Prolonged sinus arrest on electrocardiogram recording during apheresis donation in young female donor with convulsive syncope.

An 18-year-old young female with a convulsive syncope during apheresis donation demonstrated a prolonged sudden sinus arrest continued for approximately 30-second on monitor ECG. This prolonged sinus arrest may relate accidental serious complications in ordinal apheresis donation. Continuous electrocardiogram monitor and correspondence are indispensable.

Recipient sepsis caused by Lactococcus garvieae contamination of platelets from a donor with colon cancer.

Lactococcus garvieae is a well-known fish pathogen that has low virulence in humans and is rarely isolated from the blood cultures of endocarditis patients. We describe herein the first reported case of transfusion-transmitted L. garvieae sepsis caused by a contaminated platelet concentrate from a donor who consumed raw octopus before blood donation. Retrospective examination of the laboratory results of the index donor revealed that his haemoglobin levels had been steadily decreasing, which led to the detection of a latent colon cancer. The donors with colon lesions involving a latent cancer may relate an asymptomatic bacteremia.

Effect of intravenous amiodarone on QT and T peak-T end dispersions in patients with nonischemic heart failure treated with cardiac resynchronization-defibrillator therapy and electrical storm.

BACKGROUND: The effect of intravenous amiodarone on spatial and transmural dispersion of ventricular repolarization in patients receiving cardiac resynchronization therapy (CRT) remains unclear. METHODS: We studied 14 patients with nonischemic heart failure who received CRT with a defibrillator, experienced electrical storm and were treated with intravenous amiodarone. Each patient underwent 12-lead electrocardiography (ECG) and 187-channel repolarization interval-difference mapping electrocardiography (187-ch RIDM-ECG) before and during the intravenous administration of amiodarone infusion. RESULTS: A recurrence of ventricular tachyarrhythmia was observed in 2 patients during the early period of intravenous amiodarone therapy. Intravenous amiodarone increased the corrected QT interval (from 470±52 ms to 508±55 ms, P=0.003), but it significantly decreased the QT dispersion (from 107±35 ms to 49±27 ms, P=0.001), T peak-T end (Tp-e) dispersion (from 86±17 ms to 28±28 ms, P=0.001), and maximum inter-lead difference between corrected Tp-e intervals as measured by using the 187-ch RIDM-ECG (from 83±13 ms to 50±19 ms, P=0.001). CONCLUSIONS: Intravenous amiodarone suppressed the electrical storm and decreased the QT and Tp-e dispersions in patients treated by using CRT with a defibrillator.

Effects of pre-shipping marbofloxacin administration on fever and blood properties in healthy Thoroughbreds transported a long distance.

The present study evaluated the effects of single-dose marbofloxacin in protecting horses against fever associated with transportation using 48 healthy Thoroughbreds. All horses were premedicated with interferon-α (0.5 U/kg, sublingually, every 24 hr) for 2 days before transportation and on the day of transportation. Horses were randomly assigned to receive marbofloxacin (2 mg/kg, IV, once; MRFX group), enrofloxacin (5 mg/kg, IV, once; ERFX group) or saline (0.9% NaCl) solution (10 ml, IV, once; control group) ≤1 hr before being transportation. Each group contained 16 horses (8 males, 8 females). Horses were transported 1,210 km using commercial vans over the course of approximately 26 hr. Clinical examinations and hematologic analyses were performed on all horses both before and after transportation. Post-transportation neutrophil to lymphocyte ratios were significantly lower in horses in the MRFX group compared with the control horses. The serum amyloid A levels were significantly lower in horses in the MRFX group and ERFX group compared with the control horses. Regarding the post-transportation rectal temperatures, fever was detected in 0 horses and 1 horse in the MRFX and ERFX groups, respectively, whereas fevers exceeding 39.1°C were detected in 2 horses in the control group. Additionally, the number of essential post-transportation treatments provided by veterinarians was reduced 3-fold in the MRFX and ERFX groups compared with the saline group. MRFX provided ERFX-like protection against fever associated with long-distance transportation, yielding significantly better protection than saline. Administration of MRFX just before transportation deserves a further study for efficacy in preventing horse fever associated with transportation.

Comparison of the Occurrence of Transportation-associated Fever in 2 Years Old Thoroughbreds before and after Introduction of Prophylactic Marbofloxacin Administration.

In order to reveal the preventive effect of marbofloxacin (MRFX) administration just before transportation, we compared the occurrence of transportation-associated fever before and after introduction of MRFX administration. After the introduction of prophylactic MRFX administration, the rectal temperatures of horses after transportation were significantly lower than before the introduction of MRFX administration (P<0.01) and the number of febrile horses was significantly lower than before the introduction of MRFX administration (P<0.01). In conclusion, these results show that prophylactic MRFX administration just before transportation is clinically effective at preventing transportation-associated fever.

Detection of peripartum myocardial burden by vector-projected 187 channel electrocardiography and serum NT-proBNP.

There is no reliable method of screening for pregnant women at high risk of developing severe myocardial disorders. In this study, we used vector-projected 187 channel electrocardiography (DREAM-ECG) and serum biochemical markers to evaluate peripartum myocardial burden in pregnant women. Forty-one pregnant women were examined at 36-37 weeks gestation (GW36), 7 days postpartum (PPD7), and 1 month postpartum (PPM1). Ten non-pregnant control women were assessed at a single time point. Heart rate, sympathetic index, and repolarization index (RTc dispersion) were quantified using the DREAM-ECG system, and serum levels of NT-proBNP, cardiac troponin T, estrogen, and progesterone were determined. Heart rate and the sympathetic index decreased from GW36 to PPM1 (P = 0.0031). The repolarization index decreased over time and was greater than in non-pregnant controls (31 ± 13 ms). Estrogen and progesterone at PPD7 and PPM1 were significantly lower than those at GW36 (P < 0.0001, P < 0.001). NT-proBNP at PPD7 was greater than at GW36 (median 29 pg/mL at GW36, 86 pg/mL at PPD7), and decreased at PPM1 in comparison to PPD7 (median 18.5 pg/mL). Troponin T was in the normal range during the whole period (< 0.003 ng/mL). In conclusion, these results indicate that the peripartum myocardial burden in pregnant women does not return to normal nonpregnant levels by PPM1. We propose that both repolarization indexes such as RTc dispersion by DREAM-ECG and serum biochemical markers may identify pregnant women at high risk of developing severe myocardial damage in the peripartum period.

Body surface two-dimensional spectral map of atrial fibrillation using vector-projected 187 channel electrocardiography.

Atrial cycle length during atrial fibrillation and flutter waves may be correlated with atrial refractoriness and organization. The nature of the frequency by spectral analysis may reflect a profile of atrial cycle length. In this study, we developed a novel body surface 2-dimensional spectral map during fibrillation using vector-projected 187 channel ECG (187ch VP-ECG).The study consisted of 28 patients (24 with atrial fibrillation (AFIB) and 4 atrial flutter (AFL) with valvular heart disease). We performed spectral analysis by maximum entropy modeling (MEM) in 4 second nonaveraged 187ch electrical current waves by 187ch VP-ECG. Body surface spectral features were displayed according to the frequency and power magnitude components. We verified the accuracy of the spectral features by a 64ch magnetocardiography (MCG). The average dominant frequency in AFL by 187ch VP-ECG was lower than those in AFIB (4.6 ± 0.9 Hz in AFL, 7.2 ± 0.9 Hz in AFIB, P < 0.01). Comparison of average dominant frequency between 187ch VP-ECG and 64 ch MCG demonstrated good agreement (y = 0.86x+0.84, r(2) = 0.89, P < 0.0001). Body surface 2-dimensional spectral features demonstrated homogenous spectrum patterns in AFL, and in-homogenous spectrum patterns in AFIB.In conclusion, novel body surface spectral mapping using 187ch VP-ECG may represent a 2-dimensional spectral feature that may be related to atrial refractoriness and organization.

Assessment of fetal autonomic nervous system activity by fetal magnetocardiography: comparison of normal pregnancy and intrauterine growth restriction.

OBJECTIVE: To clarify the developmental activity of the autonomic nervous system (ANS) of the normal fetus and intrauterine growth restriction (IUGR) cases using fetal magnetocardiography (FMCG). SUBJECTS AND METHODS: Normal pregnancy (n = 35) and IUGR (n = 12) cases at 28-39 and 32-37 weeks of gestation, respectively, were included in this study. The R-R interval variability was used to calculate the coefficient of variance (CV(RR)) and low frequency/high frequency (LF/HF) ratio. RESULTS: The value of CV(RR) in the normal pregnancy group displayed a slight increasing trend with gestational age. However, no such trend was observed in the IUGR group. In contrast, the LF/HF ratio in both the normal pregnancy group and the IUGR group clearly increased over the gestational period; the normal group showing statistical significance. CONCLUSION: The development of fetal ANS activity in IUGR cases might differ from that observed in the normal pregnancy group, and this may facilitate early detection of IUGR.

Clinical significance of combined CYP2C9 and VKORC1 genotypes in Japanese patients requiring warfarin.

The individual management of anticoagulation therapy is important for safe medical outcomes, including those of oral surgery. Here, Japanese patients who received warfarin (n = 35) and normal controls (n = 125) were analyzed by real-time PCR to determine the frequencies of single nucleotide polymorphisms in VKORC1 (vitamin K epoxide reductase complex, subunit 1) and CYP2C9 and how these frequencies related to warfarin dose and PT-INR. The genetic polymorphisms CYP2C9(*2) (416 C > T), CYP2C9(*3) (1061 A > C), and intron 1-136 C > T in VKORC1 (1173 C > T) were measured. All patients had the wild-type CYP2C9 gene (*1/*1). All 160 cases had the wild-type (CC) type CYP2C9(*2), 93.8% had AA type CYP2C9(*3), 6.2% had AC type CYP2C9(*3), 1.2% had CC type VKORC1, 13.8% had CT type VKORC1, and 85% had TT type VKORC1. The CC type VKORC1 genetic polymorphism was associated with a significantly higher mean warfarin maintenance dose (4.5 ± 0.5 mg) than other VKORC1 genotypes (TT type 2.9 ± 0.1 mg: CT type 3.4 ± 0.3 mg). Categorization of the patients in terms of the combined CYP2C9 and VKORC1 haplotype (the warfarin-responsive index; WRI) revealed the mean daily warfarin maintenance dose was 3.0 ± 0.1 mg for WRI 1 and 3.7 ± 0.3 mg for WRI 2 (P < 0.012). The event survey revealed 2 patients with nonfatal cerebral hemorrhage had a WRI score of 2 (VKORC1 C/T heterozygosity genotype). Thus, CYP2C9 and VKORC1 haplotype analysis allows prediction of warfarin maintenance dosage. The findings may provide a personalized use of warfarin in the field of oral surgery.

Novel algorithm for identifying T-wave current density alternans using synthesized 187-channel vector-projected body surface mapping.

The noninvasive evaluation of ventricular T-wave alternans (TWA) in patients with lethal ventricular arrhythmias is an important issue. In this study, we propose a novel algorithm to identify T-wave current density alternans (TWCA) using synthesized 187-channel vector-projected body surface mapping (187-ch SAVP-ECG). We recorded 10 min of 187-ch SAVP-ECG using a Mason-Likar lead system in the supine position. A recovery time (RT) dispersion map was obtained by averaging the 187-ch SAVP-ECG. The TWCA value was determined from the relative changes in the averaged current density in the T-wave zone (Tpeak ± 50 ms) for two T-wave types. We registered 20 ECG recordings from normal controls and 11 ECG recordings from nine subjects with long QT syndrome (LQT). We divided LQT syndrome subjects into two groups: group 1 provided 9 ECG recordings without visually apparent TWAs, and group 2 provided 2 ECG recordings with visually apparent TWAs. The QTc interval values in the LQT groups were higher than those in the control (515 ± 60 ms in LQT G-1, 600 ± 27 ms in LQT G-2 vs. 415 ± 19 ms in control, P < 0.001). The RTendc dispersion values among the LQT subjects were higher than those of the control subjects (48 ± 19 ms in LQT G-1, 65 ± 30 ms in LQT G-2 vs. 24 ± 10 ms in control, P < 0.01). The mean TWCA value was significantly higher in the LQT G-2 group with visually apparent TWCAs (0.5 ± 0.2% in control, 2.1 ± 1.2% in LQT G-1, and 32.3 ± 6.9% in LQT G-2). Interestingly, the two-dimensional distribution of TWCA in LQT was inhomogeneous and correlated with the distribution of increased RT dispersion. We conclude that a novel algorithm using 187-ch SAVP-ECG might provide new insights into body surface TWCA.

Interlead difference between T-peak to T-end intervals in resynchronization patients with an implantable cardioverter-defibrillator.

BACKGROUND: The effectiveness of cardiac resynchronization therapy (CRT) in preventing sudden cardiac death is controversial. Epicardial left ventricular pacing reverses the direction of activation of the left ventricular wall from the epicardium to the endocardium. We evaluated whether the interlead difference between T-peak to T-end (Tp-e) intervals determined by a 187-channel repolarization interval-difference mapping electrocardiograph (187-ch RIDM-ECG) is related to the occurrence of ventricular tachyarrhythmia requiring implantable cardioverter-defibrillator (ICD) therapy in heart failure patients receiving CRT with a defibrillator (CRT-D). METHODS AND RESULTS: Repolarization interval-difference mapping electrocardiograph (187-channel) was performed on 61 patients who received CRT-D. Twenty-one patients experienced appropriate ICD therapy. The interlead difference between corrected recovery time intervals was not significantly different between patients with and without appropriate ICD therapy (98 ± 24 milliseconds versus 88 ± 24 milliseconds). The interlead difference between corrected Tp-e intervals was significantly higher in patients with appropriate ICD therapy than in those without (88 ± 22 milliseconds versus 59 ± 23 milliseconds, P < .001). CONCLUSION: The interlead difference between corrected Tp-e intervals determined by 187-ch RIDM-ECG may be related to appropriate ICD therapy in heart failure patients receiving CRT-D.

Prenatal diagnosis of polymorphic ventricular tachycardia using 64-channel magnetocardiography.

We describe polymorphic ventricular tachycardia (VT) diagnosed using fetal magnetocardiography (FMCG). The fetus of a 33-year-old Japanese female at 24 weeks of pregnancy was diagnosed as bradycardia (60 beats/min) by fetal cardiotocography (CTG). Ultrasound findings indicated a diagnosis of an atrioventricular (AV) block involving extrasystole, but FMCG revealed a polymorphic VT followed by ventricular asystole. Standard ECG immediately after cesarean section at 37 weeks of pregnancy confirmed long QT syndrome followed by nonsustained polymorphic VT and an advanced AV block with wide QRS. Echocardiography demonstrated moderate left ventricular dysfunction in the neonate requiring implantation with a permanent pacemaker.

[Usefulness of bifonazole for treatment of tinea pedis in the 20th year after approval].

We studied the usefulness of Mycospor Cream 1% (hereinafter referred to as "bifonazole cream"), which was approved 20 years ago in Japan, with once-daily application in 16 patients with tinea pedis (plantar tinea pedis, n = 8; interdigital tinea pedis, n = 8). One of them discontinued after 2 weeks of study treatment due to aggravation of skin symptoms. This subject was excluded from assessment of mycological activity and skin-symptom improvement at 4 weeks after initiation of treatment, but included in overall clinical efficacy rating and usefulness rating as an "ineffective" and "useless" case. The mean (+/- SD) duration of study treatment among the 15 subjects (excluding the discontinued subject) was 26.5 +/- 2.3 days (range: 21 to 28 days). The mycological eradication rate at Week 4 was 100% (15/15 subjects). The scores on all skin symptoms (itching, redness, papules, blisters, pustules, maceration, and scaling) at Week 4 significantly improved from the respective baseline scores (p<0.05), and almost all skin symptoms disappeared. The skin-symptom improvement rate was 93% (14/15 subjects). The overall clinical efficacy rate, which was assessed based on mycological efficacy and skin-symptom improvement rating, was 81% (13/16 subjects). No adverse reaction was observed in any of the subjects. The usefulness rate, which was assessed based on overall clinical efficacy and safety rating, was 88% (14/16 subjects). In this study, we confirmed that the usefulness of bifonazole cream for the treatment of tinea pedis was consistent with the results of studies performed before approval and 10 years after approval. About 20 years have passed since its launch, but bifonazole cream still remains a useful antifungal drug for topical treatment of tinea pedis.

Development and significance of a fetal electrocardiogram recorded by signal-averaged high-amplification electrocardiography.

Although ultrasonic diagnostic imaging and fetal heart monitors have undergone great technological improvements, the development and use of fetal electrocardiograms to evaluate fetal arrhythmias and autonomic nervous activity have not been fully established. We verified the clinical significance of the novel signal-averaged vector-projected high amplification ECG (SAVP-ECG) method in fetuses from 48 gravidas at 32-41 weeks of gestation and in 34 neonates. SAVP-ECGs from fetuses and newborns were recorded using a modified XYZ-leads system. Once noise and maternal QRS waves were removed, the P, QRS, and T wave intervals were measured from the signal-averaged fetal ECGs. We also compared fetal and neonatal heart rates (HRs), coefficients of variation of heart rate variability (CV) as a parasympathetic nervous activity, and the ratio of low to high frequency (LF/HF ratio) as a sympathetic nervous activity. The rate of detection of a fetal ECG by SAVP-ECG was 72.9%, and the fetal and neonatal QRS and QTc intervals were not significantly different. The neonatal CVs and LF/HF ratios were significantly increased compared with those in the fetus. In conclusion, we have developed a fetal ECG recording method using the SAVP-ECG system, which we used to evaluate autonomic nervous system development.

Screening the single nucleotide polymorphisms in patients with internal carotid artery stenosis by oligonucleotide-based custom DNA array.

UNLABELLED: Early screening of individuals considered to be at risk for severe internal carotid artery (ICA) stenosis is an important strategy for preventing ischemic cerebral stroke. The purpose of this study is to screening candidate single nucleotide polymorphisms (SNPs) associated with severe ICA stenosis using a newly developed oligonucleotide-based custom DNA array. The subjects consisted of 47 controls and 46 patients with severe ICA stenosis (>/=70%) who underwent carotid endarterectomy (CEA). Subjects gave informed consent and we obtained samples of blood and genomic DNA. We studied 8 candidate genes: renin-angiotensin system [angiotensinogen (AGT), angiotensin II receptor type 1 (AGTR1), nitric oxide synthase 3 (NOS3)]; growth factor [hepatocyte growth factor (HGF)]; transgelin (SM22); cytokine [chemokine receptor 2 (CCR2)]; coagulation-fibrinolysis system [5,10-methylenetetrahydrofolate reductase (MTHFR)]; and plasminogen activator inhibitor 1 (PAI-1). Genotyping of candidate SNPs was done with a line probe assay (LiPA) based on an oligonucleotide-based DNA array. RESULTS: The allele frequency of PAI-1 -1965 delG (odds ratio (OR), 0.3; 95% confidence interval (CI), 0.2-0.6) and MTHFR (OR 1.3, 95% CI, 1.0-1.5) were significantly different between controls and cases with ICA stenosis by Fisher's exact test. Multiple logistic analysis revealed that diabetes mellitus (DM), SNPs in PAI-1 -1965 delG and MTHFR were an independent risk for ICA stenosis. In conclusion, genetic factors of coagulation-fibrinolysis as well as diabetes mellitus (DM) were relevant in ICA stenosis.

Newly developed signal-averaged vector-projected 187-channel electrocardiogram can evaluate the spatial distribution of repolarization heterogeneity.

The purpose of this study was to verify the spatial distribution of myocardial repolarization heterogeneity using a newly developed 187-channel signal-averaged vector-projected ECG (187-ch SAVP-ECG). We constructed corrected recovery time (RTc) and Tpeak-end (corrected Tp-e) dispersion maps using a 187-ch SAVP-ECG based on vector-projection theory using a Mason-Likar lead system. We compared the spatial distribution and quantitative values of dispersion maps by 187-ch SAVP-ECG with those by 64-ch magnetocardiography (MCG) in 27 normal controls (control) and 16 patients (12 myocardial infarction (MI), and 4 dilated cardiomyopathy (DCM)). The wave pattern of the 187-ch SAVP-ECG in the representative cases was similar to those in 64-ch MCG. Spatial distribution increased RTc and corrected Tp-e dispersion maps defined by 187-ch SAVP-ECG were in agreement with those by 64-ch MCG. The value of RTc dispersion in MI was higher than that in control (41 +/- 21 ms in MI versus 30 +/- 12 ms in control, P < 0.05). The value of corrected Tp-e dispersion in DCM was higher than that in control (58 +/- 12 ms in DCM versus 30 +/- 13 ms in control, P < 0.001). There was a good correlation between RTc and corrected Tp-e dispersion values determined by 187-ch SAVP-ECG and 64-ch MCG modalities (y = 0.46x + 18, r = 0.62, P = 0.02 for RTc dispersion; y = 0.52x + 15, r = 0.63, P = 0.01 for corrected Tp-e dispersion). RTc and corrected Tp-e dispersion maps by 187-ch SAVP-ECG based on vector-projection theory can evaluate the spatial distribution of myocardial repolarization heterogeneity.

Serum levels of cystatin C in patients with malignancy.

BACKGROUND: Serum levels of cystatin C have been proposed to be an ideal marker of the glomerular filtration rate (GFR). However, some reports have shown that serum levels of cystatin C increase independently of GFR. In this study, we evaluated the clinical utility of cystatin C in monitoring GFR, especially in patients with a malignancy. METHOD: Study subjects consisted of 82 patients with a malignancy, 39 patients with a non-malignancy, 31 healthy volunteers, and 206 patients with various degrees of renal function. We measured serum cystatin C, beta2-microglobulin (beta 2mG), and creatinine (CRE) levels in all patients. Serum CRP levels were measured in 21 patients with a malignancy and 28 patients with a non-malignancy whose creatinine clearance (Ccr) was > or =70 ml/min. Cystatin C, beta 2mG, and CRP were measured by immune nephelometry and CRE was measured by an enzyme assay. RESULTS: In patients with a malignancy, regression analysis yielded the equation: 1/cystatin C = 0.06 x Ccr + 0.710, correlation coefficient, r, of 0.33. The r was significantly lower than in patients with various degrees of renal function. There were no significant differences when the r performed on beta 2mG and CRE was compared between the same groups of patients. In 74 patients with a malignancy, in whom serum CRE levels were < or =1.1 mg/dl, increased levels of cystatin C were observed in 25 patients and increased levels of beta 2mG were observed in 39 patients. In comparing patients with a malignancy and a non-malignancy, the number of patients with an increased level of cystatin C, despite a Ccr > or = 70 ml/min (8/33) or a CRE < or = 1.1 mg/dl (13/41), was larger in the former group than the latter group, although the result was not statistically significant. Similarly, the number of patients with an increased level of beta 2mG, despite a Ccr > or = 70 ml/min or a CRE < or = 1.1 mg/dl was significantly larger in the former group compared to the latter group. Regression analysis between the serum levels of cystatin C and CRP in patients with a malignancy whose Ccr were > or =70 ml/min had a weak correlation (r = 0.31). CONCLUSION: The results of our study suggest that the serum levels of cystatin C are not always a reliable marker of the GFR in patients with a malignancy, probably in relation to its nature as a cysteine protease inhibitor.

[Development of three-dimensional analysis of current density distribution by 64-ch magentocardiography and clinical application].

Magnetocardiography (MCG) using a SQUID sensor is characterized by three dimensional cardiac electrical phenomena from magnetic fields, because it is hard to be affected by organ constitution of lungs and torso configuration. We have developed three-dimensional (3D) electric current density distribution analysis by a spatial filter method. At this symposium, we report clinical utility of 64-channel (64-ch) MCG. Subjects consisted of 20 normal volunteers, 10 cases with old myocardial infarction, 13 cases with atrial fibrillation (AFIB) who received surgical pulmonary (PV) isolation, and representative case with fetus premature ventricular complex (PVC). We recorded 10-min MCG data of magnetic field composition (a Bz ingredient) which was perpendicular to body surface in a magnetism shield, using 64-ch SQUID sensors (17.5 x 17.5 cm) built-in in MCG instrumentation(sampling; 500ms, total frequency characteristic; 0.1-200 Hz). We conducted 3D heart outline from electric current density calculated by magnetic field distribution. We also generated 3D functional images of the RT (activation recovery time) dispersion and spatial spectral distribution of a fibrillation wave. Increased fluctuation on RT dispersion map corresponded with space location of myocardial infarction. The mean frequency of 3D spectral map in persistent AFIB showed a higher value than that with restored a sinus rhythm (7.7 +/- 0.5 Hz vs. 6.5 +/- 0.7 Hz). We also demonstrated a fetus PVC. We concluded that 64-ch MCG can evaluate 3D spatial location of myocardial injury, 3D spectral map and characteristic frequency, and fetus arrhythmia. In future, further technical development in the fields of MCG measurement would be necessary for avoiding the used of unshielded room or liquid He.

Three-dimensional spectral map of atrial fibrillation by a 64-channel magnetocardiogram.

We verified the significance of 3-dimensional (3D) spectral mapping during atrial fibrillation (AFIB) using a 64-channel magnetocardiogram (MCG). The study consisted of 16 patients with valvular heart disease who had chronic AFIB. All 16 patients had surgical pulmonary vein (PV) isolation followed by valvular repair. We performed spectral mapping by fast Fourier transform analysis in nonaveraged 64-channel MCG data. The 3D spectral map was superimposed on a 3D heart polygon. At 1 year after surgical PV isolation for AFIB, followed by valve repair, 7 patients had restoration to sinus rhythm, and 9 patients remained in persistent AFIB. The preoperative mean 3D frequency of AFIB was 6.1 +/- 0.9 Hz in patients with restored sinus rhythm and 7.2 +/- 0.7 Hz in patients with sustained AFIB after PV isolation (P = .02). In addition, the preoperative 3D spectrum was distributed on the right side of the heart in patients with persistent AFIB. In conclusion, 3D spectral mapping using 64-channel MCG may represent a meaningful noninvasive strategy for patients with AFIB who receive an interventional procedure.

Development of a signal-averaged vector-projected 187-channel high-resolution electrocardiogram for the evaluation of the spatial location of high-frequency potentials and abnormal ventricular repolarization.

Noninvasive risk stratification is important for screening for lethal arrhythmia. We developed a 187-channel signal-averaged vector-projected high-resolution electrocardiograph (187-ch SAVP-ECG) for detecting abnormalities in the spatial location of ventricular high-frequency late potentials (HFLPs) and ventricular repolarization. The subjects consisted of 30 normal controls (CONTROL) and 13 patients with HFLPs (6 with myocardial infarction [MI], 6 with cardiomyopathy, and 1 with Brugada syndrome). The modified X, Y, Z-lead ECG and the synthesized signals from vector-projected 187-channel ECGs were amplified and passed through a digital filter. We calculated the integration of the HFLPs area between QRS(end) and 30 ms before QRS(end). The integrated HFLPs map was superimposed on the corrected recovery time (RTc) and Tpeak-end dispersion maps composed by 187-ch SAVP-ECG. All patients received an examination by 64-channel magnetocardiography (64-ch MCG) on the same day. The spatial distribution of HFLPs by the 187-ch SAVP-ECG map was in agreement with the location of increased RT dispersion in MI. The spatial distribution of HFLPs in DCM demonstrated a wide variety of patterns. Interestingly, the spatial distribution of HFLPs in cases with ARVC was located at around a right ventricular outflow region. The spatial distribution of HFLPs by 187-ch SAVP-ECG was in agreement with those determined by 64-ch MCG. The 187-ch SAVP-ECG might be useful for evaluating the spatial distribution of nonuniform conduction and ventricular repolarization heterogeneity.