Masayuki Inagaki

Brugada Syndrome Characterized by the Appearance of J Waves

We describe a patient with Brugada syndrome. The ST‐segment elevation in precordial leads was revealed during admission, but the appearance of J waves was characteristic before ventricular fibrillation (VF), rather than ST‐segment elevation. J waves have been reported to be associated with the presence of an Ito‐mediated prominent action potential notch in the epicardium. It is considered that one of the mechanisms of this VF is due to heterogeneous distribution of the refractory period according to changes in K+ channels including Ito. Brugada syndrome, idiopathic VF, J wave, current Ito

Prognostic values of perfusion-metabolic mismatch in Tl-201 and BMIPP scintigraphic imaging in patients with chronic coronary artery disease and left ventricular dysfunction undergoing revascularization

Objectives: The aim of this study was to assess the prognostic value of the amount of perfusion-metabolic mismatch in revascularized patients with left ventricular (LV) dysfunction by means of Thallium (Tl)-201 and BMIPP imaging.Methods: Seventy-six patients with LV dysfunction and coronary artery disease underwent Tl-201 and BMIPP imaging. They were revascularized with either coronary artery bypass graft or balloon angioplasty and were entered into this study. To quantify the amount of perfusion-metabolic mismatch, SPECT images were displayed as polar maps and analyzed semiquantitatively. The patients were followed up for a mean period of 32 months for cardiac mortality and non-fatal cardiac events. Standard follow-up left ventriculography was performed 6 to 12 months after revascularization.Results: Thirty-two patients exhibited a large amount of perfusion-metabolic mismatch (≥7 segments, group A), 28 patients had a small amount of perfusion-metabolic mismatch (2 to 6 segments, group B), and 16 patients were found to have no perfusion-metabolic mismatch (group C). Similar pre-revascularization LVEF of 35±5%, 34±8% and 36±6% increased to 45±8% (p<0.0001), to 38±8% (p<0.05), and to 36±3% (n.s.), respectively, after revascularization. The functional improvement after revascularization in group A was accompanied by a low rate of cardiac events during follow-up and better cardiac event free survival as judged by the Kaplan-Meier method (p<0.05, vs. group B and C).Conclusion: In revascularized patients with severe LV dysfunction, the presence of a large amount of perfusion-metabolic mismatch evaluated by Tl-201 and BMIPP imaging identifies patients with the best prognosis.

Prospective survey of implantable defibrillator shock anxiety in Japanese patients: Results from the DEF-Chiba study: MIYAZAWA et al.

Patient‐reported outcomes of implantable cardioverter defibrillator (ICD), such as those with shock anxiety, have emerged as important endpoints that are related to quality of life (QOL), but they have not been well studied in a sample of the Japanese population. Therefore, we prospectively examined changes in shock anxiety in a large sample of Japanese patients with an ICD.

Tc-99m tetrofosmin myocardial perfusion SPECT after dipyridamole combined with low-level exercise in the diagnosis of coronary artery disease

Tc-99m tetrofosmin is a lipophilic, cationic perfusion imaging agent that changes to Tl-201 in detecting coronary artery disease during exercise testing. The purpose of this study is to evaluate the usefulness of Tc-99m tetrofosmin dipyridamole stress imaging combined with low level exercise for the detection of coronary artery disease. We examined 42 patients and 10 normal volunteers who also underwent coronary angiography. A one-day protocol was used: in the stress study, 296 MBq of tetrofosmin was injected and in the rest study 888 MBq was injected. After intravenous administration of dipyridamole (0.142 mg/kg/min for 4 minutes), the patient was exercised on a bicycle ergometer for 3 min (25 Watts). Tetrofosmin was injected 2 minutes after dipyridamole infusion during the exercise. Single photon emission computed tomographic images were obtained 30 minutes after the tracer injection. Images were interpreted as abnormal in 36 of 42 patients with coronary artery disease, and normal in all of 10 normal volunteers. The overall sensitivity of detection of coronary artery disease was 83.3% and the normalcy rate was 100%. The diagnostic values for the detection of significant stenosis in the three major arteries were: LAD sensitivity 83%, specificity 92%; LCX sensitivity 47%, specificity 91%; RCA sensitivity 75%, specificity 83%. Of the 66 arteries with more than 50% stenosis, 48 arteries were correctly identified. Of the 36 with more than 70% stenosis, 31 were identified. Scintigraphic evidence of multivessel disease was found in only 9 patients (50%).A protocol of Tc-99m tetrofosmin SPECT combined with low level exercise after dipyridamole is therefore useful for the detection of the coronary artery disease.