Incorporation of organometallic Ru complexes into apo-ferritin cage.

Spherical protein cages such as an iron storage protein, ferritin, have great potential as nanometer-scale capsules to assemble and store metal ions and complexes. We report herein the synthesis of a composite of an apo-ferritin cage and Ru(p-cymene) complexes. Ru complexes were efficiently incorporated into the ferritin cavity without degradation of its cage structure. X-Ray crystallography revealed that the Ru complexes were immobilized on the interior surface of the cage mainly by the coordination of histidine residues.

What variables were associated with the inducibility of ventricular fibrillation during electrophysiologic stimulation test in patients without apparent organic heart disease?

OBJECTIVE: The purpose of our study was to determine what variables were associated with ventricular fibrillation (VF) induced during electrophysiological stimulation test in patients without apparent organic heart disease. METHODS: Our study evaluated 77 patients (51+/-15 years) who underwent electrophysiological stimulation test, signal averaging, and Na+ channel-blocker challenge test (pilsicainide test). The subjects were divided into two groups, the Brugada group and non-Brugada group. Further, the patients were divided into three subgroups on the base of symptoms (8, 7 symptomatic; 9, 13 syncope; 28, 12 asymptomatic group; in the Brugada and non-Brugada groups, respectively). Multivariate analyses evaluated the association between baseline clinical factors and the induction of VF. RESULTS: The inducibility of VF was significantly (p<0.0001) higher in the Brugada group (n=33, 73%) than the non-Brugada group (n=4, 13%). The multivariate analysis demonstrated that symptoms (odds ratio (OR) 31.6; 95% confidence interval (CI): 2.3-430.6; p<0.01), type 1 electrocardiogram after pilsicainide test (OR 21.3; CI: 1.7-272.2; p<0.02), and syncope (OR 13.5; CI: 1.2-158.8; p<0.05) were strongly associated with the inducibility of VF, but not with family history, type 1 electrocardiogram in control, positive in late potential, maxDeltaST elevation (>==200microV) after pilsicainide test. CONCLUSIONS: The symptoms, syncope, and type 1 electrocardiogram after pilsicainide test were independently associated with the electrophysiological substrate of VF in patients without apparent heart disease.

Activation patterns and conduction velocity in posterolateral right atrium during typical atrial flutter using an electroanatomic mapping system.

BACKGROUND: To investigate the activation patterns and conduction velocity (CV) in the posterolateral right atrial (RA) wall during typical counterclockwise atrial flutter (AFL) using an electroanatomic mapping system. METHODS AND RESULTS: During typical AFL in 25 patients, the transverse conduction pattern and CV were classified and calculated. The line blocking transverse conduction was defined by the conduction pattern and double potentials recorded during mapping. There were 3 types (including 2 subtypes) of transverse conduction pattern based on the conduction blocks across the posterolateral RA in a line between the superior and inferior venae cava. Trans-cristal conduction activation in a horizontal direction was seen in all but 4 patients. The CV in the gap area was 0.59+/-0.21 m/s. CONCLUSIONS: Three types of transverse conduction pattern were observed during trans-ctristal conduction and the trans-ctristal CV was relatively slower than that in other parts of the RA, except for the isthmus.

Pilsicainide-induced Brugada-type ECG and ventricular arrhythmias originating from the left posterior fascicle in a case with Brugada syndrome associated with idiopathic left ventricular tachycardia.

The patient was a 50-year-old male in 2002, who was first suspected of having a Brugada-type electrocardiogram (ECG). A drug challenge test using pilsicainide was performed and unmasked a typical coved type ST elevation followed by ventricular arrhythmias (VAs) manifesting a QRS pattern with a right bundle branch block and left axis deviation. Three years later, he was transferred to the emergency room due to a wide QRS tachycardia with the same QRS morphology as the VA that previously occurred in the drug challenge test. An ECG just after the recorded termination of the tachycardia exhibited a typical Brugada-type ECG. In an electrophysiological study, ventricular fibrillation could be easily induced with reproducibility. Since the clinical tachycardia could not be sustained by an isoproterenol infusion, mapping and catheter ablation targeting the pilsicainide-induced VAs was performed. The successful ablation site was the left mid-lower septal wall where a Purkinje potential was recorded and a false tendon was attached just to it.

Spectral analysis of atrial fibrillation cycle lengths: comparison between fast Fourier transform analysis and autocorrelation function analysis using multipurpose physio-informatic analysis software.

BACKGROUND: Fast Fourier transform (FFT) analysis is a popular method of spectral analysis of atrial fibrillation cycle lengths (AFCL). Autocorrelation function (ACF) analysis is also available, so the aim of this study was to elucidate the relationship between FFT and ACF analyses in the spectral analysis of AFCLs. METHODS AND RESULTS: A total of 75 atrial fibrillation (AF) data from 39 patients were subjected to analysis. The dominant frequencies (DFs) from 4 different spectral resolutions of the FFT and peak AFCL from the ACF analysis were compared. In the FFT analysis using rectified signals, the DF was influenced by spectral resolution, no matter how the signals were tapered by the Hanning or Hamming window or filtered with the low-pass filter. There was a significant relationship between the DF from each spectral resolution and the peak AFCL. The DF from the 4,096-point FFT analysis had the strongest relationship to the peak AFCL with the smallest difference, when using 30-s AF data. In a study of the different lengths of the atrial fibrillation data, the DF also had a strong correlation to the peak AFCL with a small difference. CONCLUSIONS: The peak AFCL obtained from ACF analysis was not of the same quality as that from FFT analysis, but had the same value as the DF from FFT analysis.

Different effect of the pure Na+ channel-blocker pilsicainide on the ST-segment response in the right precordial leads in patients with normal left ventricular function.

BACKGROUND: The response of the ST-segment in the right precordial leads to Na+ channel blockers in patients without structural heart disease and a typical Brugada-type ECG has not been fully elucidated. METHODS AND RESULTS: A pilsicainide challenge test was performed in 161 patients and according to recently established ECG criteria and an organized computer algorithm, the ST morphology was classified and the maximum increase in the J wave amplitude (maxDeltaJ) from the standard and high right precordial leads V1-3 was examined. Before the test, subjects exhibiting type 1 ECG in the standard leads were excluded. After administering pilsicainide, type 1 ECGs in the standard leads were observed in 31 cases and a maxDeltaJ of >or=200 microV was observed in 29 cases (23 type 1, 2 type 2/3 and 4 normal ECGs). In the additional higher right precordial leads, type 1 ECGs were observed in 55 cases and a maxDeltaJ of >or=200 microV was observed in 45 cases (42 type 1 and 3 type 2/3 ECGs). CONCLUSIONS: A maxDeltaJ>or=200 microV induced by pilsicainide, including that measured in the high right precordial leads, was associated with a change mainly to a type 1 ECG.