Fractional Flow Reserve Versus Angiography in Left Circumflex Ostial Intervention After Left Main Crossover Stenting

BACKGROUND AND OBJECTIVES: Discrepancy between angiographic percent (%) diameter stenosis and fractional flow reserve (FFR) exists in non-left main bifurcation lesions. The aim of this study was to compare angiographic stenosis severity and FFR in jailed ostial left circumflex artery (LCX) lesions after left main (LM)-to-left anterior descending artery (LAD) crossover stenting. SUBJECTS AND METHODS: Twenty-nine (n=29) patients with distal LM or ostial LAD lesions treated by LM-to-LAD crossover stenting were consecutively enrolled. After successful stenting, FFR was measured at the jailed LCX. Additional intervention was performed in lesions with FFR 50%) at the ostial LCX occurred in 59% (17/29) of cases. Among them, only five (29%) lesions had functional significance, and underwent additional procedure. During follow-up, three patients in the deferral group and two patients in the additional intervention group had target lesion revascularization. CONCLUSION: There was a discrepancy between angiographic percent diameter stenosis and FFR in jailed LCX lesions after LM crossover stenting.

The Effect of Preinfarction Angina as Ischemic Preconditioning on Myocardial Protection

BACKGROUND AND OBJECTIVES: By measuring the coronary flow reserve (CFR) and echocardiographic left ventricular function, the purpose of this study was to evaluate the effect of pre-infarction angina (PA) on myocardial protection in patients with acute myocardial infarction (AMI). SUBJECTS AND METHODS: Sixty-two patients (mean 54+/-10 years, 51 males) with first anterior AMI were studied. CFR, defined as the ratio of hyperemic (hAPV) to baseline APV (bAPV), was measured at least 24 hours after the onset of AMI at the left anterior descending artery (mean 7+/-4 days) with a Doppler wire. Echocardiography was performed at admission (baseline) and during follow-up periods (mean 9+/-7 month). All patients were divided into two groups according to the presence of PA within 72 hours prior to AMI:group A (with PA, n=27) and group B (without PA, n=35). RESULTS: Between the two groups, CFR were higher in group A (2.1+/-0.5 vs.1.6+/-0.5, p<0.001). The baseline left ventricular ejection fraction (LVEF, %) and wall motion score index (WMSI) were better in group A than in B (53.4+/-9.7 vs. 45.1+/-8.8, p=0.001;1.42+/-0.23 vs. 1.72+/-0.28, p<0.001, respectively). LVEF (%) and WMSI during follow-up periods were better in group A than in B (61.3+/-10.2 vs. 54.4+/-13.3, p=0.03;1.24+/-0.21 vs. 1.47+/-0.37, p=0.004, respectively). CONCLUSION: Patients with PA had a significantly higher CFR and better LVF at the baseline and during follow-up periods. This study suggests that brief and repeated myocardial ischemia prior to AMI as ischemic pre-conditioning might have the effect of myocardial protection.

The Time Course and Determinants of B-Type Natriuretic Peptide in Healthy Men during Supine Bicycle Exercise

BACKGROUND AND OBJECTIVES: Circulating B-type natriuretic peptide (BNP) has been used as a marker of left ventricular hypertrophy and heart failure, and known to be increased after exercise in healthy men as well as patients with left ventricular dysfunction. However, the relationship between exercise duration and BNP level, and the determinants of circulating BNP concentration during exercise have not been fully elucidated. For these reason, we measured circulating BNP level during exercise, and exercise-induced changes of cardiac function by echocardiography in healthy men. MATERIALS AND METHODS: Ten healthy male volunteers (mean age 27+/-3 year-old) underwent symptom-limited bicycle ergometer in supine position for 30 min. The workload started at 25 W for 6 min with increment of 50 W every 3 min. Blood samples for BNP were obtained at baseline, every 1 min for first 3 min, 25 W, 75 W, 125 W, peak exercise and 10 min after resting. RESULTS: BNP level was increased only at peak exercise (mean:5.3+/-0.5 vs 7.7+/-4.1 pg/ml, median:5.0 vs 6.3 pg/ml, p<0.05), not during submaximal exercise, and sustained 10 minutes after exercise (190+/-25 watt, 14.9+/-12 min). Peak BNP level was significantly correlated with baseline BNP level (r=0.723, p<0.05), E' (0.18+/-0.04 vs 0.29+/-0.08 m/sec, r=-0.649, p<0.05) and E/E' (4.18+/- 0.87 vs 5.66+/-2.31, r=0.769 p<0.01) by bivariate correlation analysis, but correlated with only baseline BNP level by multiple linear regression analysis (p<0.05). CONCLUSION: Circulating BNP concentration was minimally increased only after peak exercise in young healthy men, not increased at submaximal exercise The BNP concentration after exercise is only determined by baseline BNP level, not by duration and workload of exercise.

Alteration of Nitric Oxide/cyclic-GMP pathway in patients with exaggerated systolic blood pressure response during exercise test / 대한내과학회지

BACKGROUND: The diagnostic and prognostic implication of exaggerated blood pressure response to exercise has not been well characterized. Endothelial dysfunction has been demonstrated in patients with atherosclerosis or with risk factors for coronary artery disease. However, whether the cause of exercise induced hypertension might be due to endothelial dysfunction has not been well elucidated. Therefore, we designed this study to evaluate the endothelial function in patients with exaggerated blood pressure response during exercise. METHODS: Exercise hypertension is defined as a systolic blood pressure >or= 210 mmHg in men and >or= 190 mmHg in female, during treadmill exercise test. The endothelial function of the brachial artery, in 35 patients with exercise hypertension and 35 control subjects (mean age of 45.5+/-8.1) were measured by a high resolution ultrasound technique. The concentrations of nitrite and cyclic-GMP were measured from exercise hypertension group and control subjects during, before and after treadmill exercise. RESULTS: There were no significant differences in the clinical variables between the control and exercise hypertension group. The LVH on ECG was detected more frequently in exercise hypertension group (14 % vs. 40 %, p0.05), a significant difference of cyclic GMP level during the maximal exercise was noted between the groups (10+/-1.8 vs. 8.3+/-2.5 pmol/mL, p<0.05). CONCLSUION: Patients with exercise induced hypertension have impaired endothelium-dependent vasodilation. This study supports the concept that endothelial dysfunction may play a significant role in exercise induced hypertension.

A Comparison of Tenecteplase(TNK-tPA) and Alteplase(rt-PA) in Korean Patients with Acute Myocardial Infarction(A Randomized, Multi-Centered Coronary Angiographic Trial)

BACKGROUND AND OBJECTIVES: This is a comparative, randomized, multi-centered, angiographic trial for the comparison of TNK-tPA with rt-PA, in Korean patients with an acute myocardial infarction (AMI). SUBJECTS AND METHODS: Fifty four patients that were eligible for thrombolysis, diagnosed with an AMI, were randomized into two groups:TNK-tPA (single bolus injection, 25-50 mg weight adjusted;n=25) or rt-PA (accelerated intravenous infusion, up to 100 mg;n=29) at the emergency room. The primary endpoint was the percentage of patients with a TIMI (Thrombolysis In Myocardial Infarction) III flow 90 min following the administration of the study drug. The secondary endpoints were an infarct-related artery patency at 90 min, the percentage of patients with ST segment resolution at 60 and 180 min, and at 30 days mortality. RESULTS: The baseline demographic data, including age, sex and body weight, and a medical history of prior myocardial infarction and risk factors were no different between the TNK-tPA and rt-PA groups. The pain-to-needle and door-to-needle times were also no different. The ST segment resolution was no different between the two groups. A TIMI grade 3, on a coronary angiogram, 90 min following the drug administration, was observed in 19 (76.0%) of the TNK-tPA and 17 (58.6%) of the rt-PA (p=0.24) patients. However, a TIMI grade more than 2 was higher in the TNK-tPA (100%;25/25) than in rt-PA group (72.4%;21/29)(p=0.0052). The in-hospital adverse events, and clinical outcomes at 30 days, were no different between the two groups. CONCLUSION: TNK-tPA is more convenient, and may be a preferred thrombolytic agent, for the revascularization of an AMI.

Coronary Flow Velocity Pattern in Patients with Myocardial Bridging of Coronary Artery

Myocardial bridging is a systolic compression(milking effect) of mainly the left anterior descending coronary artery with coronary angiography. This phoenomenon is known to occur when a segment of an artery travels through the myocardium. The function significance of this finding remains controversial. We identified angiographic systolic compression of the coronary artery in two patients and documented the coronary flow velocity patterns and coronary flow velocity reserve with intracoronary injection of adenosine. The intracoronary flow velocity patterns distal to the myocardial bridging segment of the left anterior descending artery show the attenuated systolic component and abnormal diastolic flow velocity pattern with the exaggerated early acceleration, a diastolic spike and dome shape of coronary flow. The coronary flow velocity reserve was reduced.

Correlation of Infarct Size and Late Troponin T Peak Concentration in Acute Myocardial Infarction / 대한내과학회지

OBJECTIVES:The estimation of infarct size has been important in evaluation of prognosis of the patients who had acute myocardial infarction. The infarct size estimated by the thallium-201 SPECT has been known to correlate with the prognosis of patient. The enzymatic estimation by the total release of creatine kinase isoenzyme MB(CK-MB) has been widely used in estimating infarct size clinically, but inconvienent and not cardiospecific. Recently, serum troponin T, cardiospecific myofibrillar protein, has been used in the diagnosis of acute myocardial infarction, and used in the estimation of reperfusion following myocardial infarction. To assess the role of the late troponin T peak concentration on the estimation of infarct size, this prospective study was carried out. METHODS: The patients with acute myocardial infarction who were admitted, within 48hours after the onset of chest pain, to Ajou University Hospital between April 1995 and August 1995 were evaluated. All patients were divided into anterior and inferior infarct and checked serum troponin T and CK-MB serially, and underwent stress Thallium-201 SPECT 1 week after infarction, In each group, we assessed the correlation of the late toponin T peak concentration, the total release of CK-MB, and the infarct size estimated by thallium-201 single photon emission computed tomography(SPECT). RESULTS: 1) The eligible subjects consisted of 22 patients (17 men and 5 women), and age ranged from 29 to 77 years(mean 57.8 +/- 12.5 years). 2) The mean arrival time to the hospital after the onset of chest pain was 15.5 +/- 13.2 hours. The 19 patients had at least one risk factor for coronaryartery disease. 3) The late troponin T peak concentration and the total release of CK-MB in patients with anterior infarction were not different from those with inferior infarction. The infarct size estimated by the thallium-201 SPECT in patients with anterior infarction was larger than patients with inferior infarction The left ventricular ejection fraction in anterio infarction was lower than inferior infarction. 4) The late troponin T peak concentration ha: positive correlation with the infarct size estimated by the thallium-201 SPECT in the total patients, and both patients with anterior infarction and inferio infarction. 5) The total release of CK-MB correlated with the infarct size estimated by the thallium-20 SPECT in the total patients, and the patients of inferior infarction. CONCLUSION: The late troponin T peak concentration was more accurate than the total release o CK-MB in the estimation of infarct size. Therefore, when the patient arrived to the hospital less than 48hr after the onset of chest pain, the late troponin T peak concentration is useful in the decision and evaluation of therapeutic intervention and in the prediction of prognosis.

A Case of Right Ventricular Infundibular and Pulmonic Valve Infective Endocarditis

A case of right-sided infective endocarditis in a 22-year-old male with ventricular septal defect of perimembranous type, right ventricular(RV) infundibular and pulmonic valve stenosis was reported. The vegetations were found on the mural endocardium of RV infundibulum and pulmonic valve. Streptococcus viridans was identified in 5 consecutive blood cultures, Pulmonary embolism and septic infarction in the lung was associated with systemic embolization, which was manifested by left renal infarction. The RV infundibular stenosis was due to anomalous muscle bundle at the proximal portion. Therefore, we thought that the mechanism of RV infundibular vegetation was probably due to 'Venturi effect and turbulence'. Several clinical features which were found in this case were also reviewed.

Effect of Infarct-Related Artery Patency on Heart Rate Variability in Acute Myocardial infarction

BACKGROUND: In survivors of acute myocardial infarction(ANI), reduced heart rate variability(HRV) has been demonstrated to be an independent predictor of sudden cardiac death and mortality. The heart rate variability can be examined and analyzed non-invasively and quantitated with 24-hour ambulatory ECG monitoring. In general, the patency of infarct-related artery appears to be one of the most important prognostic factor after AMI. Therefor, the correlation between infarct artery patency and HRV was examined in survivors of AMI. METHODS: The 24-Hour ambulatory electrocardiogram was performed in 23 patients with AMI and 20 normal controls, and analyzed for frequency & time domain HRV. HRV was recorded dwithin 7 days after AMI, and coronary angiogram was performed at 7th day after AMI. The AMI patients were divided into two groups, depending upon patency of infarct-related artery and correlated to clinical manifestations. Thirteen patients had patent vessel(Group 1) and ten patients had non-patent vessel(Group 2). Parameters of frequency domain HRV include LF, HF & LF/HF ratio and time domain HRV include SDNN, SDANN, SD, rMSSD and pNN50. RESULTS: All parameters of HRV was depressed in patients of AMI than in normal control(p or =40%. There was a significant correlation between LVEF and LF, between LVEF and HF and between LVEF and LF/HF ratio(r:0.55, p<0.05;r:0.67, p<0.05;r:-0.56, p<0.05). CONCLUSION: HRV was depressed due to reduced vagal activity in patients with AMI. The values of LF, SDNN, SDANN, and SD in group of patent infarct-related artery were reduced significantly than in non-patent group.

Selective pulsed dye laser thrombus ablation : Can contrast media replace fiberoptics in pulsed dye laser delivery system?

BACKGROUND: The absorption coefficient of the arterial thrombus is 7~10 fold greater than that of arterial wall for the wave lengths of 480~510nm. This fact suggest that selective laser thrombus ablation could be possible without ablation of surrounding vessel wall in this wavelengths. METHODS: Pulsed dye laser(488nm, 2.2micros, 10Hz) thrombus ablation was investigated in viro. Ablation threshods of whole blood clot and normal aortic tissue were measured using a 1.5mm multifiber laser catheter(14x150microm). Whole blood clot samples were lasered to determine the ablation efficiency. The operative fluence was 80mJ/mm2. The transmission efficiencies of 488nm wave length through various transmission media(including contrast media of saline solution) were observed using a upsilon Fr arterial sheath filled with transmission medium. RESULTS: The ablation threshold for fresh whole blood clot in saline solution was 36.5+/-2.4mJ/mm2(9.0+/-0.6mJ/pulse) as compared with that for normal human aortic tissue which was over 405mJ/mm2(>100mJ/pulse)(p<0.05). Pulsed dye laser ablated whole blood clot with the efficiency at 0.026+/-0.009gm/J. The role of thrombus ablation was 0.154+/-0.056gm/min. This experiment also revealed that cotrast media(Ultravist(R) 370, Schering, France) allows light tramission of 488nm wave length at relatively high efficiency. CONCLUSIONS: These facts suggested that selective pulsed dye laser ablation of fresh intravascular thrombi can be obtained at relatively low energy fluence without damaging the surrounding vascular tissue. A new pulse dye laser delivery system such as catheter system or native coronary artery filled with contrast media, which has large area of frontfiring face, may facilitate a safe and effective thrombus ablation.

Coronary Thrombolysis with Intravenous Urokinase in Acute Myocardial Infarction

Recent studies showed effective early recannalization of infarct-related artery achieved by intravanous urokinase, but dosage of urokinase is still arbitary. Thirty-five patients with acute trasmural myocardial infarction were treated with intraveous urokinase from April 1984 to October 1988. The incidence of coronary thrombolysis, left ventricula function and effect on fibrinolytic system were investigated. Inital 18 patients recieved 0.5 to 2.0 million unitis of urokinase and remaining 17 patients received 3 million units of urokinase intravenously for 1 hour. Thirteen of 17 patients(76.4%) with 3 million units but only four of 18 patients(22.2%) with 0.5 to 2.0 million units showed patent infarct-related coronary artery. Left ventricular function was significantly better in patients with patent infarct-related coronary artery, and the difference was marked in anterior myocardial infarction. There were three local bleeding at puncture site in 3 million units group, one of which required transfusion. Thus, intravenous infusion of 3 million units of urokinase provide rapid reperfusion of infarct-related coronary arterty and myocardial salvage is more lkiely to occur.

A Case of Main Pulmonary Artery Aneurysm Associated with Patent Ductus Arteriosus

Pulmonary artery aneurysms are extremely rare. Even though their etiology or mechanism remain uncertain, congetial anenrysms follow the congenital heart defects which elevate the pulmonary artery pressure or increase the pulmonary blood flow and acquired aneurysms are developed by syphilis, mycotic change and atherosclerosis. Pulmonary artery aneurysms involve the artery trunk rupture and exanguination if untreated, there has been an emphasis in the need for surgical intervention whenever the diagnosis is made regardless of the presence or absence of symptoms. Here we report a case of patient ductus arterious associated with main pulmonary artery aneurysm in 39 year old female patient with review of literatures.

Percutaneous Transluminal Angioplasty of a Stenosis of an Internal Mammary Artery Graft

Successful percutaneous transluminal angioplasty (PTA) of an internal mammary artery graft was performed in a 40 year old male patient who had recurrent angina soon after bypass surgery. Coronary angiography showed total occlusion of proximal portion of the left anterior descending artery and normal right coronary artery. Angiography of the left internal mammary artery graft revealed a tight stenosis (90% diameter narrowing) in the mammary artery at its insection into the left anterior descending artery.Angiography after the angioplasty demonstrated a widely patent graft (residual stenosis 10%) and translesional pressure gradient was 10 mmHg.

Mitral Regurgitation after Percutaneous Balloon Mitral Valvuloplasty(PMV): Results and Relationships to Valve Morphology

To evaluate the change in valvular morphology and occurence and severity of mitral regurgitation produced by PMV, 45 patients(33 women and 12 men,mean age 38+/-10 years) were studied using two-dimensional(2-D) and Doppler echocaediography before and 1-2 days after this procedure. Mitral valve area after PMV increased in all patients, from 0.9+/-0.2 to 1.8+/-0.4cm2(P<0.0001). In valve area estimation, the correlation between Gorlin`s method and 2-Dechocardiography was better(r=0.61, p<0.0001) than that between Gorlin`s method and Doppler pressure halftime(r=0.38, P<0.01) before valvuloplasty, but after the procedure Gorlin`s and 2-D image valve area correlated less well(r=0.33, P<0.05) than Gorlin`s-Doppler pressure halftime correlation(r=0.46, P<0.002). Before PMV, 37 patients had no mitral regurgutation, 7 had grade 1 and 1 had grade 2 mitral regurgutation. After PMV, new mitral regurgutation occurred in 14 patients, increased in severity in 5 patients and so mitral regurgutation newly developed or increased in severity in 19(42%) patients. There were no differences between the patients with and those without an increase in mitral regurgutation after PMV, in age, sex, caediac rhythm, initial mitral valve area, increase in mitral valve area and fluoroscopic calcification. However, morphologic characteristics especially mobility(P<0.01) and thickening(P<0.05) of mitral leaflets were better pressured, and EBDA/BSA(effective balloon dilating area/body surface area) was significantly smaller(P<0.02) in patients without an increase in mitral regurgutation. Thus, an increase in mitral regurgutation after PMV might be related to the features of valve morphology especially and thickand EBDA/BSA.

Determinants of Functional Left Ventricular Aneurysm Formation after Acute Anterior Myocardial Infarction: A Clinical and Angiographic Study

To determine factors involved in left ventricular aneurysm formation after transmural anterior myocardial infarction, 74 patients with a first myocardial infarction who underwent cardiac catheterization within 6 weeks of infarction were evaluated.Patients were divided into four groups depending on the status of the left anterioe descending artery(LAD) and the presence Group I(n=15);aneurysm with occluded LAD, Group II(n=16);no aneusrysm and occluded LAD, Group III(n=18);aneusrysm and patent LAD, and Group IV(n=25);no aneusrsm with patent LAD. Neither age, sex nor risk factors for coronary disease correlated with aneusrysm formation,but the duration of chest pain in patients with previous angina was significantly longer in group II(no aneusrysm with occluded LAD) compared with other groups(P<0.01). Single vessel disease was more commom in Group I and III(aneusrysm) compared with II and IV(no aneusrysm)(P<0.06). Collateral blood supply was more frequently observed in Group I and II(occluded LAD) compared with Group III and IV(patent LAD)(P<0.01) and was slightly less in Group I(aneusrysm) compared with Group II(no aneusrym)(P<0.07). Delta area decreasing rate of the left ventricle was significantly lower in Group I and III(aneusrysm)compared with Group II and IV(no aneusrysm)(P<0.01). Single vessel disease in assocition with poor collateral circulation tends to be a determinant of left ventricular aneusrysm formation after anterior myocardial infarction.