Ablation of idiopathic ventricular arrhythmias originating from basal cardiac crux region

Background@#Ablation of idiopathic ventricular arrhythmias (VAs) in the cardiac crux region is one of the challenging procedures due to the complex anatomical structure where the four chambers of the heart are offset. Although this region is complex, the contiguous cardiac structures allow for the ablation of arrhythmias from adjacent sites.Case presentation: We present different anatomical approaches in radiofrequency ablation and the ECG character‑ istics from a case series of VAs originated from the basal inferior ventricular septum, the corresponding endocardial aspect of the basal cardiac crux region. @*Conclusions@#Ablation of VAs originated from the basal cardiac crux region requires detailed mapping in the proxi‑ mal coronary venous system and the adjacent structures including the RV, RA, and LV. In addition to the characteristic ECG of basal crux VAs, our three cases present an abrupt precordial transition in V2 with R wave amplitude greater than in V1 and V3.

A case of infra‑nodal Wenckebach conduction block with alternating bundle branch block

Background@#Atrioventricular (AV) node normally has decremental conduction property and a longer refractory period than His-Purkinje system (HPS). This results in AV conduction delay or block at the level of AV node in response to short-coupled atrial premature beats. Prolonged refractoriness in HPS can produce unusual physiological patterns of AV conduction such as conduction delay or infra-nodal block in the distal elements of HPS.Case presentation: We present a case in which atrial premature stimulation produces infra-nodal Wenckebach conduction block which initiates long-short cycle sequence within the bundle branches resulted in alternating bundle branch block and atypical pattern of Ashman phenomenon. @*Conclusions@#This case highlights the importance of recognizing the unusual physiological AV conduction patterns of HPS. The long-short cycle sequence in the bundle branches of distal HPS and linking phenomenon can result in alternating bundle branch block without the presence of HPS disease.

Ablation of idiopathic ventricular arrhythmias originating from basal cardiac crux region

Background@#Ablation of idiopathic ventricular arrhythmias (VAs) in the cardiac crux region is one of the challenging procedures due to the complex anatomical structure where the four chambers of the heart are offset. Although this region is complex, the contiguous cardiac structures allow for the ablation of arrhythmias from adjacent sites.Case presentation: We present different anatomical approaches in radiofrequency ablation and the ECG character‑ istics from a case series of VAs originated from the basal inferior ventricular septum, the corresponding endocardial aspect of the basal cardiac crux region. @*Conclusions@#Ablation of VAs originated from the basal cardiac crux region requires detailed mapping in the proxi‑ mal coronary venous system and the adjacent structures including the RV, RA, and LV. In addition to the characteristic ECG of basal crux VAs, our three cases present an abrupt precordial transition in V2 with R wave amplitude greater than in V1 and V3.

A case of infra‑nodal Wenckebach conduction block with alternating bundle branch block

Background@#Atrioventricular (AV) node normally has decremental conduction property and a longer refractory period than His-Purkinje system (HPS). This results in AV conduction delay or block at the level of AV node in response to short-coupled atrial premature beats. Prolonged refractoriness in HPS can produce unusual physiological patterns of AV conduction such as conduction delay or infra-nodal block in the distal elements of HPS.Case presentation: We present a case in which atrial premature stimulation produces infra-nodal Wenckebach conduction block which initiates long-short cycle sequence within the bundle branches resulted in alternating bundle branch block and atypical pattern of Ashman phenomenon. @*Conclusions@#This case highlights the importance of recognizing the unusual physiological AV conduction patterns of HPS. The long-short cycle sequence in the bundle branches of distal HPS and linking phenomenon can result in alternating bundle branch block without the presence of HPS disease.

Prognostic Value of Inferior Shift of P wave Axis after Catheter Ablation for Longstanding Persistent Atrial Fibrillation based on Dallas Lesion Set Including Anterior Line

BACKGROUND AND OBJECTIVES: Although an anterior linear ablation is an effective lesion set in radiofrequency catheter ablation (RFCA) for longstanding persistent atrial fibrillation (L-PeAF), its durability for bidirectional block (BDB) is only about 60% at repeat procedure. We hypothesized that changes in electrocardiogram (ECG) may predict an anterior line block state and the clinical outcome of L-PeAF ablation. SUBJECTS AND METHODS: We studied 304 L-PeAF patients (77% male, 60±10yrs), who consistently underwent RFCA Dallas lesion set (circumferential pulmonary vein isolation, posterior box lesion, and anterior line) protocol with subsequent comparison of pre-procedural and post-procedural P wave axes, and one year follow-up (n=205) sinus rhythm (SR) ECGs. RESULTS: 1. P wave axis shifted inferiorly at immediate post-procedure (p<0.001), and was independently correlated with BDB of anterior line (β=10.4, 95% confidence interval [CI] 2.79-17.94, p=0.008). 2. The degree of post-procedural inferior shift of P wave axis did not reflect clinical recurrence within one-year (n=205, p=0.923), potentially due to conduction recovery of an anterior line. However, among 160 patients without clinical recurrence within one-year, P wave axis at one-year ECG was independently associated with very late recurrence of AF after one-year (n=160, hazard ratio [HR] 0.98; 95% CI 0.97-0.99, p=0.001), during 45.6±16.7 months of follow-up. 3. Among 22 patients who underwent repeat procedures, P wave axis shift was more significant in patients with maintained BDB of an anterior line than in those without (p=0.015). CONCLUSION: An inferior shift of P wave axis reflects the achievement and the maintenance of an anterior line BDB, and is associated with better long-term clinical outcome after catheter ablation for L-PeAF based on Dallas lesion set.

Pitfalls of Atrial Advancement Using a Ventricular Extra-stimulus During Supraventricular Tachycardia

The delivery of single His-refractory ventricular extra-stimulus during supraventricular tachycardia is useful to identify the mechanism of the tachycardia. We present the different responses based on the ventricular extra-stimulus site. Our findings demonstrate that the atrial activation via an accessory pathway was not advanced based on the ventricular pacing site. Therefore, atrioventricular tachycardia could masquerade as atrioventricular nodal reentrant tachycardia.

Interatrial septal thickness as a marker of structural and functional remodeling of the left atrium in patients with atrial fibrillation

BACKGROUND/AIMS: There have been reports that interatrial septal (IAS) thickness is increased in patients with atrial fibrillation (AF). This study was performed to investigate whether IAS thickness determined by transthoracic echocardiography (TTE) represents the amount of left atrium (LA) structural and functional remodeling. METHODS: The study population consisted of 104 consecutive patients who underwent catheter ablation (CA) for AF (paroxysmal atrial fibrillation [PAF], 82; persistent atrial fibrillation [PeAF], 22). IAS thickness and left atrium volume (LAV) using TTE, and LA voltage (LAVOL) using 3-dimensional electroanatomical mapping system were assessed during sinus rhythm. RESULTS: IAS thickness was significantly correlated with maximal LAV (LAVmax) (r = 0.288, p = 0.003), mean LAVOL (r = -0.537, p or = 2) compared to other groups according to CHA2DS2-VASc score (p = 0.019). During a follow-up of 19.6 months, 23 subjects (22.1%; PAF, 17; PeAF, 6) had recurrence of arrhythmia. Univariate analysis showed that LAVmax, minimal LAV, mean LAVOL, LVEFtotal, LVEFactive, and IAS thickness were associated with recurrence of arrhythmia. However, on multivariate analysis, only mean LAVOL and LAEFactive were independent risk factors for recurrence. CONCLUSIONS: Although IAS thickness showed significant correlations with parameters for LA structural and functional remodeling, this parameter alone could not independently predict recurrence of arrhythmia after CA for AF.

How to Achieve Complete and Permanent Pulmonary Vein Isolation without Complications

The efficacy and safety of catheter ablation for the management of atrial fibrillation (AF) has been improved in recent years. Radiofrequency (RF) catheter ablation for maintaining sinus rhythm is superior to the current antiarrhythmic drug therapy in selected patients. Pulmonary vein isolation (PVI) is the cornerstone of various catheter ablation strategies. It is well recognized that pulmonary vein (PV) antrum contributes to the AF initiation and/or perpetuation. Since PV stenosis is a complication of ablation within a PV, the ablation site for PVI has shifted to the junction between the left atrium and the PV rather than the ostium of the PV. However, PV reconnection after ablation is the major cause of recurrence of AF. The recovery of PV conduction could be caused by anatomical variations such as the failure to produce complete transmural lesion or gaps at the ablation line due to the transient electrophysiologic effects from the RF ablation. In this review, we discussed several factors to be considered for the achievement of the best PVI, including clinical aspects and technical aspects.

Electroanatomical Characteristics of Idiopathic Left Ventricular Tachycardia and Optimal Ablation Target during Sinus Rhythm: Significance of Preferential Conduction through Purkinje Fibers

PURPOSE: We hypothesized that Purkinje potential and their preferential conduction to the left ventricle (LV) posteroseptum during sinus rhythm (SR) are part of reentrant circuits of idiopathic left ventricular tachycardia (ILVT) and reentry anchors to papillary muscle. MATERIALS AND METHODS: In 14 patients with ILVT (11 men, mean age 31.5+/-11.1 years), we compared Purkinje potential and preferential conduction during SR with VT by non-contact mapping (NCM). If clear Purkinje potential(SR) was observed in the LV posteroseptum and the earliest activation site (EA) of preferential conduction at SR (EASR) was well matched with that of VT (EAVT), EASR was targeted for radiofrequency catheter ablation (RFCA). Also, the anatomical locations of successful ablation sites were evaluated by echocardiography in five additional patients. RESULTS: 1) All induced VTs exhibited clear Purkinje potential(VT) and preferential conduction in the LV posteroseptum. The Purkinje potential(VT) and EAVT was within 5.8+/-8.2 mm of EASR. However, the breakout sites of VT were separated by 30.2+/-12.6 mm from EAVT to the apical side. 2) Purkinje potential(SR) demonstrated a reversed polarity to Purkinje potential(VT), and the interval of Purkinje potential(SR)-QRS was longer than the interval of Purkinje potential(VT)-QRS (p<0.02) 3) RFCA targeting EASR eliminated VT in all patients without recurrence within 23.3+/-7.5 months, and the successful ablation site was discovered at the base of papillary muscle in the five additional (100%) patients. CONCLUSION: NCM-guided localization of EASR with Purkinje potential(SR) matches well with EAVT with Purkinje potential(VT) and provides an effective target for RFCA, potentially at the base of papillary muscle in patients with ILVT.

Pericardial Approach for Cardiac Therapies: Old Practice With New Ideas

Treatment of cardiac disease via the epicardium fell under the domain of cardiac surgery due to the need for an open thoracotomy. Since an open thoracotomy is invasive in nature and has the potential for complications, a minimally invasive and percutaneous approach would be more attractive for suitable patients. The recent success of epicardial ablation of refractory arrhythmia via the percutaneous pericardial approach has increased the potential for delivery of epicardial therapies. Epicardial ablation has increased the success and safety since anti-coagulation and transseptal catheterization for left atrial arrhythmias is not required. The pericardial space has also been used to deliver therapy for several cardiac diseases. There are reports on successful delivery of drugs and their efficacy. Even though there was a wide range of efficacies reported in those studies, the reported complication rates are strikingly low, which suggests that direct delivery of drugs to the epicardium via the pericardial space is safe. Furthermore, recent animal studies have supported the feasibility of epicardial delivery of biological agents, including genes, cells, and even genetically engineered tissue for therapeutic purposes. In conclusion, percutaneous pericardial cannulation of closed pericardial space can play a significant role in providing non-surgical therapy for cardiovascular diseases. However, it requires skills and operator experiences. Therefore, there is need to further develop new tools, safer techniques, and effective procedure environment before generalizing this procedure.

Unilateral Undercutting Laminoplasty in the Treatment of Lumbar Spinal Stenosis: Comparison with Conventional Bilateral Partial Laminectomy / 대한척추외과학회지

STUDY DESIGN: A retrospective study OBJECTIVES: Contralateral undercutting laminoplasty via a unilateral laminotomy has been performed instead of bilateral partial laminectomy in lumbar spinal stenosis. This study compared the radiographic and clinical results of undercutting laminoplasty with bilateral partial laminectomy. SUMMARY OF LITERATURE REVIEW: Less invasive surgery has become attractive for minimizing soft tissue injury and reducing the recovery time. MATERIALS AND METHODS: Twenty five patients, who underwent decompressive surgery for lumbar spinal stenosis and were followed-up more than one year, were enrolled in this study. Unilateral undercutting laminoplasty and bilateral partial laminectomy was performed in 13 and 12 cases, respectively. The blood loss was compared and the presence of instability was observed. The increase in dural cross sectional area was measured in the preoperative and postoperative CT scans. In the clinical assessment, the Oswestry disability index (ODI) and visual analogue scale (VAS) to pain was used. RESULTS: The average blood loss per segment was 273 ml and 436 ml in the laminoplasty and laminectomy group. There was no case of instability after surgery but there was a significant difference in the increase in dural cross sectional area between the two groups: 109.7 mm2 and 78.6 mm2 in the laminoplasty and laminectomy group, respectively. The preoperative and final change in the ODI and VAS scores was similar between the two groups. CONCLUSIONS: Unilateral undercutting laminoplasty is a minimally invasive procedure with less blood loss than the conventional technique and is equally effective.

Human Mesenchymal Stem Cell Transplantation Induces Sympathetic Nerve Sprouting and Reduces the Gap Junction With Potential Proarrhythmias in Dogs

BACKGROUND AND OBJECTIVES: Although human mesenchymal stem cell (hMSC) transplantation has been known to improve ventricular function, the potential proarrhythmic effects have not yet been studied. MATERIALS AND METHODS: We monitored the heart rhythm of 6 dogs for 4 weeks after transplantation of hMSC (1x10(7), epicardial injection) (hMSC group) and in 5 Sham dogs after the injection of the vehicle alone. Cardiac sympathetic nerve sprouting {nerve growth factor (NGF)-beta; tyrosine hydroxylase (TH)} and gap junction expression {connexin (Cx) 43} were evaluated in 10 dogs (5 hMSC and 5 Sham) that survived longer than 4 weeks. RESULTS: The hMSC group expressed higher levels of NGF-beta messenger ribonucleic acid (mRNA) (56.0+/-66.8 fold; p<0.01) with TH+ sympathetic nerves (0.51+/-0.40 vs. 0.15+/-0.13% area; p<0.03) than the Sham control. In contrast, the hMSC group expressed lower levels of Cx43 mRNA (0.59+/-0.29 fold, p<0.001) and Cx43+ (1.64+/-1.79 vs. 2.12+/-1.07% area, p<0.001) than the Sham control. The incidences of ventricular fibrillation were 33.3% and 0% in the hMSC group and Sham control, respectively. One of the dogs with ventricular fibrillation (VF) in the hMSC group died suddenly. CONCLUSION: hMSC transplantation may be proarrhythmic since NGF-beta expression increased with cardiac sympathetic hyperinnervation and the expression of Cx43 and the gap junction decreased.

Adjustable hexagonal external fixator / 대한정형외과학회잡지

No abstract available.

Congenital Coxa Vara, Acquired Coxa Vara and Valga / 대한정형외과학회잡지

In 5 cases of congenital coxa vara, 7 cases of acquired coxa vara and 4 hips in 3 cases of acquired coxa valga, we performed subtrochanteric osteotomies at Department of Orthopedic Surgery, SeoulNational University Hospital, from December 1980 to February 1984. At a relatively short interim follow-up, following observations were made on the correction of the femoral neck-shaft angle deformities. l. In the congenital coxa vara group, at an average follow-up of 1 year and 3 months, 97.9% of the correction obtained by osteotomy was maintained, based on the roentgenographic measurements of femoral neck-shaft angle. In the acquired coxa vara group, at an average follow-up of 1 year and 2 months, 93.3 % of the correction obtained by osteotomy was maintained. In the acquired coxa valga group, at an average follow-up of 1 year and 5 months, 92.9% of the correction obtained by osteotomy was maintained. 2. At final follow-up, leg length gain averaged 1.26cm in the congenital coxa vara group and 2.23cm in the acquired coxa vara group. An average 0.70cm decrease in leg length was noted in the acquired coxa valga group. 3. Trendelenburg sign, which was positive in all the cases of the congenital and acquired coxa vara group, reverted to negative in all. 4. Slight overcorrection in cases of the acquired coxa vara and undercorrection in cases of the acquired coxa valga, is recommended for later loss of surgically corrected femoral neck-shaft angle. In the congenital coxa vara, it appeared that loss of correction was relatively minor.

Comparison of the Ordinary , Vascularized Bone Grafting and Electrical Stimulation in the Treatment of the Congenital Pseudarthrosis of Tibia / 대한정형외과학회잡지

No abstract available in English.

Effect of the Orthopedic Immobilization on Ca, P and Blood Pressure / 대한정형외과학회잡지

No abstract available in English.

Leg Length Equalization by Correction of Pelvic Obliquity and Acetabular Dysplasia / 대한정형외과학회잡지

Fixed pelvic obliquity refers to a composite deformity induced by contractures both above and below the pelvis and the elements of this deformity are frequently interrelated during the period of growth. From the functional standpoint, leg length discrepancy is caused by deformities of the pelvis and lower extremities, such as pelvic obliquity and acetabular dysplasia, as well as by inequality of true limb bone length, and these deformities either aggravate or compensate functional discrepancy. During fhe fourteen years period, from August 1968 to August 1982, at the Department of Orthopaedic Surgery, Seoul National University Hospital, we treated 35 cases of fixed pelvic obliquity and acetabular dysplasia associated with true or functional limb length discrepancy by means of lumbodorsal fasciotomy or pelvic osteotomies such as Salters innominate osteotomy or Steels triple osteotomy, combined, if necessary, with contralateral abductor fasciotomy to gain functional limb length as well as to improve posture and balance. In many cases of residual poliomyelitis, epiphysiodesis was also performed when indicated. These cases were reviewed and following observations were made: 1. Of the 35 cases, residual poliomyelitis with 29 cases (83%) was by far the main cause of leg length discrepancy. Cerebral palsy (2cases), Legg-Perthes disease (2 cases), and fibrous ankylosis secondary to septic hip (2 cases) comprised the remainder. 2. The male-to-female ratio was about equal, being 17 to 18. 3. The average age at the time of operation was 17.9 years, the youngest being 7 years and the oldest being 30 years. The average age at the time of current follow-up was 18.8 years. 67% of those followed was skeletally mature. 4. An average of 1.35cm of bone length was gained radiographically by pelvic osteotomies. Steels triple osteotomy was more effective in gain than Salters innominate osteotomy. 5. An average of 2.43cm of functional length when standing was gained radiographically by lumbodorsal fasciotomy alone. 6. An average of 2.61cm of functional length when standing was gained radiographically by lumbodorsal fasciotomy and combined contralateral Soutters or Campbells fasciotomy. 7. An average of 3.57cm of functional length when standing was gained radiographically by lumbodorsal fasciotomy and combined ipsilateral Steel's triple osteotomy. 8. An average of 1.73cm of functional lengthening when standing was corrected radiographically by ipsilateral Soutter's fasciotomy. 9. When lumbodorsal fasciotomy and Steel's triple osteotomy were combined with contralateral Soutter's or Campbell's fasciotomy, the average radiographic gain in standing length was 3.77cm. 10. Leg length discrepancy in terms of true bone length is conventionally corrected either by epiphysiodesis or bone shortening on the longer limb, or by bone lengthening on the shorter limb. We believe that when leg length discrepancy is associated with fixed pelvic obliquity, frequently aggravating the disability functionally, lumbodorsal fasciotomy and/or pelvic osteotomies on the shorter side and, combined if necessary, Soutters or Campbells fasciotomy on the longer side, can, in many instances, successfully correct or reduce functional limb discrepancy and improve balance, posture and function. Any residual discrepancy, true or functional, may then be corrected by conventional methods.

Clinical Application of Direct Current Stimulation in the Treatment of Infected Non-Unions / 대한정형외과학회잡지

In the treatment of an infected ununited fractures of a long bone, it often is difficult to achieve union and eradicate the infection. Over the past two decades, the electrical behaviour of bone has been studied with increasing interest and several reports reveal that electricity can stimulate osteogenesis. We have experienced 11 cases of infected non-union who were treated by immobilization plus direct current stimulation from January, 1980 to July, 1982. In all cases satisfactorv union occurred within averaging 8.1 months. The results obtained are as follows: 1. The direct current stimulation has revealed to be effective with antibiotics and some kinds of immobilization in treatment of infected non union. 2. If bone graft is combined with electrical stimulation, time from beginning of electrical treatment to union is shortened, as compared with cases of electrical stimulation alone. 3. The electrical stimulation is preferable to other surgeries in treatment of infected non-union due to its effectiveness and simplicity. 4. It is considered treatment of chronic osteomyelitis with silver anode is not due to electrically generated silver ion but its electricity per se. 5. To prevent refracture and assure complete healing, continued immobilization such as cast brace, walking cast, or conventional brace is necessary after electrical stimulation for the time being.

Slipped Femoral Capital Epiphysis: Report of Two Cases / 대한정형외과학회잡지

Slipped femoral capital epiphysis is a rare entity in Korea and only three cases have been reported so far1,2,3). One of our cases was a unilateral mild chronic slip in a 14 year old boy with Frohlich body type. It was treated by gentle closed reduction followed by knowles' pin fixation. The other case, a 20 year old female, presented chondrolysis of the left hip. Scrutinization of roentgenograms revealed typical features of an unrecognized slipped femoral capital epiphysis. It was treated by Wagner resurfacing replacement arthroplasty.