Atheroma appears as a very low signal intensity area on 2-dimensional time-of-flight (TOF) magnetic resonance (MR) images, and its components have various signal intensities on spin-echo (SE) images. The present study investigated atheroma of the carotid arteries in 37 subjects with risk factors (63±10 years of age; 19 men) by magnetic resonance imaging (MRI). On 2-dimensional (2D) TOF images, the carotid arteries were clearly demonstrated in all cases and atheroma was detected in 23 patients. The most common location of atheroma was at the origin of the internal carotid artery. There was vascular remodeling in all patients with atheroma. 2D-TOF images showed 97% agreement with ultrasonography. SE images clearly demonstrated atheroma in all 23 patients with atheroma. All patients with atheroma showing high signal intensity on T1-weighted images had hyperlipidemia. These findings indicate that the 2D-TOF imaging method is useful for detecting atheroma and SE-images are useful for its characterization. (Jpn Circ J 2001; 65: 139 - 144)

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Percutaneous cardiopulmonary support (PCPS) is now available for hemodynamic support in patients with cardiogenic shock, but there are no guidelines for its use. The present study determined the appropriate indications for the use of the PCPS in patients with cardiogenic shock complicating acute myocardial infarction (AMI). Sixty-four consecutive patients with cardiogenic shock complicating AMI had hemodynamic support with an intraaortic balloon pump (IABP; n=38) and/or PCPS (n=26). The shock score (0-15) was calculated immediately before starting these support systems to quantify the severity of shock. Multivariate logistic regression analysis determined the clinical factors affecting in-hospital mortality. The relationship between in-hospital prognosis and the shock score was also examined in the 2 groups. The most significant factor related to the in-hospital prognosis was the shock score (p=0.0007; OR 2.16, 95% CI: 1.37-3.39). Another related factor was revascularization; however, this relationship did not reach statistical significance (p=0.069; OR 0.06). Among the 13 cases whose shock score was 4-8 (moderate shock), 5 survived in the PCPS group, but only 1 of 19 patients survived in the IABP group (p<0.05). None of the patients in either group whose shock score was more than 9 survived. The severity of shock is the most reliable independent predictor of in-hospital mortality in patients with cardiogenic shock complicating AMI. Using PCPS in patients with moderate cardiogenic shock may improve their in-hospital survival, but it must be used before the shock becomes severe. (Jpn Circ J 2001; 65: 145 - 149)

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This study evaluated the reduction in regional work of the left ventricle caused by acute myocardial ischemia during coronary angioplasty, and correlated it with ST-segment elevation. Regional work of the left ventricular myocardium, which is derived from a stress - strain loop, is a useful index of the function of a diseased heart. However, the effects of transient ischemia on the regional work of the myocardium have not been fully elucidated. The subjects consisted of 25 patients who had proximal left anterior descending artery stenosis with normal wall motion and without collateral circulation. The patients were classified as showing ST-segment elevation ≥0.2 mV (group A, 10 patients), or ST-segment elevation <0.2 mV (group B, 15 patients) during coronary angioplasty. Group A showed a greater reduction in the regional work of the interventricular septum than group B. Regional work recovered to the baseline level 30 s after balloon deflation in group B, but took 40 s in group A. A greater ST elevation during balloon inflation was associated with a greater, prolonged reduction of work performance in the ischemic region and a greater concomitant increase in the opposite nonischemic region. (Jpn Circ J 2001; 65: 150 - 154)

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This study assessed the prognostic value of Iodine-123-metaiodobenzylguanidine (MIBG) imaging and of the plasma level of cardiac natriuretic peptides in patients with left ventricular dysfunction resulting from cardiomyopathy. Predictors of cardiac death or hospitalization related to progressive heart failure were examined in 171 patients with chronic heart failure (96 patients with idiopathic cardiomyopathy and 75 patients with ischemic cardiomyopathy). All patients underwent MIBG imaging at rest and other hemodynamic studies. During a mean (±SD) follow-up period of 27±11 months, 11 patients died from heart failure and 16 required hospitalization. High MIBG washout was an independent predictor of cardiac death (relative risk [RR] = 1.158, p<0.0001) whereas the plasma level of brain natriuretic peptide (BNP: relative risk [RR] = 1.005, p<0.0001) and high MIBG washout (relative risk [RR] = 1.094, p<0.0001) were predictors of progressive heart failure (ie, combined cardiac death and hospitalization). Accelerated myocardial adrenergic nerve activity as assessed by MIBG imaging and the plasma levels of BNP are powerful predictors of the patient's prognosis. (Jpn Circ J 2001; 65: 155 - 160)

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The present study evaluated the risk in cardiac patients of rupture of a plaque by a jet stream from the arch cannula. The entire thoracic aorta and cardiac function were routinely monitored by transesophageal echocardiography (TEE) in 88 adult patients who underwent coronary artery bypass surgery. The changes in the atheromatous plaque in the distal aortic arch were observed before and after cardiopulmonary bypass. Of the 88 patients, 13 were found to have preoperative atheromatous plaque at the distal aortic arch and 8 (61.5%) of them suffered plaque rupture caused by jet stream from the arch cannula. Only 1 patient experienced apparent embolic episodes manifesting as cerebral and left leg embolisms; the remaining 7 had no clinical embolic symptoms. In order to prevent atheroembolic events, attention should be paid not only to the ascending aorta, but also to the distal arch and in this regard TEE is useful for detecting atheromatous changes of the aorta. (Jpn Circ J 2001; 65: 161 - 164)

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There are only a few studies of the relationship between hemostatic abnormalities and intraarterial pressure, so the present study investigated the association of various newer lipid and hemostatic variables with intraarterial pressure levels. Levels of total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, triglyceride, lipoprotein-(a), remnant-like particle cholesterol, cholesteryl ester transfer protein, uric acid, blood glucose, fibrinogen, free form of tissue factor pathway inhibitor (TFPI), C-reactive protein, serum amyloid A protein, anti-Chlamydia pneumoniae immunoglobulin G and immunoglobulin A, and apolipoproteins (apo) A-I, B, and E were measured in 176 patients who underwent diagnostic coronary angiography. Intraarterial blood pressure was determined from central aortic pressure using a standard fluid-filled catheter-external transducer system. Multivariate regression analyses showed that TFPI level was the only independent factor associated with aortic diastolic pressure. The linear regression equation demonstrated a significant negative correlation of TFPI level with aortic diastolic pressure (r=−0.395, p=0.0011). With respect to the association with other parameters, the TFPI level showed significant correlations between the HDL-C level and the apo A-I level, both in the overall patients and in the patients with coronary artery stenosis. This is the first evidence that the level of the plasma free form of TFPI is inversely correlated to aortic diastolic pressure. (Jpn Circ J 2001; 65: 165 - 170)

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The ratio of acceleration time to right ventricular ejection time (AcT/RVET) can be derived from the blood flow patterns recorded by pulsed wave Doppler echocardiography. In chronic cor pulmonale, AcT/RVET negatively correlates with pulmonary artery pressure (PAP). The present study evaluated the diagnostic value of AcT/RVET by comparing this variable with indices derived from pulmonary angiography (PAG) and PAP in 16 patients with acute pulmonary thromboembolism (APTE). AcT/RVET, PAP, and PAG severity indices (Miller index (MI) and UPET objective angiographic index (UI)) were measured during the acute phase on admission and the chronic phase after treatment. In the acute phase, AcT/RVET correlated with mean PAP (mPAP) (r=-0.68, p<0.05) and total pulmonary resistance (TPR) (r=-0.66, p<0.05), but not with MI or UI. During the chronic phase, AcT/RVET did not correlate with mPAP or TPR, but with both PAG indices (MI: r=0.76, p<0.05, UI: r=0.65, p<0.05). Before treatment of the APTE, AcT/RVET remained at low levels and could be used as an index of pulmonary hypertension. After treatment, however, following improvement of PAP, AcT/RVET was not useful for evaluating PAP, but might serve as an index for evaluating the volume of residual thrombi. (Jpn Circ J 2001; 65: 171 - 176)

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The present study investigated the agreement between low-dose dobutamine stress echocardiography (LDDSE) and fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and compared each technique's ability to detect myocardial viability and predict functional recovery in 30 patients. All patients underwent revascularization, followed by echocardiography 5±3 months. Of the 390 segments analyzed by echocardiography before revascularization, 110 (28%) had abnormal wall motion. LDDSE showed viability in 66 sites of the 110 dyssynergic segments and 58 of these viable segments recovered their wall motion. With FDG-PET, 78 of the 110 dyssynergic segments were diagnosed as viable and 62 of these showed improvement of the wall motion. The sensitivities for LDDSE and FDG-PET to assess functional recovery were 84% and 90%, respectively; specificities were 80% and 64%, respectively. Positive predictive values for LDDSE and FDG-PET were 88% and 79%; negative predictive values were 75% and 78%, respectively. Both methods had good sensitivity for detecting improvement in regional function after revascularization, but LDDSE had a higher specificity for detecting viability and a better positive predictive value for left ventricular functional recovery. (Jpn Circ J 2001; 65: 177 - 181)

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Recent studies suggest an association between Chlamydia pneumoniae infection and coronary artery disease (CAD). To examine this relationship in Japanese men, serum IgA and IgG antibodies to Chlamydia-specific lipopolysaccharide were measured by enzyme-linked immunosorbent assay in 507 patients with CAD and 200 age-matched controls. CAD patients were divided into (1) 269 patients with myocardial infarction (MI) and (2) 238 patients with chronic coronary heart disease (CCHD). Compared with the control group, the CAD group did not differ in the prevalences of both antibodies (IgA: 23.7 vs 18.0%, p=0.10; IgG: 52.7 vs 51.0%, p=0.6). The index of IgG antibody was not significantly different between CAD and control groups (median 1.19 vs 1.18, p=0.3), whereas the index of IgA antibody was significantly higher in CAD than control group (median 0.60 vs 0.46, p<0.0001). Compared with the control group, the MI group had a significantly higher prevalence of IgA antibody (28.6 vs 18.0%, p=0.007); however, there was no difference in the prevalence of IgG antibody (58.0 vs 51.0%, p=0.13). The CCHD group did not differ in the prevalences of both antibodies (IgA: 18.1 vs 18.0%, p=0.9; IgG: 45.6 vs 51.0%, p=0.2). After the adjustment for coronary risk factors, odds ratios (ORs) of seropositive antibodies for CAD were 1.59 [95% confidence interval (CI): 0.88-2.87, p=0.12] for IgA seropositivity and 0.92 (95% CI: 0.58-1.47, p=0.7) for IgG seropositivity in all cases. In the MI and control groups, ORs of seropositive antibodies for MI were 2.67 (95% CI: 1.32-5.38, p=0.007) for IgA seropositivity, and 1.36 (95% CI: 0.79-2.36, p=0.2) for IgG seropositivity. This study discovered that IgA antibody to Chlamydia was significantly associated with CAD, especially with MI, in Japanese Men and the findings suggest that chronic infection of Chlamydia may be linked to the pathogenesis of MI. (Jpn Circ J 2001; 65: 182 - 187)

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The present study analyzed the helical computer-assisted tomography (CAT) findings in 30 patients with pulmonary hypertension (PH) associated with left-to-right shunts; specifically, ventricular septal defect, 23; atrioventricular septal defect, 6; patent ductus arteriosus, 1. Eight patients had 21 trisomy. Age ranged from 1 to 18 (mean, 4.1) months, and body weight ranged from 2.6 to 10.7 (mean, 4.9) kg. In all patients, the chest CAT revealed patchy areas of high and low attenuation (mosaic pattern) and regional atelectasis in the lung fields. The volume of low attenuated lesions and of atelectasis, and the total lung volume were derived from integration of areas measured on the CAT image. The ratios of low attenuated lesion/total lung volume (Lo), volume of atelectasis/total lung volume (Ate) and low attenuated lesion and volume of atelectasis/total lung volume (Lo&Ate) were compared with hemodynamic parameters measured at cardiac catheterization. The pulmonary to systemic resistance ratio correlated with Lo (r=0.61, p<0.01) and Lo&Ate (r=0.69, p<0.01), whereas the pulmonary vascular resistance correlated with Ate (r=0.53, p<0.01). Lo, Ate and Lo&Ate in the chest CAT are reliable parameters that can be used to estimate pulmonary vascular resistance in patients with PH associated with left-to-right shunts. (Jpn Circ J 2001; 65: 188 - 192)

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Visceral fat accumulation plays an important role in the occurrence of coronary artery disease (CAD) associated with a cluster of multiple risk factors, such as glucose intolerance, insulin resistance and hyperlipoproteinemia. To clarify the detailed features of these factors, based on visceral fat accumulation, the present study examined the relationship between fat distribution and the characteristics of glucose metabolism and serum lipoproteins in middle-aged non-obese Japanese men. First, the influence of visceral fat accumulation on glucose metabolism, insulin sensitivity, and the extent and severity of coronary artery lesions was investigated in 50 subjects with CAD and compared with 15 control subjects without CAD (Study 1) and with the lipoprotein characteristics in 44 subjects without CAD who were not treated with lipid-lowering drugs (Study 2). Body fat distribution was determined by abdominal computed tomography. In Study 1, the visceral fat area (VFA), blood pressure, fasting immunoreactive insulin (FIRI), and the plasma insulin area (PIA) obtained by oral glucose tolerance test in the subjects with CAD were all significantly higher than in the control subjects. The VFA was significantly correlated with FIRI, the homeostasis model of insulin resistance, PIA and steady state plasma glucose (SSPG) concentration as an index for insulin resistance (r=0.57, p<0.001, r=0.49, p<0.01, r=0.36, p<0.01, and r=0.50, p<0.05, respectively). Although the SSPG concentration did not correlate with the coronary atherosclerosis index as a score of the extent and severity of coronary lesions, the VFA was significantly correlated with this index (r=0.43, p<0.01). In Study 2, the VFA had significant positive correlations with serum total cholesterol, triglyceride, and apolipoprotein B and E levels and the cholesterol and triglyceride concentrations of very-low-density lipoprotein, intermediate-density lipoprotein, and low-density lipoprotein (LDL) fractions. There was a negative correlation between the VFA and LDL particle size (r=-0.34, p<0.05). In conclusion, visceral fat accumulation may contribute to the development of CAD through the progression of insulin resistance and the increase of apo B-containing lipoproteins and small-sized LDLs in middle-aged non-obese Japanese men. (Jpn Circ J 2001; 65: 193 - 199)

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Most studies of diet and coronary heart disease (CHD) have focused on constituents rather than on whole foods. The present study examined the relationship of selected foods to nonfatal acute myocardial infarction (AMI) in Japan, with special reference to vegetables, fruits, fish, and tofu. A total of 660 cases with their first episode of AMI aged 40-79 years living in Fukuoka City or adjacent areas and 1,277 controls matched for age, sex, and residence were surveyed on lifestyle, including dietary factors. Participation rates were 87% of cases and 52% of controls. Consumption frequencies of 19 food/beverages items and daily amounts of 4 items were ascertained by interview. The final analysis was done with 632 cases and 1,214 controls. Although consumption of vegetables showed no clear association with the risk of AMI, fruit consumption appeared to reduce the risk of AMI in both men and women. The results also suggested that fish consumption was related to a decreased risk of AMI in men, although the trend was not statistically significant. In women only, tofu consumption was inversely related to the risk of AMI; relative risks for eating tofu <2, 2-3, and 4+ times per week were 1.0, 0.8, and 0.5, respectively, after adjustment for non-dietary factors (p for trend = 0.01). Further adjustment for consumption of fruit, fish and tofu did not alter the findings generally. The findings suggest that, in women at least, tofu consumption may be protective against the risk of AMI. Further studies are needed to corroborate the relationship of consumption of fish and fruit to AMI risk in Japanese men and women. (Jpn Circ J 2001; 65: 200 - 206)

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To investigate the time course of superoxide generation in ischemia-reperfusion in the in-vivo rat lung, the present study used an enhanced chemiluminescence method with 2-methyl-6-[p-methoxyphenyl]-3,7-dihydroimidazo[1,2-α]pyrazin-3-one (MCLA) as a specific probe. The right pulmonary artery was occluded for 120 min, followed by 90-min reperfusion. Chemiluminescence induced by MCLA was continuously monitored by a photomultiplier exposed to the right lung. Chemiluminescence increased gradually in 30 min of reperfusion and remained elevated throughout reperfusion. The ratio of the luminescence count during reperfusion to the preischemic value increased to 2.20±0.31 (mean ± SEM) (p<0.02 vs preischemic level), 2.50±0.39 (p<0.005), and 2.69±0.44 (p<0.005), at 30, 60, and 90 min of reperfusion, respectively. Bolus administration of superoxide dismutase during the reperfusion period significantly attenuated the chemiluminescence by 45.0±6.7% (p<0.01). The present results suggest that increasing oxygen radical formation leading to ischemia - reperfusion lung injury may occur even after a short period of occlusion of the pulmonary artery alone in vivo. (Jpn Circ J 2001; 65: 207 -212)

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Oxygen-derived free radicals cause cytotoxic damage during reperfusion after a period of ischemia and the production of these free radicals may be proportionate to oxygen tension (PO₂). The present study tested the hypothesis that oxidative damage may be limited by maintaining a more physiologic PO₂ following ischemia. An experimental study in Wistar rats were mounted on a Langendorff apparatus was conducted to estimate baseline aortic flow (AF), coronary flow (CF), cardiac output (CO), systolic pressure (SP), heart rate (HR), and the rate - pressure product (RPP: HR × SP). The hearts were divided into 3 groups (n=7, hearts/group): group 1, hypoxic (PO₂ = 300±50 mmHg) reperfusion; group 2, middleoxic (PO₂ = 500±50 mmHg) reperfusion; and group 3, hyperoxic (PO₂ = 700±50 mmHg) reperfusion. Following 30 min of warm ischemia, hearts in all groups were reperfused at each oxygen pressure. The recovery of cardiac function of each heart was measured at the end of reperfusion. Concentrations of lactate (LAC), lactate dehydrogenase (LDH), and creatine kinase (CK) in the coronary perfusate during reperfusion were measured. The recovery rate of CO, SP, and RPP in group 2 were all significantly better than in the other 2 groups. CK leakage in group 2 was significantly lower than in group 3. A clinical study was also conducted during elective coronary artery bypass grafts in 16 consecutive patients who underwent either hyperoxic (n=8, PO₂ = 450-550 mmHg) or more physiologic (n=8, PO₂ = 200-250 mmHg) cardiopulmonary bypass after aortic unclamping. The clinical study assessed CK-MB, LDH, LAC, and malondialdehyde (MDA) in patient blood prior to starting the surgical procedure and at 30 min and 3, 9, and 21 h after unclamping. Cardiac index (CI), central venous pressure, pulmonary capillary wedge pressure, systolic arterial pressure, and the dose of cathecholamines were also measured. Although no significant differences were present in the dose of cathecholamines, the CI in the more physiologic oxygen tension group was significantly higher than in the hyperoxic group at 3 and 6 h after unclamping. The levels of MDA in the more physiologic PO₂ group was significantly lower at 30 min after aortic unclamping than in the hyperoxic group. The present results suggest that in the experimental as well as in the clinical study, high PO₂ leads to myocardial reperfusion damage; however, maintaining a more physiologic PO₂ during reperfusion following ischemia may attenuate reperfusion injury. (Jpn Circ J 2001; 65: 213 - 218)

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The leakage of electrical current to the body surface during defibrillation shock delivery by an implantable cardioverter - defibrillator (ICD) device (the Medtronic Jewel Plus PCD system) was evaluated in 5 dogs. The defibrillation shocks were delivered between the active-can implanted in the left subclavicular region and the endocardial lead placed in the right ventricle at the energy levels of 1, 2, 8, 12, 24 and 34 J. During each delivery, the electrical current leakage from the body surface was measured by electrodes connected to a circuit at 4 recording positions: (A) parallel-subcutaneous (the electrodes were fixed in the subcutaneous tissue of the left shoulder and the right lower chest, and the direction of the electrode vector was parallel to the direction of the defibrillation energy flow); (B) cross-subcutaneous (the electrodes were fixed in the subcutaneous tissue of the right shoulder and the left lower chest, and the vector of the electrodes was roughly perpendicular to the direction of the energy flow); (C) parallel-surface (the electrodes were fixed with ECG paste on the shaved skin surface at the left shoulder and the right lower chest); and (D) surface grounded (the electrodes were fixed on the shaved skin surface at the left shoulder and the left foot, which was grounded). The circuit resistance was set at a variable level (100-5,000 Ω) in accordance with the resistance measured through each canine body. Leakage energies were measured in 750 defibrillation shocks with each circuit resistance in 5 dogs. The leakage energy increased in accordance with the increase of the delivered energy and the decrease of the circuit resistance in all 4 recording positions. When the circuit resistance was set at 1,000 Ω, the leakage energy during shock delivery at 34 J was 32±17 mJ at position A, 5±9 mJ at B, 10±9 mJ at C, and 4±3 mJ at D (p=0.042). The peak current was highest at position A and was 87±22 mA with a circuit resistance of 1,000 Ω. The power of the leakage energy depended on the delivered energy and the impedance between the electrodes. The angle between the alignment of the recording electrodes and the direction of the energy flow was another important factor in determining the leakage energy. Although the peak current of the leakage energy reached the level of macro shock, the highest leakage energy from the body surface was considerably less because of the short duration of the shock delivery. (Jpn Circ J 2001; 65: 219 - 225)

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The effects of gene transfer of the secreted form of fibroblast growth factor-2 (FGF-2) were tested using an adenovirus vector in the microembolized rabbit heart. Japanese white rabbits underwent an intracoronary injection of 25-μm microspheres followed by recombinant adenovirus vectors encoding a secreted form of FGF-2 (FGF group), LacZ (LacZ group), or saline (saline group). Left ventricular (LV) systolic function was serially assessed by echocardiography. Vascular density was measured at 14 days with Azan and CD31 staining. The development of collateral vessels was assessed by measuring myocardial blood flow before and after the occlusion of the left anterior descending coronary artery. Percent fractional shortening (%FS) decreased after the microembolization, and improved gradually for 14 days in the FGF group only (41±1% (FGF) vs 32±1% (LacZ), 31±1% (saline), p<0.01). The vascular density and myocardial collateral blood flow were significantly higher in the FGF group in comparison with other groups. Transcoronary arterial gene transfer of the secreted form of FGF-2 was beneficial for the recovery of LV systolic function and development of collateral vessels in the microembolized rabbit heart. (Jpn Circ J 2001; 65: 226 - 231)

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Stent thrombosis is rare with anti-platelet therapy, which consists of aspirin and ticlopidine as a post-stenting administration. A 77-year-old man had repeated stent thrombosis, which was not predicted by coronary angiography, despite using contemporary periprocedural anti-platelet therapy. Only intravascular fiberscopy was able to detect the cause of the stent thrombosis. (Jpn Circ J 2001; 65: 232 - 235)

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A 70-year-old woman with dilated cardiomyopathy and ventricular tachyarrhythmia was initially treated in 1990 with intravenous amiodarone (240 mg). She developed a junctional escape rhythm (48 beats/min) with QT prolongation (QT: 0.68 s) and 8 h later developed torsade de pointes (TdP). Because other antiarrhythmic drugs did not suppress the arrhythmia, oral amiodarone (100 mg/day) was started in 1995, 7 weeks before she presented with congestive heart failure. The QT prolongation (QTc: 0.64) increased after administration of dopamine, and TdP again developed. This case suggests that amiodarone induces proarrhythmias by different mechanisms when administered intravenously or orally. (Jpn Circ J 2001; 65: 236 - 238)

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Aneurysms of the sinus of Valsalva often remain undiagnosed until they rupture. A 61-year-old man had a huge, heavily calcified unruptured aneurysm, originating from the right sinus of Valsalva, detected incidentally on a chest radiograph taken for the diagnosis of cardiomegaly. Two-dimensional echocardiography revealed pericardial effusion with a huge calcified mass compressing the right ventricular outflow tract. The Doppler color-flow echocardiogram showed blood flow from the aortic root into the aneurysm. A chest computed tomographic scan revealed a large thrombosed aneurysm originating from the aortic root and measuring 10×10 cm. After pericardiocentesis, cardiac catheterization was performed, which showed that the right ventricular systolic pressure had elevated to 80 mmHg. Aortic root aortography demonstrated a huge unruptured calcified aneurysm in the sinus of Valsalva arising from the right coronary sinus. The patient underwent surgical correction to prevent aneurysmal rupture and to relieve the right ventricular outflow obstruction. (Jpn Circ J 2001; 65: 239 - 241)

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Radiofrequency catheter ablation (RFCA) was performed on a 5-year-old boy with congenital junctional ectopic tachycardia (JET) that was refractory to medical management. Because of the lack of retrograde atrial depolarization during tachycardia, radiofrequency energy was delivered during atrial overdrive pacing to confirm the presence of preserved atrioventricular (AV) conduction. Although the procedure was complicated by complete right bundle branch block after ablation of the para-Hissian region, the patient regained sinus rhythm accompanied by normal AV conduction. Rapid atrial pacing during RFCA of JET may be safely used to avoid AV block. (Jpn Circ J 2001; 65: 242 - 244)

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