Insulin resistance and coronary risk factors in Japanese type 2 diabetic patients with definite coronary artery disease

Insulin resistance is known as an important risk factor for coronary artery disease (CAD). However, CAD-related mortality in Japanese type 2 diabetics is lower than in Caucasians. To investigate whether insulin resistance is related to CAD in Japanese type 2 diabetics, we measured insulin sensitivity and several coronary risk factors in Japanese patients with type 2 diabetes with and without CAD. Thirty-three patients with definite CAD and 33 age- and sex-matched patients without CAD (control) were studied. Insulin sensitivity was assessed by the K index of insulin tolerance test (KITT). Clinical characteristics, classical risk factors, lipoprotein (a), and insulin sensitivity were compared between the two groups. Patients with CAD had a significantly longer duration of diabetes (9.0 +/- 1.4 vs. 5.5 +/- 0.9 years, P < 0.05, respectively), were mostly hypertensive (69.7 vs. 39.4%, P < 0.05), and more likely to be treated with insulin (45.5 vs. 18.2%, P < 0.05) compared with the control. Concerning the metabolic parameters, patients with CAD had a significantly higher insulin resistance than control (2.40 +/- 0.15 vs. 3.23 +/- 0.17%/min, P < 0.01, respectively), higher triglyceride (1.39 +/- 0.10 vs. 1.05 +/- 0.05 mmol/l, P < 0.05), lower HDL cholesterol (1.05 +/- 0.05 vs. 1.28 +/- 0.06 mmol/l, P < 0.05), and higher lipoprotein (a) (27.5 +/- 4.3 vs. 17.4 +/- 2.0 mg/dl, P < 0.05). Multiple logistic regression analysis indicated that hypertension, insulin resistance, high lipoprotein (a) and triglyceride, and low HDL cholesterol were independently related to CAD. Our results suggest that insulin resistance per se is a significant risk factor for CAD in Japanese patients with type 2 diabetes.

Double ventricular response via dual atrioventricular nodal pathways resulting with nonreentrant supraventricular tachycardia and successfully treated with radiofrequency catheter ablation

We report a patient with a complex nonreentrant supraventricular tachycardia because of double ventricular response resulting from antegrade dual atrioventricular (AV) nodal pathways. We could induce double ventricular response and confirm dual AV nodal pathways by AV simultaneous pacing during basic stimulation proceeding with programmed atrial single extrastimulation. As far as we know, it is the first report about the application of the AV simultaneous basic stimulation to prove the sustained nonreentrant tachycardia because of simultaneous conduction over dual AV nodal pathways. This was also confirmed by absence of the arrhythmia immediately after the elimination of the slow pathway conduction by radiofrequency ablation.

A fatal case of fulminant myocarditis with human herpesvirus-6 infection

We report a case of fulminant myocarditis after steroid pulse therapy for acute hepatitis. Serological studies demonstrated a four-fold increase in the antibodies against human herpesvirus-6 (HHV-6) IgG, and a PCR showed the existence of HHV-6 virus DNA. HHV-6 virus DNA was also isolated from the liver and the heart. We believe that exacerbation of fulminant myocarditis was probably associated with the reactivation of HHV-6 due to the immunosuppressive state of the host.

Radiofrequency catheter ablation of a concealed atrioventricular accessory pathway associated with a coronary sinus diverticulum

A 31-year-old woman underwent radiofrequency catheter ablation of a concealed left posteroseptal accessory pathway associated with a coronary sinus diverticulum. The patient had previously undergone unsuccessful catheter ablation of the posteroseptal region of the mitral annulus. Coronary sinus venography revealed the presence of the diverticulum near the ostium. An electrogram in the neck of the diverticulum showed the shortest ventriculoatrial conduction time and a large accessory pathway potential during atrioventricular reciprocating tachycardia. The pathway was successfully ablated within the neck of the diverticulum. The findings in this case underscore the importance of coronary sinus venography before ablation.

[Emergency perfusion lung scan for pulmonary embolism]

Six cases of pulmonary embolism were reported. As pulmonary embolism often becomes critical condition, early diagnosis and medical treatment is need. Perfusion lung scan for pulmonary embolism may be useful for a diagnosis and evaluation of the degree of its disease and therapeutic value.

[Lung perfusion scintigraphy by SPECT--new application of Bull's eye analysis]

The present study reports the characteristic performance using lung segmental phantom filled in Tc-99m-pertechnetate. To evaluate the segmental defect in lung perfusion scintigraphy, we applied Bull's eye analysis in addition to planar image set. Bull's eye analysis especially facilitated the interpretation in both middle and lower lobes.