal of Chest Surgery
• /
• v.23 no.5
• /
• pp.844-853
• /
• 1990

We have performed 27 cases of orthotopic homologous cardiac transplantation using Korean mongrel dogs and one case of sham operation for the evaluation of harmful effect of cardiopulmonary bypass itself on the dog from April, 1989 to June, 1990. Our previous reports have already demonstrated basal hemodynamic and hematologic data on the canine homologous heart transplantation and the fundamental principles of transplantation of the heart. The mean body weight of recipients was 13.2$\pm$1.2kg with a rage of 11 ~ 15kg, and the hemodynamic and hematologic pictures were almost same as the result of previous reports from our hospital, except marked decrease in postoperative platelet count[from 3.18 $\pm$0.80x106/mm3 to 1.41$\pm$0 37x 106/mm3]. Mean survival time was 24.82$\pm$49.40 hours with the longest survival of 264 hours. Donor cardiectomy included coronary vasodilatation with diltiazem, potassium arrest, and the rapid cooling of the heart suspending in the specially designed ice-bath. Median sternotomy provided excellent exposure of the surgical field. 6 \ulcorner0 prolene suture was used for the anastomosis of both atrial cuffs and the great arteries, and we found the fact that stenosis, bleeding, thrombus formation around the anastomotic site could be decreased with the use of everted horizontal mattress suture techniques. Immunosuppression was done with a combination of lower dose Cyclosporin-A, Azathioprine, methyl-prednisolone, but our cases still showed too short survival to worry about graft rejection. Still poor was our quality control of experimental animal, we had much difficulties in postmortem evaluation of the dogs. Low cardiac output due to biventricular failure, intractable supraventricular or ventricular tachyarrhythmia, postoperative massive bleeding, sepsis were most frequent findings that could be thought as a cause of death. A few cases showed subendocardial patch hemorrhage in both ventricular cavity or atrial septum at autopsy, suggesting acute subendocardial infarction. Although our team overcome most of the technical problems of orthotopic heart transplantation, we should pile up further knowledges about donor heart preservation, quality control of animal, infection, rejection, the effect of the cardiopulmonary bypass to improve the results.

• Journal of Chest Surgery
• /
• v.25 no.1
• /
• pp.32-41
• /
• 1992

From August 1982 to December 1991, 58 consecutive infants with tetralogy of Fallot underwent primary repair. Age ranged from 22 days to twelve months [n=58, 8.7$\pm$2.7 months] and body weight from 3.1 to 13 kilograms [n=58, 7.8$\pm$1.7 kilograms]. Qne infant had absence of the pulmonary valve; one had Ebstein`s anomaly and one had supramitral ring. Thirty-two patients [56%] experienced anoxic spell. Preoperative pulmonary artery indices were measured in 38 cases, ranging 126-552mm2/M2BSA[n=38, 251$\pm$79mm2/M2BSA]. All infants required a right ventricular outflow tract patch; in 41, the patch extended across the pulmonary valve annulus, in 13 of them, monocusps were constructed. All had patch closure of ventricular septal defect. Two infants had REV operation for avoiding injury to the canal branch of the right coronary artery which cross the right ventricular out flow tract. Post repair PRV/LV were measured at operating room in 40 cases, which revealed mean value of 0.49$\pm$0.12 [range: 0.25-0.74]. The hospital mortality was 10.3% [6 patients], and causes of deaths were right heart failure due to sustained right ventricular hypertension[4] and right ventricular outflow tract obstruction, intractablesuraventricular tachyarrhythmia[1], hypoxia[1] due to residual right to left shunt across the atrial septal defect in patient associated with Ebstein`s anomaly. All infants were doing well at follow-up from 1 to 101 months[20.6 months /patient, 1, 072 patient-month] Serial postoperative echocardiograms revealed no residual ventricular septal defects and estimated RVOT gradients between 0 and 40 mmHg except 3 cases [50, 50, 60 mmHg]. There were no late deaths and late ventricular arrhythmias or congestive heart failure. Redo operations were done in 2 cases because of residual right ventricular outflow tract obstruction. This experience with infants with tetralogy of Fallot suggests that, if mortality is tolerable, eletive repair of tetralogy of Fallot could be reasonably undertaken during the first year of life, and even better results could be anticipated along with improvement of methods of myocardial protection and postoperative care.

• Clinical and Experimental Pediatrics
• /
• v.50 no.1
• /
• pp.40-46
• /
• 2007

Purpose : This study assessed the long term survival rate and long term complications of patients who had a modified Fontan operation for functionally univentricular cardiac anomaly. Methods : Between June 1986 and December 2000, 302 patients with a functional single ventricle underwent surgical interventions and were followed up until February 2006. The mean follow-up period was $8.3{\pm}5.3years$ (range 3.5-18 years). Their median age was 2.4 years at the Fontan operation. The survival rate, the incidence and the risk factor of late complications were evaluated retrospectively. Results : The verall survival rate was 91 percent at 5 years and 87 percent at 10 years. In multivariate analysis, early calendar year of operation and significant regurgitation were risk factors of death. The surviving patients showed NYHA functional class I in 82 percent, class II in 15 percent, and class III in 3 percent. Redo Fontan operations were necessary in 8.8 percent of patients at average $12.8{\pm}3.6years$ after initial Fontan operation. The most common cause of Fontan conversion was atrial arrhythmia. The incidence of thromboembolic events was 9.3% and these complications were associated with the occurrence of atrial tachyarrhythmia. Supraventricular tachycardia including atrial flutter or fibrillation were reported on the follow-up examination by 11.2 percent of survivors after $8.4{\pm}5.6years$. Atriopulmonary connection showed higher rates of late tachycardia than lateral tunnel operation. Conclusions : This study revealed that the recent survival rate of Fontan type operation was satisfactory, but the occurrence of late complications after a Fontan type operation increased with the longer survival. There is a need for strict follow up and early treatment of late complications in patients who had a Fontan operation.

• Clinical and Experimental Pediatrics
• /
• v.50 no.11
• /
• pp.1085-1090
• /
• 2007

Purpose : Radiofrequency catheter ablation (RFCA) has become an effective therapeutic modality for treating pediatric tachyarrhythmias. Using conventional RFCA catheters, ablation of parahisian accessory pathways may be difficult and have high risk for heart block. We reviewed the efficacy and complications of the RFCA in children and adolescent with arrhythmias including parahisian accessory pathways. Methods : We studied 48 patients (aged 2 years to 20 years) who had undergone RFCA from August 2003 to March 2007. We reviewed clinical findings, electrophysiologic studies, RFCA data, complications, and follow-up results of the patients. Results : Mean age of the patients was 13.1 years. Numbers and types of arrhythmias (age, acute success rate) were as follows: 19 WPW syndrome including 5 parahisian accessory pathways ($13.7{\pm}4.6yr$, 18/19), 11 atrioventricular reentrant tachycardia with concealed bypass tract ($12.3{\pm}5.0yr$, 10/11), 13 atrioventricular nodal reentrant tachycardia ($12.6{\pm}4.4yr$, 13/13), 4 atrial flutter ($13.0{\pm}7.4yr$, 3/4), and 1 ventricular tachycardia (20 yr, 1/1). Associated cardiac structural lesion was not detected in 48 patients. The recurrence rate was 6.5%, and the final success rate was 93.8%. Conclusion : These results suggest that RFCA is a highly effective treatment method in children and adolescent with tachyarrhythmia.