Idiopathic Ventricular Arrhythmias Originating from the Papillary Muscles in the Left Ventricle: Prevalence, Electrocardiographic and Electrophysiological Characteristics, and Results of the Radiofrequency Catheter Ablation

Idiopathic VAs Originating from the LV Papillary Muscles.   Introduction: Idiopathic ventricular arrhythmias (VAs) can originate from the left ventricular (LV) papillary muscles (PAMs). This study investigated the prevalence, electrocardiographic and electrophysiological characteristics, and results of catheter ablation of these VAs, and compared them with other LV VAs.
Methods and Results: We studied 71 patients with VAs originating from the LV anterolateral and posteroseptal regions among 159 patients undergoing successful catheter ablation of idiopathic LV VAs. PAM VAs were uncommon, rare in a sustained form, and more common from the posterior papillary muscle (PPM) than anterior papillary muscle (APM). A younger age was a good predictor for differentiating left posterior fascicular VAs from PPM VAs. There were several electrocardiographic features that accurately differentiated PAM and LV fascicular VAs from mitral annular VAs. However, an R/S ratio ≤1 in lead V6 in the LV anterolateral region and a QRS duration >160 ms in the LV posteroseptal region were the only reliable predictors for differentiating PAM VAs from LV fascicular VAs. A sharp ventricular prepotential was recorded at the successful ablation site during 42% of the PAM VAs. Radiofrequency current with an irrigated or conventional 8-mm tip ablation catheter was required to achieve a lasting ablation of the PAM VA origins whereas that with a nonirrigated 4-mm tip ablation catheter produced excellent results in LV fascicular and mitral annular VAs.
Conclusions: There are differences in the electrocardiographic and electrophysiological features among VAs originating from these regions that are helpful for their diagnosis and effective catheter ablation. (J Cardiovasc Electrophysiol, Vol. 21, pp. 62–69, January 2010)     

A case of X-linked α-thalassemia/mental retardation syndrome: Analysis of hemoglobin by an automated glycated hemoglobin analyzer

A 5-year-old male patient with X-linked α-thalassemia/mental retardation syndrome is reported. He showed multiple minor anomalies including characteristic facial abnormalities, α-thalassemia, severe mental retardation, and hypogonadism. Analysis of his hemoglobin by high performance liquid chromatography using an automated glycated hemoglobin analyzer revealed an abnormal peak. Identification of an abnormal peak by an automated glycated hemoglobin analyzer will aid in the diagnosis of patients with X-linked α-thalassemia/mental retardation syndrome.     

Effect of tetanic stimulation on subsequent train-of-four responses at various levels of vecuronium-induced neuromuscular block

Tetanic stimulation influences subsequent neuromuscular responses.In addition, the tetanus- induced changes in neuromuscular responsesdiffer according to the level of neuromuscular block at whichtetanic stimulation is delivered. We studied the tetanus-inducedeffect on subsequent train-of-four (TOF) responses at variouslevels of vecuronium-induced neuromuscular block in 45 anaesthetizedpatients. Tetanic stimulation was applied when a twitch heightof T1 returned to 25%, 50% and 75% of its control twitch height(T0) (groups 1, 2 and 3, respectively) after administrationof vecuronium 0.1 mg kg^–1. Maximum post-tetanic percentageincreases in TOF responses in groups 1, 2 and 3 were 257 (SD119)%, 107 (75)% and 68 (54)% for T1/T0 (P < 0.001 for group1 vs 2; P < 0.001 for group 1 vs 3) and 535 (259)%, 421 (213)%and 292 (171)% for T4/T1 (P < 0.01 for group 1 vs 3), respectively.Durations of post-tetanic increases in TOF responses in groups1, 2, and 3 were 52 (19)s, 37 (14)s, and 32 (13) s for T1/T0(P / 0.05 for group 1 vs 2; P < 0.01 for group 1 vs 3) and53 (17)s, 46 (15)s and 35 (12)s for T4/T1 (P < 0.05 for group1 vs 3), respectively. These data suggest that the tetanus-inducedeffect on subsequent TOF is more apparent and lasts longer atgreater degrees than at lesser degrees of neuromuscular block.     

Genotypic subtyping of hepatitis C virus

Four subtypes of hepatitis C virus (HCV), Pt(I), K1(II), K2a(III) and K2b(IV), have been suggested based on the nucleotide sequences of the non-structural (NS) 5 region. A fifth subtype from Japanese patients, Tr(V), which shows a less than 68% homology in nucleotide sequence when compared with other subtypes has been identified. A one-step method which enables a quick determination of subtype using polymerase chain reaction with a mixed primer set deduced from the sequence of each subtype has been developed. Using this technique, the subtypes of 418 out of 478 Japanese patients (87.4%) were determined. The incidence of each subtype in Japan was as follows: K1(II), 307 (73.4%); K2a(III), 74 (17.7%); K2b(IV), 28 (6.7%); and Tr(V), 3 (0.7%). This one-step subtyping technique should be useful for studying the epidemiology or biology of the HCV.     

Crucial role of thalami and basal ganglia in emotional memory and cognition: association with the recognition of Niigata Ken Chuetsu earthquake 2004

Objective: It is suggested that thalami, basal ganglia, putamina and caudate heads play a crucial role in strong emotion such as the fear of serious earthquake. The aim of this study was to elucidate the radiographic findings (mainly the lacunae) in these regions, mental abilities and the extent of the activities of daily livings (ADL) of moderately demented patients who could recognize the Niigata Ken (prefecture) Chuetsu earthquake 2004 Japan. Methods: In patients with moderate dementia, mainly Alzheimer’s disease, who could recognize the Niigata Ken (prefecture) Chuetsu earthquake 2004 in Niigata prefecture in Japan, their radiographic findings regarding thalami, basal ganglia, putamina and caudate heads were investigated by counting the numbers of lacunae using magnetic resonance imaging. In addition, their mental abilities were examined by Mini‐Mental Examination Score and Hasegawa Dementia Scale–Revised. Their activities of daily living were also assessed. Results: The patients who could recognize the earthquake have statistically fewer lacunae in the thalami, basal ganglia, putamina and caudate heads, than those who could not (P < 0.01 by Student’s t‐test). This analysis revealed that the patients who could recognize the earthquake have statistically significant higher scores in both Mini‐Mental Examination Score, Hasegawa Dementia Scale–Revised (P < 0.05 by Student’s t‐test) and activities of daily living (P < 0.01 by Student’s t‐test). However, statistical significance was not obtained regarding education between two groups. Conclusion: Thalami and the structures around them such as basal ganglia, putamina and caudate heads play an important role in emotion and cognition. Therefore, we concluded that numbers of lacunae might be a valuable marker in evaluating the cognitive abilities of the demented patients.