The Therapeutic Effects of Adenosine Triphosphate(ATP) on Paroxysmal Supraventricular Tachycardia : Based on Analysis of Electrocardiograms

BACKGROUND: ATP is an endogenous nucleotide that has potential electrophysiologic effects. The effects of ATP are largely mediated by its metabolite, adenosine, which acts on A1 receptor in myocardium and mediates negative chronotropic, dromotropic, and inotropic action. The purpose of this study is to determine the efficacy and side effects of ATP in the treatment of paroxymal supraventricular tachycardia(PSVT). METHODS: We analyzed 28 episodes of PSVT in 22 patients(7 men and 15 women, mean age 467.+/-15.9 years), who were selected from Jan. 1992 to Sep. 1992. After measuring blood pressure and obtaining a standard 12 leads electrocardiogram(ECG), we rapidly injected ATP intravenously with dose of 10, 15, 20mg every 1 min, until the termination of PSVT. We recorded peri-injection and post-injection ECG, interval between ATP injection and the termination of PSVT, the pause after termination, side effects and blood pressure immediately after termination. RESULTS: 1) Among 28 episodes of PSVE, 26 episodes(92.9%) were terminated successfully : 21 episodes(75%) with 10mg, 3 episodes(10.7%) with 15mg, and 2 episodes(7.2%) with 20mg of ATP. 2 episodes(7.1%) were failed. 2) The PSVT ended 21.2+/-9.2 seconds after injection of ATP(maximally 40 seconds). 3) The mechanisms of PSVT in 9 patients were atrioventricular nodal reentrant tachycardia(AVNRT), those in 13 patients were atrioventricular reciprocating tachycardia(AVRT). 4) The side effects of ATP included 13 episodes of chest pain(46.6%), 9 episodes of ventricular arrhythmia(32.1%), 6 episodes of sinus pause(21.4%) and 5 episodes of atrioventricular block(17.9%), and these were uncomplicated and short-lasting. CONCLUSION: The ARP is a safe and effective therapy for the conversion of PSVT to sinus rhythm and perhaps more importantly, a valuable new approach to the management and diagnosis of wide-complex tachycardia.

Protection of Myocardial Ischemia during PTCA with the Autoperfusion Balloon Catheter

BACKGROUND: An autopersion balloon catheter(ABC) was developed to allow passive myocardial perfusion during balloon inflation, through a central and multiple side hole in the shaft proximal and distal to the balloon. The ABC affords greater safety in performing PTCA of high risk stenosis involving the near ostium of the right coronary, the proximal left anterior descending(LAD) just proximal to the left circumflex artery and left main equivalent coronary arteries. METHODS AND RESULTS: In case 1, a seventy five percent right coronary ostial stenosis was reduced to less than 10 percent residual narrowing after PTCA with the ABC. In case 2, a seventy five percent proximal LAD(just proximal to left cirumflex artery) stenosis was reduced to less than 20 percent residual narrowing after PTCA with the ABC. In case 3, coronary angiogram demonstrated a 40 percent stenosis in the distal left main coronary artery as well as 80 percent stenosis in the proximal LAD.PTCA with the ABC was performed without significant hemodynamic compromise, achieving a less than 20 percent and 40 percent residual stenosis of the distal left main and proximal LAD respectively. CONCLUSIONS: 3 patients who would have required CABG had PTCA using the ABC.This ABC significatly reduces ischemic symptoms and signs during PTCA, allowing prolonged of balloon inflation.

Early and Late Prognostic Factors of Acute Myocardial Infarction

We identified the early and late prognostic factors of acute myocardial infarction, and evaluated the clinical differences and the prognosis between Q-wave myocardial infarction and non-Q wave myocardial infarction. Total 146 patients who were managed from Jan 1987 to Aug. 1989 at hallym University hospital were evaluated. According to the presence or absence of Q wave on electrocardiogram, the patients were divided into two groups : a Q wave myocardial infarction group(QMI) and a non-Q wave myocardial infarction group (NQMI). Among 146 patients 109 patients(74.7%) had QMI and 37 patients(25.3%) had NQNI. The mean age, male to female ratio and serum cholesterol level were similar in both groups. But peak level of CPK was significantly higher in the QMI group than that in the NQMI group(P<0.01). Left ventricular end-systolic dimension and ratio of left ventricular dimension to wall thickness in the QMI group were significantly higher than that in the NQMI group(P<0.01). There were no significant differences between two groups in the incidences of mortality, postinfarction angina and re-infarction. During the in-hospital period female gender, old age(more than 60 years), Killip class at admission, early reinfarction and a history of hypertension were significant prognostic factors. main causes of death during the in-hospital period were ventricular tachyarrthymia, heart failure and cardiogenic shock. The incidences of mortality, heart failure and post-infarction angina during a mean follow-up period of 14 months (6~30months) were same in the two groups. The late prognostic factors were old age(more than 60 years), Killip class at admission, heart failure occured during follow-up period(P<0.001) and a history of diabetes mellitus(P<0.05). The patients with late postinfarction angina had more dilated left ventricular end-systolic demension(P<0.05) and lower fractional shortening(P<0.01) than those of patients without late postinfraction angina. There were no significant difference in long term survival rate between QMI group and NQMI group. Further prospective study should be performed to clarify the short and long term prognosis in patients with acute myocardial infarction treated by reperfusion.