Hemodynamic Effects of Simulated Ventricular Tachycardia and Supraventricular Tachycardia in Dogs

BACKGROUND AND OBJECTIVES: Tachycardias have various clinical features according to the heart rate, the left ventricular systolic function, the site of origin and the mechanisms of the tachycardias. The primary purpose of this study was to evaluate the role of the origin site and cycle length on the ventricular tachycardia (VT) hemodynamics. Our secondary purpose was to explore the possible hemodynamic differences between the two common supraventricular tachycardias (SVT). MATERIALS AND METHODS: VT was simulated in 18 dogs that had there chests opened by using ventricular pacing (VP) at 3 different sites: the left ventricular apex (LVA), the right ventricular outflow tract (RVOT), and the right ventricular apex (RVA). The mean arterial pressure (MAP), the mean left atrial pressure (MLAP) and the mean pulmonary artery pressure (MPAP) were monitored during VP. To simulate SVT, the right atrial appendage and the right ventricular basal septum were stimulated at different cycle lengths with different ventriculo-atrial (VA) time intervals in another 11 dogs that had their chests opened. The arterial pressure, the pulmonary capillary wedge pressure and the cardiac output was observed during simulated atrial tachycardia (Group I), AVRT (Group II) and AVNRT (Group III). RESULTS: In the VT study, at the same pacing site as of the VP, the MAP was significantly decreased with the VP, and the deltaMAP was significantly increased as the length of the VP cycle shortened. At the same pacing cycle length of the VP, the deltaMAP was significantly greater at the RVA or RVOT than at the LVA. At the same pacing site of the VP, the MLAP and the deltaMLAP were significantly increased as the VP cycle length shortened. In the SVT study, MAP was highest in Group I and it decreased with the decreasing VA interval, but this was not significant. The systolic arterial pressure was significantly higher in Group II than in Group III. The CO was higher in Group I than in the other two groups, with a significant difference, and the CO decreased with shortening of the VA interval, but this was not significant. CONCLUSION: The above results suggest that in addition to the tachycardia rate, the origin site could be an independent factor of the VT hemodynamics. Episodes of AVRT and AVNRT may have a different hemodynamic impact that probably originates from the different timing of the ventricular and atrial contraction.

The Effects of Perichondrium on Cartilage Tissue Engineering

Despite many successful reports of cartilage tissue engineering, actual clinical application has not been performed due to several critical problems in this new pioneering field of tissue restoration. The problems of progressive absorption and distortion of engineered cartilage are one of those problems preventing clinical application. Distortion of tissue engineered cartilaginous tissue may be induced by internal and external factors such as gradual absorption of biomaterials, inappropriate production of matrix and contractile force in the process of wound healing. Naturally, cartilage tissue is completely enveloped by a layer of connective tissue, the perichondrium, and it continually provides chondrocytes and cartilage matrix. The author's speculation is that we may need the perichondrial layer in cartilage tissue engineering. Perichondrium may be another important element of cartilage tissue engineering. After harvesting a cartilaginous tissue from ear of 12 rabbits, we cultured rabbit ear chondrocytes. Polylactide-co-polyglycolide(PLGA) and fibrin glue were used as chondrogenic scaffold to compare the effect of different biomaterials in cartilage tissue engineering. Tissue engineered construct (TEC) were incubated for 4 weeks and autogenous implantation was performed. During the implantation procedure, some of the TEC were wrapped with perichondrial graft to find out the effect of perichondrium on cartilage tissue engineering. Four weeks after implantation, gross and histologic examinations were performed.With this experiment, we could obtain perichondrium covered cartilage tissue similar to natural cartilage. It was observed that there was less distortion or absorption in TEC with perichondrial graft than TEC without perichondrial graft. As far as the biomaterials are concerned, PLGA group showed less distortion or absorption than fibrin glue group after 4 weeks of in vivo implantation. In conclusion, we could find out the positive effect of perichondrium in cartilage tissue engineering with simple perichondrial graft on TEC. Also, less absorbable biomaterial such as PLGA, seems to provide more reliable results than fibrin glue which is quite easily degraded.

A Clinical Study of Subcutaneous Mastectomy with Immediate Reconstruction as Treatment for Early Breast Carcinoma

Immediate breast reconstruction following subcutaneous mastectomy for early breast carcinoma remains controversial. According to the recent reports however, it has become a recommendable option for the care of breast cancer patients whether it involves prosthetic implantation or myocutaneous flap procedure. Many technical problems have been introduced to reconstruct the breast; choice of incision, volume estimation, mobility of skin flap including nipple-areolar complex, irregularity of flap thickness, location of inframammary fold and choice of implant type. We have experienced 43 cases of immediate breast reconstruction by using tissue expander, breast implant and transverse rectus abdominis musculocutaneous(TRAM) flap after subcutaneous mastectomy. We believe that immediate breast reconstruction with autogenous tissue is very satisfactory in aesthetic, economic aspects, whereas reconstruction with prosthetic implantation is a convenient method but prone to unsatisfactory long-term results.

Electrocardiographic Predictors for Successful Radiofrequency Catheter Ablation in Patients with Idiopathic Ventricular Tachycardia showing Left Bundle Branch Block and Inferior Axis

BACKGROUND: Although radiofrequency catheter ablation (RFCA) is useful in the treatment of idiopathic ventricular tachycardia, especially right ventricular outflow tract tachycardia (RVOTT), some tachycardias remain resistant despite several attempts. This study was focused to search of electrocardiographic characteristics suggestive of successful radiofrequency ablation of idiopathic ventricular tahycardia showing LBBB and inferior axis. MATERIALS AND METHODS: The study subjects were 19 patients (mean age 4415, male 5, female 14) those we tried RFCA under the diagnosis of RVOTVT. The study subjects were grouped into success group (N=14) and failed group (N=5). We analyzed the morphologic characteristics of QRS complex during ventricular tachycardias or ventricular premature beats in both groups. RESULTS: Acute success was obtained in 14 of 19 patients. For RFCA of RVOTT, pace mapping and/or activation mapping were used to select an ablation site as described previously(1). Activation mapping was possible only for 5 patients. All patients except one patient of success group showed inferior axis of QRS during VT. We didn't find significant difference in QRS axis, QRS morphologies in lead 1 and aVL, and QRS width in lead II and V2 between success (N=14) and failed group (N=5). However, in analysis of morphologic comparison of precordial leads, 12 out of 14 patients in success group showed initial r wave in V1 (p=0.017) and 11 patients had precordial transition >V3 (p=0.038). Whereas, in failed group, 4 patients had precordial transition V3 and only one patient showed precordial transition >V3. Initial r of V1 was seen in one patient and remaining 4 patients showed QS pattern in V1. CONCLUSION: Analysis of QRS morphology in V1 and precordial transition site may identify patients with high and low success rate during RFCA of idiopathic RVOTT

A Case of Early Developed Left Ventricular Free Wall Rupture Followed by Acute Inferior Myocardial Infarction

Myocardial free wall rupture is the most serious complication of acute myocardial infarction. Although it is not uncommon, it is difficult to treat successfully. We report a case of acute inferior myocardial infarction complicated with left ventricular free wall rupture that occurred 8 hours after onset of chest pain. In this case, progression of mild pericardial effusion to cardiac tamponade was monitored by transhtoracic echocardiography. Pericardiocentesis and draninage failed to treat cardiac tamponade, and surgical repair was performed successfully. The patient discharged uneventfully on 28th day and followed regularly at the outpatient department.

A Case of Early Gastric Carcinoma Combined with Hypereosinophilic Multiple Liver Abscesses / 대한소화기내시경학회지

Eosinophilia is defined as the presence of more than 500 eosinophil/mL of blood and is common in the clinical condition such as parasite infestation, drug, allergy, hypereosinophilic syndrome, and malignant diseases. Determining the cause of eosinophilia may be one of the most frustrating endeavors in clinical medicine. Hepatic infiltration of eosinophils and microabscess formation are observed in many disorders. Gastric cancer and intestinal malignancies show frequent liver metastasis and blood eosinophilia. Several cases of an early gastric carcinoma (EGC) with metastasis of the liver have been reported. When multiple intrahepatic lesions of suspicious malignancy appear in radiologic study, clinicians must differentiate malignancy from benign diseases. A case is herein reported of a 56- year-old male patient with synchronously developed, multiple low density hepatic lesions with early gastric carcinoma. He was managed with systemic chemotherapy at another hospital, because he was diagnosed with distant metastasis of early gastric carcinoma. Upon operating these lesions were proved to be EGC combined with hypereosinophilic multiple liver abscesses. This case is herein reported with a review of relevant literatures.

A Dieulafoy-like Lesion of the Rectum as a Cause of Massive Lower G-I Bleeding / 대한소화기내시경학회지

Dieulafoy's lesion is an exposed submucosal artery associated with a minute mucosal defect in the stomach, and it is a rare cause of profuse, but intermittent gastrointestinal bleeding. Less commonly, similar lesions have been identified in the duodenum, jejunum, colon, and in rare cases, the rectum. Only four cases of rectal Dieulafoy's lesion have been reported in English Medical literature: one case involved a child, two in otherwise healthy young men, and one in on elderly man. In this report, two elderly men are described, who suffered an massive hematochezia from a small rectal mucosal defect with a visible vessel. Control of the bleeding was successfully achieved with on endoscopic sclerotherapy or hemoclipping. The fact that rectal Dieulafoy disease is one of the causes of massive hematochezia should serve as a reminder in future cases, especially involving alcoholics and elderly men.

Polypoid Stenosing Papillitis of the Ampulla of Vater / 대한소화기내시경학회지

Stenosing papillitis is a descriptive term for an anatomic deformity of the Ampulla of Vater due to chronic inflammation and fibrosis, which is characterized by narrowing of the lower end of the bile and pancreatic duct, and by clinical symptoms resembling pancreticobiliary disease. Duodenoscopic finding of "stenosing papillitis" usually shows edema, erythema, and laceration on Ampulla of Vater, but endoscopic finding such as polypoid mass is rare. We recently experienced one case of polypoid stenosing papillitis and report with a review of relevant literatures A 54-year-old man was admitted to our hospital because of chronic right upper abdominal pain for 2 years. Duodenoscopy re-vealed a polypoid mass with erythemaous color change on Ampulla of Vater, which was endoscopically resected by using a polypectomy snare, and pathologic examination showed chronic inflammation and fibrosis.

Clinical Charateristics of Pyrethroids Poisoning / 대한내과학회지

OBJECTIVES: Pyrethroids are commonly used pesticides, and acute human poisoning by these insecticides is common in Korea. It has a high affinity to the sodium channel on cell membranes causing blockage, which results in neurotoxicity, hyperexcitation, and death. The purpose of this study was to analyze the clinical characteristics of acute pyrethroid poisoning. METHODS: To evaluate the clinical characteristics (age, sex, causative agents, cause of ingestion, severity of poisoning and its clinical feature, prognosis, complication and results of the treatment), we analyzed the clinical reports of 30 patients with pyrethroid poisoning who were admitted to Soonchunhyang Chunan hospital from January 1992 to July 1997. RESULTS: 1) 18 out of 30 patients with pyrethroid poisoning were male and the largest age group was above 60 years old. 2) The most common cause of ingestion was suicide, in 24 cases (80%). 3) There were 7 classes of causative agents of poisoning and all of these were classified into 2 grades according to the degree of WHO toxicity. Fenvlaerate and cypermethrin were the most common agents. 4) The degree of severity was classified into three groups - mild, moderate and life -threatened. Of these groups, mild poisonig was the most common. There was no significant difference in the age, type of pyrethoid and interval between pyrethroid ingestion and arriving at the emergency room between the three groups. However, the amount of ingestion was significantly higher in the life-threatened group. 5) The most common symptom of the patients was vomiting, in 19 patients. The classification were of three types (5 type I, 11 type II and 1 intermediate type) according to clinical characteristics. 6) There is no specific antidote, therefore therapy is generally supportive. There were three deaths, and the cause of death was respiratory failure. 7) The most common complication was pneumonia, in 3 cases (10%), which occured in almost all patients in the life-threatened group. CONCLUSIONS: The most common age group of poisoing was over 60 years old, and suicide was the most common cause of ingestion. Treatment is supportive, and most causal exposures require only decontamination. There were three deaths, and the cause of death was respiratory failure in each case. The most common complication was pneumonia.