Usefulness of a "Push Technique" for Atrial Lead Implantation

BACKGROUND AND OBJECTIVES: Dual-chamber pacing is commonly used as a pacing mode maintaining at-rioventricular synchrony. However, traditional technique for atrial J lead implantation is relatively time-consuming and not easy to get optimal sites for both atrial and ventricular leads, especially for less-experienced operators. We developed a new "push technique" for atrial J lead implantation. MATERIALS AND METHOD: This study included sixty-two consecutive patients (26 males 36 females, 55+/-10 years, 56 patients received DDD and 6 received AAI pacemakers) from Jan. 1992 through Dec. 1996. Atrial J leads were implanted using a "push technique", that is, simply advancing a straightened lead while holding the stylet in the pacing lead at the junction of the superior vena cava and the right atrium. We evaluated the early and long-term result of atrial J lead implantation by the "push technique". RESULTS: 1) Atrial leads were successfully inserted by the first or second trial of the "push technique" in the 62 patients (100%). The sensed P wave amplitude was 3.1+/-1.0 mV, pacing threshold 0.6+/-0.2 V at the pulse width of 0.5 ms, impedance 547.4+/-118.5 ohms at 5 V. 2) During follow-up of 28.1+/-15.7 months, significant changes in the pacing parameters and the dislodgement of atrial leads were not seen. CONCLUSION: The early and long-term result of atrial J lead implantation by the "push technique" was excellent. This "push technique" can be used as an easy alternative technique for atrial J lead implantation.

Early Outcome of Long Coronary Stent Implantation

BACKGROUND: Percutaneous transluminal coronary angioplasty(PTCA) for long coronary lesion is known to be associated with low success rate,suboptimal outcome,high complication and restenosis rates. Here we report the early clinical and angiographic results of long coronary stent implantations for long coronary lesions. METHOD: We analyzed the clinical,angiographic features and early results after stent implantations in 46 patients who were implanted long coronary stent(> or =20mm in length)among 174 stented patients at Chonnam University Hospital from Jan.through Nov.1996. RESULT: 1) Age was 59+/-7(35-78) years,and sex ratio was 2.5:1(33 male:13 female). clinical diagnosis was as follows; 24 patients with unstable angina, 21 with acute myocardial infarction, 1 with stable angina and 6 with old myocardial infarction. Left ventricular ejection fraction by left venriculogram was 58+/-10(27-87)%. 2) Involved numbers of vessel were single in 27 patients, two in 14 patients, and three in 5 patients. Target stented coronary arteries were 28 left anterior descending arteries, 17 rigtt coronory arteries, and 1 left circumflex artery. Morphologic types of target lesions were type C in 26 patients, type B2 in 20, and diameter stenosis(DS) was 76+/-13%, minimal luminal diameter(MLD) 1.0+/-0.3mm, length 21+/-6(10-38)mm. Indications for stent were 28 denovo lesions, 10 restenoses, 5 suboptimal PTCAs and 3 bailout procedures. Twenty six Microstents 2, 15 Wallstents, 4 Freedom stents, and 1 Wictor stent were used. Stent diameter was 3.2+/-0.3(2.5-5.0)mm and length 30+/-3(20-49)mm, stent diameter/reference diameter(RD) ratio 1.0+/-0.1, and stent minus lesion length 9.0+/-3.7mm. 3) Stents were deployed successfully in all 46 patients. No procedure-related death, myocardial infarction, emergency bypass surgery, and laboratory evidences of acute or subacute stent thrombosis were observed. 4) DS was decreased to 3.5+/-7.5%, MLD was increased to 3.2+/-0.3mm(p<0.0001, respectively). Acute gain was 2.2+/-0.4mm(71.8+/-15.6%,p<0.0001). CONCLUSION: We observed high success rate without major complications in long stent implantations for long coronary arterial lesions. Long-term follow-up should be required to prove long coronary stent as a better treatment modality to reduce acute complications and late restenosis.

Hibernation Myocardium in Chronic Coronary Artery Disease

BACKGROUND: Reversibly dysfunctional myocardium caused by chronic reduction of coronary perfusion was named as hibernating myocardium. The clinical characteristics, however, was not well studied. METHOD: To observed the effects of revascularization on regional wall motion(RWM) abnormalities in patients with chronic ischemic heart disease, letf ventriculogram and dipyridamole stress Tl reinjection scan with reinjection imagine were done in 60 patients with angina or old myocardial infarction before and after PTCA. Subjects were divided into two groups, group A(21 patients, improved RWM after PTCA) and group B(39 patients, no change or aggravated RWM after PTCA). RESULTS: There were no significant differences in age and sex distribution between two group. Single vessel disease was more prevalent in group A (7/21, 33.3%) than in group B(1/39, 2.6%, p<0.05), and old myocardial infarction was more prevalent in group B(24/39, 61.5%) compared to group A(7/21, 33.3%, p<0.05). Reversible perfusion defects on Tl scan were found in 19 patients, 15 of whom(78.9%) showed improved RWM after PTCA. CONCLUSION: Hibernating myocardium was more prevalent in single vessel disease and angina patients. Sensitivity of Tl reinjection scan for detection of viable myocardium was 78.9%.

Successful Coronary Stent Implantation without Systemic Heparin Therapy: Use of Local Heparin Delivery

BACKGROUND: Acute or subacute stent thrombosis, bleeding complications and restenosis remain major clinical concerns in coronary stenting despite high pressure inflation and intravascular ultrasound guidance. A new strategy of local heparin delivery may maintain sustained local concentration and limit systemic complications. To observe the feasibility and efficacy of local heparin delivery in stenting, local heparin deliveries were performed in stented patients. METHOD: Heparin was delivered(5,000 Units, 1.0ml/min over 10 min) using the Dispatch Catheter, after predilation of target lesons in 10 patients(4 unstable angina, 6 acute myocardial infarction, mean age 52+/-7 yr) in the left anterior descending artery without systemic heparin loading. After local heparin delivery. Palmaz-Schatz stents were placed using standard methods. APTT and CK were checked at 1hr, 3hrs and 24 hrs after local heparin delivery and stenting. Follow-up coronary angiograms were done at 48 hrs and 6 months after stenting. RESULTS: All patients had no ischemic symptoms or ECG changes during and after local heparin delivery. All APTT and CK values were unchanged at 3 hrs and 24 hrs after local heparin delivery and stenting. Follow-up quantitative coronary angiograms at 48 hrs and 6 months showed all stents patent, with TIMI III distal flow, and without intra-stent thrombus(%diameter stenosis : 79.4+/-4.2% before predilation, 32.9+/-7.7% after predilation, 32.4+/-13.1% after local delivery, 14.2+/-2.3% immediately after stenting, 13.9+/-2.5% at 48 hrs and 21.7+/-8.8% at 6 months after stenting). CONCLUSION: Intracoronary stenting may be performed safely and effectively without systemic heparin therapy by using local heparin prior to stent implantation. Long-term stent patency and lack of coronary events appear favorable.

Postoperative Effusive Constrictive Pericarditis in Ventricular Septal Defect Repair

Effusive constrictive pericarditis after open heart surgery is a rare complication occuring in 0.2% to 0.3%. Presenting symptoms after surgery are associated with right heart failure and an elevated jugular venous pressure is most common abnormal physical sign. Predisposing factors include hemorrhage, perioperative pericardial injury or inflammation, presence of postpericardiotomy syndrome and open pericardium. Early diagnosis is important because(1) if it is unrecognized, the patient may deteriorate clinically, and(2) if surgery is delayed, the patient may have an increased risk of operative death. Hereby we report a case of effusive constrictive pericarditis after ventricular septal defect repair, in which constriction physiology was suggested by Doppler echocardiography after pericardiostomy.

Clinical Effects of Simvastatin in Patients with Hypercholesterolemia

BACKGROUND: To evaluate the clinical efficacy of Simvastatin, a HMG-CoA reductase inhibitor, We ibsweved the changes of clinical characteristics and lipid profiles after Simvastatin administration in patients with hypercholesterolemia. METHODS AND RESULTS: Simvastatin 10mg was given once daily for 12 weeks in 35 patients (60+/-6.0 years : 14 male, 21 female) with hypercholesterolemia. High density lipoprotein-cholesterol (HDL-C) was increased from 38+-10 to 45+-9mg/dl(p<0.05). Simvastatin significantly decreased total cholesterol(TC) from 235+-15 to 181+-21mg/dl(23.0%), low-density lipoprotein cholesterol (LDL-C) from 164+-19 to 104+-18mg/dl(36.5%), TC/HDL-C from 7.0+-2.0 to 4.4+-1.1, LDL-C/HDL-C from 4.9+-1.7 to 2.5+-0.8(p<0.01 respectively). Apo B was decreased by 31%(119+-19 to 87+-15mg/dl), apo B/A1 ratio was decreased by 41%(1.2+-0.2 to 0.7+-0.2) amd lipoprotein(a) edcreased by 12%(33+-22 to 29+-17), while apo A1 was increased by 25%(104+-18 to 130+-23mg/dl, p<0.01 respectively). No patients complained of chest pain, but two had skin rashes. Creatine kinase and creatinine were not changed in all patients. CONCLUSIONS: Somvastatin is an effective and well tolerated cholesterol lowering agent in patients with hypercholesterolemia.